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Chapter 1 notes The human species are Homo sapiens Hominins are members of the same evolutionary lineage as Homo sapiens The early hominins fossilized footprints were found several years later In Laetoli and other places scientists also found fossilized parts of skeletons of an animal we call Australopithecus afarensis These hominins were defenseless against most predators and had a brain about one third the size of ours Physical or biological anthropology is the scienti c discipline concerned with the biological and behavior characteristics of human beings our closest relatives the nonhuman primates and our ancestors This kind of research helps us explain what it means to be human and how we came to be the way we are It is the study of the interaction between biology and culture as it pertains to evolution Evolution is a change in the genetic make up of a population from one generation to the next and it can be de ned and studied at two levels Over time some genetic changes in populations do result in the appearance of new species speciation especially when those populations are isolated from one another Change at this level is called macroevolution At the other levels there are genetic alterations within populations and it does cause population of species to differ from one another in the frequency of certain traits Evolution at this level is microevolution We have many similarities to other organisms Our behavior has direct connections with nonhuman species such as the primates and so do our cells and muscles and bones This proves that humans are a product of the same evolutionary forces that produced all living things Humans are one contemporary component of a vast biological continuum at a particular point in time Culture can be de ned as the strategy by which humans adapt to the natural environment Culture includes technologies and types of clothing religion values kinship marriage rules etc Each culture shapes people s perceptions of the external environment or worldview Culture is not genetically determined it is learned behavior Humans and other primates have the predisposition to assimilate culture and function within it Humans are the result of longterm interactions between biology and culture We call this Biocultural evolution Anthropology is divided into 4 main sub elds cultural archaeology linguistic and biologicalphysical Together they all offer a means of explaining variation in human biological and behavioral adaptations The sub elds have practical applications This kind of anthropology is called applied anthropology Cultural anthropology is the study of patterns of belief and behavior found in modern and historical cultures Early anthropologists studied societies now mostly extinct These studies produced ethnographies that covered a range of topics such as religion ritual myth symbols technology gender rules etc Ethnographies helped form the basis of comparative studies of many cultures Archaeology is the study of earlier cultures by anthropologists who specialize in scienti c recovery analysis and interpretation of material remains of past societies They obtain information from artifacts left behind by studied cultures The goal of this is to study human behavior not simply to look at the old artifacts Linguistic anthropology is the study of human speech and language Linguists have been able to trace historical ties between particular language and groups of languages thus facilitating the identi cation of language families and past relationships between human populations Paleoanthropology is the study of anatomical and behavioral human evolution as revealed in the fossil record This is a major sub eld of physical anthropology Primate paleontology is the study of primate fossil record which extends back to the beginning of primate evolution some 65 million years ago Visible physical variation was the other major area of interest for early physical anthropologists Enormous effort was spent in measuring describing and explaining visible differences among various human populations such as skin color body proportions and the shape of the head and face Although some approaches were misguided and even racist they gave birth to many body measurements that are sometimes still used Today physical anthropologists are concerned with human variation because of its possible adaptive signi cance and because they want to identify the factors that have produced not only visible physical variation but genetic variation as well An important aspect of human variation is how populations respond to environmentally induced stress Such stresses are altitude cold or heat Genetics is a crucial eld for physical anthropology Osteology is the study of the skeleton and is central to physical anthropology Paleopathology is the study of disease and trauma in ancient skeletal populations is a major component of bioarchaeology Forensic anthropology is directly related to osteology and paleopathology Forensic anthropologists help identify remains in mass disasters or other situation sin which a human body has beenfound Primatology is the study of the living nonhuman primates Primates are our closest living relatives so identifying the underlying factors related to their social behavior communication infant care reproductive behavior and so on helps us develop a better understanding of the natural forces that have shaped so many aspects of modern human behavior Science is a method of explaining natural phenomena It involves observation developing a hypothesis and developing a research design or series of experiments to test these hypotheses This is an empirical approach of gaining information Because biological anthropologists are engaged in scienti c research they adhere to the principles of the scienti c method by identifying a research problem and then gathering information to solve it A hypothesis is a tentative explanation The step involved in testing the hypothesis includes data If a hypothesis stands up to repeated testing it may become part of a theory or perhaps a theory itself Theories usually concern broader more universal views than hypotheses However theories like hypotheses are not facts They are tested explanations of facts Scienti c testing of hypotheses may take several years and may involve researchers who didn t participate in the original work New methods may permit different kinds of testing that weren t previously possible The purpose of scienti c research is not to establish absolute truths rather it is to generate ever more accurate and consistent explanations of phenomena in our universe based on observation and testing The anthropological perspective is the big picture of being human across and through time Through this perspective we can begin to grasp the diversity of human experience within the context of biological and behavioral connections with other species Avoid ethnocentrism Human adaption to the environment is culture Culture is all acquired and transmitted knowledge Ethnocentrism is when you believe your culture is the only way for you This is a very limited way to look at humanity The relativistic view of culture is perhaps more important now than ever before Likewise by examining our species as part of a wide spectrum of life we realize that we can t judge other species using only human criteria Each species is unique with needs and behavioral repertoire not exactly like that of any other Chapter 2 Charles Darwin was the rst person to explain the basic mechanics of the evolutionary process But while he was developing his theory of natural selection a Scottish naturalist named Alfred Russel Wallace independently reached the same conclusion Fixity of species All life forms could not and did not change In feudal society there was a powerful religions system and the teachings of Christianity were regarded as the only truth It was generally accepted that God had created all life on earth and the beings he created were the same then as they are now Anyone who questioned this was accused of heresy The plan of the entire universe was viewed as God s design Limbs internal organs and eyes all t the functions they performed The Grand designer was thought to have completed his work as recently as 4004 BC The prevailing belief in the earth s brief existence together with xity of species was an obstacle to the development of evolutionary thought Speeds bumps on road to knowledge of evolutionary thought I No one knew how to record data There was lack of scienti c method I Notion of divine and separate creation for humans l Lack of knowledge of age of the earth I ldea that there was a religions explanation for natural phenomenon The development of evolutionary theory came about as a result of a paradigm shift The discovery of the new world and circumnavigation of the globe in the 15th century overturned some very basic European ideas about the planet The earth could no longer be seen as at Also Europeans began seeing animals and plants they had never seen before their awareness of biological diversity expanded Copernicus in 1514 challenged a notion by Aristotle that suns and planets existed in a series of concentric spheres that revolved around the earth Then it came to be accepted that the earth was the center of the solar system Copernicus did not believe that earth was the center of the solar system This contradicted the beliefs of the Catholic church which believed that the earth was the main focus of God s plan so it should be at the center Galileo Galilei restated Copernicus s views using logic and math to support his claim The pope however sentenced him to house arrest for the last nine years of his life But the idea that the earth was the center of the solar system changed and it came to be the sun that was the center of the solar system John Ray proposed the concept of species in the 17th century He was a minister educated in Cambridge University He recognized that groups of plants and animals could be differentiated from other groups by their ability to mate with one another and produce fertile offspring He placed such groups as reproductively isolated Ray also recognized that species frequently share similarities with other species and he grouped these together in a second level of classi cation called genus He was the rst to use the labels genus and species in this way Carrolus Linnaeus 17071778 was a Swedish naturalist who developed a method of classifying plants and animals In his work Systema Naturae he standardized Ray s use of genus and species terminology and established the system of binomial nomenclature He added class and order Linnaeus four level system became basis of taxonomy the system of classi cation we still use today Linnaeus includes humans and refers to their genus as Homo and their species as sapens He however still believed in xity of species GeorgesLouis Leclerc de Buffon 17071788 a French naturalist recognized the dynamic relationship between the external environment and living forms In his Natural History he recognized that different regions have different plants and animals He also stressed that animals had come form a center of origin but he never discussed the diversi cation of life overtime He also recognized that alterations of external environment including the climate were agents of change in species Erasmus Darwin expressed the view that life had originated in the seas and that all species had descended from a common ancestor He introduced many ideas his grandson Charles would propose 56 years later Jean Baptiste Lamarck 17441829 suggested a dynamic relationship between species and environment such that if the external environment changed an animal s activity patterns would also change to accommodate the new circumstances This would result in increased or decreased use of body parts consequently those body parts could be modi ed He believed in the idea which is now proven false that if the parts weren t used they would disappear with time The parts that are used would change overtime Therefore the new trait would be passed on to offspring This theory is known as the inheritance of acquired characteristics An example is when giraffes get longer necks in order to strip all the leaves from the upper branch of a tree This trait is acquired by an animal during its lifetime and passed on to offspring inheritance of acquired characteristics Today we know that this explanation is wrong because only those traits that are in uenced by genetic information contained within sex cells can be inherited Lamarck coined the term biology to refer to study of living organisms and a central feature of this new discipline was the idea of species change Georges Cuvier 17691832 introduced the concept of extinction to explain the disappearance of animals represented by fossils He was Lamarck s opponent Cuvier believed in xity of species and did not grasp the dynamic concept of nature He proposed a variation of a doctrine known as catastrophism Catastrophism was the belief that earth s geological features are the result of sudden worldwide cataclysmic events Cuvier s version of catastrophism suggested that a series of regional disasters had destroyed most or all of the local plant and animal life in many places These areas were stocked with new similar forms that migrated in from unaffected regions His explanation accounted for evidence of change but did not account for evolution exactly Thomas Malthus 17661834 wrote an essay called An essay on principle of population and this essay inspired both Charles Darwin and Alfred Russell Wallace in their separate discoveries of natural selection Malthus however was not interested in species change at all Instead he was arguing for limits to human population growth He pointed that in nature there is a tendency for animal populations to increase in size but the amount of resources remain relatively the same Therefore population size is held in check by resource availability He basically believes that more organisms are born than can survive creating competition for resources like food water mates and space Competition is key to understanding natural selection Charles Lyell 17971875 is considered the founder of modern geology He published the Principles of Geology In his work he argued that the geological processes we see today are the same as those that existed in the past This theory is called geological uniformitarianism James Hutton proposed this in the late 17005 He believed that the processes were ongoing indicating that geological change was still happening and that the forces driving such change were consistent or uniform over time So various aspects of the earth s surface vary but the underling processes that in uence them are constant Lyell proposed that for such slowly acting forces to produce momentous change the earth must be far older than anyone suspected By providing an immense time scale and thereby changing perceptions for the earth s history form a few thousand to many million years Lyell changed the framework within which scientists viewed the geological past Thus the concept of quotdeep timequot This concept remains one of Lyell s most signi cant contributions to the discovery of evolutionary principles Lyell studied material in dirt Mary Anning 17991847 was one of the lesserknown contributors She lived in the town of Lyme Regis in south coast of England Mary had to provide for her family by collecting and selling marine fossils to collectors who were becoming interested in the remains of creatures that many people thought had been killed in the Noah ood Anning s discovery of the lchthyosaurus a large marine reptile and the rst Peiosaurus fossil some of the most famous scientists in England repeatedly visited her home Anning contributed to the understanding of evolution of marine life by sharing her extensive knowledge of fossil species with the leading scientists of the day Charles Darwin18091882 lived during a time where the concept of evolution was feared Many believed that it was associated with atheism They believed that the church would crash the moral fabric of society would be torn apart and civilized man would return to savagery Darwin sailed aboard the Beagle on December 17 1831 This would forever change Darwin s life as well as the history of biological science He used to believe in xity of species until he saw fossils of ancient giant animals that except for size looked very much like species that lived in the same vicinity ln Galapagos lsland Darwin saw that many of the plants and animals looked like those on South American mainland but they were a bit different Darwin collected 13 varieties of Galapagos nches and it was clear that they represented a closely related group with different physical traits particularly shape and size of beaks Darwin later realized that the various Galapagos nches had all descended from a common mainland ancestor and had been modi ed over time in response to different island habitats and dietary preferences After Darwin got married he began to develop the idea of natural selection This concept was borrowed from animal breeders who would select as breeding stock those animals that possess certain traits that breeders want to emphasize in offspring Darwin realized that sexual reproduction increased variation He also believed in Malthus s competition of resources He used the idea that more organisms are born than can survive to develop his theory of natural selection Darwin had written a summary of natural selection hypothesis but he postponed publishing because 1 He didn t have enough data to support it so he continued his research without publishing 2 Because it would trouble Emma since his ideas would counter her religions convictions 3 He was a member of established order and he knew that his associates and friends were concerned with threats of the status quo and evolutionary theory was viewed as a serious threat Alfred Russel Wallace 18231913 published in 1855 that the current species were descended from other species and that the appearance of new ones were in uenced by environmental factors He believed in the succession of species This article caused Lyell and others to urge Darwin to publish but he hesitated In 1858 Wallace sent Darwin a paper called quotOn the Tendency of Varieties to Depart Inde nitely from the Original typequot This urged Darwin to publish since he did not want Wallace to get credit for natural selection Both papers were read before the Linnaean society of London and neither author were present Darwin was mourning the death of his young son and Wallace was out of the country Darwin nally published his quotOn the Origin of Speciesquot in 1859 The question of species was now explained Darwin received both negative and positive feedback Darwin realized that natural selection was the key to evolution He set up the basic processes as he understood them 1 All species are capable of producing offspring at a faster rate than food supplies increase 2 There is biological variation in all species 3 In each generation more offspring are produced than survive and because of limited resources there is competition among individuals 4 Individuals who possess favorable variations or traits have an advantage over those who don t They have greater tness This is because favorable traits increase the likelihood that they will survive to adulthood and reproduce 5 The environmental context determines whether or not a trait is bene cial 6 Traits are inherited and passed on to the next generation Because individuals who possess favorable traits contribute more offspring to the next generation than do others over time those favorable traits become more common in the population Individuals who produce more offspring in comparison to others are said to have greater reproductive success N 39 Over long periods of time successful variations accumulate in a population so that later generations may be distinct from ancestral ones Geographical isolation contributes to formation of new species As populations continue to respond to different selective pressures they may become distinct species Natural Selection operates on individuals but it s the population that evolves The unit of natural selection is the individual the unit of evolution is the population The fundamentals of evolutionary change A trait must be inherited if natural selection is to act on it Natural selection cannot occur without population variation in inherited characteristics Fitness is a relative measure that changes as the environment changes Natural selection can only act on traits that affect reproduction Fertility is the ability to have children Net Reproductive success is the number of young raised successfully to the point where they themselves can reproduce Scientists used to believe that inheritance was a blending process in which parental characteristics were mixed together to produce intermediate expressions in offspring In 1953 the DNA molecule was discovered and the human genome was sequenced in 2003 The genomes of many other species were also sequenced which made scientists realize how these species evolved Christian fundamentalists renewed their campaign to eliminate evolution from public schools curriculum in the 20th century They wanted instead for public schools to include creation science Proponents of creation science are creationists ID or Intelligent design is another word for creation science Chapter 3 The biological basis of life Genetics is the study of how genes work and how traits are passed from one generation to the next Cells are fundamental units of life in all organisms An adult human body consists of about 1 trillion cells Life on earth began with single celled organisms about 35 billion years ago and eukaryotic cells appeared about 12 billion years ago eukaryotic cells are found in multicellular organisms All living things are ultimately connected A eukaryotic cell consists of lipids carbohydrates nucleic acids and proteins It also contains organelles and a unit that surrounds the cell called a nuclear membrane DNA and RNA are found in the nucleus of the cell The nucleus is surrounded by gel like cytoplasm Two organelles mitochondria and ribosomes are important Mitochondria produce energy and can be thought as the cell s engines Mitochondrion has mitochondrial DNA which has the same molecule structure as DNA but its organized somewhat differently mtDNA has attracted a lot of attention because of the traits it in uences and because it can be used to study certain evolutionary processes Ribosomes are partly composed of RNA They re important to protein synthesis There are two types of cells somatic cells and gametes Somatic cells make up body tissues such as muscles bones and organs Gametes sex cells are involved in reproduction Two types of gametes are egg cells produced in female ovaries and sperm cells which develop in male testes The sole function of a sex cell is to unite with a gamete from another individual to form a zygote which has the potential of developing into a new individual DNA directs all cellular activities It is the very basis of life James Watson along with Francis Crick Maurice Wilkins and Rosalind Franklin developed a structural and functional model of DNA The DNA molecule is composed of two chains of even smaller units called nucleotides A nucleotide is made of three components deoxyribose a phosphate group and four nitrogenous bases DNA replication is when cells multiply by dividing to make exact copies of themselves There are two kinds of cell division In simpler form a cell divides to produce two daughter cells each of which receives a full set of genetic material Replication begins when enzymes break the bonds between bases throughout the DNA molecule separating the two previously joined strands of nucleotides and leaving their bases exposed These exposed bases then attract unattached DNA nucleotides that have been made by DNA elsewhere in the cell nucleus Each base can pair with only one other At GC This attraction is called complementary An important activity of DNA is to direct the assembly of proteins Proteins bind to other molecules For instance hemoglobin found in red blood cells is able to bind to oxygen which carries to cells throughout the body Enzymes are also proteins which regulate chemical reactions For example a digestive enzyme called lactase breaks down lactose a milk sugar into two simple sugars Hormones are another class of proteins Hormones are produced by specialized cells and then released into the blood stream to circulate to other parts of the body Insulin is a hormone produced by cells in the pancreas but it functions in the liver where it causes cells in the liver to absorb energy producing glucose from the blood Proteins are made of amino acids In all there are 20 amino acids 8 of which must be obtained from food The remaining 12 are produced in cells What makes proteins different is the number and sequence of their amino acids Sequence of DNA bases that determines the order of amino acids in a protein First step in protein synthesis is to copy DNA message into mRNA Unlike DNA RNA is single stranded contains a different type of sugar and contains the base uracil as substitute for the DNA base thymine Anyways the mRNA strand arrives at the ribosome and is translated So the mRNA strand is quotreadquot in codons which are mRNA triplets Another form of RNA is transfer RNAtRNA which brings amino acids to the ribosomes The ribosome then joins that amino acid to another amino acid in the order dictated by the sequence of mRNA codons In this way amino acids are linked together to form a molecule that will be a protein If a mutation occurs some proteins may not be made or they may be defective A gene is a segment of DNA that specifies the sequence of amino acids in a particular protein In 2001 scientists determined that humans have about 25000 genes However in 2012 it was discovered that there are about 21000 Coding sequences make up about 2 to 3 percent of the entire human genome Noncoding DNA is what s left over when DNA segments are transcribed into proteins Geneticists have learned that only some parts of genes called exons are actually transcribed into mRNA and thus code for speci c amino acids In fact most of the nucleotide sequences in genes are not expressed during protein synthesis Many sequences called introns are initially transcribed into mRNA and then clipped out lntrons are not translated into amino acid sequences The introns that are snipped out of the gene aren t always the same ones This means that exons can be combined in different ways for more than one protein This is how 21000 coding sequences can make 90000 proteins The combination of introns and exons interspersed along a DNA strand is what a gene is made up of Regulatory genes work to control the expressions of other genes They make various kinds of RNA proteins and other molecules that switch other DNA segments or genes on or off They play a fundamental role in embryological development cellular function and evolution Homeobox genes are regulatory genes They determine the identity of individual embryonic tissue segments Hox genes interact with other genes to determine the characteristics of developing body segments and structures but not their actual development Homeobox genes are highly conserved meaning that they ve been maintained throughout much of evolutionary history The nches of Galapagos are an example of how regulatory genes in uence evolutionary change Scientists explained the genetic basis for some of the nch variation by identifying two of the regulatory genes involved in the shape and size of bird beaks One of these genes is expressed to a greater degree during embryonic development of widebeaked ground nches than in that of nches with narrower beaks Therefore the length and width of bird beaks are controlled by the activity of at least two different regulatory genes allowing each aspect of beak size to evolve separately We have genes that are similar to a sea sponge and this was found out by the recent sequencing of the sea sponge genome These genes ultimately laid the foundation for the evolution of complex animals and they re crucial to many of the basic cellular processes that are fundamental to life today These processes include a cell s ability to recognize foreign cells the development of speci c cell types and signaling between cells during growth and development Regulatory genes are present in all complex organisms including humans and this makes it the basis of biological continuity between species SickleCell anemia results from a defect in the beta chain People with sickle cell inherit a mutated form of the gene that directs the formation of the beta chain This mutation is caused by the substitution of one amino acid valine for amino acid that s normally present glutamic acid People who inherit the altered form of the gene from only one parent don t have sickle cell anemia however they have the sickle cell trait The cause of sickle cell anemia is a very slight change in the Hb gene Remember that hemoglobin beta chains each have 146 amino acids Triplets of DNA are required to specify amino acids So it takes 438 bases to produce the chain of 146 amino acids that form the adult hemoglobin beta chain But a change in only one of these 438 bases produces the life threatening complications seen in sicklecell anemia A single base substitution can result in an altered amino acid sequence this kind of change is point mutation Point mutation is a base substitution In evolution these changes are important sources of new genetic variation in populations Point mutations probably occur frequently But for a new mutation to be evolutionarily signi cant it must be passed on to offspring and eventually become more common in a population Point mutations fate in populations depends on the other evolutionary forces especially natural selection Cell division produces new cells and at the beginning of this process DNA becomes tightly coiled and is visible under a microscope as a set of discrete structures called chromosomes Chromosomes are composed of a DNA molecules and proteins Every species has a speci c number of chromosomes in somatic cells Humans have 46 while chimpanzees and gorillas have 48 There are two basic types of chromosomes autosomes and sex chromosomes Autosomes carry information that governs all physical characteristics except primary sex determination The two sex chromosomes are the X and Y chromosomes in mammals the Y chromosome is directly involved in determining maleness The X chromosome is called a sex chromosome determines sex and other traits All genetically normal females have two X chromosomes and all genetically normal males have two Ychromosomes Chromosomes occur in pairs So all normal human somatic cells have 22 pair of autosomes and one pair of sex chromosomes 23 in all Abnormal number of sex chromosomes can be fatal and they may result in sterility To function normally human cell must have total 46 chromosomes Offspring inherit one member of each chromosomal pair from the father and one from the mother On both copies of a person39s ninth chromosome there39s a locus or gene position that determine which of the four ABO blood types he or she will have At numerous genetic loci there may be more than one possible form of a gene and these different forms are called alleles Alleles are alternate forms of a gene that can direct the cell to produce slightly different forms of a product and results in different expression of a trait One method frequently used to examine a chromosome in an individual is to produce a karyotype The chromosomes used in karyotypes are obtained from dividing cells White blood cells can be cultured chemically treated and microscopically examined to identify the ones that are dividing These cells are then photographed through a microscope to produce photomicrographs Partner chromosomes are then matched up and the entire set is arranged in descending order by size so that the largest chromosome appears rst Karyotyping has had numerous applications Doctors and genetic counselors use karyotypes to help diagnose chromosomal disorders in patients and they re used for prenatal testing 0 Cell division in somatic cells is called mitosis this is the way somatic cells reproduce Mitosis occurs during growth and development it also plays a role in repairing injured tissues and replacing older cells with new ones Meiosis may lead to the development of new individuals since it produces reproductive cells or gametes Process of Mitosis Somatic cell starts out with 46 double stranded chromosomes When the cell begins to divide these chromosomes split up so that two strands separate Once the two strands are apart they pull away from each other and move to opposite ends of the dividing cell At this point each strand is a distinct chromosome composed of one DNA molecule After the separation of chromosome strands the cell membrane pinches in and seals so that there are two new cells each with a full complement of DNA or 46 chromosomes Mitosis is referred to as simple cell division because a somatic cell divides to produce two daughter cells that are genetically identical to each other This whole process is made possible by DNA replication Therefore DNA replication ensures that the amount of genetic material remains constant from one generation of cells to the next 0 Certain types of somatic cells like red blood cells don t divide Somatic cells are regularly duplicated by mitosis with the exception of red blood cells mature neurons and liver cells Meiosis leads to the development of new organisms because it produces gametes ln meiosis there are two divisions instead of one also meiosis produces four daughter cells not two and each of these four cells contains only half the original number of chromosomes 0 During meiosis specialized cells in male testes and female ovaries divide and eventually develop into sperm and egg cells These cells start out with 46 chromosomes but after the rst division the number of chromosomes in the daughter cells is 23 This reduction of chromosome number is crucial because the resulting gamete with its 23 chromosomes may eventually unite with another gamete that also has 23 chromosomes The product of this union is a zygote The original number of chromosomes is restored in this zygote So the zygote gets half from each parent During rst division partner chromosomes come together to form pairs of double stranded chromosomes that line up along the cell s center They exchange genetic material in a process called recombination or crossing over As cell begins to divide the chromosomes themselves remain intact however the members of the pairs pull apart and move to opposite ends of the cell After the rst division there are two daughter cells but they are not identical because each daughter cell contains only one member of each chromosome pair And because of recombination each chromosome has alleles it didn t have before In the second division the chromosomes split at the centromere and the strands move to opposite sides of the cell Once this is complete there are 4 daughter cells each containing 23 single stranded chromosomes Mitosis Meiosis 2 daughter cells 0 Four gametes Exact duplication 0 Reduction division Goes on an entire lifespan Only during reproduction years Body cells somatic Leads to creation of new complex individuals Creates new cells 0 1 cells splitting into two Meiosis occurs in all sexually reproducing organisms and is important evolutionary innovation because it increase genetic variation in populations Genetic diversity is enhanced by meiosis and this diversity is essential if species are to adapt to changing selective pressures Natural selection acts on genetic variation An adult human has 1000 billion cells Complex life forms are made up of billions of cells The basic unit of life is the cell The basic unit of evolution is the population The basic unit of selection is the individual Mutation is the only source of new genetic variation because it produces new alleles But sexually reproducing species have an additional advantage because recombination produces new arrangements of genetic information potentially providing additional material for selection to act on Sexual reproduction and meiosis are of major evolutionary important because they contribute to the role of natural selection in populations An embryo cannot survive without an X chromosome Polymerase Chain reaction was developed in 1986 It enabled scientists to make thousands of copies of small samples of DNA PCR allows DNA sequences to be examined in Neanderthal fossils for example or Egyptian mummies It is also used to identify ngerprints It can give limitless potential to forensic science medicine and paleoanthropology Recombinant DNA technology has been used to transfer genes from the cells of one species into those of another Insulin is a product of altered bacterial cells Chapt Human Genome Project s goal was to sequence the entire human genome which consists of 3 billion bases making up about 21000 protein coding genes It was completed in 2003 and since then the genomes of many other species were sequenced By comparing different primates genomes molecular anthropologists are revealing more details regarding phylogenetic relationships among all primate species Scientists sequenced the Neanderthal genome and found that interbreeding of Neanderthal and modern human is possible and that some people have the Neanderthal gene Among other things genetic comparisons can educate us about population movements in the past and what selective pressures may have been exerted on different populations to produce some of the variability we see The ENCODE project determined that about 9 percent of the human genome has regulatory functions It has also determined that the regulation of protein coding genes is more complex and has evolved more quickly in humans than in most other species Moreover evolution occurs more rapidly in regulatory elements These facts may partly explain the acceleration of evolutionary change in modern humans compared to animals 1 to 4 mutations occur per gamete Mutations are random Cell replication makes cells more vulnerable to mutations er 4 Heredity and Evolution For 10000 years people have domesticated plants and animals They have used selective breeding which has proven to increase the frequency of desirable characteristics Gregor Mendel 18821884 was a botanist who questioned heredity He investigated how physical traits such as color or height could be expressed in plant hybrids He worked with garden peas and concentrated on different traits He chose a group of tall pea plants and a group of short pea plants to experiment on He crossed tall plants with short plants and all the hybrid offspring were all tall Then he let the plants self fertilize to produce a second generation and only three quarters of the offspring were tall So the short gene which was not expressed in the rst generation showed up in the second generation He came up with the principle of segregation Genes alleles occur in pairs because chromosomes occur in pairs During gamete formation the members of each pair of alleles separate so that each gamete contains one member of each pair However in the zygote the full complement of chromosomes is restored Mendel realized that the unit for the absent characteristic hadn t disappeared it just was not expressed He described this lost expression as recessive and the expressed trait as dominant In the peas the dominant allele was the tall and the short allele was recessive In his experiment the parent plants had two copies of the same allele When there are two copies of the same allele the individual is said to be homozygous An example would be each parent plant since a group was all tall and another group was all short Heterozygous are individuals that have two different alleles at a locus An example would be the F1 plants the offspring of the tall and short plants Letters that represent alleles or genes are italicized with uppercase letters referring to dominant and lowercase letters referring to recessive The same symbols are combined to describe a person s genotype or genetic makeup Phenotypes are the observed physical manifestations of genes illustrating why Mendel saw approximately three tall plants for every short plant in the F2 generation The only way that recessive traits can be expressed is if it occurs with another recessive allele that s if the individual is homozygous recessive at the particular locus The Punnett square represents possible genotypes and phenotypes Each square receives one allele form the gamete above it and another from the gamete to the left Mendel developed the principle of independent assortment He demonstrated that plant height and seed color are independent of each other So this principle would mean that the distribution of one pair of alleles into gametes does not in uence the distribution of another pair The genes controlling different traits are inherited independently from each other Random assortment is the chance of distribution of chromosomes to daughter cells during meiosis Mendel s pea experiment was not an example of independent assortment because the plant height gene was on the same chromosome Menedelian traits or discrete traits are controlled by alleles at only one genetic locus A number of genetic disorders are caused by dominant alleles That means if a person inherits only one copy of a harmful dominant allele the condition it causes will be present regardless of the presence of a different recessive allele on the partner chromosome Recessive conditions are associated with lack of substance usually an enzyme A person must have two copies of recessive allele to have the recessive disorder IF they don t get the recessive condition they can pass it on to their children For this reason they re frequently called carriers If one parent has the recessive allele it is possible for offspring to be homozygous for the allele Mating between two carriers makes the risk of having an affected child about 25 percent likely Blood groups such as the ABO system provides some of the best examples of Mendelian traits in humans These alleles determine a person s ABO blood type by coding for the production of molecules called antigens on the surface of red blood cells When antigen A is present it is blood type A When only B is present there is blood type B When blood type is AB then the blood type is AB but when neither AB are present the blood type is 0 If a person has an 0 allele it must have two copies of it Someone with blood type 0 can have AA or A0 The same is true for B BB and B0 Type AB represents codominance where two different alleles are present and both are expressed 0Pedigree chart is a diagram of mating and offspring in a family over the span of a few generations Pedigree analysis helps researchers determine if a trait is Mendelian and also helps establish the mode of inheritance lt asses risk of genetic disease By determining if a gene is located on an autosome or sex chromosome researchers have identi ed six different modes of Mendelian inheritance in humans autosomal dominant autosomal recessive Xlinked recessive Xlinked dominant Y linked and mitochondrial Squares and circles in pedigree charts indicate males and females Horizontal lines connecting individuals indicate matings and offspring are connected to horizontal mating lines by vertical lines Sibling are joined by a horizontal link connected to a vertical link that descends from parents Autosomal dominant traits are governed by dominant alleles located on autosomes any chromosome except X or y One example is achondroplasia a form of dwar sm by a normal sized trunk and head but shortened arms and legs Because it is a dominant allele anyone who inherits even one copy of it will have the trait The Symbol A refers to the dominant allele and a represents the recessive normal allele Since the allele is rare everyone who gets achondroplasia is a heterozygote Unaffected individuals are homozygous aa and they do not have the dominant allele For an autosomal dominant trait even if only one parent has the trait it is highly possible for offspring to develop that trait Autosomal recessive traits can occur in offspring with two normal parents An example is albinism a metabolic disorder caused by an autosomal recessive allele that prevents production of a pigment called melanin When both parents have it though all of their offspring are affected Unaffected parents who produce an albino child must both be carriers and their child will be homozygous for the recessive allele causing the abnormality Genes located on the X and Ychromosomes control sex linked traits Genes on the X chromosome in uence almost all of more than 1000 sexlinked traits Hemophilia is one of the bestknown Xlinked traits and this prevents the formation of a clothing factor in the blood Individuals can suffer bleeding episodes The most famous pedigree is that of Queen Victoria The most striking feature shown by this pattern of inheritance is that almost all affected people are males because males have only one x chromosome and therefore only one copy of Xlinked genes This means any allele even a recessive one located on X chromosome will be expressed Females have two x chromosomes so they have the same pattern of expression of x linked traits as for autosomal traits Females who have one copy of hemophilia allele are carriers and may have some bleeding tendency even if they are not severely affected 0 Non Menedelian Inheritance Polygenic inheritance Polygenic traits are continuous traits quite opposite of Mendelian traits which are discontinuous or discrete Mendelian traits are governed by only one genetic locus but polygenic characteristics are governed by alleles that are two or more loci and each locus has some in uence on phenotype The most frequently discussed examples of polygenic inheritance in humans have been skin hair and eye color 0Coloration is determined by melanin a pigment produced by specialized cells called melanocytes The amount of melanin produced determines how dark or light a person s skin will be A study by Lamason and colleagues showed that one single highly conserved gene called MC1R with two alleles makes a greater contribution to melanin production than some other melanin producing genes 0 For many Mendelian traits the approximate or exact position of genetic loci are known which makes it possible to examine the mechanisms and patterns of inheritance at these loci This type of study isn t yet possible for polygenic traits because they re in uenced by several genes that are only now being traced to speci c loci Eye color is in uenced by more than one gene and some of these genes that in uence skin color are also involved A gene called OCA2 located on chromosome 15 apparently is the most important gene in the development of blue eyes OCA2 is involved in pigmentation of the iris of the eye and mutations in this gene lead to a form of albinism When we examine a trait we must look at genes and DNA sequences that regulate it Polygenic traits account for most of the readily phenotypic variation in humans and they ve traditionally served as a basis for racial classi cation IN addition to skin hair and eye color there are many other polygenic characteristics incuding stature shape of face and nger print pattern Because they exhibit continuous variation most polygenic traits cane be measured on a scale composed of equal increments Menedelian traits cant be measured the same way because they re either present or absent expressed one way or another Mendelian traits can be analyzed for mode of inheritance Another component of inheritance involves the organelles called mitochondria Each mitochondrion contains several copies of a ring shaped DNA molecule or chromosome While mtDNA is distinct from chromosomal DNA its molecule structure and functions are the same The entire molecule has been sequenced and is known to contain around 40 genes that direct the conversion of energy within the cell mtDNA is subject to mutations some of which cause genetic disorders mtDNA is inherited from only one parent meiosis and recombination don t occur This means that all variation in mtDNA among individuals is caused by mutation which makes mtDNA extremely useful for studying genetic change over time Geneticists use mtDNA to investigate evolutionary relationships between species to trace ancestral relationships between human lineages and to study genetic variability among individuals or populations 0Pleiotropy is a situation where a single gene in uences more than one characteristic Autosomal recessive disorder is one example Individuals who are homozygous for the PKU allele don t produce the enzyme involved in initial conversion of amino acid phenylalanine to another amino acid tyrosine Because of this block in metabolic pathway phenylalanine breaks down into substances that accumulate in central nervous system Tyrosine is converted to several other substances including pigment melanin therefore numerous systems can be affected Thus another manifestation of PKU owing to a diminished ability to produce melanin is that affected people usually have blue eyes fair skin and light hair Thus the action of one gene can in uence a number of seemingly unrelated traits Genotypes set limits and potentials for development but they also interact with the environmental and many aspects of phenotype are in uenced by this geneticenvironmental interaction Adult stature for example is in uenced by both genes and environment Mendelian traits are less likely to be in uenced by environmental factors For example ABO blood type is determined by fertilization and remains xed throughout an individual s lifetime regardless of diet exposure to the sun temperature or altitude Even for polygenic characteristics Menedelian principles still apply at individual loci In other words if a trait is in uenced by six loci each one of these loci may have two or more alleles with some perhaps being dominant to others It s the combined action of the alleles at all six loci interacting with the environment that produces the phenotype Evolution is a two stage process 1 the production and redistribution of variation 2 natural selection acting on this variation whereby inherited differences or variations among individuals differently affect their ability to successfully reproduce Darwin saw evolution as a gradual unfolding of new varieties of life from preexisting ones We can de ne evolution as a change in allele frequency from one generation to the next To show how allele frequencies change we can use a simpli ed example of an inherited trait again the ABO blood types An individual s blood type is xed Therefore only a population can evolve over time individuals can t Microevolution is the short term effects through time and macroevolution are the longterm effects called speciation Point mutations must have sex cells and this is because for evolutionary change to occur mutation must be passed from one generation to the next If a mutation occurs in somatic cells it won t be passed onto offspring It is rare however for evolution to occur only because of mutations Mutations are the only way to produce new gens and is the basic creative force in evolution Many DNA sequences have copy number variants CNVs quotnoncoding DNAquot When CNVs occur in regulatory genes particularly those involved in development they can cause dramatic phenotypic changes CNVs occur as a result of deletions or duplications of DNA segments within a gene Tandem repeats are a type of duplication that has attracted a great deal of attention in recent years because they have much higher mutation rates than single alleles do Gene ow is the exchange of genes between populations Gene ow can only happen if there is interbreeding In humans mating factors are usually socially determined Migration does play a factor in gene ow only if populations interbreed Signi cant changes in allele frequencies can come about through long term patterns of mate selection whereby members of a group traditionally obtain mates from certain other groups Genetic drift is the random factor in evolution and it s a function of population size Drift occurs because the population is Chapt small If an allele is rare it may disappear if not passed onto offspring One kind of genetic drift is Founder effect which is seen in many modern human and nonhuman populations It can occur when a small band of founders leaves its parent group and forms a colony somewhere else A new population will be established and mates are chosen only within that population Founding groups can also be survivors from a disaster The outcome is reduction in genetic diversity Shift in allele is adaptation We can determine if allele frequencies have changed in a population where sickle cell hemoglobin is found by determining the percentage of individuals with the Hbquots allele versus those with the normal allele Hbquota The only way the Hbquots could ve arisen is by mutation But this is not an evolutionary change This new allele must spread in the population Genetic drift can alter the frequencies of alleles as well Some alleles may not be passed and they will be lost So there s a loss a variation Individuals who carry a particular allele or combination of alleles produce more offspring than other individuals with different alleles If a certain allele is bene cial in a particular environment its frequency should increase slowly from generation to generation Likewise detrimental alleles are less common This shows differential net reproductive success and how it is related to natural selection er 5 Macroevolution Processes of vertebrate and Mammalian evolution Classi cation organizes diversity into categories and at the same time indicates evolutionary relationships Chordata is one of the phyla within the kingdom Animala Most Chordates are vertebrates because they have a vertebral column At each succeeding level suborder superfamily family subfamily genus and species ner distinctions are made between categories until at the species level only those animals that can interbreed and produce viable offspring are included Taxonomy coined by Linnaeus in the 18th century is the rst systematic classi cation system Structures that are shared by species on the basis of descent from a common ancestor are called homologies Homologies alone are reliable indicators of evolutionary relationship Similarities based on independent functional adaptation and not on shared evolutionary descent are called analogies The process that leads to the development of analogies such as wings in birds and butter ies is termed homoplasy A clade is lineages that share a common ancestor Cladistics is the eld that seeks to identify and interpret these groups If there is one common ancestry it is monophyletic if it has more than one common ancestor it is polyphyletic When we try to identify a clade it can be derived or modi ed The biological species concept is preferred by zoologists to de ne species To understand what species are you might consider how they come about in the rst place This is what Darwin calls an origin of species This most fundamental of macroevolution is speciation The way new species are rst produced according to biological species concept is that there is some form of isolation Gene exchange will be limited and there is a geographical barrier that separates populations This is geographical isolation Recognition species concept Who s mating with whom leads to differentiation Speciation is the process by which species appear Sympatric speciation is when species are not competing with one another Isolation leads to speciation Ecological species concept is when a species is de ned as a group of organisms exploiting a single niche An ecological niche is a physical as well as biological position of an organism in biological world For each population ecological niche will vary slightly The ecological species concept stresses the role of natural selection Sexual dimorphism is when there are differences between males and females of the same species It can result in marked variation in body size and proportions in adults of the same species Paelospecies Species based only on fossil evidence The genus is a level of taxonomy that is very broad and presents challenges It is a group of species that is composed of members more closely related to each other than they are to species from any other genus lf members of normally separate species interbreed and produce live offspring they can be grouped in genus Cladistic analysis helps scientists to make judgments about evolutionary relationships that means members of genus should all share derived characters not seen in other members of other genera Fossils are traces of ancient organisms and can be formed in many ways 0 Continental drift is explained by plate tectonics which states that the earth s crust is a series of gigantic moving and colliding pales The continents came together to form a single colossal landmass called Pangea and then separated 0 Adaptive radiation is an evolutionary process that can be seen in the divergence of the stem reptiles into the profusion of different forms of the late Paleozoic and especially those of Mesozoic It s a process that takes place when life form rapidly takes advantage 0 the many newly available ecological niches Chapter 14 Modern Human Biology Patterns of Variation 0 Human polymorphism A genetic trait is polymorphic if the locus that governs it has two or more alleles Geneticists use polymorphism as a tool to understand evolutionary processes Population genetics de nition in list of vocabulary words 0 HardyWeinberg theory of genetic equilibrium is a mathematical model that gives us a baseline set of evolutionary expectations under known conditions It established a set of conditions in a hypothetical population where no evolution occurs In other words no evolutionary forces are acting and all genes have an equal chance of recombining in each generation list on pg 403 read over Calculating allele frequencies 404405 Nonrandom mating and inbreeding 407 0 Lactase persistence 409 The forces of evolution are mutation gene ow genetic drift natural selection and recombination of sex cells Chapter 15 The adaptive signi cance of human variation Vocabulary list for Course Content Section 1 exam 1 1 Acclimatization Physical responses to changes in the environment that occur during an individual39s lifetime 2 Adaptation An anatomical physiological or behavioral response of organisms or populations to the environment Adaptations result from evolutionary change speci cally as a result of natural selection 3 Adaptive radiation The relatively rapid expansion and diversi cation of life forms into new ecological niches 4 Alleles Alternate forms of a gene Alleles occur at the same locus on paired chromosomes and thus govern the same trait but because they re different their actions may result in different expressions of that trait 5 Allele frequency In a population the percentage of all the alleles at a locus accounted for by one speci c value 6 Allopatric speciation Species formation that occurs following the geographical isolation of populations 7 Amino acids Small molecules that are the components of proteins 8 Analogies homoplastic character Similarities between organisms based strictly on common function with no assumed common evolutionary descent 9 Anthropology The eld of inquiry that studies human culture and evolutionary aspects of human biology includes cultural anthropology archaeology linguistics and physical or biological anthropology 10 Physical or biological anthropology Scienti c discipline concerned with the biological and behavior characteristics of human beings our closest relatives the nonhuman primates and our ancestors 11 Autosomes All chromosomes except the sex chromosomes 12 Balanced polymorphism The maintenance of two or more alleles in a population due to the selective advantage of the heterozygote 13 Binomial nomenclature ln taxonomy the convention established by Carolus Linnaeus whereby genus and species names are used to refer to living things 14 Biological continuity A biological continuum When expressions of a phenomenon continuously grade into one another so that there are no discrete categories they exist on continuum 15 Biocultural evolution The mutual interactive evolution of human biology and culture the concept that biology makes culture possible and that developing culture further in uences the direction of biological evolution This is the basic concept in understanding the unique components of human evolution 16 Biological species concept A depiction of species as groups of individuals capable of fertile interbreeding but reproductively isolates from other such groups 17 Fixity of species The notion that species once created can never change is diametrically opposed to theories of biological evolution 18 Founder effect A type of genetic drift in which allele frequencies are altered in small populations that are taken from larger populations or are remnants of the latter 19 Gametes Reproductive cells egg and sperm in animals developed form precursor cells in ovaries and testes 20 Gene A sequences of DNA bases that specifies the order of amino acids in an entire protein a portion of a protein or any functional product such as RNA A gene may be composed of thousands of DNA bases 21 Gene ow Exchange of genes between populations 22 Gene pool All of the genes shared by the reproductive members of a population 23 Genetic drift Evolutionary changes or changes in allele frequencies produced by random factors in small populations Genetic drift is a result of small population size 24 Genetics Having to do with the study of gene structure and action and the patterns of inheritance of traits from parent to offspring Genetic mechanisms are the foundation of evolutionary change 25 Genome The entire genetic makeup of an individual or species In humans it s estimated that the human genome comprises about 3 billion DNA bases 26 Genotype The genetic makeup of an individual Genotype usually refers to an organism s genetic makeup or alleles at a particular locus 27 Genus genera A group of closely related species 28 Haploid sex cells 29 HardyWeinberg Theory of genetic equilibrium The mathematical relationship expressing under conditions which no evolution is occurring the predicted distribution of alleles in populations the central theorem of population genetics 30 Heterozygotes see hybrids Offspring of parents who differ from each other with regard to certain traits or certain aspects of genetic makeup 31 Homologies Similarities between organisms based on descent form a common ancestor 32 Pedigree chart A diagram showing family relationships It is used to trace the hereditary pattern of particular genetic usually Mendelian traits 33 Phenotypes The observable or detectable physical characteristics of an organism the detectable expression of genotypes frequently in uenced by environmental factors 35 Pleiotropy A situation where the action of one gene affects several different traits 36 Point mutation A change in one of the four DNA bases 37 Polygenic Referring to traits in uenced by genus t two or more loci Examples include stature skin color eye color and hair color Many polygenic traits are in uenced by environmental factors such as nutrition and exposure to sunlight 38 Polymorphism Loci with more than one allele Polymorphisms can be expressed in the phenotype as the result of gene action or they can exist solely at the DNA level within noncoding regions 39 Population Within a species a community of individuals where mates are usually found 40 Population genetics The study of frequency of alleles genotypes and phenotypes in populations from a micro evolutionary perspective 41 Principle of independent assortment The distribution of one pair of alleles into gametes does not in uence the distribution of another pair The genes controlling different traits are inherited independently of one another 42 Principle of segregation Genes alleles occur in pairs because chromosomes occur in pairs During gamete formation the members of each pair of alleles separate so that each gamete contains one member of each pair 43 Protein synthesis The manufacture of proteins that is the assembly of chains of amino acids into functional protein molecules DNA directs protein synthesis 45 Random assortment The chance distribution of chromosomes to daughter cells during meiosis Along with recombination random assortment is an important source of genetic variation but not new alleles 46 Recessive Describing a trait that isn t expressed in heterozygotes it also refers to the allele that governs the trait For a recessive allele to be expressed an individual must have two copies of it the individual must be homozygous 47 Biological evolution is a process that starts with genetic variation by recombination or mutation There must be a change in the proportion of heritable traits from one generation to another It can occur without natural selection 48 Biological continuum Refers to the fact that organisms are related through common ancestry and that behaviors and traits seen in one species are also seen in others to varying degrees When expressions of a phenomenon continuously grade into one another so that there are no discrete categories they are said to exist on a continuum Color is one such phenomenon 49 Catastrophism The view that the earth s geological landscape is the result of violent cataclysmic events Cuvier promoted this view especially in opposition to Lamarck 50 Chromosomes Discrete structures composed of DNA and proteins found only in the nuclei of cells Chromosomes are visible under magni cation only during certain phases of cell division 51 Codominance The expression of two alleles in heterozygotes In this situation neither allele is dominant or recessive so they both in uence the phenotype 52 Culture Behavioral aspects of human adaptation including technology traditions language religion marriage patterns and social roles Culture is a set of learned behaviors transmitted from one generation to the next by non biological means 53 DNA Deoxyribonucleic acid The double stranded molecule that contains the genetic code DNA is a main component of chromosomes 54 Deme local population of one species that actively interbreeds with one another and shares a distinct gene pool 55 Diploidsomatic cells 56 Dominant ln genetics describing a trait governed by an allele that s expressed in the presence of another allele ie in heterozygotes Dominant alleles prevent the expression of recessive alleles in heterozygotes this is the de nition of complete dominance 57 Ecological species concept This concept that a species is a group of organisms exploiting a single niche This view emphasizes the role of natural selection in separating species from one another 58 Empirical Relying on experiment or observation from the Latin empiricus meaning experience 59 Epigenetics Changes in phenotype that are not related to changes in underlying DNA 60 Evolution A change in the genetic structure of a population The term is also frequently used to refer to the appearance of a new species 61 Extant living representatives of species 62 Extinct No living representative of species exists 64 Fitness Pertaining to natural selection a measure of the relative reproductive success of individuals 66 Homozygous Having the same allele at the same locus on both members of a chromosome 67 Hypoxia Insuf cient levels of oxygen in body tissues oxygen de ciency 68 Hypothesis A provisional explanation of a phenomenon Hypotheses require veri cation or falsi cation through testing 69 Inbreeding A type of nonrandom mating in which relatives mate more often than predicted under random mating conditions 70 Karyotype The number of visual appearance of chromosomes of an individual or what is typical of a species viewed microscopically and displayed in a photograph The chromosomes are arranged in pairs and according to size and position of the centromere 72 Locusloci the position or location on a chromosome where a given gene occurs The term is sometimes used interchangeably with gene 73 Macroevolution Changes produced only after many generations such as the appearance of a new species 74 Meiosis Cell division in specialized cells in ovaries and testes Meiosis involves two divisions and results in four daughter cells each containing only half the original number of chromosomes These cells can develop into gametes 75 Mendelian traits Characters that are in uenced by alleles at only one genetic locus Examples include many blood types such as ABO Many genetic disorders including sickle cell anemia and TaySach s disease 76 Microevolution Small changes occurring within species such as changes in allele frequencies 77 Mitosis Simple cell division the process by which somatic cells divide to produce two identical daughter cells 78 Morphology The form shape size of anatomical structures can also refer to entire organism 79 mtDNA Mitochondrial DNA DNA found in the mitochondria Mitochondrial DNA is inherited only from the mother 80 Mutation A change in DNA The term can refer to changes in DNA bases or speci cally called point mutation as well as to changes in chromosome number andor structure 81 Natural selection The most critical mechanism of evolutionary change rst described by Charles Darwin the term refers to genetic change or changes in the frequencies of certain traits in populations due to differential reproductive success between individuals 82 Nonrandom mating Pattern of mating in which individuals choose mates preferentially with mate choice based on criteria such as social status ethnicity or biological relationship In nonrandom mating an individual doesn t have an equal chance of mating with all other individuals in the group 83 Paradigm shift A transition from one conceptual framework or prevailing and widely accepted viewpoint to another The acceptance of the discovery that the sun is the center of our solar system is an example of a paradigm shift 84 Recombination the exchange of genetic material between paired chromosomes during meiosis also called crossing over 85 Reproductively isolated Pertaining to groups of organisms that mainly because of genetic differences are prevented from mating and producing offspring with members of other such groups For example dogs cannot mate and produce with cats 86 Reproductive success The number of offspring an individual produces and rears to reproductive age or an individual s genetic contribution to the next generation 87 Science A body of knowledge gained through observation and experimentation from the Latin scientia meaning knowledge 88 Scienti c method An approach to research whereby a problem is identi ed a hypothesis is stated and that hypothesis is tested by collecting and analyzing data 89 Selective pressures Forces in the environment that in uence reproductive success in individuals 90 Sexlinked Traits that are controlled by genes located on the X and Y chromosomes 91 Sexual selection A type of natural selection that operates on only one sex within a species It s the result of competition for mates and it can lead to sexual dimorphism with regard to one or more traits 92 Sicklecell trait Heterozygous condition where a person has one HbquotA allele and one Hbquots allele Thus they have some normal hemoglobin 93 Somatic cells Basically all the cells in the body except those involved with reproduction 94 Species A group of organisms that can interbreed to produce fertile offspring Members of one species are reproductively isolated from members of all other species 95 Stress environmentalphysiological ln physiological context any factor that acts to disrupt homeostasis more precisely the body s response to any factor that threatens its ability to maintain homeostasis 96 Taxa A taxonomic group of any rank 97 Taxonomy The branch of science concerned with rules of classifying organisms on the basis of evolutionary relationships 98 Theory A broad statement of scienti c relationships or underlying principles that has been substantially veri ed through testing of hypotheses 99 Uniformitarianism The theory that the earth s features are the result of longterm process that continues to operate in the present just as they did in the past Elaborated on by Lyell this theory opposed catastrophism and greatly contributed to the concept of immense geological time 100 Variation genetic ln genetics inherited differences among individuals the basis of all evolutionary change 101 Worldview General cultural orientation or perspective shared by the members of a society 102 Zygote A cell formed by the union of an egg cell and a sperm cell It contains the full complement of chromosomes in humans 46 and has the potential of developing into an entire organism People to know on Exam 1 1 Georges Cuvier Discovered the notion called Catastrophism It was a model to explain animals getting wiped out of their environment and other animals taking their place Cuvier identi ed bones of animals and one day someone brought him crocodile and hippo bones and that was when he rst though of catastrophism 2 JaneBaptiste Lamarck Lamarck developed the theory of inheritance of acquired characteristics Discovered the false idea that if you don t use something it will go away He could not account for extinction 3 Charles Lyell Lyell came up with the idea of uniformitarianism and the concept of deep time He also studied dirt with Huten Through deep time Lyell demonstrated that earth is very old and says there was a lot of time after evolution 4 Thomas Malthus He observed organisms He wrote that more organisms are born than can survive creating competition for resources like food water mates and space Competition is key to how natural environment works 5 8 9 10 11 A R Wallace Observed succession of species Animals change as environment changes He wrote Darwin a letter he and Darwin wrote a joint paper Charles Darwin He was a wealthy man who married his cousin Emma He went on the Voyage of the Beagle where he went to Brazil and then Galapagos Island He sat on an idea for 15 years Gregor Mendel He came up with principle of segregation dominance and recessiveness independent assortment intermediate expression codominance phenotypes simple traits and alleles Mary Anning discovered marine fossils and shared her knowledge with scientists Georges Louis Buffon John Ray Carolus Linnaeus taxonomy and binomial nomenclature Came up with the groups called genus and species Jurmain Anthropology exam 2 notes Chapter 5 Macroevolution Processes of vertebrae and Mammalian evolution Biologists need methods to deal scienti cally with all diversity One way to do this is to use a system of classi cation that organizes diversity into categories and at the same time indicates evolutionary relationships 0 Multicellular organisms that move and ingest foods are in the Kingdom Animalia there are more than 20 majors groups called phyla Chordata is one of these phyla it includes all animals with a nerve cord gill slits and a supporting cord along the bag In turn most chordates are vertebrates so called because they have a vertebral column Further dividing mammals into orders makes the statement for example all carnivores are more closely related to each other than they are to any species placed in another order At each succeeding level suborder superfamily family subfamily genus and species ner distinctions are made between categories until it reaches species level 0 The eld that specializes in establishing the rules of classi cation is called taxonomy This was the basis of the rst systematic classi cation devised by Linnaeus in the 18th century Today basic physical similarities are useful but to be useful they must re ect evolutionary descent For example the bones of the forelimb of all air breathing vertebrates initially adapted to terrestrial land environments are so similar in number and form that obvious explanation for the striking resemblance is that all four footed tetrapod vertebrates derived their forelimb structure from a common ancestor Physical similarities help identify fossils too 0 Pg 109 chart of classi cation 0 Structures that are shared by species on the basis of descent from a common ancestor are called homologies Analogies are quite different from homologies but can be mistaken for them Analogies are similarities between organisms based strictly on common function with no assumed common evolutionary descent The process that leads to the development of analogies such as wings in birds and butter ies is termed homoplasy Homoplasy is the separate evolutionary development of similar characteristics in different groups of organisms Evolutionary systematics is a traditional approach to classi cation and evolutionary interpretation in which presumed ancestors and descendants are traced in time by analysis of homologous characters Cladistics is an approach to classi cation that attempts to make rigorous evolutionary interpretations based solely on analysis of certain types of homologous characters They have similarities First both schools are interested in tracing evolutionary relationships and in constructing classi cations that re ect these relationships Second both schools recognize that organisms must be compared using speci c features called characters and that some of these characters are more informative than the others Third both approaches focus on homologies Primary difference between them is that cladistics more explicitly de nes the kinds of homologies that yield most useful information Cladistics shows that some homologous characters are much more informative than others Ancestral characters Referring to characters inherited by a group of organisms form a remote ancestor and thus not diagnostic of groups lineages that diverged after the character rst appeared also called primitive Cladistics focuses on traits that distinguish particular evolutionary lineages such traits are far more informative than ancestral traits Lineages that share a common ancestor are called a clade a group of organisms sharing a common ancestor It is the most fundamental point of cladistics that evolutionary groups all share a common ancestor and thus said to be monophyletic If an evolutionary grouping is found to have more than one ancestor it is said to be polyphyletic When we try to identify a clade characters of interest are said to be derived or modi ed Derived refers to characters that are modi ed from ancestral condition and thus diagnostic of particular evolutionary lineages Theropods are small to medium sized ground living dinosaurs dated to about 150 mya and thought to be related to birds Speci cally they were thought to be related to primitive birds from Madagascar which show many similarities to the Velociraptor Shared derived relating to speci c character traits shared in common between two life forms and considered the most useful for making evolutionary interpretations Phylogenetic tree a chart showing evolutionary relationships as determined by evolutionary systematics Cladogram a chart showing evolutionary relationships as determined by cladistics analysis It is based solely on interpretation of shared derived characters Phylogenetic trees usually try to make some hypotheses regarding ancestordescendant relationships Cladistic analysis makes no attempt whatsoever to discern ancestordescendant relationships Strict cladists are quite skeptical that the evidence really permits such speci c evolutionary hypotheses to be scienti cally con rmed Biological species concept a depiction of species as groups of individuals capable of fertile interbreeding but reproductively isolated from other such groups To understand what species are you might consider how they come about in the rst place what Darwin called the origin of speciesquot This most fundamental of macro evolutionary processes is called speciation Speciation is the process by which a new species evolves from an earlier species It is the most basic process in macroevolution Recognition species concept is another process that can contribute to the further differentiation of populations It is a depiction of species in which the key aspect is the ability of individuals to identify members of their own species for purposes of mating Ecological species concept the concept that species is a group of organisms exploiting a single niche This view emphasizes the role of natural selection in separating species from one another An ecological niche is the position of a species within its physical and biological environments Organisms within a species tend to vary An example of this is sexual dimorphism and sexual dichromatism When trying to identify fossils you cannot apply the biological species concept In studying a fossil group we may observe obvious variation such as some individuals being larger and with bigger teeth than others The question is what s the biological signi cance of this variation Two possibilities come to mind Either the variation is accounted for by individual age and sex differences seen within every biological species intraspeci c or the variation represents differences between reproductively isolated groups interspeci c Paleospecies are species de ned from fossil evidence often covering a long time span The act of interpreting Paleospecies is so dif cult that most researchers today de ne species by using cluster of derived traits Genus is a broader level of taxonomy than species A genus is described as a group of closely related species Species that are a part of the same genus share the same broad adaptive zone An adaptive zone represents a general ecological lifestyle more basic than the narrower ecological niches characteristic of individual species Fossils are traces or remnants of organisms found in geological beds on the earth s surface Fossils are made after mineralization Mineralization is the process in which parts of animals become transformed into stonelike structures The study of how bones and other materials come to be buried in the earth and preserved as fossils is called taphonomy Among the topics that taphonomists try to understand are processes of sedimentation and burial including the action of streams preservation properties of bone and carnivore disturbance factors Geologists have formulated the geological time scale in which very large time spans are organized into eras that include one or more periods Periods in turn can be broken down into epochs For the time span encompassing vertebrate evolution there are three eras the Paleozoic Mesozoic and Cenozoic The earliest vertebrates are represented in the fossil record dating to early in the Paleozoic at 500 mya Continental drift is the movement of continents on sliding plates of the earth s surface As a result the positions of large landmasses have shifted drastically during the earth s history During most of the Mesozoic reptiles were the dominant land vertebrates they exhibited a broad expansion into a variety of ecological niches which included aerial and marine habitats Epochs are categories of geological time scale subdivisions of periods In the Cenozoic era epochs include the Paleocene Eocene Oligocene Miocene and Pilocene We can learn about mammalian evolution from fossils as well as from studying the DNA of living species How do we account for the relatively rapid success of the mammals during the late Mesozoic and early Cenozoic Several characteristics relating to learning and general exibility of behavior are of prime importance Mammals were selected for larger brains than those typically found in reptiles making them better equipped to process information In particular the cerebrum became generally enlarged especially the outer covering the neocortex which controls higher brain functions A distinctive feature of mammals is the dentition While many living reptiles consistently have similarly shaped teeth mammals have differently shaped teeth This varied pattern is termed Heterodont dentition is re ected in the ancestral primitive mammalian arrangement of teeth which includes three incisors one canine four premolars and three molars in each quarter of the mouth So with 11 teeth in each quarter of the mouth the ancestral mammalian dental complement includes a total of 44 teeth Such a Heterodont arrangement allows mammals to process a wide variety of foods lncisors are used for cutting canines for grasping and piercing and premolars and molars are crushing and grinding Mammals and birds are endothermic which means they maintain internal body temperature by producing energy through metabolic processes within cells There are three major subgroups of living mammals the egg laying mammals or monotremes the pouched mammals or marsupials and the placental mammals The most notable difference between marsupials and placental concerns fetal development In marsupials the young are born extremely immature and must complete development in an external pouch Placental mammals develop over a longer period of time in utero made possible by the evolutionary development of specialized tissue that provides for fetal nourishment With a longer gestation period the central nervous system develops more completely in the placental fetus What s more after birth the quotbond of milkquot between mother and young allows more time for complex neural structures to form We should also emphasize that form a biosocial perspective this dependency period not only allows for adequate physiological development but also provides for a wider range of learning stimuli Macroevolutionary mechanisms operate more on the whole species than on individuals or populations and they take much longer than micro evolutionary processes to have a noticeable impact As mentioned in chapter 2 the potential capacity of a group of organisms to multiply is practically unlimited but its ability to increase its numbers is regulated largely by the availability of resources As population size increases access to resources decreases and the environment will ultimately prove inadequate Depleted resources induce some members of a population to seek an environment in which competition is reduced and the opportunities for survival and reproductive success are increased Adaptive radiation is the relatively rapid expansion and diversi cation of life forms into new ecological niches The principle of evolution illustrated by adaptive radiation is important A species or group of species will diverge into as many variations as two factors allow 1 it s adaptive potential 2 the adaptive opportunities of the available niches The term generalized and specialized are sometimes used when speaking of the adaptive potential of whole organisms Consider the Ayeaye of Madagascar It is a highly specialized animal structurally adapted to a narrow rodentwoodpecker like econiche digging holes with prominent incisors and removing insect larvae with an elongated bony nger Only a generalized ancestor can provide the exible evolutionary basis for rapid diversi cation Only a generalized species with potential for N 39 adaptation to varied ecological niches can lead to all the later diversi cation and specializing of forms into particular ecological niches Rates of evolutionary change can speed up at certain times and slow down during others Most crucially natural selection is in uenced by how fast the environment is changing In all lineages the pace assuredly speeds up and slows down due to factors that in uence the size and relative isolation of populations Some groups of primates simply have slower or faster durations of speciation which is why Old World monkeys typically speciate more slowly than the great apes Chapter 6 Survey of the Living primates Chimpanzees aren t monkeys and neither are gorillas or orangutans They re apes If we want to identify the components that have shaped the evolution of our species a good starting point is to compare ourselves with our closest living relatives the nonhuman primates This chapter describes the physical characteristics that de ne the order Primates gives a brief overview of the major groups of living primates and introduces some methods currently used to compare living primates genetically Primates are members of the mammalian order Primates which includes lemurs lorises tarsiers monkeys apes and humans Evolution is not a goal directed process Anthropoids are members of the primate infraorder anthropoidea which includes monkeys apes and humans All primates share basic mammalian traits like long gestation period followed by live birth body hair mammary glands different types of teeth incisors canines premolars molars the ability to regulate body temperature increased brain size and considerable capacity for learning To differentiate primates from other mammals we must describe those characteristic that taken together set primates apart Primates have speci c traits that set them apart and they are A tendency toward an erect posture A exible generalized limb structure which allows most primates to practice many forms of locomotion Prehensile hands and sometimes feet derived trait primates use their hands and frequently their feet to grasp and manipulate objects this ability is there due to retention of ve highly mobile digits Primates have nails instead of claws derived trait 5 Tactile pads enriched with sensory nerve bers at the ends of digits derived 6 Lack of dietary specialization ancestral trait 7 A generalized dentition 8 Primates rely on vision the diurnal ones and less on olfaction especially when compared with other mammals 9 Color vision stereoscopic vision three dimension vision derived 10 Depth perception derived 11 Eyes placed toward the front of the face 12 Decreased reliance on sense of smell 13 Expansion and complexity of brain derived ln primates this expansion is most evident in the visual and association areas of the neocortex portions of the brain where information from different sensory modalities is combined 14 Long period of gestation 15 Tendency to be social 0 A lot of primates are arboreal meaning they live in trees Primates found adaptive niche an organism s entire way of life where it lives what it eats how it gets food in the trees Increased reliance on vision coupled with grasping hands and feet are also adaptation to an arboreal life style Their dietary shaft is most of the time omnivorous because living in trees resulted in this An alternative to this traditional arboreal hypothesis is based on the fact that animals such as squirrels are also arboreal yet they haven t evolved primate like adaptations such as prehensile hands or forward facing eyes Forward facing eyes binocular vision grasping hands and feet and presence of nails instead of claws may be the hallmarks of an arboreal visual predator Susman suggested that the basic primitive traits were developed in conjunction with another major evolutionary occurrence the appearance of owering plants which began around 140 mya Flowering plants provide many resources for primates including nectar seeds and fruits 0 With a few exceptions nonhuman primates are found in tropical or semitropical areas of new and old worlds In the New World these areas include southern Mexico Central America and parts of South America Old world primates are found in Africa India southeast Asia and japan A lot of primates are arboreal and live in forest or woodland habitats However some old world monkeys tend to be on the ground The same is true for the African apes gorillas chimps and bonobos But all nonhuman primates spend some time in the trees especially when sleeping Diet and Teeth There is lack of specialization when it comes to food A lot of primates eat nuts fruits seeds leaves and some may need animal protein and may eat insects of small animals Some examples of primates that sometimes eat small animals are capuchins bonobos chimps baboons But others like colobus and gorilla eat mostly leaves Generalized dietitian has its advantages but it brings forth a lot of competition for food Primates have four kinds of teeth They have incisors canines for biting and cutting premolars and molars for chewing and grinding Biologists use what s called a dental formula to describe the number of each type of tooth that typi es a species All old world monkeys anthropoids have two incisors one canine two premolars and three molars 2123 The dental formula for generalized placental mammal is 3143 Primates have fewer teeth than this ancestral pattern because of a general evolutionary trend toward fewer teeth New World primates have dentition 2133 The overall lack of specialization in primates is re ected in the lack of specialization in the size and shape of the teeth because tooth shape and size are directly related to diet Most primates have premolars and molars with low rounded cusps a molar morphology that enables them to process most types of food Cusps are the bumps on the chewing surface of premolars and molars Locomotion Siamangs and gibbons are brachiators Brachiation or arm swinging is a suspensory form of locomotion in which the body moves by being alternatively supported by one forelimb and then the other Orangutans gorillas bonobos and chimps brachiate as well Brachiation is seen in species characterized by arms longer than legs a short stable lower back long curved ngers and shortened thumbs Lemurs and tarsiers characterize vertical clinging and leaping Vertical clingers and leapers support themselves vertically by grasping onto trunks of trees or other large plants while their knees and ankles are tightly exed Almost all primates are quadrupedal meaning they use all forelimbs However most primates use more than one form of locomotion and they re able to do this because of their generalized anatomy Some New World monkeys such as spider and muriquis are called semibrachiators Because they practice a combination of leaping with some arm swinging Also some new world monkeys enhance arm swinging by using a prehensile tail which serves as a fth limb Old world monkeys particularly in superfamily Hominodiea gorillas bonobos chimps practice knuckle walking They support the weight of their upper body with the back surfaces of their bent ngers Primate classi cation All primates are in the Order Primates The suborder is when primates are divided into two smaller categories strepsirhini and haplorhini Strepsirhini includes lemurs Iorises Haplorhini includes tarsiers monkeys apes and humans By considering only physical characteristics its possible to overlook the unknown effects of spate evolutionary history This is why traditional system of taxonomy was not full proof Geneticists can now make direct comparisons between the genes and indeed the entire genetic makeup of different species This is comparative genomics Lemurs and lorises Suborder Strepsirhini includes the lemurs and lorises the most nonderived or primitive living primates Remember that by primitive we mean that lemurs and lorises are more similar anatomically to their earlier mammalian ancestors than other primates tarsiers monkeys apes and humans For example they retain certain ancestral traits like a more pronounced reliance on olfaction And a rhinarium or wet nose Many other characteristics distinguish lemurs and lorises from other primates like eyes placed more to the side of the face differences in reproductive physiology and shorter gestation and maturation periods They also have a dental comb formed by forward projecting lower incisors and canines These modi ed teeth are used in both grooming and feeding They also have a grooming claw Lemurs are found only in Madagascar and adjacent islands off east coast of Africa Lemurs are possibly the most endangered group of vertebrates Lemurs range in size from tiny mouse lemur to the indri Larger lemurs are diurnal and eat variety of foods such as leaves fruit buds bark and shoots but the tiny mouse and dwarf lemurs are nocturnal insectivores Some lemurs are arboreal Sifakas ringtails and indris are arboreal vertical clingers and leapers They live in a group of 10 to 25 animals comprising males and females of all ages lndris live in social units composed of mated pairs and dependent offspring Several nocturnal forms are mostly solitary Lorises live in Africa and Asia There are at least 8 species of Loris and they are found in tropical forest and woodland forests of India sri lanka southeast Asia and Africa In the same general category are the galagos or bush babies which are distributed throughout most of the forested and woodland savanna areas of subSaharan Africa All galagos are VCL while lorises are slow cautious climbers Some lorises and galagos are almost entirely insectivorous while others may eat fruits leaves and other plant stuff Lorises and galagos usually forage alone But feeding ranges can overlap and 2 or more females may feed and nest together Females also leave young infants in nests while they search for food They have good vision but not as well as anthropoids o Tarsiers Most tarsiers are found in Southeast Asia where they live in tropical rain forests They are nocturnal They use VCL They appear to form stable pair bonds and the basic tarsier social unit is a mated pair and their young offspring Tarsiers are highly specialized derived animals They share several traits from haplorhini and strepsirhini So they are hard to categorize They have some anthropoid characteristics Anthropoids monkeys apes and humans Although there is a lot of variation in this group they share some common anthropoid traits 1 Larger body size 2 Larger brain in absolute terms and relative to body weight 3 Reduced reliance on olfaction and absence of rhinarium 4 Increased reliance on vision binocular vision and stereoscopic vision 5 Greater degree color vision 6 Back of eye socket protected by a bony plate 7 Fusion of two sides of the mandible at midline to form one bone not in lemurs and lorises since their two distinct bones joined by cartilage at the middle of their chin 8 Increased parental care 9 Differences in female internal reproductive anatomy Estrus sex skin 10 More mutual grooming New World monkeys Most new world monkeys can be found in southern Mexico Central America or South America In size they vary from marmosets and tamarins to 20pound howler monkey They are almost exclusively arboreal Like the old world monkeys most are diurnal except for night monkey New world monkeys have broad noses with outward facing nostrils Old world monkeys have downward facing nostrils Their difference in nose gave rise to the terms platyrrhines and catarrhines to refer to new and old world anthropoids In addition to being the smallest of all monkeys marmosets and tamarins have many distinguishing features They have claws instead of nails and unlike other primates they usually have twins They re mostly insectivorous and marmosets eat gums from trees and tamarins may eat fruit Marmosets and tamarins are quadrupedal and they use claws for climbing Social group consists of one female and two males with babies Males take care of babies Other new world primates include squirrel monkeys and howler monkeys New world monkeys rely on fruit and leaves supplemented to varying degrees with insects Most are quadrupedal but some are semibrachiators Muriquis howlers and spider monkeys have prehensile tails that are used only in locomotion but also for hanging from branches Socially most new world monkeys live in mixed sex groups of all age categories Some form monogamous pair and live with their sub adult offspring Old world monkeys Except for humans old world monkeys are the most widely distributed of all primates They re found throughout subSaharan Africa and southern Asia and Southern Asia ranging from tropical jungle to semiarid deserts and even seasonally snow covered areas in northern japan All Old world monkeys are placed in one taxonomic family Cercopithecidae In turn this family is divided into two subfamilies Cercopithecines and colobines Most old world monkeys are quadrupedal and primarily arboreal but some like baboons are terrestrial The Cercopithecines are more generalized than colobines they re more omnivorous and as a group will eat almost anything Colobines is common name for subfamily of old world monkeys African colobus monkeys and Asian langurs Cercopithecidae are the taxonomic family that includes all old world monkeys Cercopithecines is the subfamily of old world monkeys that includes baboons macaques and guenons The majority of ceropithecines species such as guenons and terrestrial baboons are found in Africa The many macaque species are widely distributed in south Asia and India Colobine species have a narrower range of food preferences and mainly eat mature leaves Which is why they re called leaf eating monkeys The colobines are mainly in Asia but both red and black and white colobus monkeys are exclusively found in Africa Other colobines include langurs and proboscis monkey of Borneo Locomotion includes Arboreal quadrupedalism in guenons macaques and langurs terrestrial quadropedalism in baboons and macaques semibrachiation and acrobatic leaping in colobus monkeys Marked differences in body size and shape between sexes is sexual dimorphism It is typical of terrestrial species and especially in baboons Females in baboons and macaques have cyclical changes of external genitalia These changes include swelling and redness which is associated with estrus a hormonally initiated period of sexual receptivity in female nonhuman primates Colobines live in small groups with only one 39WFQWDWNH or two adult males Savanna baboons and most macaques are found in large social units comprising server adults of both sexes and offspring of all ages Monogamous paring is in a few angurs and one or two guenon species Old and New World monkeys A case of homeoplasy The consensus is that both old and new world monkeys came form a common ancestor The animals have gave rise to todays new world species reached South America by rafting over on chunks of land that had broken away from mainland areas Hominoids Apes and Humans Apes and humans are classi ed as hominoids members of superfamily hominoidea Apes are found in Asia and Africa Smallbodied gibbons and siamangs live in south east Asia and two orangutan subspecies live on islands of Borneo and Sumatra A Apes and Humans differ from monkeys in many ways including Generally larger body size No tail Shorter or more stable lower back Arms longer than legs only in apes Anatomical differences in shoulderjoints Generally more complex behavior More complex brain Increased period of infant development and dependency Gibbons and Siamangs Gibbons and siamangs are smallest of the apes with long slender bodies They use Brachiation They mostly eat fruit and sometimes owers insects or leaves The basic social unit for both is an adult male and female with dependent offspring Both males and females are highly territorial and protect their territory with songs or whoops Many gibbons are endangered Hunting is part of the reason Orangutans orangutan means wise man of the forest They are severely endangered due to poaching and habitat loss on islands They are found in Borneo and Sumatra islands in Indonesia Orangutans are slow cautious climbers They are quadrupedal and almost completely arboreal They exhibit sexual dimorphism They are solitary but social They are primarily frugivorous but may eat bark leaves insects and rarely meat Gorillas Gorilla is largest living primate They are found in forested regions of western and eastern equatorial Africa Western lowland gorillas are most numerous and found in west central Africa Eastern lowland gorillas live in Dominican Republic of Congo Mountain gorillas were found in mountainous region in Central Africa Gorillas have sexual dimorphism Adult gorillas are terrestrial quadrupeds Mountain gorillas live in groups composed of one or two large silverback males and many females Both females and males leave their natal group as young adults Females join other groups and males who appear to be less likely to emigrate may live alone for a while Gorillas eat leaves The social structure of western lowland gorillas are almost the same as mountain gorillas Western lowland may eat more fruit Chimpanzees Chimps are often found in equatorial Africa in west to lake Tanganyika in the east They are anatomically similar to gorillas but chimps spend more time in trees Chimps are frequently active noisy and excitable Gorillas are quiet Chimps are smaller than orangutans and gorillas They are sexually dimorphic They sometimes walk bipedally when carrying food Chimps are omnivores They may eat little monkeys like the colobus monkey Chimps live in large uid communities A closely bonded male group forming ls especially common in East Africa Females leave their natal group to join another community This reduces risk of mating with relatives Bond between mother and child is strong Bonobos found in Zaire river in Dominican republic of Congo Bonobos kind of look like smaller chimps They are less excitable and aggressive than chimps and their sexual dimorphism isn t that much Bonobos have a lot of sex They are omnivores and they live in uid communities Malefemale bond is very important Humans They are the only exclusive bipedal Human teeth are typical primate teeth except for reduced canine size The human dependency on vision and decreased olfaction reliance as well as exible limbs and grasping hands are rooted in our primate arboreal past Humans are omnivorous Humans are completely dependent on culture The neurological basis for intelligence is rooted in our evolutionary past and its something that connects us to other primates Humans use spoken language Habitual bipedalism sets us apart from other apes Endangered Primates There are three basic reasons for the worldwide depletion of nonhuman primates habitat destruction human hunting and live capture for export or local trade Bush meat trade was the reason for slaughter of nonhuman primates in Africa and few other places Logging has been a major factor in the development of the bush meat trade Hunting for nonhuman primates for food is common in South America and Africa and parts of Asia GRASP great ape survival project is an alliance of many of the world s major great ape conservation and research organizations It goes without saying that GRASP must succeed if the great apes are to survive in the wild for even a few more decades Chapter 7 Primate Behavior Behavior is anything organisms do that involves action in response to internal or external stimuli An example would be a cat chasing a mouse Behavior is extremely complex because its been shaped over evolutionary time by interactions between genetic and environmental factors Scientists study primates form an ecological and evolutionary perspective focusing on the relationship between behaviors the natural environment and various physiological traits This approach called behavioral ecology is the study of the evolution of behavior emphasizing the role of ecological factors Behaviors are adaptations to environmental circumstances that existed in the past and remain in the present Behaviors have evolved through the operation of natural selection In most vertebrates and primates especially behavior is not really genetic but mostly learned Behavior must be viewed as the product of complex interactions between genetic and environmental factors Behavioral genetics is the study of how genes affect behavior It is a relatively new eld Because primates are among the most social of all animals social behavior is one of the major topics in primate research Social behavior includes all aspects of behaviors that occur in social groupings such as feeding and mating Its necessary to determine how it s in uenced by other factors Social structure is the composition size and sex ration of a group of animals Social structure itself in uences behavior Some Factors that in uence Social Structure Body size Larger animals need less energy overall They require fewer calories and they can retain heat more easily Basal Metabolic Rate BMR BMR concerns metabolism which is the rate at which the body uses energy to maintain all bodily functions while in a resting state It is closely correlated with body size Smaller primates have high BMR and thus require a lot of energy rich food like insects and fatty stuff like nuts and seeds and fruits Larger primates have a lower BMR and have reduced energy requirements Diet Small bodied primates focus on energy rich foods and larger ones usually eat less caloric food An example is gorillas who eat leaves and don t expend a lot of energy getting food Colobines are leaf eaters as well colobus and langurs They have elongated intestines and pouched stomachs that enable them with the assistance of intestinal bacteria to digest the tough bers and cellulose in leaves In at least two langurs there s a duplicated gene that produces enzyme that further helps digestion Distribution of Resources Many kinds of foods are distributed in different ways Leaves can be abundant and dense and can support large groups of animals lnsects however may be widely scattered therefore animals that rely on them usually feed alone or with only one or two others Fruits nuts and berries occur in dispersed trees and shrubs These are usually exploited by smaller groups Such subunits may include one male multi female some baboons or Matrilines macaques Matrilines are groups that consist of female and her daughters and their babies Species that subsist on abundantly distributed resources may also live in one male groups and because food is plentiful these one male units are able to join with others to form large stable communities Howlers and some baboons These communities can be multimale and female Some species that depend on certain foods may be protective of resources Some live in small groups composed of a mating pair marmosets and tamarins and their offspring Foods like fruit nuts and berries are only seasonally available This favors smaller feeding groups Predation Primates can be vulnerable to predators like snakes birds wild dogs and even other primates depending on their size Their responses to predation depend on their body size social structure and the type of predator Large communities are usually formed where predation pressure is high and primate is small Dispersal Dispersal is when members of one sex leave the group in which they were born natal group when they sexually mature Male dispersal is more common ring tailed lemurs vervets and macaques Female dispersal is seen in hamadryas baboons chimps mountain gorillas and some colobus species In a species where there is mated pair offspring of both sexes leave or are driven away by their parents siamangs and gibbon Males may live alone when they disperse females usually join another group Life history traits Life history traits are characteristics or developmental stages that typify members of a given species and in uence potential reproductive rates Examples of this include length of gestation length of time between pregnancies period of infant dependency age at sexual maturity life expectancy Strategies Behaviors that increase individual reproductive success There are life history strategies social strategies feeding strategies reproductive strategies and predator avoidance strategies Distribution and Types of Sleeping sites Primate sleeping sites can be on trees or on cliff faces Only gorillas sleep on the ground Their spacing can be related to social structure and predator avoidance Activity pattern Most primates are diurnal but galagos lorises ayeayes tarsiers and night monkeys are nocturnal Nocturnal primates forage for food alone Human activities Human hunting and forest clearing impact all nonhuman primates This causes extinction by disrupting or isolating groups reducing resource availability and reducing numbers Why be Social There are many advantages to being social Predator avoidance is a major factor in primate tendency to be social Multi malemulti female groups are advantageous in places where predation pressure is high particularly in mixed woodlands and on open savannahs ln savannah baboons adult males may join forces to chase intruders Larger social groups can also outcompete smaller groups of conspeci cs foraging in the same area Also perhaps males were attracted to related females and that is why multi malemulti female groups evolved Also costs of competition are offset by the bene ts of predator defense Primate Social Behavior Dominance Many primate species are organized into dominance hierarchies which is a system of social organization wherein individuals within a group are ranked relative to one another Higherranking primates have greater access to preferred food and mating partners than lower ranking primates This usually decreases the need for aggression Dominant animals alpha males and females are given priority over others Higherranking males and females have high reproductive success Females do because they get greater access to a food which gives them more energy to care for offspring and produce offspring In a study on chimps there was higher infant survival rate on higherranking females Their daughters matured faster and they had shorter interbirth intervals so they produced more babies Babies can get their social status from their mother Communication Communication is any act that conveys information to another individual It is universal among animals it includes scents and unintentional autonomic response as well as behaviors that convey meaning Autonomic means pertaining to physiological responses not under voluntary control An example would be crouching indicates submission insecurity or fear Striding gait implies con dence Raised body hair is autonomic responses to threat Enhanced body odor indicate excitement or fear in gorillas Primates have many facial expressions An intense stare indicates a mild threat in some primates Other threat gestures can be a quick yawn to expose canine teeth baboons and macaques crouching and bobbing back and forth and branch shaking many monkeys Primates show reassurance by patting hugging touching or holding hands Some primates may show displays Chest slapping and tearing vegetation are common gorilla threat displays Communications is important to be social Aggressive and Af liative behaviors Aggression Within primate species there is an interplay between aggressive behaviors and Af liative behaviors Con ict within a group usually develops out of competition for resources including mates or food Aggression usually involves certain signals and displays frequently within the context of hierarchy High ranking female macaques tend to take food out of other females mouths They may even attack lower ranking females to keep them away from their food Low ranking females may suffer weight loss and have a lower reproductive success due to lack of nutrition Males may ght to the point of injury and even death Squirrel monkeys for example ght during breeding season In baboons and chimps competition between males is ongoing Af liative behaviors Af liative behaviors include amicable associations between individuals This includes grooming reinforcing social bonds and promoting group cohesion Some of these behaviors include touching hand holding and grooming Social grooming involves using the ngers to pick through the fur of another individual to remove insects dirt and other materials It serves hygienic functions and usually chimps do this Some males will do this for dominant males to gain favor lt betters social relationships Mothers groom their infants males groom sexually receptive females and friends groom friends Reproduction and Reproductive Behaviors Estrus is characterized by behavioral changes and in old world monkeys and apes that live in multimale groups it is also accompanied by swelling and changes in color of the skin around the genital area It shows a female is ready for mating Permanent bonding between males and females isn t common However when a female is in estrus in savannah baboons male and female form a consortship and spend time together mating often This is common among bonobos In fact in bonobos females don t need to be in estrus for them to spend time together Malefemale bond increase reproductive success for both sexes Female probably gets protection from predation or may get assistance in caring for her babies Reproductive strategies Reproductive strategies are behaviors that have been favored to produce and successfully real to adulthood as many offspring as possible Primates are K selected if they have few young and invest much time caring for them They are rselected if they have a lot of young and spend little time caring for them Example of rselected is insects mice and rabbits Primates are helpless at birth and need a lot of care from their parent Female primates are pregnant most of their adult life They re either lactating and or caring for offspring and this take a lot of energy from them They need to eat the same number of calories per day and even then physical resources are drained Since there are lengthy interbirth intervals female primates usually make up for physiological costs by being very competitive for resources Marmosets gibbons and macaques are highly competitive with other females and are aggressive when it comes to resources Sexual selection Is a type of natural selection that operates on only one sex within a species Sexual selection long term effects are to increase the frequency of those traits in males that bring about greater success in acquiring males In the animal kingdom many male attributes are result of sexual selection For instance in mandrills males are more brightly colored than females and have sexual dimorphism This is because females are attracted to brightly colored males It is common in species in which mating is Polygnous which means male mates with more than one female There is a lot of competition for female in this group Sexual selection produces sexual dimorphism with regard to a number of traits most noticeably body size Presence of sexual dimorphism can be good indicator of mating structure lnfanticide as a Reproductive strategy One way males can increase their changes of reproducing is to kill infants fathered by other males Hanuman langurs live in one male several female groups Males without mates form bachelor groups and may try to join a group by chasing out the male out of his own group They also may want to mate with a female and will sometimes kill the baby of that female in order to get her to be in estrus sooner so he can mate with her lnfanticide is a way that primates try to maximize their reproductive success Male also doesn t have to risk defending infants who don t carry his genes Red colobus monkeys savanna baboons orangutans gorillas and chimps commit infanticide lnfanticide may occur in encounter with unfamiliar female and infant lnfanticidal males do not kill their own offspring Once a male has killed an infant he subsequently fathers another infant by the victim s mother Mothers fathers and infants Basic social unit is a mother and her babies Except in monogamy and polyandry female has one or more male with whom she mates males usually don t directly participate in caring for young Mother and child bond is very close and the infant is always holding on to its mother Mothers don t always know how to care for offspring it is a learned behavior that they learned from their own mothers Male siamangs actively care for their young and provide most of the infant care It is this case in marmosets and tamarins as well Savanna baboons may take more than a casual interest in their young also by intervening on behalf of their young Nonhuman Primate Models for the Evolution of Human Behavior Chimps are often used as models for early hominin behavior However once human and chimp lineages diverged from a common ancestor they traveled down different evolutionary paths and continued to evolve Primatologists examine behavioral patterns and identify similar patterns in humans and try to draw conclusions about the ecological and genetic factors that may have produced similarities between our closest relatives and ourselves Our own evolutionary story maybe began with exploiting a mixed woodland niche an econiche different from that of the great apes and exploiting different types of resources Brain and Body size One predominant characteristic that clearly differentiates humans from other primates is brain size Brain and body size are directly correlated The ration between brain size and body weight is not the same in all species The predictable relationship between body and brain size has been called the index of encephalization New world capuchins and squirrel monkeys also show a degree of encephalization that considerably exceeds predictions According to studies Australopithecus early hominins weren t nearly as encephalized as modern humans Primitive ancestral brains are mostly composed of structure related to basic physiological functions and theirs a small cortex that receives sensory In mammals the relative size of the neocortex is increased In primates expansion of neocortex has accounted for much of the increase in brain size It s the part of the brain in humans that is associated with cognitive functions related to reasoning complex problem solving forethought and language It accounts for 80 percent of the total volume of the human brain In nonhuman primates the most rapid period of brain growth occurs shortly before birth But in humans it occurs after birth In evolutionary terms the metabolic costs of a large brain must be compensated for by bene ts Some of these bene ts are that primates need a large brain to be familiar with their home range to solve the problem of extracting food from shells hard peels and under ground roots Brain size may have increased due to social groups also Language Nonhuman communication consists of involuntary vocalizations and actions that convey information solely about an animal s emotional state Vervets use certain vocalizations to refer to predators like snakes birds of prey and leopards Their calls are not involuntary and do not express emotional state it is to warn others about predator Humans use language a set of writing and or spoken symbols that refer to concepts objects and so on Humans can combine linguistic symbols in an in nite number of ways Language is uniquely human trait Some apes like gorillas are able to learn sign language Evolution of language In most people language function is located in left hemisphere of the brain Two regions in particular Broca s area in the left frontal lobe and Wernicke s area in left temporal lobe are directly involved in the production and perception respectively of spoken language Broca s area is located in motor cortex immediately adjacent to a region that controls the movement of muscles in the face lips larynx and tongue Then its sent to adjacent motor areas which in turn activate the muscles involved in speech Wernicke s area is an association area that lies near structure involved in the reception of sound But perception and production of speech involve more than these two areas and so does written language Magnetic resonance imaging in chimps bonobos and gorillas show that a region analogous to part of the Broca s side is larger on the left side than on the right side These authors further report that in captive great ape studies gestures are preferentially made by the right hand Specialization of auditory centers of the left hemisphere of the brain for language may have preceded the evolutionary divergence of humans and apes ln rhesus macaques evidence suggests that the left temporal lobe is specialized for processing the vocalizations of other rhesus macaques in particular The identi cation of a regulatory gene involved in speech may provide another piece to the puzzle of human language This gene is called FOXP2 It produces a protein that in uences the expression of other genes In turn these genes control the embryological development of brain circuits that relate to language in humans FOXp2 is common in mice as well as humans Some other mammals may have it too When examined the FOXP2 protein in chimps and gorillas different from the human protein by two amino acids This is due to two point mutations during the course of human evolution In chimps and gorillas there was no mutation Primate Cultural behaviors Culture applies to both humans and other primates Cultural behavior is learned not genetically determined but capacity to learn is greatly in uenced by genes Humans deliberately teach their young free ranging nonhuman primates don t appear to do so By watching their mothers nonhuman primate infants learn about food items appropriate behaviors and how to use and modify objects to achieve certain ends In turn their own offspring will observe their activities What emerges is a cultural tradition In japan macaques were given sweet potatoes A young female started washing her potatoes before eating them and within 3 years several other monkeys were doing the same How nests are built is learned in orangutans Other learned behaviors include swatting insects and pressing leaves or hands to the mouth to amplify sound The use of tools or objects to accomplish tasks is in nonhuman primates as well as humans Chimps use tool use A gorilla was seen wading bipedally in a pool to see the depth of the water She used the branch as her walking stick Chimps insert twigs and grass blades into termite mounds in a practice called termite shing Chimps may use stones to crack nuts and hardshelled fruits Chimps have dietary preferences They don t really like oil palm fruits and nuts Capuchins do tool use They are found in South America in Colombia Venezuela and Brazil They are the most encephalized of all monkeys and live in forests They are arboreal Some live in savannahs theses are sort of terrestrial Capuchins use leaves to extract water from cavities in trees and they use small modi ed branches to probe holes in logs for invertebrates They also use stones to crack open hard nuts break open hollow tree branches and dig for tubers and insects Capuchins who use stones to crack nuts and dig for roots have one important thing in common with chimps who dig with sticks and hunt galagos with sharpened branches they all live in seasonally dry open woodland environments and not in forests Chimps and capuchins are also the most encephalized nonhuman primates An anthropocentric View is viewing nonhuman organisms in terms of human experience and capabilities It s like saying tool use is like modern human technology and that primates are on their way to becoming human Since evolution has no goal this would be incorrect Con ict between Groups Primate groups are associated with home range which is where they live permanently A core area is a portion of home range which has the highest concentration of predictable resources and its where the group is most likely to be found The core area can be seen as a group s territory Not all primates are territorial its mainly when the ranges are small to permit patrolling and protecting gibbons and vervets Chimps are also territorial Groups of male chimps studied have attacked lone wanderers who came near their territory Groups of male chimps sometimes accompanied by two females patrol the boundaries of their home range They stop frequently to sniff look around or climb trees Before they enter peripheral areas they usually hoot and display to determine if other animals are present If members of another community appear some form of aggression occurs until onegroup retreats They practice lethal aggression If they nd a female with her infant or a lone male they will attack and most likely the infant or single male will be killed females are usually allowed to escape Sometimes chimps would attack without being provoked Sometimes infants are killed and eaten and males would be severely injured or killed Even though explanation for lethal raiding isn t simple it is apparent that protection and acquisition of resources are of major importance Prosocial behaviors Af liation Altruism and Cooperation Prosocial behaviors are actions that bene t other individuals and or society as a whole Humans are the most pro social primates These types of behaviors include sharing caregiving assistance and maybe even compassion It s not uncommon for people to save the lives of others Bonobos and capuchins tend to choose to eat with another individual rather than get food for only themselves Altruism Altruism is behavior that bene ts another individual while involving some risk or sacri ce to the individual performing it It is risky to say there is compassion in nonhuman primates since that is motivated by empathy which is the ability to identify with the feelings and thoughts of another person But studies show that perhaps nonhuman primates are empathetic Some chimps will protect victims during an attack help younger siblings and remain near ill relatives Another example is a chimp trying to save a drowning infant and risking drowning himself Recipients of altruism may not be related to the individual performing altruism Female Hanuman langurs often join forces to protect infants from Infanticidal males and male baboons protect infants and cooperate to chase predators Adopting orphans is another form of altruism Evolutionary explanation of altruism is based on premise that individuals are more likely to be altruistic towards relatives According to this hypothesis known as kin selection an individual may enhance his or her reproductive success by saving the life of a relative There s also reciprocal altruism where the recipient may later return the favor Group selection is a third hypothesis that some primatologists have supported According to this an individual may act altruistically to bene t other group members because it s the performer s bene t that the group be maintained But this may be erroneous because according to natural selection acting selfisth produces more reproductive success Altruism is a result of primates tending to live in groups The Primate Continuum Biological continuum is the fact that organisms are related through common ancestry and that behaviors and traits seen in one species are also seen in others to varying degrees Humans are connected not only to our closest relatives but also to all life on earth Where do humans t Well humans would be classi ed as more intelligent intelligence being referred as problem solving abilities and abstract thinking Our differences between humans and other primates are quantitative and not qualitative Even though the human brain is relatively larger neurological processes are functionally the same Necessity of close bonding with parent and need for physical contact is the same Developmental stages and infant dependency are the same However humans are much more adept at cruelty and compassion Humans understand suffering but chimps don t Primates and humans also have a sweet tooth due to high energy rich sugar contained in ripe fruit Chapter 8 Overview of the Fossil Primates oln this chapter we focus on bridging the gape between these creatures and ourselves between Strepsirrhines and haplorhines to help us better understand our own evolutionary history Our primate cousins share many of the traits we generally think of as uniquely human Many of these similarities can be traced to shared origins in highly social groups living in the trees We see these origins in the structure of our body and in the retention of many primitive features such as pentadactyly ve ngers and toes and unfused lower arm bones but also in more derived skeletal traits that come later Derived means being or having a feature that is not present in ancestral form Among the most important of these derived primate traits are evolutionary trends toward a more orthograde upright body position and forward facing eyes binocular Background to Primate Evolution Late Mesozoic Following the extinction of the dinosaurs at the end of the Mesozoic the reign of giant reptiles was over and the Age of Mammals had begun Primates were just one of the many groups of small mammals that were left to diversify and explore the many niches left vacant with the passing of the dinosaurs Primates started diverging from closely related mammals in lineages during the Cretaceous era Some scientists place these closely related lineages into a superorder a taxonomic group ranking above an order and below a class or subclass This group consists of tree shrews ying lemurs Sister groups are the related new clades that result from the splitting of single common lineages The closest relatives of this superorder are rabbits rodents and their relatives Primate Origins Cenozoic era was broad time period when primate evolution unfolded There are seven epochs in this era There is Paleocene rst archaic primates plesiadapiforms Eocene rst euprimates Oligocene early catarrhines Miocene monkeys and apes Pliocene early hominin diversi cation Pleistocene early Homo Holocene modern humans The last common ancestor is the hypothetical species that was the last to exist before it speciated into the myriad of sister orders related to primates The LCA does not have derived traits found in crown group A crown group is easier to identify because it includes all of the taxa that comes after a major speciation event All extant groups and fossils sharing their speci c derived traits are crown Stem group includes all of the taxa in a clade before a major speciation event For this reason like the LCA stem group taxa are often dif cult to recognize in the fossil record Molecular anthropology uses genetics to investigate the biology and evolution of humans and our closest relatives The time when we can rst con dently identify an archaic primate is almost assuredly an underestimate of the actual time of divergence assumed date LCA lived Molecular data have often provides us with overestimates of this time What is important however is that 1 since molecular estimates of divergence dates are calibrated using known fossil dates the two approaches are inextricably linked and 2 determining the appropriate range of mutation which joins these two together can be tricky Together these two approaches now place the origins of indisputable primates at some time during the Paleocene about 65 mya Made to Order Archaic Primates Fossil evidence indicates that during the earliest Paleocene between 65 and 52 mya a major radiation of archaic primates known as plesiadapiforms occurred Plesiadapiforms are members of an extinct group that occupies a controversial position in primate phylogeny When rst discovered these creatures were considered early members of the primate order but then they were found to have their own order Plesiadapiformes But now they are once again placed in the order Primates They are now gaining acceptance as a semi order which is the taxonomic category above suborder and below order within primates that is separate from the later euprimates true primates Plesiadapiformes are best known from a large number of fossil nds from American West Some members of this group exhibit a striking resemblance with some of the earliest Strepsirrhines from later Eocene epoch We ll concentrate on three families that are commonly recognized within this group Purgatoriidae members of this extinct genus are believed to have been about the size of modern rats Species lived in earliest Paleocene in American northwest It is important to note that postcranial material referring to all or part of the skeleton including the skin from Garbani channel in northeastern Montana reveals arboreal adaptation within the feet The second family is Plesiadapidae they were chipmunk to groundhog sized mammals with large incisors similar to rodents The best known of this family is genus Plesiadapis The last family we will talk about is Carpolestidae whose name means fruit stealer It was quite common during Paleocene in north America and Asia These creatures are smaller generally rat sized They also have dental traits that allow them to efficiently process brous vegetation as well as nuts and insects Carpolestes genus displays no adaptations for leaping though it almost certainly is a terminal branch feeder Eocene Primates During Eocene there is gradual extinction of plesiadapiforms and their replacement by the euprimates These mammals unlike plesiadapiformes have de nite recognizable and modern derived primate traits like forward facing eyes greater encephalization postorbital bar nails instead of claws and opposable big toe These and other primitive features suggest an adaptation to environmental conditions Environment was warmer and had year round rainfall and lush broadleaved evergreen forests At the beginning of Eocene North America and Europe were still attached they didn t split until middle of Eocene North America was also connected to Asia and shared many species in common Euprimates are part of this wave of diversi cation and adaptive radiation They came to be in North America Europe and Asia during 56 mya There are two main branches of euprimates grouped into different super families Adapoidea and Omomyoidea These two super families include primitive primates described as being either more lemur like adapoid or tarsier or Galago like omomyoid Lemur connects The Adapoids Adapoids had 2143 dental formula Adapoids are the best known of the Eocene stem Strepsirrhines They are divided into ve families the notharctids that includes genus Cantus This was earliest notharctid and one of the earliest of any of the anthropoids It was a diurnal creature and was found in North America and two species were in Europe It was probably a leaper Another notharctid was Darwinius which has no dental comb or a grooming claw which shows that they are more than lemur relatives Researchers said lda a Darwinius skeleton was a basal haplorhine Just months later a new adapid Afradapis a large bodied adapiform genus Afradapis belongs to third family of Adapoids Phylogenetic relationships for this group is not well understood Homology similar traits based on descent Homoplasy is similar traits that evolve independently in different groups Afradapis dentition shows that it may have exploited niches in Africa eating leaves like a monkey Bestknown fossil of this group is Adapis Georges Cuvier discovered this fossil but confused it for a hoofed mammal or an ungulate Adapis was probably arboreal quadruped lt foraged for leaves probably Closer Connections to Living Primate the evolution of True lemurs and lorises The evolution of lemurs and other Strepsirrhines is of great interest because of their basal position as sister group to all other primate lineages Lorisoids are the earliest examples of strepsirhine primates in fossil record They ve been found in late Eocene deposits of the Fayum Depression in Egypt Late Eocene fossil shows that it has a dental comb This and other features have led to conclusion that it s a stem galagid It can be inferred that lorises and galagos likely diverged by the close of the middle Eocene Existence of bush baby in Egypt shows that Strepsirrhines initially developed in African mainland These primates may have colonized Madagascar to give rise to crown Lemuriformes which would mean that lemurs have never existed outside of Madagascar Colonization may have occurred when animals crossed Mozambique Channel This may have occurred in Cenozoic era There are few if any truly fossilized lemurs remains Madagascar but there are many sub fossils bones not old enough to be completely mineralized as a fossil Many of these sub fossils were large Many lled unusual econiche not shared by any living lemurs These strange adaptations provide examples of convergence with higher primate niches found elsewhere in old world For example extinct Archaeolemur with its fused mandible and Bilophodont molars in many ways more closely resembles a monkey Best known of giant lemurs is Megaadapis They are kind of like koalas They have low reproductive rates and extinction was caused by predation and deforestation Remaining lemurs of Madagascar will meet the same fat unless the continued destruction of their habitat by humans ceases Tarsiers Connections The Omomyoids Omomyoids are more tarsierlike and are earliest haplorhine group They have a similar dental formula 1133 as well as large orbits and small snouts Earlier members of the group are more generalized than later ones Paleoprimatologists are anthropologists specialization in the study of the nonhuman primate fossil record Some of them are in Eocene and early Oligocene of North America and Europe with a small number also known from Asia Members of the genus Teilhardina are found on three continents They engaged in rapid westward dispersal with evidence pointing to Asia as euprimates starting point The oldest and most primitive were in Asia while the youngest were in North America Biostratigraphic or faunal correlation is a method of dating strata that relates the fossil content of an unknown stratum to a like one that has been securely chronometrically dated Studies show that Teilhardina may have moved east to west from Asia to North America before moving into Western Europe Other Eocene fossils of family Omomyidae from North America is Shoshonius and in Europe Necrolemun These animals have convergent eye orbits as well as details of the ear region that unite them to tarsiers Necrolemur has fused tibia and bula as well as elongated calcaneus a lever like construction that gives modern tarsiers their fantastic leaping ability Evolution of True Tarsiers Fragmentary remains of fossil tarsiers were found in Egypt China Myanmar and Thailand The rst cranium remains discovered were identical to anatomy in living tarsiers Tarsiers did not change that much since their ancestor All living tarsiers are now limited to a few islands in Southeast Asia Towards the end of Eocene there was a shift from tropical to drier and more seasonal climates This change led to more diverse landscapes opening more niches for the highly adaptable primates to exploit Eocene and Oligocene Early Anthropoids The Fayum Depression in Egypt an arid region provides most of our early anthropoid record for Eocene and Oligocene Biretia was one of the discoveries 37 mya and represented early African anthropoid lts dental morphology resembles that of basal anthropoid The structure 0 upper molar teeth root points to large orbits implying that organism is nocturnal Which is unusual since anthropoids are mainly diurnal So Elwyn Simons placed them into superfamily Parapithecoidea This super family is signi cant as the most primitive anthropoid group and therefore the possible rootstock form which the entire new world anthropoid evolutionary group evolved Catopithecus clearly had anthropoid features and some derived catarrhines features such as dental formula 2123 Molecular and biological data con rms that anthropoids had an African origin much like our genus Homo Oligocene Primates True Anthropoids The early primates of Oligocene are generally placed into 3 families oligopithecids parapithecids and propliopithecids They are among the earliest catarrhines anthropoid primates Crushed crania represent Catopithecus They have a complete postorbital closure and derived dentition 2133 The most abundant of the Oligocene fossils from the Fayum belong to genus Apidium They are small and have it has dental formula of 2133 They re likely relatives of new world monkeys or platyrrhines Teeth suggest diet of fruit and seeds There is also an unusually large amount of sexual dimorphism in canine size This may indicate that they form Polygnous social groups of single male multifemale and offspring Limb remains show that they were small arboreal quadruped adept at leaping and springing Parapithecus is a close relative of Apidium Members of third major family is propliopithecids A genus in this family is Aegyptopithecus This genus has been proposed as ancestor of later old world monkeys and hominoids It was roughly the size of howler monkeys with considerable sexual dimorphism lts dental formula was 2123 lts brain is small and at best resembles brains of Strepsirrhines The small brain size indicates encephalization which must have evolved independently within the two anthropoid parvorders below infraorder Platyrrhini and Catarrhini It was also probably arboreal quadruped The next genus Saadanius de es current attribution to any existing catarrhines family or superfamily They lack derived feature of cercopithecoids or hominoids Their features include large broad molars projecting midface a tube like middle ear The tubelike middle ear is what it shares with catarrhines This would make it an advanced stem catarrhine though perhaps intermediate between Aegyptopithecus and Miocene ape Early Platyrrhines New World Anthropoids Earliest platyrrhine fossils were found in late Oligocene of Bolivia and belonged to genus BranseIa They appeared to be small monkeys with diets mainly of fruits It is thought to be so primitive that it is not placed in any platyrrhine lineage Molecular evidence shows that living platyrrhines converge on a shared ancestor that is 25 million years old Based on presence of platyrrhines in South America it is likely that they rst appeared in late Eocene Island hopping is one of the theories behind how new world monkeys got to South America Island hopping is traveling from one island to the next This scenario suggests that the tarsier like Omomyoids from North America journeyed to South America giving rise to later platyrrhines The most likely scenario involves their oating between closely spaced islands across the Atlantic Ocean from Africa to South America on rafts made of naturally formed mats of vegetation Miocene Primates Throughout Miocene we see diversi cation of anthropoids into the groups were familiar with today The Cercopithecoids monkeys and hominoids competed for the dominant position on the primate landscape in the old world Monkeying Around Cercopithecidae includes monkeys like macaques and baboons Most fossil macaques appear remarkably similar to each other and other life forms In east Africa the baboon like Theropithecus was the dominant Cercopithecines genus of the Pliopleistocene Today the living gelada is con ned to the high wet grasslands of the Amhara Plateau Ethiopia This was where Papio baboons were found Aping monkeys The apelike proconsuloids rst apelike fossils share many postcranial characteristics with monkeys Proconsuloidea the only apelike feature is the presence of the Y 5 molar pattern Molar that has ve cusps with grooves running between them forming a Y shape This is characteristic of hominoids Monkeys have Bilophodont cusps True apes appear in early to middle Miocene They had thick enamel in their molars Sivapithecus was a large hominoid It has a concave pro le broad zygomatics cheekbones and a procumbent projecting maxilla and incisors resembling the face of the modern orangutan Hylobatids Lesser apes lesser apes include gibbons From molecular environments and fossil remains of small bodied Yuanmoupithecus we can determine that the gibbon radiation most likely began in mainland Asia perhaps in China Gibbons are in the taxa Hylobates African Great Apes European Ouranopithecus is considered best candidate for a stem African apehominoid 99 million year old Nakalipitheucs from Kenya may be last common ancestor of the African great apes It is terrestrial Asia39s lone Great Ape Of all the living apes the orangutan s ancestry is probably the best documented It might be descended from Sivapithecus and pongo based on similarities The face of Lufengpithecus is also very similar to that of the modern orangutan But its post crania is more similar to Pongo Word list exam 2 1 Adaptive niche An organism s entire way of life where it lives what it easts how it gets food how it avoids predators and so on 2 Af liative Af liative behaviors are amicable associations between individuals such as grooming reinforcing social bonds and promote group cohesion 3 Alloparenting is performed by any group member other than the mother or father and thus is distinguished from parental care 4 Allopatric species formation that occurs following the geographic isolation of populations 5 Altruism Actions that bene t another individual but at some potential risk or cost to oneself 6 Ancestral Referring to characters inherited by a group of organisms from a remote ancestor and thus not diagnostic of groups lineages that diverged after the character rst appeared also called primitive 7 Anthropocentric Viewing nonhuman organisms in terms of human experience and capabilities Emphasizing importance of humans over everything else 8 Arboreal Tree living adapted to life in the trees 9 Biogeography the scienti c study of the geographic distribution of organism 10 Behavior Anything organisms do that involves action in response to internal or external stimuli the response of an individual group or species to its environment 11 Behavioral ecology The study of the evolution of the behavior emphasizing the role of ecological factors as agents of natural selection Behaviors and behavioral patterns have been favored because they increase the reproductive tness of individuals 12 Bilophodont Referring to molars that have four cusps oriented in two parallel rows resembling ridges or quotlophsquot This trait is characteristic of Old World monkeys 13 Binocular vision Vision characterized by overlapping visual elds provided by forwardfacing eyes Binocular vision is essential to depth perception 14 Bipedal On two feet walking habitually on two legs 15 Brachiation Arm swinging a form of locomotion used by some primates It involves hanging from a branch and moving by alternately swinging from one arm to the other 16 Bunodont molars Teeth possessing major cusps arranged in a rectangle 17 Canopy System of horizontal branches and foliage formed by tree crowns 18 Cathemeral Varying active cycles from nocturnal to diurnal depending on food availability 19 Cercopithecines Common name for members of the subfamily of Old World monkeys that includes baboons macaques and guenons 20 Character features 21 Complex stomach Amazing adaptation to allow bacterial fermentation of leaves 22 Conservation biology Multidisciplinary scienti c study of biodiversity with the goal of protecting species 23 Conspeci cs Members of the same species 24 Core area The portion of a home range containing the highest concentration and most reliable supplies of food and water The core area is defended 25 Cusps The bumps on the chewing surface of premolars and molars 26 Crepuscular active when daylight is increasing or decreasing dawn or dusk 27 Daily path length Refers to the onedimensional distance travelled by a primate during its daily active period 28 Day range twodimensional area used by a primate throughout a 24 hour period 29 Dental formula Numerical device that indicates the number of each type of tooth in each side of the upper and lower Jaws 30 Derived modi ed Referring to characters that are modi ed from the ancestral condition and thus diagnostic of particular evolutionary lineages 31 Diastema space or gap between two teeth Most commonly between incisors and molars 32 Diphyodonty dentition is a characteristic of mammals in which milk teeth appear in the young ones but as they grow and jaw becomes larger milk teeth are replaced by larger permanent ones to t in largerjaw bone 33 Diurnal Active during the day 34 Dominance hierarchy Systems of social organization of wherein individuals within a group are ranked relative to one another Higher ranking animals have greater access to preferred food items and mating partners than lowerranking individuals Dominance hierarchies are sometimes called pecking orders 35 Eco geographical patterns similar patterns of variation within and across species and their correlation to biogeography 36 Ecological niche The position of a species within its physical and biological environments A species ecological niche is de ned by such components as diet terrain vegetation type of predators relationships with other species and activity patterns and each niche is unique to a given species 37 Ecology Study of relationships between organisms and all aspects of their environment temperature predators non predators vegetation availability of food and water 38 Ectothermy the ability to regulate body temperature by environmental exposure 39 Emergent layer topmost level of the tree which is usually exposed to sunlight 40 Endemic Continuously present in a population 41 Estrus a recurring period of sexual receptivity 42 Foraging coherence Which individuals forage together in time and space 43 Frugivorous Having a diet composed primarily of fruits 44 Gallery forest named for its shape Long parallel set of wooded area there s a river greenery is near river 45 Grooming Picking through fur to remove dirt parasites and other materials that may be present Social grooming is common among primates and reinforces social relationships 46 Habitat A place that provides adequate nutrients water and living space 47 Habituate to allow a primate group to become used to the presence of human observers by quietly and carefully following the group 48 Heterodontheterodonty Having different kinds of teeth characteristic of mammals whose teeth consist of incisors canines premolars and molars 49 Home range Twodimensional area used by a primate throughout months or years 50 Homeothermic the ability to use energy from food to produce heat and selfregulate internal body temperature 51 Hominids Great ape family that includes humans and gorilla chimps and orangutans 52 Homoplasy The separate evolutionary development of similar characteristics in different groups of organisms 53 Hybrid zone A region in which genetically distinct populations come into contact and produce at least some offspring of mixed ancestry 54 lncest avoidance when primates avoid incest by leaving their family group to mate 55 lnterspeci c Between species refers to variation seen within the same species 56 lntraspeci c Within species refers to variation seen within the same species 57 lschial callosities Well developed sitting pads 58 K selected Pertaining to K selection an adaptive strategy whereby individuals produce relatively few offspring in whom they invest increased parental care Chances of survival are increased for each one because of parental investments of time and energy 59 Knuckle walking is a form of Quadrupedal walking in which the forelimbs hold the ngers in a partially exed posture that allows body weight to press down on the ground through the knuckles 60 Life history traits Characteristics and development stages that in uence reproductive rates Examples include longevity age at sexual maturity and length of time between births 61 Last common ancestor The nal evolutionary link between two related groups 62 Mastication process of chewing by which food is crushed and ground by teeth Food is positioned by cheek and tongue between teeth for grinding 63 Mating system A way in which a group is structured in relation to sexual behavior 64 Matrilines Groups that consist of a female her daughters and their offspring Matrilines are common among macaques 65 Natal group The group in which animals are born and raised 66 Sectorial premolar A premolar adapted for cutting found in most apes but not in humans 67 Sexual dichromatism Differences in color between males and females of same species 68 Sexual dimorphism Differences in physical characteristics between males and females of the same species 69 Natural history the study of animals plants and minerals 70 Nuchal crest A horizontal ridge of bone where large neck muscles attach to the back of the skull 71 Nocturnal Active during the night 72 Omnivorous Having a diet of many food types such as plant materials meat and insects 73 Philopatric Tendency of primate to stay in family group 74 Phylogenetic species concept modi ed phylogenetic species concept states that a species is the smallest aggregation of sexual populations diagnosable by a unique combination of character states 75 Phylogenetic tree A chart showing evolutionary relationships as determined by evolutionary systematics It contains a time component and implies ancestordescendant relationships 76 Polyandry Social group of one female and several males 77 Polyphyletic Referring to an evolutionary group composed of descendants with more than one common ancestor and thus not a true cade 78 Postorbital bar a ring of bone around the eye socket 79 Prehensility Quality of an appendage that has adapted for grasping and holding 80 Prehensile tail a tail that can support the entire body weight of the animal 81 Primates Members of the mammalian order Primates include lemurs lorises tarsiers monkeys apes and humans 82 Primatology The study of the biology and behavior of nonhuman primates lemurs lorises tarsiers monkeys and apesL 83 Primitive featurecharacter A trait that is old on a phylogenetic scale of development 84 Prosimians type of primates that includes lemurs lorises bush babies 85 Quadrupedal Using all four limbs to support the body during locomotion the basic mammalian and primate form of locomotion 86 Quadrumanous climbing The use of varying combinations of all four limbs to move through an arboreal habitat 87 Recognition species concept A depiction of species in which the key aspect is the ability of individuals to identify members of their own species for purposes of mating and to avoid mating with members of other species 88 Residence group competition Primate social groupings based on the number of individuals in differing agesex classes 89 Reproductive strategies Behaviors or behavioral complexes that have been favored by natural selection to increase individual reproductive success The behaviors need not be deliberate and they often vary considerably between males and females 90 Resource defense adaptation for competition by ghting for resources 91 Retinal fovea A characteristic of the eye that reduces night vision but improves visual acuity 92 Rhinarium The moist hairless pad at the end of the nose seen in most mammalian species The rhinarium enhances an animal s ability to smell 93 Ritualized behavior Behavior that occurs typically in member of a given species in a highly stereotyped fashion It is a learned repetitive behavior 94 rselected Pertaining to rselection a reproductive strategy that emphasizes relatively large numbers of offspring and reduced parental care compared with Kselected species 95 Sagittal crest A lengthwise ridge of bone among the top of the skull where strong chewing muscles attach to the top of the skull 96 Savannah characterized by lack of trees leaves are leathery and there is distance between small trees 97 Social structure The composition size of a group 98 Shared derived Relating to speci c character traits shared in common between two lifeforms and considered the most useful for making evolutionary interpretations 99 Socioecology scienti c study of how social structure is in uenced by an organism s environment 100 Stereoscopic vision Organism has overlapping elds of vnsnon 101Subspecies A uniform genetically distinct population of a species often in a speci c geographic region 102 Sympatric a process which new species evolve from a single ancestral species while inhabiting the same geographic region 103 Symplesiomorphy Ancestral trait shared by two or more taxa 104 Tapetum lucidum An extra layer of tissue in the eye that re ects light thereby enhancing night vision 105 Taphonomy The study of how bones and other materials came to be buried in the earth and preserved as fossils Taphonomists study the processes of sedimentation the actions of streams preservation properties of bone and carnivore disturbance factors 106 Taxa groupings of organisms given a formal scienti c name 107 Temperate forest characterized by wide leaves large and tall trees and non seasonal vegetation Located in temperate reagions like North America british Columbia washington Oregon 108 Territoryterritorial Pertaining to the protection of all or a part of the area occupied by an animal or group of animals Territorial behaviors range fro scent marking to outright attacks on intruders 109 Rainforests characterized by high rainfall Example amazon rainforest 110 Understorey Area between ground and the lowest horizontal branches 111 Vertical clinging and leaping Primates like tarsiers and Strepsirrhines using their lower limbs to hop from tree to tree 112 Y5 molar cusp pattern Molar that has 5 cusps with grooves running between them forming a Y shape This is characteristic of hominoids 113 Zoology The scienti c study of animals 114 Pair Monogamous animals 115 Harem one or two males and multifemale group 116 Agegraded single male single male usually the oldest leading a group 117 Multimalemultifemale many males and females in a group 118 Fissionfusion society size and composition of social group change as time passes and animals move throughout the environment Animals merge fusion animals split ssion 119 Noyau a social structure in which a male s territory overlaps the smaller territories of several females found in nocturnal primates 120 Polyandrous family group When a female has more than one male mate and they reside with her offspring 121 Solitary but social Animal forages separately but some individuals sleep in the same location or share nests 122 Polygyny A relationship in which a male has more than one mate Synapomorphy is a derived trait shared by taxa due to common ancestry Sivapithecus Siva39s Ape is a genus of extinct primates Sivapithecus was a large hominoid Their facial structure is basically a concave pro le broad zygomatics and procumbent maxilla and incisors remarkably resembling an orangutan The body however id very unlike an orangutan or any other hominoid For instance the forelimb exhibits a unique mixture of traits probably indicating some mode of arboreal quadropedalism with no ability for Brachiation The order primates include all primates However there are two suborders One is strepsirhini lemurs and Iorises and haplorhini tarsiers monkeys apes and humans Strepsirrhines members of the primate suborder Strepsirhini which includes lemurs and Iorises Lemurs are located in Madagascar Lorises are found in India Africa and Southeast Asia In primate taxonomic classi cation lemurs and lorises are in strepsirhini and haplorhini are anthropoidea and tarsiformes Tarsiformes includes all tarsiers and is a group by itself Anthropoidea includes old world and new world monkeys Platyrrhini refers to all New World monkeys spider monkeys sakis titis owl monkey marmosets muriquis howlers Catarhini refers to all old world monkeys apes and humans Pleiotropy is a situation where a single gene in uences more than one characteristic Arboreal means tree living Almost all primates are quadrupedal meaning that they use all four limbs to support the body during locomotion Most primates however use more than one form of locomotion Vertical clinging and leaping is characteristic of lemurs and tarsiers They support themselves by grasping onto trunks of trees or other plants while their knees and ankles are tightly exed Brachiation or arm swinging is a suspensory form of locomotion in which the body moves by being alternatively supported by one forelimb and then the other Only small gibbons and siamangs of Southeast Asia use this form of locomotion exclusively Brachiation is usually in species with arms longer than legs a short stable lower back long curved ngers and shortened thumbs New world monkey are semibrachiators because they leap and arm swing Orangutans gorillas bonobos and chimpanzees don t habitually brachiate today New world monkeys have prehensile tail that they use as a grasping fth hand Lemurs and Lorises Lemurs and lorises have greater olfactory capabilities they have good sense of smell since they have a moist eshy pad at the end of their nose and relatively long snout Their eyes are placed on the side of the face differences in reproductive physiology and short gestation and maturation periods They have a dental comb formed by forward projecting incisors and canines They are used for grooming and feeding One other characteristic that sets lemurs and lorises apart is the retention of a grooming claw on the second toe Lemurs are mostly arboreal but some like ringtailed lemurs are more terrestrial Some arboreal species are quadrupeds and others sifakas ring tails and indris are vertical clingers and leapers Many lemurs live in groups of 10 to 25 animals comprising of male and females of all ages lndris however live in social units composed of mated pairs and dependent offspring Lorises are nocturnal Locomotion is slow cautious climbing form of quadropedalism All galagos are highly agile vertical clingers and leapers They are almost entirely insectivorous while others eat fruits leaves and other plant Lorises and galagos frequently forage alone but feeding ranges can overlap and 2 or more females may feed and even nest together All in all both lemurs and lorises have well developed visual apparatus both exhibit good grasping and climbing vertical clinging and leaping New World monkeys New world monkeys are almost exclusively arboreal Some never come to the ground All except one species owl monkey nocturnal is diurnal One characteristic that distinguishes new world from old world monkeys is the shape of nose New world monkeys have narrow noses with outward facing nostrils while old world have narrower noses with downward facing nostrils Some examples of new world aremuriguqi squirrel monkey white faced capuchins and uakari Their nose shape is what gives them different taxonic names In addition to being the smallest of all monkeys marmosets and tamarins have several distinguishing features For example they have claws instead of nails and they give birth to twins They are mostly insectivorous although marmosets eat gums from trees and tamarins eat fruits New world monkeys rely on a combination of fruits and leaves Most are qudrupedal but some are semibrachial like the spider monkey Howlers muriquis and spider monkeys have prehensile tails Socially most new world monkeys live in mixed sex groups of all ages Atelidae is one of the ve families of New World monkeys now recognized It was formerly included in the family Cebidae Atelids are generally larger monkeys the family includes the howler spider woolly and woolly spider monkeys the latter being the largest of the New World monkeys Old World primates Found in subSaharan Africa southern Asia All old world monkeys are placed in one taxonomic family Cercopiethecidae This family is divided into two subfamilies the ceropithecines and colobines Most old world countries are qudrupedal and primarily arboreal such as baboons They spend a lot of time on ground and return to trees at night Cercopithecines are more generalized than colobines They re more omnivorous Locomotion in old world monkeys includes arboreal quadropedalism in guenons macaques and langurs terrestrial quadropedalism in baboons and macaques semibrachiation and acrobatic leaping in colobus monkeys There is sexual dimorphism which is typical for terrestrial species and is especially in baboons Females have sexual skin to show that they are ready for mating The Basal metabolic Rate concerns metabolism Smaller animals have a higher BMR than larger ones So smaller primates like galagos and marmosets require an energy protein rich diet of insects fats like nuts and seeds and carbs fruits and seeds Some larger primates tend to have lower BMR and reduced energy requirements They can do with just leaves or low quality plant Gorillas for instance eat leaves and pith from bamboo stems These foods have less caloric value than fruits nuts or seeds Some monkeys like colobines and langurs are primarily leaf eaters They re fairly large bodied They have elongated intestines and pouched stomachs that allow them to digest tough bers and cellulose in leaves Polygnous male competition for females Polyandry There is one female and several males Example is a marmoset There is nutritional stress on female Males take care of babies Multiple malemultiple female groups marked by female philopatry female enters group and stays there until death Male dispersal male grows in one group and moves to other group to nd mate Characterized by dominance hierarchy There is alpha and omega Noyau separate territories where different sexes overlap with one another Solitary but social members of different sexes choose to be around each other when they want to be social Members of same sex do not like to be around each other lntermembral Index simple ration that tells us how long forelimbs are relative to the hind limbs Quadruped primates have fore and hind limbs almost identical in length suspensory primates have longer forelimbs than hind limbs Arboreal quadruped usually have an IM between 7585 Capuchin monkey is an example Gorillas have lM of 116 They are quadruped but capable of suspensory Sexual dichromatism males and females of the same species having different fur colorations andor marking patterns Apidium phiomense has a dental formula of 2133 on both the upper and lowerjaws The incisors are small in this species and the canines are sexually dimorphic Teeth also suggest a diet composed of fruits and some seeds They have a large degree of sexual dimorphism in canine size and may live in Polygnous social groups of single male and multi female and offspring Limb remains show that this creature was a small arboreal quadruped adept at leaping and springing Catopithecus is an ancient old world monkey which is found in fossil lts dental formula is 2123 They have derived Catarhini features old world They have anthropoid features such as postorbital closure and derived features like 2123 dental formula Apes and humans re classi ed in superfamily hominoids Apes are found in Asia and Africa Small bodied gibbons and siamangs live in Southeast Asia And two orangutan subspecies live on the islands 0 Borneo and Sumatra Gibbons and siamangs are the smallest of the apes They have long slender bodies that weigh about 13 pounds in gibbons and 25 in siamangs Their most distinctive features are adaptations to feeding while hanging from tree branches or Brachiation They have extremely long arms They eat mostly fruit leaves and insects The basic social unit of gibbons and siamangs comprises an adult male and female with dependent offspring Both males and females are territorial and protect their territories with elaborate whoops and siren like songs Orangutans are slow cautious climbers whose form of locomotion is quadruped and almost completely arboreal But they sometimes travel on ground They have sexual dimorphism They re primarily frugivorous Gorillas are largest of all living primates Mountain gorillas have sexual dimorphism Adult gorillas are primarily terrestrial They live in groups of one or two silverback gorilla males and many adult females and their babies Females and males leave their natal group as young adults They are frugivorous Chimpanzees are anatomically similar to gorillas But chimps are more excitable and noisy than gorillas Chimps are also smaller than orangutans and gorillas and even though they are sexually dimorphic sex difference isn t as pronounced as in gorillas and orangutans Males may weight 150 and females weight 100 pounds In addition to knuckle walking chimps may brachiate Chimps eat fruits leaves insects nuts birds eggs berries caterpillars and small mammals Chimps live in large uid communities ranging in size from 10 to as many as 100 individuals Bonobos are often called pygmy chimps Bonobos are more arboreal than chimps and less aggressive and excitable Physical violence is uncommon They eat a variety of foods Bonobo community centered on male female bond They are not centered on male group They have a lot of sex Baboons have one male multifemale group and so do macaques They may live like this because food is plentiful Some species depend on foods distributed in small clumps so they live in small groups of mated pairs siamangs or a female with one or two males marmosets and tamarins Male dispersal is common in lots of primates Female dispersal is present in some colobus species humadryas baboons chimpanzees and mountain gorillas lnfanticide is what baboon males use to increase reproductive success Males migrating into new group will kill infants and will have to father children from the victim s mother Primate groups are associated with a home range where they remain permanently Within home range is a core area This area contains highest concentration of predictable resources and tis where the group is most likely to be found Not all primates are territorial Territorial primates are usually territorial because the range is small to permit patrolling Bilophodont molars molars with four cusps oriented in two parallel rows resembling ridges This trait is characteristic of old world monkeys The extinct archaeolemur with its fused mandible and Bilophodont molars in many ways more closely resembled a monkey than a 37pound lemur 0 Y5 molars Molar that has 5 cusps with grooves running between them forming a Y shape This is characteristic of hominoids The only apelike feature in super family Proconsuloidea is the presence of Y5 molar pattern Consequently proconsuloids were once commonly called dental apes re ecting their apelike teeth but monkey like postcranial skeleton o Guenon belongs in group Cercopithecus httpswwwkooferscom ashcardsanthanth120midterm 2review Lehman text notes Chapter 3 Microevolution and Evolutionary Anthropologl Two fundamental issues in evolutionary anthropology are de ning species and understanding speciation which encompasses the various evolutionary processes that result in new species The typological study of systematic classi cation of types that have traits in common de nition in which scientist simply lump similar looking individuals into discrete categories is similar to Linnaeus and his taxonomists These taxonomists held the view that each species has discrete properties such as beak length and feather colors in birds The common de nition of typological species was modi ed as follows individuals are the same species if they can successfully produce fertile offspring The modi ed typological species concept however is no longer favored for 3 reasons First it fails to account for geographic variations within species Second strict applications of the concept can lead to erroneous conclusion that males of the same species or conspeci c males represent separate species Because two males cannot sexually reproduce then a typological de nition of species would imply that they are not in the same species Thirdly this concept cannot account for instances in which distinct species mate and produce fertile hybrid For instance there is a hybrid zone that involves hamadryas baboons and olive baboons in eastern Africa These two species look and act very differently as do their hybrid offspring Biological species concept implicit in the BSC is that increased species diversity can occur within a geographic region of the species involved are reproductiver isolated from one another Phylogenetic species concept states that a species is the smallest aggregation of populations diagnosable by a unique combination of character states It means that use of the PSC requires a researcher to measure and analyze character states of a sample of individuals in and between populations These data are then analyzed using cladistics which is the study of evolutionary relationships within and between organisms on our planet Cladistics came about in response to weakness with phenetics the process of classifying organisms based on their overall patterns of shape and appearance In allopatric speciation some form of physical barrier causes geographic isolation and reduced gene ow between populations The barrier only has to limit gene ow complete isolation is not necessary There are two major models of allopatric speciation vicariant and peripatric Vicariant speciation occurs when a physical barrier creates large geographically separated populations which then diverge from each other and then no longer interbreed Peripatric speciation occurs when a small peripherally isolated colony of the main populations diverges to become a new species Key differences between the two are population size after the split and extend of the separation between populations Macroevolution focuses on the patterns of evolutionary changes in complex integrated natural systems Evolutionary anthropologists and biologists observe patterns of evolutionary change by investigating lineage stasis reduced or nonexistent morphological changes over long periods within a lineage typi ed by no changes in the shape or appearance of species over geological time Evolutionary radiation is the rapid formation of a new specie within a geological time period Chapter 4 Living primates Understanding primate taxonomy which involves the scienti c technique of classifying organisms is important because it enables us to make some sense of the hundreds of living primate species The primate order is within the class Mammalia Mammals are de ned by a number of characteristics associated with their general morphology ability to control their body temperature and reproductive biology They have hair or fur a fourchambered heart a spinal cord and neocortex region in the brain that controls sensory perception spatial reasoning and conscious thought Mammals are Homeothermic meaning they have the ability to use energy from food to produce heat and self regulate internal body temperature Reptiles regulate their body temperature by environmental exposure Ectothermy Mammals use a variety of thermoregulation strategies One strategy is to exploit local microenvironments They produce sweat glands to cool the body through evaporation How are primates different from other mammals Primates are distinguished by their form or structure sensory and neural systems and life history patterns Primates have grasping hands and feet which are critical for holding onto branches They have a clavicle that allows extensive shoulder motion which is important for life in an arboreal environment Primates have a radius and ulna The morphology enables precise movement of forearms and hands Primates have forwardfacing eyes and stereoscopic vision meaning they use both eyes to see which produces overlapping elds of vision The combination of visual traits results in depth perception visual ability to judge distance Primates are also characterized by long periods of infancy childhood and adult hood Primates have a long life span The primate order is subdivided into two suborders Strepsirhini and Haplorhini Strepsirhini includes lemurs Iorises and galagos bush babies Haplorhini includes tarsiers monkeys apes and humans Strepsirrhines retain primitive features of the dentition and skull similar to those seen in Eocene primates meaning they have some aspects of their bones and teeth that have remained largely unchanged over millions of years Strepsirrhines have a remarkable dental toothcomb which allows them to use their lower incisors as a grooming device They also have a moist rhinarium wet nose which is associated with an enhanced sense of smell The upper lip of Strepsirrhines connects to the nose or gum which limits the range of facial expressions Strepsirrhines have a tapetum lucidum which is a biological system improving the animal s ability to see in low light conditions Tapetum lucidum is an extra layer of tissue in the eye that re ects light thereby enhancing night vision They also have a postorbital bar a ring of bone around the eye socket Strepsirrhines have one infraorder Lemuriformes and two super families lemuroidea and Lorisoidea Living lemurs only exist in Madagascar and Comoro Madagascar contains an incredible diversity of endemic plants insects and animals Endemic means restricted to a speci ed locality Lemurs range from pygmy mouse lemur to the largest lndri lndri The indris if famous for its haunting calls Most lemurs are arboreal quadrupeds lndriids and lepilemurids have elongated hind limbs that allow them to use vertical clinging and leaping as their primary form of locomotion Many smallbodied lemurs are nocturnal They have large eyeballs relative to their body size Most of the large bodied lemurs are diurnal A few are cathemeral In lemurs females are often dominant to males in ecological and social settings The super family Lorisoidea contains one primate family Lorisdae known as the lorises and galagos Lorises range throughout the forested regions of subSaharan Africa and Southeast Asia They range in body mass form 100 g to 16 kg Most lorises are arboreal quadrupeds that use slow deliberate hand over hand movement in trees Lorises eat a variety of foods but most of their diet is composed of plant materials fruit tree exudates shoots and insects They are nocturnal solitary foragers Galago or bush babies are located in subSaharan Africa All galagos are nocturnal and they are arboreal They are solitary foragers Smaller bodied galagos have a diet composed of birds insects and fruit Larger galagos mostly eat more fruit and tree exudates than animal prey Haplorhini Most haplorhines have evolved derived features characteristics that differ from those of their ancestors which differentiate them from Strepsirrhines All haplorhines have dry nose and a greater reliance on their visual senses They have lesser sense of smell Thus the eyes of haplorhines have a retinal fovea which reduces night vision but improves visual acuity ln haplorhines the upper lip does not directly connect to the nose or gum enabling a wide range of facial expressions All haplorhines have nails instead of claws all except tarsiers Haplorhines comprise the following three infraorders Tarsiiformes Platyrrhini and Catarrhini Tarsiiformes contain only one genus Tarsius Tarsiers exist in tropical forests on the islands of Philippines Sulawesi and others in south East Asia A tarsier s eyeball is bigger than its brain They have long legs relative to body size Tarsiers are faunivores which means they eat small insects snakes and lizards Flat noses and side facing nostrils characterize platyrrhines They are also known as New World monkeys They are found in Central and South America They encompass three primate families Cebidae Atelidae and Callitrichidae They range in body mass from the smallest monkey a pygmy marmoset to the black howler monkey Neotropical primates are arboreal Although all platyrrhines have tails only the Atelidae and monkeys in the genus Cebus have a prehensile tail which can support their entire body weight to stabilize themselves during arboreal travel foraging and resting For example male muriquis will diffuse tension by cuddling while hanging upside down by their tails Platyrrhines eat a variety of food like a fruit owers leaves and insects All platyrrhines live in social groups and some have unique forms of communication Within the platyrrhines is the unique family of the Callitrichidae a primate family that includes tamarins marmosets and Goeldi s monkey Most of these monkeys give birth to twins and they are often brightly colored Common marmosets have a remarkable reproductive adaptation Marmosets live in groups comprising one breeding female and several adult males who mate with this female and care for the offspring Goeldi s monkey has small body size but mostly give birth to single offspring Catarrhines are characterized by their narrow noses and comprises three primate families Cercopithecidae Hylobatidae and Hominidae Cercopiethecidae and Hylobatidae have lschial callosities or what we d call sitting pads because they sit on them The presence of Bilophodont molars and relatively narrow noses distinguish Cercopithecidae from the Hylobatidae and Hominidae which have Bunodont molars teeth that has four major cusps arranged in a rectangle Bilophodont molars are associated with the chewing of leafy plant materials whereas Bunodont molars are characteristic of animals that eat different kinds of foods with different physical consistencies fruits owers grains meat Hylobatidae and Hominidae lack a tail and they have larger brains and body size than Cercopithecidae All extant catarrhines are diurnal The two families Cercopithecidae has two subfamilies Cercopithecinae and Colobinae Cercopithecinae are located predominantly in Africa One widespread genus known as macaques range into Gibraltar northern Africa Asia and Southeast Asia Male mandrills are also noteworthy for their red and blue snouts and the brilliant colors on their rumps Many ceropithecines are sexually dimorphic in body and canine size with males larger than females Cercopithecines prefer ripe fruit which they often pack into their cheek pouches Most Cercopithecines are arboreal quadrupeds Large bodied Cercopithecines like baboons and geladas are terrestrial quadrupeds Cercopithecines live in a variety of social groups from monogamous groups containing an adult male and female to large multimale multifemale groups Field researchers have observed mandrills occasionally forming huge super groups of 250 animals Colobines exist in the forested regions of Africa and Asia They have high cusps on their molar teeth long tails and hind limbs and short thumbs Most species are arboreal quadrupeds in tropical rain forests Leaf eating monkeys predominantly eat leaves with marked preference for young palatable leaves Because leaves are extremely difficult to digest colobines shave evolved a multichambered complex stomach Most primates like humans have single chambered stomach meaning we cannot subsist on a diet composed of plant leaves Colobines live in social troops of 590 individuals Hylobatids are smallbodied apes of Southeast Asia They retain many skeletal features similar to those seen in monkeys However they are unique in having the longest forelimbs relative to body size of any extant primate Gibbons are incredible arboreal aerialists Their special form of locomotion swinging from branch to branch using two arms is known as Brachiation Smallbodied gibbons are among the fastest and most agile of all arboreal non ying mammals Gibbons eat plenty of ripe fruit Gibbons are famous for their haunting vocalizations which can last up to 30 seconds The Hominidae are large bodied apes orangutans gorillas and chimpanzees and humans Orangutans Genus pongo are the only large bodied apes in Asia Gorillas and chimps range into the equatorial regions of subSaharan Africa Body mass in the Hominidae ranges from an average of 42 kg in chimps up to 175 kg in the awesome adult male eastern lowland gorilla Orangutans gorillas and chimps have long arms hands and feet All the large bodied apes are sexually dimorphic in body size and dentition with males being larger than females Orangutans gorillas and chimps are less suspensory than gibbons meaning that these large bodied apes are not acrobatic swingers through the forest Instead they employ Quadrumanous climbing meaning that they use three to four limbs to move carefully and methodically through the forest On the ground large bodied apes use Quadrupedal walking and running However gorillas and chimps use knuckle walking Gorillas have a folivorous diet they eat leaves Orangutans prefer to eat fruit frugivorous diet When fruit is unavailable they supplement their diet with leaves and nuts Chimps also eat small animals like red colobus monkeys Groups of adult and adolescent male chimps conduct most hunts Researchers have documented improved hunting success when animals hunt socially versus when individuals hunt alone Large bodied apes may use tools Chimps in western Africa use stones and small tools to extract small seed fragments from the hard husk Nut cracking is a learned behavior that requires years of observation and practice which produces plenty of bruised ngers In eastern Africa chimps alter local plant materials to create long exible strips to fish for termites or ants There have been many studies of the social life of orangutans chimps and gorillas Orangutans lead a largely solitary life although males and females will spend considerable amounts of time together Conversely all gorillas and chimps are highly social and live in groups ranging from 9 to 12 individuals in gorillas and up to 50 animals in chimps Chimps practice infanticide Body size is a fundamental aspect of the evolutionary anthropology of primates Large primates are not simply scaled up versions of small primates Size related scaling applies to almost every ecological aspect of an organism including locomotion diet and life history Large primates like gorillas eat more food and require more energy than small primates like galagos However a smallbodied primate requires more energy per unit of weight than a large bodied primate These size related differences in energy requirements also mean that large primates can subsist on large amounts of low quality foods whereas small primates must eat small amounts of high quality foods For example a smallbodied primate is more likely to be insectivorous than folivorous because an insect represents a compact energy rich package A small primate cannot survive on a diet of bulky low energy leaves Conversely a primate weighing more than 500 g cannot acquire enough energy from a diet composed entirely of insects which are energetically expensive to catch in large numbers 0 Primates are adapted for forest habitats particularly tropical rainforests Some primates exploit habitat types other than those found in tropical forests ranging from deserts to mountainous pine forests Each primate species tends to occupy a speci c and largely nonoverlapping ecological niche in a forest habitat Ecological niche is a sum of all the interactions between an organism and an ecosystem A primate s niche can be best understood by looking at the vertical aspects of its habitat The Understorey the area beneath the system of horizontal branches called canopy is a remarkably dark and humid place dominated by the vertical trunks of large mature trees Many insectivorous primates hunt in the understorey However few food resources tend to be available for frugivorous and folivorous primates in the understorey Higher in the forest the canopy provides more horizontal branches that are ideally suited to primates seeking plants foods Many primate species prefer the canopy layer particularly the upper parts of the canopy Although primates will forage in the emergent layer the top of the tree that is exposed to sunlight few do so for any great length of time o The evolutionary ecology of primates is a result of complex bottomup resource driven and topdown consumerdriven processes The energy and important food resources for most primates derive from plants Notes from review Know types of forests gallery rainforest primary secondary savannah desert Haplorhini Sterescopic vision and binocular vision in order to see well It is necessary for hunting Color vision Cercopithecoidea are all arboreal Hominoidea gorillas and chimps Orangutans arboreal Spider monkey semi brachiate prehensile tail Ceboidia Squirrel monkey semi brachiate Gorillas have female philopatry Hominidaea traits No tail bigger brain compared to body size stable lower back shoulderjoint strength in clavicle Lemuroidea smaller primates more speci ed diet dental comb Madagascar grooming claw shorter gestation periods focus on olfaction rhinarium wet nose Eye shine tapetum lucidum Vertical clingers and leapers ln lemurs females rule Mostly insectivores Lemurs used to be nocturnal now they re usually diurnal They have Diastema and cartilage on jaw no fused mandible Lorises are diurnal wet nose eye shine forage alone limited color vision woodlands they park young in nests to go feed Lorises leave poison coat on babies Tarsiers claws VCL park babies in nest nocturnal always in pairs monogamy with child highly specialized derived traits dry nose long gestation Ceboidea part of Platyrrhini all new world monkeys mostly arboreal quadrupeds diurnal semiBrachiation at dry noses prehensile tail howler muriquis and spider monkey multimalemultifemale tend to be insectivorefrugivore Marmosets and tamarins is where female has two or more male partners who care for babies and the males take care of young Good example of Kselected Eyes are far off to the side of their face Cercopithecidaea Old World monkey They are omnivores no prehensile tail Colobus monkeys semibrachiate but Cercopithecidaea are mostly arboreal quadrupeds terrestrial quadrupeds baboons sexual dimorphism sexual dichromatism sex skin estrus lschial callistus 2123 dental structure cheek pouches downward facing nostrils they live in tropical jungle tactile pad hands natal coat complex stomach omnivorous Colobus are Cercopithecidaea Hominodiea bigger brains compared to body size no tails because they are apes arms are bigger than legs knuckle walking They have extra bone in clavicle gibbons and siamangs are lesser apes and they live mostly in Africa and east Asia Great apes are from Africa lesser apes are in east Asia Biggest primate is gorilla Silverback represents alpha male There are sexual dimorphism Gorillas leave their natal group there is Alloparenting Gibbons and siamangs brachiate They have curved ngers they are territorial they sing and holler they are kselected They are frugivorous Chimps are examples of ssionfusion Orangutans are solitary but social Hanuman langur they practice infanticide There are no baboons where there are macaques Gelada baboon have sex skin on chest Macaque is biomedical choice Symplesiomorphic traits Ancestral traits Strepsirhini Synapomorphy derived traits Haplorhini Example spider monkey has prehensile tail at nose trac pad Only ancestral traits that catarrhines have are mobile digits Night monkey no eye shine nocturnal Female philopatry in savannah baboon Black and white colobus monkey natal coat Mandrill sex skin sexually dichromatic Red uakari Red face signals good health Squirrel monkey frugivore Muriquis wooly monkey prehensile tail Females disperse between groups Fissionfusion Spot nose guenon lschial callosities only old world monkeys have this Hominodiea lntermembral index over 100 Howlers have prehensile tails Chimps are Philopatric y5 molar meant for mastication usually in old world primates Biophodont lower molars have 2 ridges example guenon Binocular vision Bunodont molars in hominoids and the molars are at Jurmain text Chapter 6 class and book notes Learning Objectives 1 FP P FP N What are the different kinds of primates What are their differences What are major characteristics of primates Why are we primates Why study nonhuman primates Why are so many endangered What do we have in common with all vertebrates classes Things we have in common with all mammals Prototheria metatheria eutheria Meet the relativesnoses Traditional Primate Taxonomy J pg 147 What is a primate A primate is a member of the mammalian order Primates which includes lemurs Iorises tarsiers monkeys apes and humans How do we de ne primates No single identifying character There are a set of general tendencies that are not equally expressed in all primates This is a general anatomical and behavioral picture of primates Major trends J pg 136 L pg 61 Primates are generalized in that they have retained several ancestral mammalian traits that many other mammals have lost over time In response to selective pressures some mammalian groups have become increasingly specialized or derived Mammalian characteristics Primates share basic mammalian traits with other placental mammals Some of these basic traits are body hair a relatively long gestation period followed by live birth mammary glands different types of teeth the ability to maintain a constant internal body temperature through physiological means or endothermy Built for life in trees Primates are built to live on trees Anatomy rather primitive and generalized pentadactly Retention of primitive bone structure robust clavicle emancipated forelimb Primates have a exible generalized limb structure which allows most primates to practice numerous forms of locomotion Primates have retained some bones and certain abilities like rotation of forearm that have been lost in more specialized mammals such as horses Many aspects of hip and shoulder morphology provide primates with a wide range of limb movements and function Primates are not restricted to one form of movement Climate change causes change in living in trees or not living in trees Humans have hentadactyl ve highly mobile digits Primates have at nails instead of claws except for grooming claw tactile pads fro traction nger prints Original name for primate Qaudrumena Human forelimbs aren t used on locomotion More anatomical trends Primates have elaborate visual power Depth perception Frontation of orbits Stereoscopic binocular color nonhuman primates are very colorful Progressive development of large and elaborate brain brain to body ratio Color allows you to judge the suitability of food It also allows primates to see things that aren t moving Toothsome trends Conservative indicator of evolutionary change They carry your life history what you are where you grew up Each species has unique prism in tooth enamel Teeth are the only thing that remains in fossils Shape of teeth tell you a lot about an animal s diet Differentiated teeth there are at least three kinds of teeth J pg 144 Dental formula Dental formula tells you the number and kinds of teeth in the mouth About these teeth Diastema Long sharp canine teeth Behavior and development Tendency toward erectness towards feeding especially Tendency to use fore and hind limbs for more than locomotion Tendency to be social Recognize each other as individuals Long life stages Lack of dietary specialization generalized dentition exibility A lot of behavior in humans is learned Humans don39t really have instincts Fear is learned mating is learned Instinct is not learned Every member of that species has to do it Humans have menopause nonreproductive periods So why all this Adaptation to life in trees 1 pg 139 The corboreal hypothesis traditional explanation by smith and wood jones Visual predation hypothesis Everything about primates is geared towards nding prey Primates as pollinators Angiosperm coevaluation hypothesis Primates evolved with angiosperm Some primates pollinate Example mouse lemurs Why study primates Behavioral and anatomical similarities closest living relatives Biomedical models of choice RH factor in blood Models for ancestors with similar anatomy Models for interaction with the environment Understand range of variation Comparison with other socially living animals We need to understand through this comparative approach how and why physiological and behavioral systems evolved as adaptive response to many selective pressures through the course of evolution So if we want to identify the components that have shaped the evolution of our species a good starting point is to compare ourselves with our closest living relatives the nonhuman primates Own intrinsic value Some history Sully Zuckerman Social life of monkeys in 1932 He studied baboons He found that there is sexual dimorphism and competition between males There is male dominance C Ray Carpenter eldwork howlers in 1934 gibbons 1940 War made it dif cult to get places to do eldwork Rebirth in 196039s Leakey39s angels 1 Absolute dating A dating technique that gives an estimate in actual numbers of years 2 Acheulian Pertaining to a stone tool industry from the Early and Middle Pleistocene characterized by a large proportion of bifacial tools Acheulian tool kits are common in Africa Southwest Asia and Western Europe but they re thought to be less common elsewhere 3 Atl atl spear throwing was a hooked rod made of bone or wood that extended the hunter s arm enhancing the force and distance of a spear throw 4 Allometry The study of relationship of body size to shape anatomy physiology and nally behavior 5 Artifacts Objects or materials made or modi ed for use by hominins The earliest artifacts are usually tools made of stone or occasionally bone 7 Auragnacian Pertaining to an Upper Paleolithic stone tool industry in Europe beginning at about 40000 ya 8 Australopiths Extinct genus of hominid Lucy is an australopiths 9 Bifacialbifacial tool tools that are aked on both sides 10 Bilophodont Referring to molars that have four cusps oriented in two parallel rows resembling ridges This trait is characteristic of Old World monkeys 11 Biocultural evolution The mutual interactive evolution of human biology and culture the concept that biology makes culture possible and that developing culture further in uences the direction of biological evolution this is a basic concept in understanding the unique components of human evolution 12 Biological determinism The concept that phenomena including various aspects of behavior are governed by biological factors the inaccurate association of various behavioral characteristics with certain biological traits such as skin color 13 Biostratigraphy A relative dating technique based on the regular changes seen in evolving groups of animals as well as the presence or absence of particular species 14 Blanks In archeology stones suitably sized and shaped to be further worked into tools 15 Brow ridges Nodule or crest of bone situated on the frontal bone of the skull forming the separation between forehead portion itself and roof of eye sockets 16 Burins Small chisellike tools with a pointed end 17 Carbon dating Form of radioactive dating that helps determine the age of certain archeological artifacts of a biological origin It is used to date things like bone cloth wood and plant bers 18 Cenozoic Began about 655 million years ago and continues through today marks the end of the Age of dinosaurs and the beginning of the age of mammals 19 Chalteperronian Pertaining to an Upper Paleolithic industry found in France and Spain containing blade tools and associated with Neanderthals 21 Chopper toos made in Oldowan Choppers are stone cores with akes removed from part of the surface creating a sharpened edge that was used for cutting chopping and scraping 22 Chronometric dating A dating technique that gives an estimate in actual numbers of years also known as absolute da ng 23 CadecadisticsCladogram A group of organisms sharing a common ancestor The group includes the common ancestor and all descendants 24 Cline 25 Clovis culture New Mexico found darts from northeast Asia 26 Context The environmental setting where an archaeological trace is found Primary context is the setting in which the archaeological trace was originally deposited A secondary context is one to which it has been moved 27 Continental drift The movement of continents on sliding plates of the earth s surface As a result the positions of large andmasses have shifted drasticay during the earth s history 28 Core The raw stone from which akes will be removed and which can be modi ed and used as a tool itself 29 Dental apes Early hominoids that lived in Miocene era A known genus is Proconsul They had sexuay dimorphic canines and largely frugivorous diet 30 Direct percussion Striking a core or ake with a hammerstone 31 Derived Referring to characters that are modi ed from the ancestral condition and thus diagnostic of particular evolutionary Hneages 32 Encephalization The proportional size of the brain relative to some estimate of overall body size such as weight More precisely the term refers to increases in brain size beyond what would be expected given the body size of a particular size 33 Endocasts A solid impression of the inside of the skull vault often preserving details relating to the size and surface features of the brain 34 Epochs Categories of the geological time scale subdivisions of periods In the Cenozoic era epochs include the Paleocene Eocene Oligocene Miocene and Pliocene and the Pleistocene and Holocene 35 Era one of approximately 11 units of geological time that cover the ca 46 billion year age of Earth 36 Euarchonta Grand order of mammals containing four orders Dermoptera Scandentia and Plesiadapiformes 37 Eugenics The philosophy of quotrace improvementquot through the forced sterilization of members of some groups and increased reproduction among others an overly simpli ed often racist view that is now discredited 38 Euprimates True primates Elwyn Simons coined this term in 1972 39 Evaporative cooling A physiological mechanism that helps prevent the body from overheating It occurs when perspiration is produced from sweat gland and then evaporated from the surface of the skin 40 Flake ake tools A thinedged fragment removed from a core 41 Foramen magnum An opening in the occipital and bottom parts of the cranium 42 Fossil Traces or remnants of organisms found in geological beds on the earth s surfaces 43 Geological time scale The organization of earth history into eras periods and epochs commonly used by geologists 44 Glaciations Climatic intervals when continental ice sheets cover much of the northern continents They are associated with colder temperatures in northern latitudes and more arid conditions in southern latitudes much notably in Africa 45 Gracile Slight slender 46 Grade social category or rank based on an age range 47 Halflife The time period in which one half the amount of a radioactive isotope is converted chemically to a daughter product 48 Hand axe Associated with Acheulean It has a core worked on both sides called biface 49 Hominins Colloquial term for members of the evolutionary group that includes modern humans and now extinct bipedal relatives 50 Hominoids Members of the primate superfamily which includes apes and humans 51 lnterglacials Climatic intervals when continental ice sheets were retreating eventually are becoming much reduced in size lnterglacials in northern latitudes are associated with warmer temperatures while in southern latitudes the climate becomes wetter 52 Knappers People who make stone tools They are frequently archaeologists 53 Last common ancestor LCA The nal evolutionary link between two related groups 54 Levallois technique Distinctive style of int knapping which makes up part of the Middle Paleolithic Acheulean and Mousterian artifact assemblages 55 Lithic Referring to stone tools 56 Magdalenian Pertaining to the nal phase of the Upper Paleolithic stone tool industry in Europe 57 Microliths Small stone tools usually produced from narrow blades punched from a core found especially in Africa during the latter part of the Pleistocene 58 Mosaic evolution A pattern of evolution in which the rate of evolution in one functional system varies from that in other systems For example in hominin evolution the dental system loco motor system and neurological system all evolved at markedly different rates 59 Mousterian Pertaining to the stone tool industry associated with Neanderthals and some modern H Sapiens groups also called Middle Paleolithic o MtDNA Eve mitochondrial DNA is always passed down from mother and everyone has the same mtDNA There is one population in Africa that gives de ning gene to different homo species 60 Multiregional hypothesis Anthropologists studied homo erectus from south east saw morphological similarities with living European homo sapiens 61 Nuchal torus A projection of bone in the back of the cranium where neck muscles attach These muscles hold up the head 62 Obligate bipedalism Habitual form of bipedalism 63 Oldowan Archaeological term used to refer to earliest stone tool industry in prehistory 64 Paleoanthropology The interdisciplinary approach to the study of earlier hominins their chronology physical structure archaeological remains habitats and so on 65 Paleomagnetism Dating method based on the earth s shifting magnetic pole 66 Paleospecies Species de ned from fossil evidence often covering a long time span 67 Phylogenetic species concept A species is the smallest diagnosable cluster of individual organisms within which there is a parental pattern of ancestry and descent 68 Phylogenetic tree A chart showing evolutionary relationships as determined by evolutionary systematics lt contains a time component and implies ancestor descendant relationships 69 Plate tectonics Geological theory that the plates of the Earth s crust move resulting in changes in the position size and shape of continents and oceans 70 Post orbital constriction Narrowing of the cranium just behind the eye sockets 71 Pressure aking A method of removing akes from a core b pressing a pointed implement 72 Principle of superposition In a stratigraphic sequence the lower layers were deposited before the upper layers Or simply put the stuff on top of a heap was put there last 73 Prognathismprognathic The positional relationship of the mandible and or maxilla to the skeletal base where either of the jaws protrudes beyond a predetermined imaginary line in the coronal plane of the skull 74 Provenience geographical or geological origin or source of an artifact or the place of origin of a specimen 75 Relative dating Age of fossil relative to another fossil 76 Replacement hypothesis States that archaic sapiens spread from Africa to Asia and Europe and modern sapiens evolved from archaic sapiens in Africa and then spread throughout the world These modern sapiens then replaced the archaic sapiens without interbreeding with them 77 Radioactive decay The process of a material giving off particles to reach a stable state 78 Retro molar gap Space between the third molar and the rear portion of the mandible 79 Sagital gap A lengthwise ridge of bone along the top of the skull where strong chewing muscles attach tot eh top of the skull 80 Sectorial Tooth made for shearing 81 Selective pressures Forces in the environment the in uence reproductive success in individuals 82 Sister groups the relationship of new clades that result form the splitting of a single common lineage 83 Stable carbon isotopes lsotopes of carbon that are produced in plants in differing proportions depending on environmental conditions By analyzing the proportions of the isotopes contained in fossil remains of animals its possible to reconstruct aspects of ancient diet and environments 84 Stem group All of the taxa in a clade before a major speciation event Stem groups are often difficult to recognize in the fossil record since they don t often have the shared derived traits found in the crown group 85 Stratigraphy Study of the sequential layering of deposits 86 Taphonomy The study of how bones and other materials came to be buried in the earth and preserved as fossils Taphonomists study the processes of sedimentation the action of streams preservation properties of bone and carnivore disturbance factors 87 Taurodontism A condition found in molar teeth of humans whereby the body of the tooth and pulp chamber is enlarged vertically at the expense of the roots 88 Thermoluminiscence TL A technique for dating certain archaeological materials that were heated in the past and that upon reheating release the stored energy of radioactive decay as light 89 Tool tradition A tool or tools with a generally consistent pattern of production 90 Type specimen The original specimen from which the description of anew species is made 91 Unilineal hypothesis Hypothesis states that multiple hominins lived together but not anymore 92 Upper Paleolithic A cultural period usually associated with modern humans but also found with some Neanderthals and distinguished by technological innovation in various stone tool industries Best known from western Europe similar industries are also known from central and eastern Europe and Africa 93 Y5 molar cusp pattern Molar that has ve cusps with grooves running between them forming a Y shape Lehman notes Chapter 5 o The cranial skeleton is unique because it provides information on both diet and locomotion in fossil primates Cranial anatomy and morphology can provide information on the activity patterns and locomotion of extinct primates o Postcranial skeleton can be examined to deduce the locomotor behavior of extinct primates We focus on basic postcranial features associated with the following four common locomotor patterns used by primates arboreal quadropedalism terrestrial leaping and suspension Chapter 8 Overview of the Fossil Primates In this chapter we focus on bridging the gape between these creatures and ourselves between Strepsirrhines and haplorhines to help us better understand our own evolutionary history Our primate cousins share many of the traits we generally think of as uniquely human Many of these similarities can be traced to shared origins in highly social groups living in the trees We see these origins in the structure of our body and in the retention of many primitive features such as pentadactyly ve ngers and toes and unfused lower arm bones but also in more derived skeletal traits that come later Derived means being or having a feature that is not present in ancestral form Among the most important of these derived primate traits are evolutionary trends toward a more orthograde upright body position and forward facing eyes binocular Background to Primate Evolution Late Mesozoic Following the extinction of the dinosaurs at the end of the Mesozoic the reign of giant reptiles was over and the Age of Mammals had begun Primates were just one of the many groups of small mammals that were left to diversify and explore the many niches left vacant with the passing of the dinosaurs Primates started diverging from closely related mammals in lineages during the Cretaceous era Some scientists place these closely related lineages into a superorder a taxonomic group ranking above an order and below a class or subclass This group consists of tree shrews ying lemurs Sister groups are the related new clades that result from the splitting of single common lineages The closest relatives of this superorder are rabbits rodents and their relatives Primate Origins Cenozoic era was broad time period when primate evolution unfolded There are seven epochs in this era There is Paleocene rst archaic primates plesiadapiforms Eocene rst euprimates Oligocene early catarrhines Miocene monkeys and apes Pliocene early hominin diversi cation Pleistocene early Homo Holocene modern humans The last common ancestor is the hypothetical species that was the last to exist before it speciated into the myriad of sister orders related to primates The LCA does not have derived traits found in crown group A crown group is easier to identify because it includes all of the taxa that comes after a major speciation event All extant groups and fossils sharing their speci c derived traits are crown Stem group includes all of the taxa in a clade before a major speciation event For this reason like the LCA stem group taxa are often dif cult to recognize in the fossil record Molecular anthropology uses genetics to investigate the biology and evolution of humans and our closest relatives The time when we can rst con dently identify an archaic primate is almost assuredly an underestimate of the actual time of divergence assumed date LCA lived Molecular data have often provides us with overestimates of this time What is important however is that 1 since molecular estimates of divergence dates are calibrated using known fossil dates the two approaches are inextricably linked and 2 determining the appropriate range of mutation which joins these two together can be tricky Together these two approaches now place the origins of indisputable primates at some time during the Paleocene about 65 mya Made to Order Archaic Primates Fossil evidence indicates that during the earliest Paleocene between 65 and 52 mya a major radiation of archaic primates known as plesiadapiforms occurred Plesiadapiforms are members of an extinct group that occupies a controversial position in primate phylogeny When rst discovered these creatures were considered early members of the primate order but then they were found to have their own order Plesiadapiformes But now they are once again placed in the order Primates They are now gaining acceptance as a semi order which is the taxonomic category above suborder and below order within primates that is separate from the later euprimates true primates Plesiadapiformes are best known from a large number of fossil nds from American West Some members of this group exhibit a striking resemblance with some of the earliest Strepsirrhines from later Eocene epoch We ll concentrate on three families that are commonly recognized within this group Purgatoriidae members of this extinct genus are believed to have been about the size of modern rats Species lived in earliest Paleocene in American northwest It is important to note that postcranial material referring to all or part of the skeleton including the skin from Garbani channel in northeastern Montana reveals arboreal adaptation within the feet The second family is Plesiadapidae they were chipmunk to groundhog sized mammals with large incisors similar to rodents The best known of this family is genus Plesiadapis The last family we will talk about is Carpolestidae whose name means fruit stealer It was quite common during Paleocene in north America and Asia These creatures are smaller generally rat sized They also have dental traits that allow them to ef ciently process brous vegetation as well as nuts and insects Carpolestes genus displays no adaptations for leaping though it almost certainly is a terminal branch feeder Eocene Primates During Eocene there is gradual extinction of plesiadapiforms and their replacement by the euprimates These mammals unlike plesiadapiformes have de nite recognizable and modern derived primate traits like forward facing eyes greater encephalization postorbital bar nails instead of claws and opposable big toe These and other primitive features suggest an adaptation to environmental conditions Environment was warmer and had year round rainfall and lush broadleaved evergreen forests At the beginning of Eocene North America and Europe were still attached they didn t split until middle of Eocene North America was also connected to Asia and shared many species in common Euprimates are part of this wave of diversi cation and adaptive radiation They came to be in North America Europe and Asia during 56 mya There are two main branches of euprimates grouped into different super families Adapoidea and Omomyoidea These two super families include primitive primates described as being either more lemur like adapoid or tarsier or Galago like omomyoid Lemur connects The Adapoids Adapoids had 2143 dental formula Adapoids are the best known of the Eocene stem Strepsirrhines They are divided into ve families the notharctids that includes genus Cantus This was earliest notharctid and one of the earliest of any of the anthropoids It was a diurnal creature and was found in North America and two species were in Europe It was probably a leaper Another notharctid was Darwinius which has no dental comb or a grooming claw which shows that they are more than lemur relatives Researchers said lda a Darwinius skeleton was a basal haplorhine Just months later a new adapid Afradapis a large bodied adapiform genus Afradapis belongs to third family of Adapoids Phylogenetic relationships for this group is not well understood Homology similar traits based on descent Homoplasy is similar traits that evolve independently in different groups Afradapis dentition shows that it may have exploited niches in Africa eating leaves like a monkey Bestknown fossil of this group is Adapis Georges Cuvier discovered this fossil but confused it for a hoofed mammal or an ungulate Adapis was probably arboreal quadruped lt foraged for leaves probably Closer Connections to Living Primate the evolution of True lemurs and lorises The evolution of lemurs and other Strepsirrhines is of great interest because of their basal position as sister group to all other primate lineages Lorisoids are the earliest examples of strepsirhine primates in fossil record They ve been found in late Eocene deposits of the Fayum Depression in Egypt Late Eocene fossil shows that it has a dental comb This and other features have led to conclusion that it s a stem galagid It can be inferred that lorises and galagos likely diverged by the close of the middle Eocene Existence of bush baby in Egypt shows that Strepsirrhines initially developed in African mainland These primates may have colonized Madagascar to give rise to crown Lemuriformes which would mean that lemurs have never existed outside of Madagascar Colonization may have occurred when animals crossed Mozambique Channel This may have occurred in Cenozoic era There are few if any truly fossilized lemurs remains Madagascar but there are many sub fossils bones not old enough to be completely mineralized as a fossil Many of these sub fossils were large Many lled unusual econiche not shared by any living lemurs These strange adaptations provide examples of convergence with higher primate niches found elsewhere in old world For example extinct Archaeolemur with its fused mandible and Bilophodont molars in many ways more closely resembles a monkey Best known of giant lemurs is Megaadapis They are kind of like koalas They have low reproductive rates and extinction was caused by predation and deforestation Remaining lemurs of Madagascar will meet the same fat unless the continued destruction of their habitat by humans ceases Tarsiers Connections The Omomyoids Omomyoids are more tarsierlike and are earliest haplorhine group They have a similar dental formula 1133 as well as large orbits and small snouts Earlier members of the group are more generalized than later ones Paleoprimatologists are anthropologists specialization in the study of the nonhuman primate fossil record Some of them are in Eocene and early Oligocene of North America and Europe with a small number also known from Asia Members of the genus Teilhardina are found on three continents They engaged in rapid westward dispersal with evidence pointing to Asia as euprimates starting point The oldest and most primitive were in Asia while the youngest were in North America Biostratigraphic or faunal correlation is a method of dating strata that relates the fossil content of an unknown stratum to a like one that has been securely chronometrically dated Studies show that Teilhardina may have moved east to west from Asia to North America before moving into Western Europe Other Eocene fossils of family Omomyidae from North America is Shoshonius and in Europe Necrolemun These animals have convergent eye orbits as well as details of the ear region that unite them to tarsiers Necrolemur has fused tibia and bula as well as elongated calcaneus a lever like construction that gives modern tarsiers their fantastic leaping ability Evolution of True Tarsiers Fragmentary remains of fossil tarsiers were found in Egypt China Myanmar and Thailand The rst cranium remains discovered were identical to anatomy in living tarsiers Tarsiers did not change that much since their ancestor All living tarsiers are now limited to a few islands in Southeast Asia Towards the end of Eocene there was a shift from tropical to drier and more seasonal climates This change led to more diverse landscapes opening more niches for the highly adaptable primates to exploit Eocene and Oligocene Early Anthropoids The Fayum Depression in Egypt an arid region provides most of our early anthropoid record for Eocene and Oligocene Biretia was one of the discoveries 37 mya and represented early African anthropoid lts dental morphology resembles that of basal anthropoid The structure 0 upper molar teeth root points to large orbits implying that organism is nocturnal Which is unusual since anthropoids are mainly diurnal So Elwyn Simons placed them into superfamily Parapithecoidea This super family is signi cant as the most primitive anthropoid group and therefore the possible rootstock form which the entire new world anthropoid evolutionary group evolved Catopithecus clearly had anthropoid features and some derived catarrhines features such as dental formula 2123 Molecular and biological data con rms that anthropoids had an African origin much like our genus Homo Oligocene Primates True Anthropoids The early primates of Oligocene are generally placed into 3 families oligopithecids parapithecids and propliopithecids They are among the earliest catarrhines anthropoid primates Crushed crania represent Catopithecus They have a complete postorbital closure and derived dentition 2133 The most abundant of the Oligocene fossils from the Fayum belong to genus Apidium They are small and have it has dental formula of 2133 They re likely relatives of new world monkeys or platyrrhines Teeth suggest diet of fruit and seeds There is also an unusually large amount of sexual dimorphism in canine size This may indicate that they form Polygnous social groups of single male multifemale and offspring Limb remains show that they were small arboreal quadruped adept at leaping and springing Parapithecus is a close relative of Apidium Members of third major family is propliopithecids A genus in this family is Aegyptopithecus This genus has been proposed as ancestor of later old world monkeys and hominoids It was roughly the size of howler monkeys with considerable sexual dimorphism lts dental formula was 2123 lts brain is small and at best resembles brains of Strepsirrhines The small brain size indicates encephalization which must have evolved independently within the two anthropoid parvorders below infraorder Platyrrhini and Catarrhini It was also probably arboreal quadruped The next genus Saadanius de es current attribution to any existing catarrhines family or superfamily They lack derived feature of cercopithecoids or hominoids Their features include large broad molars projecting midface a tube like middle ear The tubelike middle ear is what it shares with catarrhines This would make it an advanced stem catarrhine though perhaps intermediate between Aegyptopithecus and Miocene ape Early Platyrrhines New World Anthropoids Earliest platyrrhine fossils were found in late Oligocene of Bolivia and belonged to genus BranseIa They appeared to be small monkeys with diets mainly of fruits It is thought to be so primitive that it is not placed in any platyrrhine lineage Molecular evidence shows that living platyrrhines converge on a shared ancestor that is 25 million years old Based on presence of platyrrhines in South America it is likely that they rst appeared in late Eocene Island hopping is one of the theories behind how new world monkeys got to South America lsland hopping is traveling from one island to the next This scenario suggests that the tarsier like Omomyoids from North America journeyed to South America giving rise to later platyrrhines The most likely scenario involves their oating between closely spaced islands across the Atlantic Ocean from Africa to South America on rafts made of naturally formed mats of vegetation Miocene Primates Throughout Miocene we see diversi cation of anthropoids into the groups were familiar with today The Cercopithecoids monkeys and hominoids competed for the dominant position on the primate landscape in the old world Monkeying Around Cercopithecidae includes monkeys like macaques and baboons Most fossil macaques appear remarkably similar to each other and other life forms In east Africa the baboon like Theropithecus was the dominant Cercopithecines genus of the Pliopleistocene Today the living gelada is con ned to the high wet grasslands of the Amhara Plateau Ethiopia This was where Papio baboons were found Aping monkeys The apelike proconsuloids rst apelike fossils share many postcranial characteristics with monkeys Proconsuloidea the only apelike feature is the presence of the Y 5 molar pattern Molar that has ve cusps with grooves running between them forming a Y shape This is characteristic of hominoids o Monkeys have Bilophodont cusps True apes appear in early to middle Miocene They had thick enamel in their molars Sivapithecus was a large hominoid It has a concave pro le broad zygomatics cheekbones and a procumbent projecting maxilla and incisors resembling the face of the modern orangutan Hylobatids Lesser apes lesser apes include gibbons From molecular environments and fossil remains of small bodied Yuanmoupithecus we can determine that the gibbon radiation most likely began in mainland Asia perhaps in China Gibbons are in the taxa Hylobates African Great Apes European Ouranopithecus is considered best candidate for a stem African apehominoid 99 million year old Nakalipitheucs from Kenya may be last common ancestor of the African great apes It is terrestrial Asia39s lone Great Ape Of all the living apes the orangutan s ancestry is probably the best documented It might be descended from Sivapithecus and pongo based on similarities The face of Lufengpithecus is also very similar to that of the modern orangutan But its post crania is more similar to Pongo Chapter 9 Paleoanthropology Reconstructing Early hominin behavior and ecology 0 Understanding our Direct Evolutionary connections What s a hominin The earliest evidence of hominins that has been found dates to the end of the Miocene and mainly includes dental and cranial pieces But those alone don t describe the special features of hominins Modern humans as well as our most immediate hominin ancestors are distinguished from apes by more obvious features than tooth and jaw dimensions For example various scientists have pointed to such distinctive hominin characteristics as bipedal locomotion large brain size and tool making behavior as being signi cant Mosaic evolution is a pattern of evolution in which the rate of evolution in one functional system varies from that in other systems For example in hominin evolution the dental system locomotor system and neurological system all evolved at markedly different rates Behavioral aspects of hominin emergence are what are going to be focused on What s in a name Throughout the book we refer to members of the human family as hominins Over the last several years molecular evidence shows that the great apes do not make up a coherent evolutionary group sharing a single common ancestor and thus are not a monophyletic group The African great apes are signi cantly more closely related to humans than is the orangutan This new classi cation further emphasizes the very close evolutionary relationship of humans with African apes and mostly with chimps and bonobos Second the term hominid which has been used for decades ad a quite different meaning in the revised classi cation now it refers to all great apes and humans together Biocultural Evolution The Human capacity for Culture One of the most distinctive behavioral features of humans is our elaboration and dependence on culture Culture is behavioral aspects of human adaptation including technology tradition language religion marriage patterns and social roles Certainly other primates modify their environments However a point to remember is that human culture involves much more than tool making For humans culture involves more than tool making capacity For humans culture integrates an entire adaptive strategy involving cognitive political social and economic components Material culture or the tools humans use is but a small portion of this cultural complex The fundamental basis for human cultural success relates directly to our cognitive abilities Some primates other than humans have language capabilities as well Even so modern humans display these abilities in a complexity several orders of magnitude beyond that of any other animal Only humans are completely dependent on symbolic communication and its cultural by products that contemporary Homo sapens could not survive without them The earliest hominins didn t regularly manufacture stone tools They may have carried objects such as naturally sharp tones or stone akes parts of carcasses and pieces of wood around their home ranges ln 6mya hominins had developed one crucial advantage They were bipedal and so could more easily carry all kinds of objects from place to place As the hominin s cognitive abilities developed more ef cient means of communication and learning resulted Largely because of consequent neurological reorganization more elaborate tools and social relationships also emerged Discovering Human Evolution The Science of Paleoanthropology Paleoanthropology is de ned as the quotstudy of ancient humansquot As such it is a diverse multidisciplinary pursuit seeking to reconstruct every possible bit of information concerning the dating anatomy behaviors and ecology of our hominin ancestors Multidisciplinary is pertaining to research involving mutual contributions and the cooperation of experts from various scienti c elds or disciplines Paleontologists can give quick and dirty approximate age estimates of fossil sites in the eld without having to wait for the results of more time consuming analyses Such material clues as artifacts inform us directly about early hominin activities Modifying rocks according to a consistent plan or simply carrying them around from one place 0 another over long distances and distributing them in a manner not explicable by natural means is characteristic of no other animal but a hominin New evidence from Dikika site in Ethiopia might indicate that hominins were using stone in an even more sophisticated way as far back as 34 mya No stone tools were found but two animal bones show cut marks Although this evidence doesn t mean hominins were yet modifying rocks to make tools but it does show advanced behavior including scavenging meat eating and marrow extraction The way the eld process goes is that the project has to have government funding and the eld crew begins searching carefully for bones and artifacts eroded in soil Detailed analyses of collected samples and other data back in the lab are time consuming Archaeologists have to clean sort label and identify all artifacts and vertebrate paleontologists must do the same for all faunal remains Analysis of fossil pollen collected from hominin sites by scientists called palynologist further aids in developing environmental reconstruction All these paleoecological analyses can assist in reconstructing the diet of early humans Also the taphonomy of the site must be worked out to understand its depositional history that is how the site formed over time and t is present state is in a primary or secondary context A context is an environmental setting where an archaeological trace is found In the concluding stages of interpretation the paleoanthropologist draws together these essentials Dating Geological paleontological and geophysical Paleoecology paleontology palynology geomorphology taphonomy Archaeological traces of behavior Anatomical evidence from hominin remains By analyzing this information scientists try to quot esh outquot the kind of creature that may have been our direct ancestor They might assist here by showing the detailed relationships between the anatomical structure and behavior of humans and that of contemporary nonhumans primates Cultural anthropologist sand ethnoarchaeologists may contribute ethnographic information concerning the varied nature of modern human behavior particularly ecological adaptations of those contemporary hunter gatherer groups exploiting roughly similar environmental settings as those reconstructed for a hominin site The end results of years of research by dozens of scientists will produce a more complete and accurate understanding of human evolution Connecting the Dots through time Paleoanthropological Dating Methods An essential objective of paleoanthropology is to place sites and fossils into a time frame In other words we want to know how old they are Scientists use two kinds of dating for this purpose Chronometric dating known as absolute dating Relative dating methods tell us that something is older or younger than something else but not how much Stratigraphy is a study of the sequential layering of deposits It was one of the rst techniques to be used by scientists working with vast period of geological time Stratigraphy in turn is based on the principle of superposition which states that a lower stratum is older than a higher stratum Because much of the earth s crust has been laid down by layer after layer of sedimentary rock much like the layers of a cake stratigraphy has been a valuable aid in reconstructing the history of the earth and life upon it The problem with stratigraphy is that volcanic activity or any earth disturbance can be difficult or impossible to reconstruct Another method of relative dating is uorine analysis which applies only to bones Bones in earth are exposed to the seeping of ground water which usually contains uorine The longer a bone lies in the earth the more uorine it will incorporate during the fossilization process Fluorine analysis however is useful only with bones found at the same location Because the amount of uorine in groundwater is based on local conditions it varies from place to place In both stratigraphy and uorine analysis its impossible to calculate the actual age of a geological stratum and the objects within it To determine the age in years scientists have developed various chronometric techniques based on the phenomenon of radioactive decay Certain radioactive isotopes of elements are unstable casing them to decay and form isotopic variation of another element The most important chronometric technique used to date early hominins involves potassium which has a halflife time period in which half the amount of radioactive isotope is converted chemically to a daughter product It s known as the potassiumargon method This procedure has been useful in dating materials in the 15 million year range especially in east Africa where past volcanic activity makes this dating technique possible The Ar Ar method reduces experimental error and is more precise than standard KAr dating Some inorganic artifacts can be directly dated through the use of thermoluminescence TL It is a technique for dating certain archaeological materials that were heated in the past and that upon reheating release stored energy of radioactive decay as light Stone material used in manufacturing tools invariably contains trace amounts of radioactive elements such as uranium or thorium This method is not precise An important means of cross checking dates is called paleomagnetism This technique is based on the constantly shifting nature of the earth s magnetic pole This is accomplished by carefully taking samples of sediments that contain magnetically charged particles Then the paleomagnetic sequence is compared against the KAr dates to see they agree Some complications may arise but these oscillations in the geomagnetic pole are worked out the sequence of paleomagnetic orientations can provide a valuable crosscheck for KAr age determinations Biostratigraphy is a relative dating technique based on the regular changes seen in evolving groups of animals as well as the presence or absence of particular species This is the nal dating technique used at several African sites that is based on the regular evolutionary changes in wellknown groups of mammals Biostratigraphy employs some of the same methods used in relative stratigraphic dating but it incorporates information on sequences of faunal remains from different sites All these methods are used in dating early hominin sites Experimental Archaeology We can learn a lot about our ancestors by understanding how they made and used their tools It is the artifactual traces of prehistoric tools of stone that provide much of our information concerning early human behavior Stone tool lithic technology Stone is the most common residue of prehistoric cultural behavior When struck properly certain types of stone will fracture in a controlled way these nodules are called blanks The smaller piece that comes off is called a ake while the larger remaining chunk is called a core Both core and ake have sharp edges that are useful for cutting sawing or scraping The earliest hominin cultural inventions probably used nondurable materials that didn t survive archaeologically Lithic refers to stone tools Choppers were thought to be central artifactual components of early lithic assemblages The earliest known stone tool industry is during the Oldowan Due to careful analysis of the Oldowan artifacts form Olduvai Potts it has been concluded that the socalled core tools and various stone choppers were simply quotincidental stopping points in the process of removing akes from coresquot Knappers are people who make stone tools The nodules found in sites in Bed at Olduvai are aked on one side only lts possible but by no means easy to produce such implements by hitting one stone the hammer stone against another the core in a method called direct percussion However in later sites especially in Olduvai most of the tools are aked on both sides Direct percussion with hammer stone can reproduce such a result Tools such as the Microliths found in uppermost beds at Olduvai Solutrean blades from Europe and Folsom projectile points form New World all require a mastery of stone matched by few Knappers today Pressure aking can remove extremely thin akes Ancient tools themselves may carry telltale signs of how they were used Lawrence Keeley performed a series of experiments in which he manufactured int tools and then used them in diverse ways Viewing these implements under a microscope revealed patterns of polishes striations and other kinds of microwear For instance Keeley was able to distinguish among tools used on bone antler meat plant materials and hides Advances in tool use studies include the application of scanning electron microscopy Working at 10000 x magni cation researchers have found that the edges of stone implements sometimes retain plant bers and amino acids as well as nonorganic resides including phytoliths Because phytoliths produced by different plant species are distinctive there is good potential for identifying the botanical materials that came in contact with the tool during its use Analysis of Bone Experimental archaeologists are interested in the ways in which bone is altered by human and natural forces It has produced a new branch taphonomy Detailed examination of bones may also provide evidence of butchering and bone breakage by hominins including cut and percussion marks left by stone tools Reconstruction of Early Hominin Environments and Behavior Paleoanthropologists are interested not just in how early hominins evolved but also why the process occurred the way it did Accordingly they frequently use the data available as a basis for broad speculative scenarios that try to explain both early hominin adaptations to a changing environment and the new behaviors that these hominins adopted Why did Hominins become bipedal The adaptation of hominins to bipedal locomotion was the most fundamental adaptive shift among the early members of our lineage But what in uenced this change The major shift could have occurred at end of the Miocene Bipedalism could have been brought on by environment changes A super cial conclusion as to why hominins are bipedal is that ground niches were so available Plenty of mammals live on the ground and they aren t bipedal Another theory for bipedalism is that it was brought on by the ability to carry objects and offspring hunting on the ground feeding from bushes and improving thermoregulation It could also be walking long distance having a better view of open country and provisioning by males of females with offspring Another assumption conducted by Clifford jolly and Owen Lovejoy is that early hominins were eating seeds acquired in similar ecological conditions to those of contemporary gelada baboons But seed eating is not directly related to bipedalism Another theory by Dean Falk was that an upright posture put severe constraints on brain size and drainage would have been altered and cooling would have been more limited than in quadrupeds So she hypothesizes that new brain cooling mechanisms must have coevolved with bipedalism There are two varying cooling adaptations by Falk She suggest that the type of radiator adapted in genus Homo was signi cant in reducing constraints on brain size The radiator theory works well Chapter 10 Hominins origins in Africa Hominins evolved from earlier primates dating form the Eocene to late Miocene The earliest members of the human lineage were con ned to Africa other 0 Only much later did their descendants disperse from Africa to areas Walking the Walk The Bipedal Adaptation Morphological means pertaining to the form and structure of organisms We ve noticed a tendency in all primates for erect body posture and some bipedalism However of all living primates ef cient bipedalism habitual form of locomotion is seen only in hominins The human mode of locomotion is most clearly shown in our striding gait where weight is alternately placed on a single fully extended hind limb Looking at our close relatives our ancestors were adapted to a fair amount of upper body erectness while still in the trees Prosimians monkeys and apes all spend considerable time sitting erect while feeding grooming or sleeping Mechanics of Walking on Two legs Maintaining a stable center of balance in this complex form of locomotion calls for many drastic structural or anatomical alterations in the basic primate quadrupedal pattern The most dramatic changes are seen in the pelvis The pelvis is composed of three elements two hip bones joined at the back of the sacrum In a quadruped the ossa coxae or hip bones are vertically elongated bones positioned along each side of the lower portion of the spine and oriented more or less parallel to it In hominins the pelvis is comparatively much shorter and broader and extends around to the side This con guration helps stabilize the line of weight transmission in a bipedal posture form the lower back to the hip joint Consequences of remodeling of pelvis were the broadening of two sides and extending them around to the side and front of the body produced a basin shaped structure that helps support the abdominal organs It also repositioned the attachments of several key muscles that act on hip and leg changing their mechanical function It also impacted the gluteus Maximus In quadrupeds it is positioned to the side of the hip and functions to pull the thigh to the side and away from the body In humans this muscle is positioned behind the hip this arrangement allows it along with ham strings to extend the thigh pulling it to the rear during walking and running Modi cations also occurred in other parts of the skeleton 1 Repositioning of foramen magnum opening at base of skull through which spinal cord emerges 2 The addition of spinal curves which help to transmit the weight of the upper body to the hips in an upright posture 3 shortening and broadening of the pelvis and the stabilization of weight transmission 4 Lengthening of the hind limb thus increasing stride length 5 angling of the femur inward to bring the knees and feet closer together under the body 6 several structural changes in the foot including development of a longitudinal arch and realignment of the big toe in parallel with the other toes Hominin bipedalism is both habitual and obligate By habitual bipedalism we mean that hominins unlike any other primate move bipedally as their standard and most efficient mode of locomotion by obligate bipedalism we mean that hominins are committed to bipedalism and cannot locomote efficiently in any other way For example the loss of grasping ability in the foot makes climbing much more difficult for humans By at least 4 mya all major structural changes required for bipedalism are seen in early hominins from Africa Fossil evidence of early hominin foot structure has come from two sites in South Africa especially important are some fossils form Sterkfontein These specimens include four articulating elements form the ankle and big toe indicate that the heel and longitudinal articulating elements form the ankle and big toe indicate that the heel and longitudinal arch were both well adapted for a bipedal gait Paleoanthropologists said that the large toe was divergent unlike the hominin pattern shown if the large toe really did have this anatomical position it is most likely would have aided the foot in grasping Further evidence for evolutionary changes in the foot comes from two sites in east Africa East African fossils suggest a welladapted bipedal gait Arches are developed but some differences in ankle also imply that considerable exibility was possible From this evidence some researchers have concluded that many forms of early hominins probably spent a lot of time in trees They may not have been efficient bipedally as previously suggested Digging for Connections Early hominins from Africa There are certain fossil groups of early hominins 1 Pre australopiths the earliest and most primitive hominins 60 to 44 2 Australopiths diverse forms some more primitive others highly derived 42 to 12 mya 3 Early Homo the rst members of our genus 20 to 14 mya PreAustralopiths 6044 mya The oldest and most surprising fo these earliest hominins is represented by a cranium discovered at a central African site called Toros Menalla in the modern nation of Chad Provisional dating using faunal correlation biostratigraphy suggests a date of between 7 and 6 mya But closer examination caused people to believe that 6 mya is more likely The morphology is unusual with a combination of traits unlike those found in other early hominins Brain case is small estimated at no larger than a modern chimp s but it is massively built with huge brow ridges in front a crest on top and large muscle attachment in the rear There is also a small vertical face containing front teeth very unlike an ape s The lower face is more tucked in under the brain vault is more of a derived feature more commonly expressed in later hominins What s even more unlike the ape dentition is that the upper canine is reduced and is worn down from the tip Lack of such a shearing caninepremolar arrangement is called a honing complex is viewed as a derived characteristic of early hominins In recognition of this unique combination of characteristics paleoanthropologists have placed the Toros Menalla remains into the genus Sahelanthropus tchadensis It is difficult to see how Sahelanthropus could be anything but a hominin However the position of its foramen magnum is intermediate between that of a quadrupedal ape and that of a bipedal hominin Ape might be a better classi cation for Sahelanthropus We don t yet know the locomotion for Sahelanthropus Probably living at about the same time as Sahelanthropus two other very early hominin genre have been found at sites in central Kenya in the Tugen hills and from the middle Awash area of northeastern Ethiopia The earliest of these nds by radiometric methods to around 6 mya comes from the Tugen hills and includes mostly dental remains but also lower limb bones These fossils have been placed in a separate early hominin genus called Orrorin The postcranial remains indicate bipedal locomotion The Orrorin is considered best evidence to establish it as a hominin The last group of possible hominins dating to late Miocene earlier than 5 mya comes from the Middle Awash in Afar triangle of Ethiopia Radiometric dating places the age to about 5852 Fossil remains are fragmentary Yohannes HaileSelassie the researcher who rst found and described these earlier materials has assigned them to the genus Ardipithecus This primate was a well adapted biped since some post cranial elements had been preserved most importantly the toe bone At a site called Aramis a very large assemblage of fossil hominins was discovered Radiometric dating rmly places these remains at about 44 Mya These nds include both large and small vertebrates Additionally fossil wood and pollen samples have been recovered All this information is important for understanding the environments in which these ancient hominins lived The site represented by a 6 foot bed of bones yielded more than 6000 fossils Isolated teeth cranial bones and a few limb bones represent 36 hominins The most important fossil was the partial skeleton It was nicknamed Ardi It was found crushed and fragmented but years of work have allowed researchers to interpret this 44 million year old individual Ardi has been sexed as female and contains several key portions including a skull a pelvis and almost complete hands and feet Ardi s brain size is estimated between 300 and 350 cm cubed This is quite small being no larger than a chimp s It is much like that of Sahelanthropus Ardi was the earliest hominin for which we have so many different parts of the body represented So it is easier to predict locomotion Height is estimated at 4 feet with body weight of 110 pounds Skeleton shows that it was a competent biped The ilium is short and broad and the foot has been modi ed to act as a prop for propulsion during walking But other parts of the pelvis show more ancestral hominoid characteristics IN fact Ardi probably walked quite adequately but might well have had difficulty running The foot is also divergent and perhaps capable of grasping Ardi was a hominin but it was a very primitive one 0 Australopiths 42 to 12 mya Australopiths are the most widely distributed and most diverse of the early African hominins This group is composed of Australopithecus and paranthropus These hominins have an established time range of over 3 million years stretching back as early as 42 mya and not becoming extinct until apparently close to 1 mya making them the longest enduring hominins yet documented They are found in Africa in places like South Africa Chad and East Africa There is a lot of evolutionary diversity There are two majors sub groups of australopiths an earlier one that is more anatomically primitive and a later one that is much more derived They dated 42 to 30 mya and show more primitive hominin characteristics than the later australopiths group whose members are more derived These more derived hominins lived after 25 mya and are composed of two different genera o All australopiths have 1 Clearly bipedal 2 Relatively small brains 3 Large teeth particularly back teeth with thick to very thick enamel on molars Earliest australopiths come from East Africa and Kenya Postcranial pieces show that it is bipedal Sectorial lower rst premolar shows that it has primitive trait The later member of australopiths is Australopithecus anamensis researchers say it may be potential ancestor for many later australopiths as well as perhaps early members of genus Homo 09 Australopithecus Afarensis Australopithecus Afarensis was discovered at Hadar Ethiopia in 1974 Laetoli Tanzania footprints were rst found in 1978 Footprints found can let us make de nite statement about the locomotor pattern and stature of early hominins So they were bipedal But some researchers say it is different bipedal than what modern humans are They said that Australopithecus Afarensis moved slower in a strolling fashion with a rather short stride One extraordinary discovery in Hadar was Lucy skeleton founded eroding out of a hillside by Don Johanson This fossil is designated as Afar Locality AL 2881 It represents almost 40 percent of the skeleton Accurate dating has provided dates of 37 to 35 mya A Afarensis is more primitive than any of the other later australopiths fossils from South or East Africa Their teeth is more primitive and lowest rst premolar is semi sectorial and tooth rows are parallel even converging somewhat toward the back of the mouth Cranial portions also show primitive characteristics like the crest in the back as well as several in cranial base Cranial capacity estimates for A afarensis show a mixed pattern compared to later hominins A Afarensis had a small brain probably averaging not much more than 420 cm cubed as a species Lucy was estimated to be about 3 to 4 feet tall She was probably also female and the species is said to be sexually dimorphic The most complete A Afarensis juvenile discovered at Dikika locale in northeastern Ethiopia It is the rst example of an immature hominin prior to about 100000 year ago Because of her wellpreserved teeth scientists say she was a woman She was capable of climbing trees and had a mixed locomotion The limb proportions anatomy of hands and feet and shape of scapula reveal a mixed locomotion The foot and lower limb indicate that she may have been a terrestrial biped The second skeleton comes from Woranso Mille research area in the central Afar The dating places the nd at close to 36 mya This was almost 400000 years older than Lucy This individual was much larger than Lucy and likely was male This individual was a habitual biped and obligate biped Australopithecus afarensis is a crucial hominin group Since it comes from the earliest poorly known group of preaustralopiths hominins but prior to all later australopiths as well as Homo it is an evolutionary bridge linking together much of what we assume are the major patters of early hominin evolution A Afarensis is a potential candidate as the ancestor of all later hominins A Contemporaneous and Very different kind of Hominin ln central Afar Ethiopia a partial foot was uncovered and was dated to about 34 mya The partial foot remains however include several nicely preserved toe bones and are very different from those of A afarensis and other obligate bipeds New nd shows a divergent opposable big toe and other ape like features that strongly suggest a good climber But other nds show that it was a biped This odd mix of characteristics looks most like that of Ardipithecus which lived a full million years earlier But one thing is for sure it is not Ardipithecus So there were two different lineages living side by side each with very different foot anatomy and varied forms of locomotion This hominin may have been partially bipedal Later More Derived Australopiths 3012 mya Following 30 mya hominins became more diverse in Africa In fact there were at least three separate lineages of hominins living between 20 and 12 mya One of these is a later form of Australopithecus another is represented by the highly derived three species that belong to the genus Paranthropus and the last consists of early members of genus Homo Paranthropus is the most derived It has even bigger toothed especially as seen in its huge premolars and molars They probably have powerful chewing due to their large deep jaws and large attachments for muscles associated with chewing Paranthropus face is atter than that of any other australopiths the broad cheekbones and a ridge develops on top of the skull this is a sagittal crest and its where the temporal muscle attaches Paranthropus was probably a rough vegetable eater But speci c chemical analysis of its teeth shows its diet could have been more varied The rst member of Paranthropus evolutionary group comes form a site in northern Kenya on west side of lake Turkana This key nd was called the Black skull It was black due to the chemical staining from manganese rich soil during fossilization lt s dated to about 25 mya The skull had cranial capacity of only 410 cm cubed and so it is among the smallest for any hominin known It has primitive features like that of A afarensis This includes a compound rest in the back of the skull and upper face projects considerably and upper dental row converges in back But there are some derived features that link it to Paranthropus species It has a broad face a very large palate and a large area for back teeth The black skull has been placed in the new species Paranthropus aethiopicus Around 2 mya different varieties of more derived Paranthropus were found It still had small cranial capacity ranging from 510 to 530 large broad face with massive back teeth and lowerjaws The larger maybe male individual also shows the characteristic raised ridge sagittal crest along the midline of the cranium Females are not as large or as robust which shows sexual dimorphism In any case Paranthropus are all very robust in terms of teeth and jaws but overall body size is similar to other australopiths From Olduvai and East Turkana this species has been named Paranthropus boisei What became of Paranthropus After 1 mya these hominins vanished No fossil nds of genus Australopithecus more recent than 3 mya have yet been found in East Africa But South Africa is another story The very rst early hominin discovery from Africa came from the Taung site and was discovered back in 1924 It was the skull of a 3 to 4 year old child Raymond Dart published his ndings of this This did not impress most experts since they believed that their larger brains and thought of Africa as an unlikely place for origins of hominins would easily identify our earliest ancestors The quotTaung Childquot and other A africanus individuals were small brained with a cranial capacity about 440 cm cubed The Taung child is remarkable in that it has a natural endocast It is a solid impression of the inside of the skull vault often preserving details relating to the size and surface features of the brain lts brain development was in line with that of other hominins It had big teeth relative to later hominins but not as big as Paranthropus It was a welladapted biped too It may have existed in 33 mya but most recent analysis approximately between 3 and 2 mya New connections Transitional Australopiths Since the earliest Homo was found in East Africa researchers assumed that Homo probably rst evolved in this region of Africa However new and wellpreserved fossil discoveries in South Africa may challenge this view In 2008 paleoanthropologists discovered two partial skeletons at the Malapa Cave located just a few miles form Sterkfontein and Swartkrans Lead researcher s 9yearold son Mathew while walking the family dog made the rst nd The researcher is Lee Burger The fossils are dated to just a little less than 2 mya and show a mix of australopiths characteristics along with some features more suggestive of Homo These fossils were named Australopithecus sediba It has australopiths characteristics such as small brain shoulder joint like australopiths long arms with curved ngers and several primitive traits in the feet It most resembles A africanus It also resembles Homo lts short ngers and possible indications of brain reorganization resemble homo What s more dental evidences show that A sediba had a surprising diet at least one that is unusual for a hominin Using an array of methods including stable carbon isotopes phytoliths residues in dental calculus and dental microwear Amanda Henry and colleagues have analyzed teeth from both skeletons thus far excavated at Malapa Their results indicate that A sediba are leaves fruit wood and bark along with grasses Its diet closely resembles that of a chimp The closest early hominin similarity is with Ardipithecus Closer Connections Early Homo 20 to 14 mya The earliest appearance of genus Homo in East Africa may date prior to 2 mya A discovery in 1990 s from Hadar area of Ethiopia suggested to many paleoanthropologists that early Homo was present in East Africa by 23 mya But the nd is incomplete Better preserved evidence of Plio Pleistocene hominin with a signi cantly large brain than seen in australopiths were rst suggested by Louis Leaky in early 19905 on the basis of fragmentary remains found in Olduvai Gorge Leakey gave a new species designation to fossil found naming them Homo habilis The species comprises particularly those early fossils from Olduvai and the Turkana basin The ones in Olduvai dates back to 18 mya Because of fragmentary nature of fossil remains evolutionary interpretations have been dif cult The estimated cranial capacity is 631 cm cubed So it has a larger brain size than any australopiths or Paranthropus Homo habilis means handy man and was meaning from two perspectives Leakey argued that members of the group were the early Olduvai toolmakers Second by calling them Homo Leakey was arguing for at least two separate branches of hominin evolution in Plio Pleistocene Only one could be on the main branch eventually leading to Homo sapens Because evidence was so fragmentary most paleoanthropologists were reluctant to accept H habilis as a valid species distinct from all australopiths Later discoveries like that found from lake Turkana of better preserved fossils have shed further light on early homo in Plio Pleistocene The most important of this was a nearly complete cranium and it had a cranial capacity of 775 cm cubed It is well outside the known range for australopiths and actually overlaps the lower boundary for later species of homo The face is quite robust and fragments of tooth crowns indicate that the back teeth were very large The East Turkana early homo material is contemporeous with the Olduvai remains The oldest date back to about 18 mya but another specimen found a few years ago dates to as recently as 144 mya making it by far the latest surviving early Homo fossil yet found So this discovery indicates that a species of early Homo coexisted in East Africa for several hundred thousand years with H erectus with both species living in the exact same area on east side of lake Turkana Fossils in South Africa are considered more distinctive of Homo than is transitional australopiths A Sediba At both Sterkfontein and Swartkrans fragmentary remains have been recognized as most likely belonging to Homo camhumus Interpretations What does it all mean Without fossils our speculations would be largely hollow and most certainly not scienti cally testable The numbering of specimens is an effort to keep the designations neutral and to make reference to each individual fossil as clear as possible From the time that fossil sites are rst located until eventual interpretation of hominin evolutionary patterns several steps take place Ideally they should follow logical order Here is a reasonable sequence Selecting and surveying sites Excavating sites and recovering fossil hominins Designating individual nds with specimen numbers Cleaning preparing studying and describing fossils Comparing with other fossil material Comparing fossil variation with known ranges of variation in closely related groups of living primates and analyzing ancestral and derived characteristics Assigning taxonomic names to fossil material Chapter 11 First Disbersal of Genus homo homo erectus and contemporaries Our most distant hominin ancestors were essentially homebodies staying in fairly restricted areas exploiting local resources and trying to stay out of harm s way One this is certain however All these early hominins were restricted to Africa When did hominins leave Africa What were they like As close to 2 mya hominins expanded widely out of Africa into other areas of the Old World The later more widely dispersed hominins were quite different both anatomically and behaviorally from their African ancestors They were much larger in body size more committed to a completely terrestrial habitat used more elaborate stone tools and probably supplemented their diet with meat There is some variation among different geographical groups of highly successful hominins The hominins that left Africa are de nitely Homo species The early Homo species for which we have the most evidence is called Homo erectus A new Kind of hominin In the last few decades discoveries from East Africa of rmly dated fossils have established the clear presence of homo erectus by 17 mya and even earlier in southeastern Europe Some researchers see anatomical differences between these African representatives of an erectus like hominin and their Asian cousins Thus they place the African fossils into a separate species one they called Homo ergasten H Erectus is different than African predecessors due to its increase in body size and robusticity changes in limb proportions and greater encephalization This all indicates that these hominins were more like modern humans in their adaptive pattern than their African ancestors The Morphology of Homo erectus Homo erectus lived in very different environments over much of the Old World They all however shared several common physical traits Body size Some H erectus adults weighed about 100 pounds and averaged a height of about 5 ft 6 They were sexually dimorphic Increased height and weight associated with a dramatic increase in robusticity Brain size The most obvious feature that Homo erectus differs from both early Homo and Homo sapiens is the cranial size Early Homo had a cranial capacity of as small as 500 cm cubed to as large as 800 cm cubed H Erectus has a large cranial capacity of about 700 to 1250 Brain size is linked to body size and H erectus was considerably larger compared to early Homo individuals Relative brain size is about the same H Erectus is less encephalized than later members of the genus Homo Cranial shape Homo erectus crania display a highly distinctive shape partly because of increased brain size but probably more correlated with increased body size The rami cations of this heavily built cranium are re ected in thick cranial bone large brow ridges above the eyes and a projecting nuchal torus at the back of the skull Nuchal torus is a projection of bone of the cranium where neck muscles attach The braincase is long and low receding from the large brow ridges with little forehead development Also the cranium is wider at the base compared with earlier and alters species of genus Homo The maximum cranial breadth is below the ear opening giving the cranium a pentagonal shape In contrast the skulls of early homo and H sapiens have more vertical sides and the maximum width is above the ear openings Most specimens also have a sagittal keel running along the midline of the skull The rst Homo erectus Homo erectus from Africa The earliest of the East African H erectus fossils come from East Turkana form the same area where earlier australopiths and early Homo fossils have been found The most signi cant Homo erectus is a nearly complete skull from East Turkana It is the oldest known member of this species from Africa It has a cranial capacity of 848 cm cubed A second nd from East Turkana has the smallest cranium of any H erectus specimen in Africa Dated to around 15 mya the skull has a cranial capacity of only 691 cm cubed Some crania from South Eastern Europe are even smaller Small skull from East Turkana also shows more Gracile features such as smaller brow ridges than other East African H erectus individuals A remarkable study by Kamoya Kimeu a member of Leakey s team discovered a small piece of skull on west side of Lake Turkana at a site known as Nariokotome Excavations produced the most complete H erectus skeleton found Known properly as WT 15000 the almost complete skeleton includes facial bones a pelvis and most of the limb bones ribs and vertebrae The skeleton is that of an adolescent about 8 years of age with an estimate height of about 5 ft 3 inches The post cranial bones look very similar though not identical to those of modern humans Cranial capacity of WT 15000 is estimated at 880 cm cubed A nearly complete female H erectus pelvis comes from the Gona area in Ethiopia and dates to about 13 mya The pelvis has a very wide birth canal It is possible that the newborn could have had a brain that was as large as what s typical for modern human babies These factors indicate a modern compromise between the demands of obligate bipedalism and that of birthing large brained infants So this evidence shows that H erectus prenatal brain growth was more like that of later humans However H erectus brain is more rapid than that of modern humans The Gona female was also primitive due to her unusual small body size Who were the Earliest African Emigrants The hominins who migrated to Asia and Europe descended from earlier African ancestors Also these travelers look like Homo with longer limbs and bigger brains H Erectus were probably the rst to leave the continent Current evidence shows H erectus in East Africa about 17 mya while similar hominins were living in the Caucasus region of southeast Europe a bit earlier than 18 mya The site of Dmanisi in the republic of Georgia has produced several individuals The age of the site is about 181 mya Dmanisi crania are similar to those of H erectus since it has long low braincase wide base and sagittal keeling However other characteristics make it different It has a less robust and thinner brow ridge a projecting lower face and relatively large upper canine lts cranial capacity is about 600 cm cubed so it is small The most remarkable nd in Dmanisi is the skull of an older adult male He died with only one tooth remaining in his jaws Researchers also found stone tools in Dmanisi The tools are similar to the Oldowan industry from Africa as would be expected for a site dated earlier than the beginning of the Acheulian industry Dmanisi hominins are thought to be H erectus although an early and quite different variety from that found almost anywhere else Evidence shows that the rst hominins to leave Africa were smallbodied very early form of H erectus and carrying with them a typical African Oldowan stone tool culture Homo erectus from Indonesia Dutch anatomist Eugene Dubois discovered a fossil a skullcap along the Solo River near the town of Trinil that would be recognized as the rst recognized human ancestor The following year a human femur was found about 15 yards upstream Many other parts were collected and all seemed to belong to this one individual It is generally accepted that most of the fossils belong to the early to middle Pleistocene and are between 16 and 1 million years old The island ofJava yielded many new hominin fossHs A late surviving hominin in Java managed to survive until less than 100000 years ago These fossils from Ngandong site are by far the most recent group of H erectus fossils from java or anywhere else At Ngandong an excavation along an ancient river terrace produced 11 mostly complete hominin skulls These individuals could be contemporary H sapiens Homo erectus from China Scientists eventually located one of the sources of these bones near Beijing at a site called Zoukoudian In 1929 a fossil skull was discovered The skull turned out to be a juvenile s and although it was thick low and relatively small there was no doubt that it belonged to an early hominin Zhoukoudian Homo Erectus The Homo erectus material found in Zhoukoudian are by far the largest collected of H erectus material found anywhere This excellent sample includes 14 skullcaps other cranial pieces and more than 100 isolated teeth but only a scattering of postcranial elements The hominin remains from China belong to upward of 40 adults and children and together provide a good overall picture of Chinese H erectus They have typical H erectus features including a large brow ridge and nuchal torus Also the skull has thick bones a sagittal keel and a protruding face and is broadest near the bottom Zhoukoudian was previously dated to about 500000 ya a relatively new radiometric dating technique that measures isotopes of aluminum and beryllium shows that Zhoukoudian is actually considerably older with a dating estimate of about 780000 ya O 90 I m Cultural Remains from Zhoukoudian The earliest tools are generally crude and shapeless but they become more re ned over time Common tools at the site are cores perhaps used as choppers but more importantly retouched akes were fashioned into scrapers points burins and awls The way of life at Zhoukoudian has traditionally been described as that of huntergatherers who killed deer horses and other animals Fragments of charred ostrich eggshells and abundant deposits of hackberry seeds unearthed in the cave seemed to suggest that these hominins supplemented their diet of meat by gathering herbs wild fruit tubers and eggs Layers of what appeared to be ash in the cave were interpreted as indicating the use of re in H erectus By comparing types of bones as well as the damage to the bones with that seen in contemporary carnivore dens Boaz and Ciochon have suggested that much of the material in the cave likely accumulated through the activities of extinct giant hyenas In fact they hypothesize that the H erectus remains are the leftovers of hyena meals There is evidence of re use in the caves H Erectus deliberately used re By providing warmth a means of cooking light to further modify tools and protection controlled re would have been a giant technological innovation Other Chinese Sites There are other paleoanthropological sites worth mentioning Three of the more important regions outside of Zhoukoudian are Lantian County Yunxian County and several discoveries in Hexian County Dated to 115 mya Lantian is older than Zhoukoudian The cranial remains of two adult H erectus females have been found at Lantian sites Two badly distorted crania were discovered in Yunxian County Due to extensive distortion of the crania from ground pressure it was very dif cult to compare these crania with other H erectus fossils The Herectus inhabitants are thought to have had limited hunting capabilities since they appear to have been restricted to the most vulnerable prey namely the young and old animals Asian and African Homo erectus A comparison The Homo erectus remains from East Africa show several differences from the Javanese and Chinese fossils Some African cranial specimens particularly ER 3733 presumably a female and WT 15000 presumably a male aren t as strongly buttressed at the brow ridge and nuchal torus and their cranial bones aren t as thick Technological Trends During Homo erectus Times O H erectus started out using Oldowan tools which the H erectus emigrants took with them to Dmanisi Java and Spain Newer industry was invented after these early African emigrants left their original homeland for other pats of the Old World This new tool kit is called the Acheulian The important change in the kit was a core worked on both sides called a biface known widely as a hand axe When Acheulian too users found a good piece of stone they would often take it with them as they traveled from one place to another This behavior suggested foresight For many years scientists felt like there was a cultural divide separating the Old World with the Acheulian technology found only in Africa the middle east and parts of Europe where the Acheulian was absent Cultural traditions relating to stone tool technology were largely equivalent over the full geographical range of H erectus and its contemporaries Evidence of butchering is widespread in Homo erectus sites But carnivore teeth marks on bone suggest that perhaps hominins were scavenging meat from animals killed by carnivores Seeing the Connections Interpretations of Homo erectus H Erectus had greater limb length and thus more efficient bipedalism and had a cranial capacity approaching the range of H sapiens became a more efficient scavenger and exploited a wider range of nutrients including meat H Erectus transformed hominin evolution to human evolution Chapter 12 Premodern Humans Many people have misconceptions about Neanderthals The fact is that their brains are larger than ours and they showed many sophisticated cultural capabilities They stood fully erect and their predecessors could easily be called human When where and what Most of the hominins discussed in this chapter lived during the idle Pleistocene a period beginning 780000 ya and ending 125000 ya Some of the later premodern humans especially the Neanderthals ived well into the late Pleistocene 125000 to 10000 ya The Pleistocene It is called the Ice Age It had gaciations and temperatures dropped dramatically Many advances and retreats of ice characterized Pleistocene Hominins living at the time all still restricted to the old world were severely affected Still the climate aso uctuated in the south During gacia periods climate in Africa became more arid while during ntergacias rainfall increased In Eurasia gacia advances made some places uninhabitable O 90 0 Dispersal of Middle Pleistocene Hominins Europe became more and more permanently and densely occupied with evidence of Middle Pleistocene hominins from England France Spain Germany Italy Hungary and Greece Africa continued as a central area of hominin occupation The middle Pleistocene premodern humans didn t vastly extend the geographical range of Homo erectus but rather largely replaced the earlier hominins in previously exploited habitats Middle Pleistocene Hominins Terminology Premodern humans of the middle Pleistocene generally succeeded H erectus Still in some areas especially in Southeast Asia there apparently was a long period of coexistence lasting 300000 years or longer you ll recall the very late dates for the Javanese Ngandong H erectus Earliest pre modern humans had several H erectus characteristics They had the large face brows were projected forehead is low and in some cases the cranial vault is still thick Compared with H erectus the premodern humans had an increased brain size a more rounded braincase a more vertical nose and a less angled back of the skull Time span encompassed by Middle Pleistocene premodern humans is at least 500000 years It has been widely debated on how to classify premodern humans Beginning perhaps as early as 850000 ya and extending to about 200000 ya the fossils form Africa and Europe is placed within Homo heidelbergensis named after a fossil found in Germany in 1907 H Heidelbergensis was a transitional group between H erectus and H sapiens These species may be both ancestors to modern humans and Neanderthals Premodern Humans of the Middle Pleistocene Africa In Africa premodern fossils have been found at several sites One of the best known is Kabew in Zambia Fieldworkers discovered a complete cranium with cranial and postcranial elements Skull s massive brow ridge low cranial vault and prominent occipital torus recall those of H erectus But occipital region is less angulated cranial vault bones are thinner and cranial base is essentially modern Bodo is another signi cant African premodern fossil It is one of the oldest specimens of H heidelbergensis from Ethiopia Europe The Gran Dolina hominins may simply represent the earliest H heidelbergensis possibly dating as early as 850000 ya This was in Spain Hominins from Sima de los Huesos are interesting These nds come from another cave in the same area as the Gran Dolina but are younger A total of 28 individuals were found in the quotPit of bonesquot It contains more than 80 percent of all hominins found in Middle Pleistocene Asia Chinese paleoanthropologists suggest that the more ancestral traits such as sagittal ridge and attened nasal bones are shared with H erectus fossils from Zhoukoudian They also point that some of these features can be found in H Sapiens in China Dali the most complete skull of later middle or early late Pleistocene fossils in China displays H erectus and H sapiens traits with a cranial capacity of 1120 cm cubed A partial skeleton was found from Jinniushan in northeast China It is said that these remains may be early H sapiens A Review of Middle Pleistocene Evolution In Africa H heidelbergensis evolved into modern h sapiens In Europe H heidelbergensis evolved into Neanderthals Middle Pleistocene Culture The Acheulian technology of H erectus carried over into Middle Pleistocene with relatively little change until near the end of the period Bone a high quality tool material remained unused during this time Stone ake tools persisted Some of the late premodern humans in Africa and Europe invented a method Levallois technique It required several complex and coordinated steps lt suggested increased cognitive abilities There is also evidence that humans controlled re There was little evidence of hunting but wood spears were discovered in 1995 The premodern humans also built temporary structures and exploited many different food sources Neanderthals Premodern Humans of the Late Pleistocene Neanderthals are mis ts They are like us and yet different Neanderthal fossil remains have been found at dates approaching 130000 Neanderthal fossils have been found in Western Europe but others were found in eastern Europe and western Asia Neanderthals tend to be robust but those living in less cold areas than Western Europe usually are not as robust One striking feature of Neanderthals is brain size which was actually larger than that of H sapiens today The average for contemporary H sapiens is between 1300 to 1400 cm cubed while for Neanderthals it was 1520 cm cubed The larger size might have something to do with the metabolic ef ciency of a larger brain in cold weather Classic Neanderthal cranium is large long low and bulging at the sides Occipital is somewhat bun shaped but marked occipital angle typical of many H erectus crania is absent The forehead rises more vertically that that of H erectus and brow ridges arch over the orbits instead of forming a straight bar Western Europe One of the most important Neanderthal discoveries was made in 1908 at La Chapelleaux Saints in southwestern France A nearly complete skeleton was found buried in a shallow grace in a exed position bent orientation with arms and legs drawn up to the chest The skull of the man who was about 40 years old was very large with a cranial capacity of 1620 cm cubed The cranial vault is low and long the brow ridges are immense with the typical Neanderthal arched shape Forehead is low and retreating and face is long and projecting Back of skull is protuberant and bun shaped La Chapelle skeleton wasn t a typical Neanderthal He had arthritis of the spine and was unusually robust New evidence from El Sidron site dated to about 49000 ya There were fragmented remains of 12 individuals show bone changes indicating that they are smashed butchered and likely cannibalized presumably by other Neanderthals They may have been a part of the same social group Their ages and sex support this interpretation 3 adult males three adult females give children and one infant Neanderthals may have practiced a patrilocal form of mating At St Cesaire Neanderthals remains were recovered from an archaeological level that also included discarded chipped blades hand axes and other stone tools of an Upper Paleolithic tool industry associated with Neanderthals Central Europe Neanderthal fossils from Vindija consist of some 35 specimens dated to between 4232 thousand ya making them some of the most recent Neanderthals It is possible that Neanderthals and modern H Sapiens were living quite close to each other for several thousand years Evidence form a number of French sites indicates that Neanderthals borrowed technological methods and tools from anatomically modern populations and thereby modi ed their own tools creating a new industry the Chatelperronian Western Asia Neanderthal specimens from Israel are less robustly built than classic Neanderthals of Europe One of the best known of these discoveries is from Tabun There a female skeleton dated by Thermoluminescence at about 120110 thousand ya A more recent Neanderthal burial of a large male comes form Kebara a neighboring cave at Mt Carmel V o 9 A most remarkable site is Shanidar Cave in northeastern Iraq This fossil was nicknamed Nandi and was severely damaged It had a crushing blow to the left side of the head fracturing the eye socket and other injuries Central Asia Neanderthals extended their range even farther to the east far into central Asia A discovery made in 19305 at site of TeshikTash in Uzbekistan of a Neanderthal child associated with tools of the Mousterian industry suggested that this species had dispersed a long way into Asia DNA analysis of the TeshikTash remains show that they are clearly Neanderthal What has been proven by mtDNA is that Neanderthals and humans differ in both mtDNA and nuclear DNA this is important in determining the evolutionary status of the Neanderthal lineage Moreover in the case of the fragmentary remains from Southern Sibera it was the DNA ndings that provided the key evidence determine whether the hominin is even a Neanderthal Surprising Connections Another contemporary Hominin In 2000 2008 and 2010 researchers found more fragmentary hominin remains in another cave Denisova Cave in Altai Mountains of southern Siberia Only a nger bone and two teeth were found and dated to as old as 80000 to 60000 ya The nger bone was sent to be analyzed and turns out that the mtDNA of this specimen did not match either a modern H Sapiens or a Neanderthal Turns out the Denisovians were a separate branch of hominins living side by side in central Asia with two other lineages Neanderthals and H Sapiens Culture of Neanderthals Anthropologists almost always associate Neanderthals with the Mousterian industry even though it isn t restricted to just Neanderthals it can include H sapiens Technology There is no evidence that they used bone tools There is indication that they developed specialized tools for skinning and preparing meat hunting wood working and hafting They were advanced in exploiting new food resources as well as fashioning personal adornments Subsistence Neanderthals were successful hunters but may not have been as successful as Upper Paleolithic modern humans It wasn t until the beginning of Upper Paleolithic that the atl atl or spear thrower came into use Bow and arrow was used after that It increased ef ciency and safety since game could be hunted while putting distance between the hunter and the game Being o 9 o 9 9 too close to the prey increased risk for Neanderthals to get hurt hunting Thomas Berger analyzed the pattern of trauma Neanderthals may have eaten marine animals a subsistence strategy They would gather shell sh and hunted seals and dolphins Their hunting behavior was much like H sapiens Speech and Symbolic behavior Some researchers argue that Neanderthals were incapable of human speech the prevailing consensus has been that they were capable of articulate speech and possibly capable of producing the same range of sounds as modern humans Research shows that Neanderthal brain is not signi cantly different from that of H sapiens The positioning of Neanderthal vocal tract has not seriously limited them Neanderthals sometimes used pigment and wore jewelry Two sites in Spain dating to 50 to 37 thousand ya was signi cant and had Mousterian stone tool industry These sites were occupied before H sapiens reached this part of Europe Objects found could ve been made by Neanderthals The nds include perforated shells ostensibly drilled to be used as jewelry Neanderthals and modern humans coexisted in some parts of Europe for up to 15000 years so Neanderthals didn t vanish suddenly We don t know what caused their disappearance after 30000 ya Burials Anthropologists know that Neanderthals deliberately bury their dead Evidence in Sima de los Huesos in Spain shows that there is some form of human activity involving deliberate disposal of the dead The recent dating of Sima de Los Huesos is more than 400000 ya This suggests that Neanderthal precursors were already handling their dead in special ways during Middle Pleistocene Later context shows that modern humans had more complex burial treatments In these later Neanderthal sites grave goods including bone and stone tools as well as animal bones are found more consistently in greater concentrations In many cases the body position was put in a exed posture This exed position has been found in 16 of 20 bestdocumented Neanderthal burial contexts Molecular Connections The Genetic Evidence Major advances in molecular biology have allowed much more of the Neanderthal genetic pattern to be determined with the ability to now sequence the entire mtDNA sequence in many individuals The most exciting breakthrough was with the completion of entire nuclear genome of European Neanderthals Findings show that Neanderthal DNA is very similar to modern Human DNA with 9984 percent of it being identical Research O O 0 shows that many people today have Neanderthal DNA These Neanderthal genes are found only in nonAfricans strongly suggesting that interbreeding did occur between Neanderthals and Homo sapiens The best hypothesis is that shortly after modern H sapiens migrants left Africa a few of them interbred with Neanderthals before these people and their descendants dispersed to other areas of the world lntermixing may have occurred in the Middle East between 80 to 50 thousand ya Denisovians are related to just some populations of modern humans sharing about 45 percent of genes with people from Melanesia Seeing Close Human connections Understanding Premodern Humans No one doubts that hominins like H heidelbergensis and H neanderthalensis are closely related to each other as well as to modern humans Everyone agrees that only some of the fossil samples represent populations that left descendants Where paleoanthropologists disagree is when they start discussing which hominins are the most likely to be closely related to later hominins The grouping of hominins into clades and assignment of different names to them is also open to disagreement Neanderthals are closely related to H sapiens They are also physically and behaviorally somewhat distinct from both ancient and modern humans They are not a fully separate biological species from modern humans and therefore theoretically capable of interbreeding with modern people We can view Neanderthals as a distinctive side branch of later hominin evolution The much less wellknown Denisovians from Siberia also likely represent another partially distinct incipient species separate from Neanderthals and early modern humans Modern humans turned out to be more successful and outcompete both Neanderthals and Denisovians We will focus on the story of modern Homo sapiens on the next chapter Chapter 13 The origin and Dispersal of Modern humans At some point 200000 ya the rst modern Homo sapiens populations appeared in Africa Within 150000 years or so their descendants had spread across most of the Old World even expanding as far as Australia lN this chapter we will discuss the dispersal of modern H sapiens African populations of H heidelbergensis are the most likely ancestors of the earliest modern H sapiens IE Approaches to Understanding Modern Human origins In attempting to organize and explain modern human origins paleoanthropologists have proposed a few major hypotheses that can be summarized into two contrasting views the multiregional continuity model and various versions of replacement model The Regional Continuity Model Multiregional Evolution Multiregional continuity model is most closely associated with paleoanthropologist Milford Wolpoff of the University of Michigan and his associates A question that needs to be answered is how could anatomically modern humans arise separately in different continents and end up so much alike both physically and genetically The multiregional model explains by 1 denying that earliest modern H sapiens originated exclusively from Africa 2 Asserting that signi cant levels of gene ow between many geographically dispersed premodern populations were extremely likely through the Pleistocene So under this model there are no taxonomic distinctions between modern and premodern hominins That is all hominins following Homo erectus are classi ed as Homo sapiens But over time this model is questioned and its validity is also questionable Replacement Model Replacement models all emphasize that modern humans rst evolved in Africa and only later dispersed to other parts of the world where they replaced those hominins already living in these other regions Two versions of replacement have been proposed The rst is complete replacement anatomically modern populations arose in Africa and then migrated from Africa completely replacing populations in Europe and Asia This mode does not account for a transition from premodern forms to modern H sapiens anywhere in the world except Africa Stringer and Andrews original hypothesis argued that anatomically modern humans appeared as a the result of a biological special event So migrating African modern H sapiens could not have interbred with local nonAfrican populations producing fertile offspring Partial replacement model Research shows that Europeans and Asian had Neanderthal DNA The most likely scenario suggests that the intermixing occurred around 80000 to 50000 ya quite possibly in the Middle East and only later in Europe and then Asia The hair of a man in Australia was tested and it was revealed that he had Denisovan genes and that Aboriginal populations diverged from other groups 7562 thousand years ago Earliest discoveries of Modern Humans Africa In Africa several early fossils have been interpreted as fully anatomically modern forms The earliest of these specimens comes from Omo Kibish in southernmost Ethiopia This is the earliest modern human Omo 1 it originated 195000 ya It is essentially modern Omo 2 has a less modern cranium since it is more robust Somewhat later modern human fossils come from the Klasies River Mouth on the South coast of Africa and from Border Cave He o Tim White and his colleagues of UC Berkeley worked for three decades in Middle Awash area of Ethiopia They have discovered a remarkable array of early fossil hominins as well as somewhat later h erectus From this same area in the middle Awash further highly signi cant discoveries came to light in 1997 These hominins are referred to as Herto remains Herto fossils include a mostly complete adult cranium a fairly complete child s cranium and few other cranial fragments First well controlled radiometric dating securely places the remains between 160000 and 154000 ya making these the best dated hominin fossils from this time period from anywhere in the world The date is clearly older than for any other equally modern H sapiens from anywhere else in the world The cranium of the adult is very large and has capacity of about 1450 cm cubed The skull is also in some respects heavily built with a large arching bro ridge in front and large projecting occipital protuberance in back The face does not project This new nd supports African origin of Homo sapiens The Near East In Israel in the Skul Cave at Mt Carmen researchers found early modern H sapiens including the remains of at least 10 individuals Asia Most signi cant discovery was Upper Cave at Zhoukoudian in Tianyuan Cave and Ordos The fossils from these Chinese sites are all fully modern and all are considered to be from the Late Pleistocene with dates probably later than 40000 ya In addition some researchers suggest that Jinniushan skeleton discussed hints at modern features in China as early as 200000 ya Finds at another cave called Tianyuan about four miles down the road from Zhoukoudian there was a fragmentary skull a few teeth and many postcranial bones The Chinese and American team proposes that there is an African origin of modern humans Niah skull is another example of a fossil found Western Europe Western Europe has yielded many anatomically modern human fossils but by far the bestknown sample is from the CroMagnon site a rock shelter in Southern France At this site the remains of 8 individuals were discovered in 1868 CroMagnon materials are associated with an Aurignacian tool assemblage an Upper Paleolithic industry Dated at about 28000 ya these individuals represent the earliest of France s modern humans The so called Old Man CroMagnon 1 became the original model for what was once termed the CroMagnon or Upper Paleolithic Skeleton of a young child in Portugal proved interbreeding of h sapiens and Neanderthals Abrigo do Lagar Velho Something new and different The quotLittle Peoplequot An extremely small bodied smallbrained hominin had been discovered in Liang Bua Cave on the island of Flores east ofJava It is dubbed the quotLittle lady of Floresquot or quot oquot They are also nicknamed hobbits LBl The female was barely 3 feet tall and her brain was about 417 cm cubed She had thick cranial bone and dentition Some researchers think this specimen is a human struck with a severe disorder Specimen is named H oreiensis Technology and Art in Upper Paleolithic Europe Cultural period known as the Upper Paleolithic began in Western Europe about 40000 ya Upper Paleolithic cultures are usually divided into ve different industries based on stone tool technologies Chatelperronian Aurignacian Gravettian Solutrean Magdalenian Many cultural innovations began with Neanderthals Far more elaborate burials were found most speci cally at the 24000 year old Sungir site near Moscow Grave goods included a bed of red ocher thousands of ivory beads long spears made of straightened mammoth tusks ivory engravings and jewelry Humans and other animals in most of Eurasia had to cope with shifts in climate conditions Homo sapiens had a major advantage in adapting since they had sophisticated technology and probably other components of culture as well Upper Paleolithic was a period of innovation Solutrean tools are good examples of Upper Paleolithic skill and as likely aesthetic appreciation as well In this lithic stone tradition skill in modifying rock called knapping developed to nest degree Specialized aking techniques were used Last stage of Upper Paleolithic is known as Magdalenian The spear thrower or Atl Atl was a hooked rod made of bone or wood that extended the hunter s arm enhancing the force and distance of a spear throw For catching salmon and other sh the barbed harpoon is a good example of skillful craftsmanship Burins were used for working bone wood and antler Western Europeans also created art There is an extremely wide geographical distribution of symbolic images Besides cave art there are many examples of sculptures excavated from sites in western central and eastern Europe The most famous of these are the female quotvenusesquot found at sites like Brassempouy in France and Grimaldi in Italy Such symbolism can be found in many parts of Europe and was already well established early in the Aurignacian by about 40000 ya Eight utes were found IN GeissenKloisterle Cave and this showed rst musicians making music is uniquely human trait New methods of mixing pigments and applying them were important in rendering painted or drawn images Africa Early accomplishments of art was found at Apollo 11 rock shelter site where painted slabs had been identi ed as dating to between 28000 to 26000 ya At Blombos Cave farther to the south remarkable bone tools beads and decorated ocher fragments are all dated to 73000 ya ln central Africa there was also considerable use of bone and antler some if it possibly quite early Humans are omnivorous due to weather They had to grind hard seeds or roots and had to domesticate both plants and animals
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