Description
Notes by: Anastasia Barbato 1
HBIO 200: The Human Animal
Midterm #1 Study Guide
I. Introduction to Biological Anthropology & Evolution
A. Types of Anthropology
1. Cultural, linguistic, archaeology, biological
B. The study of humans as a biological organism, considered in an evolutionary framework
C. Sub-disciplines
1. Paleoanthropology: study of human fossils
2. Bioarchaeology: studies the other plants and animals around a fossil site to study how humans interacted with that environment
3. Skeletal biology: human skeletal study (osteology) If you want to learn more check out What are the 7 schools of thought?
4. Paleopathology: ancient diseases
5. Forensic anthropology: applying these studies to investigations of human death (think of “Bones” the TV show)
6. Primatology: understanding how primate behaviors have evolved over time and how it relates to humans
7. Human biology: studying genetics and adaptation of humans based on certain factors
D. Biological Evolution
1. Genetic change in groups/populations of living things over generations 2. Microevolution
3. Forces of evolutionary change = mechanisms by which change occurs and is either maintained or eliminated
a) Ex: natural selection, genetic drift, mutation and recombination,
sexual selection, gene flow
4. Raw material + shaping force + TIME = evolution
5. Why do we study it?
a) General understanding of life We also discuss several other topics like in the short run, a purely competitive seller will shut down if
b) Practical applications (medicine, agriculture)
(1) Conservation efforts as well; population genetics
6. Evolution: the central, unifying theory of biology
II. Science & Evolution We also discuss several other topics like art appreciation fau
A. What is science?
1. Scientific Method: identify a research problem and follow steps:
Notes by: Anastasia Barbato 2
2. Process of studying the natural world
3. Hypothesis testing
4. Falsifiable = meaning the data can be refuted
5. Seeks natural explanations for observable phenomena; NEVER seeks to PROVE 6. Constantly changing
B. Ideas of Evolution in the US
1. Religion: specific religious groups in US and media insistence on giving science and religion equal clout in their arguments about evolution → US
one of the lowest ranked in belief in evolution in the world
2. Politics: Democrats and Independents tend to believe in evolution whereas Republicans tend not to Don't forget about the age old question of byu stat 201
3. Education: those w/higher education believe in evolution while the others tend not to; lack of understanding may also be more likely for rejection
a) Only 38% of adults NOW believe in Creationism; young adults today
less likely to identify w/one religion
b) Only 28% of public high school biology teachers introduce evidence
of evolution in their curricula
C. History of Evolution in Education
1. 1925: Scopes v. Tennessee - Butler Act stated one couldn’t teach evolution; Supreme Court found this unconstitutional Don't forget about the age old question of phy101
2. 1958: President Eisenhower - National Defense of Education Act stated science couldn’t be limited in schools If you want to learn more check out ucla ls7a midterm 1
3. 1970’s: “Creation Science” came about to be taught alongside evolution; Supreme Court overturned this
4. 1980’s: “Intelligent Design” created to circumvent the Supreme Court’s ruling, but it didn’t work
5. 2005: Selman v. Cobb County - disclaimers of evolution in textbooks found to be unconstitutional
D. Options for Religion and Science
1. Mutually exclusive
2. Non-overlapping magisteria (separate and NOT competing)
3. Complementary/can be joined
4. Religion is an adaptation
E. Origins of Evolutionary Thought
1. Ancient Greeks: first writings of the natural world
a) Anthropocentric view of the Universe
(1) Many obstacles in history that limited how we understood
evolution
b) Middle Ages: Fixity of Species (species are unchanging)
c) Aristotle: founder of Western natural history
(1) Believed in Fixity of Species; “The Great Chain of Being”
w/humans on top and plants and animals below (dominance
hierarchy); we were separate from them
Notes by: Anastasia Barbato 3
2. God’s Design/Grand Design (Judaism and Christianity)
a) Everything has a purpose; Earth is young (b. 4004 BC)
b) St. Augustine: first person to recognize species could change
3. Renaissance (~14-17th cent.)
a) Earth is very old; physicists - age of cosmos
b) Natural historians; heritable traits, micro-organisms discovered,
fossils and extinction, embryology
c) Copernicus and Galileo
4. Georges-Louis Leclerc (1707-1788)
a) Recognized adaptability of species when they went to different
geographical locations
5. John Ray (1627-1705)
a) Naturalist and minister; recognized organisms capable of
interbreeding
6. Carolus Linnaeus (1707-1778)
a) Father of taxonomy; included humans (homo sapiens)
b) God created; first to assign race
c) Kingdom, Phylum, Class, Order, Family, Genus, Species
7. Erasmus Darwin (1731-1802)
a) Physician, naturalist, philosopher, poet, inventor
b) Zoonomia (1794) discussed transformation of species and common
ancestors
c) No mechanism; discussed competition and deep time
8. Jean-Baptiste Lamarck (1744-1829)
a) Inheritance of acquired characteristics (heritable traits); within the
lifetime of the individual
b) Environment causes changes to species; however, not w/in the
lifetime of an individual
9. George Cuvier (1769-1832)
a) French naturalist and zoologist
b) Catastrophism: a way to explain (away) fossils by saying the
catastrophic events cause extinction; did it in a Biblical context
10. James Hutton (1726-1797)
a) Uniformitarianism: geologic processes constant across time
b) Charles Lyle expanded on these ideas and made the father of
geology (1797-1875)
11. Mary Anning (1799-1847)
a) Self-taught fossil collector; one of the leading intellectuals of her
time; found ichthyosaurs; anatomist
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III. Evolution by Natural Selection
A. Charles Darwin (1809-1882)
1. Traveled in intellectual circles that talked about evolution; fairly wealthy w/a family background in science (Erasmus Darwin = grandfather)
B. Alfred Russell Wallace (1823-1913)
1. Came up w/a theory of natural selection around the same time as Darwin (1858)
C. Darwin’s Discoveries
1. The Galapagos Islands
a) On certain islands were certain species that adapted to take
advantage of the environments of the islands (adaptive radiation)
2. On the Origin of Species by Means of Natural Selection (1859) - talked about both artificial and natural selection; farmers could relate to artificial
selection, so could understand natural selection
a) Talked about humans evolving this way, too
D. Darwin & Wallace Theory
1. Linnean Society of London in 1858
2. Natural Selection as a mechanism for evolutionary change (individual reproductive success)
3. Three requirements
a) Variation
b) Heritability of traits
c) Selection pressure(s)
E. Genetics
1. Genetic research approaches
a) cellular/molecular (basic structure and function)
b) classical/Mendelian (pedigree)
c) Population (populations of biological organisms vary w/in a species)
d) Phylogenetics (evolutionary relationships between species)
e) Behavioral (how genes affect behaviors)
2. Uses in BioAnth
a) Past, present, future
b) Mapping genomes (chimp & human = 98% genetically identical)
c) Polymerase chain reaction (PCR); getting DNA from fossils, hair,
saliva, etc.
d) Mitochondrial DNA (mtDNA); maternal and not recombined
3. DNA
a) Adenine, Thymine, Guanine, Cytosine
b) Primary function: replication, protein synthesis
c) DNA replicated → transcribed to mRNA → translated to encode a
product
4. Codons & Genes
a) Proteins made of polypeptides (chains of amino acids)
Notes by: Anastasia Barbato 5
b) Amino acid (created from codon, three bases)
5. Gene = fundamental unit of heredity
a) Sequence of DNA coding for a particular protein
b) Humans have ~25,000 genes (small % of DNA)
c) Specific location (locus) on a chromosome
6. Chromosomes
a) DNA & proteins; genes = 2 versions (allele)
b) Paired maternal & paternal; homozygous (same allele) and
heterozygous (different alleles)
c) Diploid vs. haploid (D = 23 pairs; H = sex cells)
7. Terminology
a) Genotype - genetic makeup (alleles)
b) Phenotype - visible characteristics under the influence of genotype
and the environment
c) Dominant vs. Recessive alleles, co-domination (differences in
proteins)
8. Gregor Mendel (1822-1884)
a) Figured out how genes work
b) Hybridization experiments w/garden pea plant
c) Bateson (1900’s)
(1) Found Mendel’s research and promoted it; coined genetics
and “Mendelism”
d) Mendelian traits
(1) Only one gene is affecting a trait
e) Hereditary Principles
(1) Particulate inheritance = heredity based on transmission of
genes
(2) Segregation = paired chromosomes will separate into sex
cells during meiosis
(3) Independent assortment = segregation of one pair doesn’t
influence separation of another pair
f) Punnett Square: illustrates mechanisms of Mendel’s theorem;
possible offspring combination proportions
9. Population Genetics
a) Gene pool & population; can predict next generation w/Punnett
Square
(1) Based on 60/40 ratio of dominant to recessive
b) Expected genotype frequencies
(1) Hardy-Weinberg Formula (p^2 (AA) + 2pq (Aa) + q^2 (aa))
(a) p^2 = homo. dominant, q^2 = homo. Recessive, pq =
heterozygous
(b) If: large population, random mating, random survival
of all types, no new allele introduction
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(c) Then: allele frequencies will not change over time and
equilibrium will be maintained
(2) Evolution disrupts the equilibrium of a population
c) Differences are significant
(1) Large population vs. genetic drift
(2) Random mating vs. non-random mating
(3) Random survival of all types vs. natural selection
(4) No new allele introduction vs. gene flow, mutation
IV. Evolutionary Mechanisms
A. Natural selection, non-random mating, genetic drift, gene flow
B. Deductive reasoning of Darwin & Wallace
1. 1st observation: # of offspring = population growth (exponential,
non-restricted)
2. 2nd observation: populations are stable; carrying capacity in environment limits exponential growth
3. Deduction 1: struggle for existence; intraspecific competition; population growth is restricted by an environmental pressure
4. 3rd observation: variation
5. Deduction 2: some variations survive while others don’t (selective factor) C. Natural selection requires: inherited traits, varied traits, & environmental pressure/selective force
D. In a population
1. Not all members will survive; diversity; some members do better than others
E. Natural selection VIOLATES the Hardy-Weinberg assumption of RANDOM SURVIVAL OF ALL INDIVIDUALS
F. Types of Natural Selection
1. Directional: a shift in the mean towards a certain trait one way or the other a) Variation stays the same
2. Stabilizing: selection against the extreme traits; more concentration around the mean
a) Decrease in genetic diversity
3. Disruptive: selection for the extreme traits; move away from the mean a) Could result in speciation
Notes by: Anastasia Barbato 7
G. Non-Random Mating
1. Mate selection based on:
a) Assortative (similarity)
b) Sexual selection (successful phenotypes)
(1) Can lead to sexual dimorphism
2. VIOLATES the H-W assumption of RANDOM MATING
H. Mutation & Recombination
1. Variation is a result of DNA; mutation gives new material to a population 2. VIOLATES the H-W assumption of NO NEW ALLELE INTRODUCTION
3. Mutation types
a) The dog ate the cat (normal sequence)
b) The dog ate the hat (point mutation)
c) The dod gat eth ecat (change length w/insertion and deletion)
d) The cat ate the dog (inversion)
e) The dog ate ate the cat (add/delete codons)
4. Causes of mutations
a) nothing/neutral (synonymous); gets fixed in population
b) Change amino acid (non-synonymous); provides selective advantage,
or is a disadvantage (corrected or die out)
c) Mutations are not always bad
(1) Blue eyes (mutation); humans, Japanese macaques, spider
monkeys, blue-eyed black lemur
(a) Convergent evolution: mutation occurred
independently in these lineages; not from a common
ancestor
I. Gene Flow & Genetic Drift
1. Gene flow: migration; movement of alleles from one location to another a) VIOLATES H-W assumption of ALLELE FREQUENCY/NON-TRANSFER
OF ALLELES
b) Effects: smaller to bigger might not make effect; vice versa could
work; diff alleles, depending on dominance, could make a change
2. Genetic drift: random chance event triggers allele change (environmental catastrophe) that wipes out majority of the population
a) VIOLATES H-W assumption of LARGE POPULATION
b) Effects:
(1) Founder Effect: small population created by a few chance
individuals who remain isolated and small
(2) Bottleneck: the leftover individuals flourish with only the
genetic makeup they were left with
(3) Both lead to a lack of genetic diversity
c) Genetic drift + non-random mating = Inbreeding Depression (increase
of deleterious homozygous recessive in population causes
mutations)
Notes by: Anastasia Barbato 8
3. These events can all occur simultaneously and at different periods of the population life cycle
V. Adaptations and Non-Adaptations
A. Adaptation
1. A trait that increases the fitness of its possessor
2. The evolutionary process that led to the development of a trait
3. Has a useful function and is molded by natural selection for that function a) Not all traits are adaptations
b) Not every adaptation is perfect
B. Traits Explained - Why else are they there?
1. Genetic drift - happenstance
2. Fixed mutation - a mutation occurs by doesn’t affect the fitness of an
organism
3. Sexual selection
4. Exaptations: traits not molded by natural selection at all but are a
by-product of another process
a) Ex: being right or left-handed is a by-product of the lateralization of
the brain; red blood is a by-product of chemistry
b) Functional Shift: traits molded by natural selection for a certain
purpose are used for a different purpose
5. Schools of Thought
a) Reductionism (Adaptationism) - every trait has a purpose
b) Holism - traits are also by-products and don’t necessarily have a
function
C. Sexual Selection
1. Goal: to reproduce offspring
a) Find mate; assess mate potential; mate; possibility of infertile
mating; carry and care for offspring (uses a lot of energy)
b) Why?
(1) Recombining genes → variety → stronger chance of survival
D. Non-Adaptive Traits Explained
1. The Descent of Man and Selection in Relation to Sex (Darwin) - people had problems with his ideas here; strong patriarchal society denied that the
females hold the mating power in nature
2. Sexual Selection: one sex chooses mates non-randomly based on particular traits; winners = increased reproductive fitness, differential fitness =
selection
a) Tungara frogs serenade the females; proboskis monkeys develop
large noses to attract females
b) Natural selection and sexual selection are constantly butting heads
c) Consequences: one sex is “choosy” (behaviors and senses for
detection of traits); other sex suffers from intrasexual competition
(combat, fertilization tactics, alternate strategies, infanticide)
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3. Competition
a) Sexual dimorphism - diffs between males and females of a species
(1) Coloration, size, anatomical features
b) Strong sexual selection - competition
c) Weak sexual selection - choosy, not much competition
E. Species
1. Group of interbreeding organisms (isolated by anatomy, ecology, behavior, geography)
2. Smallest evolutionary independent unit (EIU)
3. Classify diversity (differing criteria)
4. Challenge: fossil species
a) Difficult to look at individual variation
b) Age-related changes
c) Sex-related changes
d) Number of fossils
5. Species concepts
a) Biological (don’t mate in the wild)
b) Mate recognition (same fertilization system)
c) Morphological
d) Ecological
e) Phylogenetic (genetic differences)
6. Biological Species Concept (BSC)
a) Individuals capable of interbreeding & producing offspring but
reproductively isolated in individual groups
b) Confirms lack of gene flow; non-arbitrary classification
c) Some populations don’t come in contact in nature; fossil & asexual
species
7. Mate Recognition Concept (MRC)
a) Common fertilization system (behavior & morphology)
b) Not mutually exclusive from BSC
c) Asexual & fossil species can’t be determined
8. Morphological Species Concept (MSC)
a) Phenotype differences
b) Widely applicable (fossils & asexual species)
c) Arbitrary; fossil species don’t have coloration & tissue so left only
with bones to analyze; cryptic species (have diffs that we can’t detect
w/o tools); individual variation
9. Ecological Species Concept (ESC)
a) Two populations living in different ecologies
b) Bacteria and Archaea; antibiotic resistance, new temp, etc.
c) Mate successfully? Fossil species
10. Phylogenetic Species Concept (PSC)
a) Phylogeny: unique derived traits
Notes by: Anastasia Barbato 10
b) Phenotype, genotype, genes; populations isolated
c) Asexual & fossil species can be used; cryptic species
d) Phenotype = arbitrary; fossil species can only tell phenotype w/o
DNA; difficult to determine intra/inter-specific individual variation
11. Problems with these Concepts
a) Biological (asexual and fossil species can’t be analyzed)
b) Mate recognition (asexual and fossil)
c) Morphological (arbitrary, cryptic species, asexual and fossil species,
variation)
d) Ecological (fossils, might/might not matter)
e) Phylogenetic (sufficient samples, variation, fossils)
12. Which concepts to use?
a) Depends (species, questions, traits deemed important)
b) Most can use BSC & MRSC
c) The IUCN - preserve genetic diversity
(1) Chimps vs. Bonobos (diff species); ecologically separated by
the Congo River, and can’t breed with each other
(2) African Elephant, forest and savanna (same species);
morphologically and ecologically different, but are capable of
mating (in captivity)
VI. Speciation
A. Groups of interbreeding populations that are evolutionarily independent from one another
1. Key: isolation
a) Can occur physically; isolating mechanisms can evolve; both disrupt
gene flow
B. What keeps populations similar over generations?
1. same/similar environment (food sources, competitors, predators)
2. Same choice factors
3. Same natural and selective forces
4. Mutations are shared w/in and between populations (gene flow)
5. No directional/genetic drift (large population)
C. What causes divergence over generations?
1. Different natural and selective pressures
2. lack/reduction of gene flow (decreased migration, decreased dispersal) 3. Divergence = speciation
D. Speciation Steps
1. Isolate the population
2. Divergence of traits (mating, food, habitat, etc.)
3. Reproductive Isolation (secondary contact = no mating)
E. Isolation
1. Pre-zygotic/pre-mating: preventing mating from occurring; less costly (energy), more selectable; no hybrids
Notes by: Anastasia Barbato 11
a) Spatial (resource/habitat)
b) Temporal (mating periods, activity)
c) Mechanical (lock & key genitalia, size difference)
d) Behavioral (mating calls, nesting, etc.)
e) Gamete isolation (vaginal pH, sperm/egg compatibility)
2. Post-zygotic: preventing fertilization/viable offspring; more costly; hybrids (sterile, reduced fitness)
a) Different chromosome count (meiosis cannot occur)
b) Reduced hybrid fitness (lacking competing traits)
c) Hybrid sterility (lion/tiger)
F. Divergence
1. Driven by: ecology (natural selection, adaptive radiation), assortative
mating, and combination
G. Reproductive Isolation
1. Reinforcement &/or genetic incompatibility
2. Selection against hybrids
3. Secondary contact
a) Fertile: hybrid speciation in a NOVEL habitat
b) Hybrids occupy transitional habitats = Hybrid Zone
H. 3 Models of Speciation
1. Geographic relationship
2. Allopatric: physical barrier, separate habitats
a) 2 mechanisms
(1) Dispersal: part of population migrates
(2) Vicariance: geological feature divides population
b) Isolating mechanism? Pre-zygotic (spatial)
c) Dispersal
(1) Most dramatic on islands; small/isolated population sizes
create genetic drift
d) Vicariance
(1) Range splitting (climate, geology, human)
(2) Chimp & bonobo split (formation of Congo River separated
the two, leading to speciation)
3. Parapatric: no geographical separation, but living in habitats alongside each other
a) Mate recognition and selective breeding; may contain a hybrid zone
in the transitional space
b) Isolating mechanism? Pre-zygotic (spatial)
c) Hybrid Zone
(1) Genetic incompatibility w/the parent population
(2) Mate w/other hybrids
(3) Can sometimes mate w/parent population
(4) Ex: yellow and anubis baboons
Notes by: Anastasia Barbato 12
4. Sympatric: No geographic separation, same habitat
a) Disruptive selection likely
b) Isolating mechanism? Anything EXCEPT spatial w/regards to habitat
c) Mutations affecting development or behavior
d) Chromosomal mutations
e) Changes in mating behavior or feeding preferences
f) Assortative mating necessary (only pick specific traits)
g) Adaptive radiation
h) Ex: Apple maggot vs. Hawthorn fly
(1) Apple trees introduced; hawthorn flies used this new
resource; their mating patterns and feeding patterns changed
to match the blooming of apple blossoms (disruptive
selection)
(2) Incipient speciation = not a new species yet
I. Speciation - Macroevolutionary Perspective
1. Anagenesis: one species develops into another over time
2. Cladogenesis: one species splits into two species and increases diversity VII. Phylogeny and Macroevolution
A. Taxonomy: classification system of species
B. Traits
1. Ancestral (Plesiomorphic): inherited from ancestor
2. Derived (Synapomorphies): new traits from natural selection; distinguishes trait from related ancestral species; shared, derived traits indicate our
relationships at a specific level
3. Hominins
a) Ancestral traits (no tail, large body & brain, Y-5 molar)
b) Derived traits (bipedal, larger brain to body size ratio, shorter arms
than legs)
4. Types of traits
a) Analogous (homoplasy): traits shared due to similar function;
convergent evolution
b) Homologous: traits shared due to common ancestry; slowly over time
(1) Synapomorphies - shared derived versions of homologous
traits
c) Homoplasy mimics homology
(1) Need to know more about ancestry to determine if one or the
other; diff environments can determine
d) Reversal: Change in DNA back to ancestral sequence/loss of derived
structure
C. Distinguishing Concepts
1. Look at more than one trait
2. More than 1 gene/locus
3. Independent evidence of relationship
Notes by: Anastasia Barbato 13
4. Parsimony: fewest and simplest changes
a) Occam’s Razor: simpler answer is the right/better one when
approaching complex theories
b) May not always be correct, but usually is
5. Cladistics: diagram to show synapomorphies and common ancestry
6. Phylogeny: diagram that shows synapomorphies and genetics over time a) Molecular phylogenetic tree: # of differences per nucleotide in a
sequence; only informs about one DNA sequence, not species as a
whole
b) Only put living species at the end
D. Macroevolution
1. Large-scale evolutionary changes
2. Examines divergence of phyletic lines
a) Change or creation in genetic lineages over time
b) Loss of genetic lineages (extinction)
3. Simple lineage: an individual connected to its parents
a) Phylogeny → lineage/species → population
4. Cladogenesis, Anagenesis, Extinction
5. Major features
a) Punctuated equilibrium: no/little change over time punctuated by
short bursts of change; dramatic, causes formation of a new lineage
(Cladogenesis)
b) Gradualism: slow change over time; causes changes w/in a lineage
(Anagenesis)
c) Stasis: little/no change in a population over time
d) Ancestral species can co-occur w/the new species (genetic drift)
6. Evidence of Macroevolution
a) Fossils of extinct organisms
b) Paleontology: scientific study of fossils
c) Fossils: traces left by organisms; parts of an organism
(1) Give a lot of information about the organism
(2) Transition organisms: contain traits of both the ancestor and
the descendant (ex: archaeopteryx)
d) Patterns of extinctions
Notes by: Anastasia Barbato 14
(1) Mass extinctions: global scale; broad range of species; rapid in
evolutionary terms (~100,000 years)
(a) Typically caused by a catastrophic event (K-T
extinction w/the meteor that killed the dinosaurs)
(b) The largest - Permian-Triassic; 96% of all species on
Earth went extinct due to volcanic activity
(2) Background extinctions: normal rate; longer period of time;
rates vary among lineages; constant, but not related to the
age of the species
(3) Phanerozoic (last 540 my of Earth)
(a) Mass = 4%
(b) Background = 96%
(4) 6th mass extinction (human caused)
(a) 1,100 species extinct since the 1600s
(b) Introduction of hunting, invasive species, habitat loss
VIII. What Defines a Primate
A. Mammalian Evolution
1. Cenozoic - mammalian diversification caused by the K-T extinction event; mammals became the dominant terrestrial vertebrates
a) Behavioral flexibility; larger brains; mammary glands; live birth
(viviparity); pentidactyl; homeothermic (endothermic)
B. Primate Traits
1. Ancestral
a) generalized 4 limbs
b) Tail
c) Heterodont teeth
2. Derived
a) Grasping hands and feet (opposable thumb & big toe)
b) Nails
c) Decreased olfaction
d) Generalized teeth (diverse, omnivorous capabilities)
e) Erect posture (spine goes in at an angle)
f) Visual emphasis (enclosed eye w/postorbital bar/closure that faces
our eyes forward; binocular vision gives us stereoscopic vision,
which gives us depth perception and 3D viewing of objects; tri- or
di-chromatic vision)
g) Life history traits
(1) Extreme mammal
(2) Single birth, long lifespan, extended ontogeny
(developmental period)
(3) Brain development (brain:body ratio where brain is larger
than expected for body size)
(4) Highly social