BIO 3321 Week 2 Notes
BIO 3321 Week 2 Notes BIOL 3321
Popular in Evolution
verified elite notetaker
Popular in Biology
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
verified elite notetaker
This 12 page Class Notes was uploaded by Tiffany Schweda on Friday January 29, 2016. The Class Notes belongs to BIOL 3321 at University of Texas at El Paso taught by Dr. Carl S. Lieb in Spring 2016. Since its upload, it has received 37 views. For similar materials see Evolution in Biology at University of Texas at El Paso.
Reviews for BIO 3321 Week 2 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/29/16
Week 2 Lecture Notes Course: Biology 3321 Evolution Professor: Dr. Carl Lieb Meetings: Tuesday and Thursday Inheritance of characteristic o will have become almost completely rejected by the end of the 1800s o resurface in early 20 century in Stalinist Russia in the form of “Lysenkoism” o 21 century “epigenetics” will be studied Charles Darwin o 1809-1882, England o called the “Father of evolution” o was a naturalist who observed many species o wrote the book “The Origin of Species” o developed the theory of natural selection o Sailed to the Galapagos Islands on the ship, The Beagle, over the span of 1831- 1836 o Heavily influenced by Charles Lyell and English geologist o Upon returning to England he indulged in a long period of writing up information on the specimens that he had collected o Didn’t immediately publish his views on evolution however Darwin’s Theory of Evolution by Natural Selection 1. Variation exists among individuals in a species. 2. Individuals of species will compete for resources (food and space) 3. Some competition would lead to the death of some individuals while others would survive 4. Individuals that had advantageous variations are more likely to survive and reproduce. Alfred Wallace o 8 January 1823- 7 November 1913 o English naturalist in southeastern Asia o Sent a manuscript to Lyell asking for him to sponsor Wallace for publication in England o Finally, a young English naturalist in southeastern Asia named Alfred Wallace sends Lyell a manuscript asking him to sponsor it for publication in England o Manuscript reveals conclusions identical to what Darwin has been telling Lyell for years privately o Influenced by Charles Darwin, Charles Lyell, Thomas Robert Malthus and Henry Walter Bates o Remembered as the “Father of Biogeography” Wallace and Darwin jointly present a paper on evolution to the Linnaean Society of London in 1858 Presentation didn’t result in much of a reaction Darwin went home and wrote a book entitled “On the origin of species by means of natural selection, or the preservation of favored races in the struggle for life.” Darwin became famous/infamous while Wallace did not Wallace continued to publish work concerning the distribution of animals and plants in Asia There is a biogeographic feature called “Wallace’s Line” that delineates the Asian from the Australian biotas Darwin launched a set of ideas that the reading public in Europe (and the U.S.) were ready for Darwin’s starting point was “Artificial Selection” Darwin’s eventual hypothesis from this starting point comes down to three observations and two conclusions: o Observations: The populations of species and populations of all organisms show variation between individuals Populations in nature tend to be stable (in numbers) from generation to generation In every generation, more individuals are produced (by reproduction) than eventually survive. o Conclusions: The environment selects those variants in every generation best fitted to survive and reproduce in that environment, and selects against those individuals less well-fitted to survive (the “principle of natural selection”) Those variations favored by selection are somehow passed on to the next generation This process will eventually produce adaptations by populations and species to specific environments Darwin’s hypothesis will eventually become a theory in biology Adaptation is produced by natural selection Only natural selection can cause adaptation The natural selection-adaptation process also causes the observed relationship between biological structures and their biological functions This relationship isn’t always true though Darwin also proposed that over time the adaptive process from natural selection will also result in the formation of new species of organisms o Populations of the same species living in different environments will gradually diverge from each other as they become adapted to the new environments o Divergence will result in a new species being formed out of the old species. This explanation for the origin of species is apparently applicable to the speciation process in nature, but it is not a comprehensive explanation There seem to be other evolutionary processes besides this one that can cause new species to come to existence These will be proposed over the next 150 years Principles of inheritance (today: “genetics”) weren’t understood by anyone at the time that Darwin’s book appears in 1859 Darwin’s best explanation for inheritance was something called pangenesis – that different parts of the body sent “messages” to the gonads, and these were somehow incorporated into the sperm and egg cells for transmission to the offspring After Darwin’s idea were made public a great deal of research took place By the late 1880s many other biologist “test” Darwin’s hypothesis using comparative means o Experimental methods weren’t used because the process of natural selection was presented as being a very gradual process Prompted by the influence of Lyell’s uniformitarianist views on Darwin Gregor Mendel: o 20 July 1822 - 6 January1884 o Moravian monk o Worked mostly in isolation on pea plants in an abbey located in what is now part of the Czech Republic o Published in obscure European journals which weren’t widely read in France or England o Works were not so much “unacknowledged” and their importance was not realized o Usually considered to be the founder of modern genetics Around 1900 the importance of Mendel’s work was finally recognized by 3 botanists simultaneously o Dutch botanist: Hugo de Vries o German botanist: Carl Correns o Austrian botanist: Erich von Tchermark-Sysenneg All were studying plant hybridization Discovered Mendel’s principles, then they discovered Mendel’s publications Corren and von Tchermark were interested agricultural applications of the work, but de Vries was interested in mutation. Hugo de Vries o 16 February – 21 May 1935 o Somewhat reluctantly promoted Mendel’s discoveries o Enthusiastically promoted his own o Encouraged many others to take up what would be a new scientific discipline Eventually called “genetics” William Bateson o 8 August 1861 – 8 February 1926 o British plant scientist o Coined new biological terms Genetics Allelomorph (later shortened to allele) Homozygote Heterozygote 1901-1906: term “gene” began to emerge as the fundamental unit of inheritance 1902-1904: Sutton-Boveri Theory of Chromosomal Inheritance developed o Was developed by Theodor Boveri and Walter Sutton o Was able to associate the events of cell division (especially “reduction division”) studied by cytologists using microscopy with Mendel’s principles Theodor Boveri o 12 October 1862 – 15 October 1915 o German biologist o Developed the “theory” called Sutton-Boveri Theory of Chromosomal Inheritance o Most notable for first hypothesizing the cellular processes that cause cancer o Work with sea urchins showed that it was necessary to have all chromosomes present in order for proper embryonic development to occur Walter Sutton o 5 April 1877 – 10 November 1916 o American geneticist and physician o Developed the “theory” called Sutton-Boveri Theory of Chromosomal Inheritance o Most significant contribution to present-day biology was his theory that Mendelian laws of inheritance could be applied to chromosomes at the cellular level of living organisms Modern concept of a “gene”: “sequence of DNA that does something” After 1910: explosion of genetic knowledge, major figure was Thomas Hunt Morgan Thomas Hunt Morgan o 25 September – 4 December 1945 o American evolutionary biologist, geneticist, embryologist and science author o Won Nobel Prize in Physiology or Medicine in 1933 for discoveries elucidating the role that the chromosome plays in heredity o Morgan was the geneticist who was persuaded to work with a fruit fly, Drosophila melanogaster as an experimental animal for genetics. Many discoveries in genetics that refined Mendel’s principles and discovered additional genetic principles and phenomena arose from the study of this insect Quite a few of these came from Morgan’s fly lab at the University of Chicago Downside of this emerging new field of genetics was the emphasis on mutation as a powerful evolutionary force Over next 20 years genetics flourishes and evolution languishes At about 1935 controversy between genetics and evolution comes down to three points: 1. Importance of mutation versus natural selection 2. Is all inheritance “hard” (immutable, fixed), meaning the genes of the organisms determine the phenotype and the phenotype is the organism’s fate 3. Gradual versus rapid (saltational) evolution Result of the argument when some analysis by mathematicians (biometricians) involved with population genetics: the “Synthetic Theory of Evolution” (aka “New Synthesis”) o This set of ideas will merge Mendelian and Darwinian principles and concepts and almost reconcile them The Synthetic Theory will reach the height of its popularity about the end of the 1950’s (it is sometimes called “NeoDarwinism). The major concepts inherent in the Synthetic Theory were: 1. Biological variations arise by mutation (de Vries). 2. Hereditary transmission of genetic variation occurs by the principles of Mendel (Mendel and his heirs). 3. Adaptation by organisms to particular environments in which they live by a natural process (Lamarck) 4. Natural selection is the mechanism by which adaptation takes place (Darwin). Some corollaries to the Synthetic Theory: A. Natural selection tends to act through tiny advantages and gradually changes populations. B. There is a long-term advantage for a population to possess variability – if the environment should change, then the variations previously selected against may now be selected for – and if they are not present, then extinction of the population (extirpation) may result. C. There is a selective advantage to having a harmonious arrangement of genes in chromosomes (or other genomic packaging, such as seen in prokaryotes). a. Fitness is measured in terms of differential reproduction, not differential survival (as per Darwin). D. Modern concept lies in how many of an individual organism’s alleles of its genes are contributed to the next generation by reproduction. a. Those individuals who have more offspring than others are thus more “fit” than those that have fewer offspring. E. Evolution is not a directed process, but instead is blindly deterministic –there is no goal, no purpose, no “teleology,” no progress in the evolution of organism. th Middle 20 century: o Synthetic Theory was embraced by biologists in general o Largely because it reinforced the link between biological structure and biological function o Virtually every biological feature at all levels of biological organization was under some type of natural selection o largely because it reinforced the linkage between biological structure and biological function, and that virtually every biological feature at all levels of biological organization was under some type of natural selection. Enthusiasm for the Synthetic Theory would only last until about the 1960s when new questions arose: o How important are random events in the overall evolutionary process? For example: “bottleneck events” have occurred where a large population of well-adapted individuals is abruptly reduced to a few individuals by a disaster that has nothing to do with that population’s general adaptiveness to the environment o Are most mutations at the molecular level selectively neutral? Only variations that appear in the phenotype (that is, those mutations that are expressed) can be acted upon by natural selection. Motoo Kimura (1968) proposed the “Neutrality Hypothesis” that strongly suggested that most mutations at the molecular level are indeed selectively neutral. o Darwinian speciation by natural selection seems to slow to explain the planetary biodiversity of today and of the past. Can evolution (and speciation) be “speeded up” without falling into the pitfalls of mutation-driven saltational evolution? Terms to be Familiar with Theory: a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained. Allelomorph: one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome. Homozygote: an individual having two identical alleles of a particular gene or genes and so breeding true for the corresponding characteristic. Heterozygote: an individual having two different alleles of a particular gene or genes, and so giving rise to varying offspring. Genetics: the study of heredity and the variation of inherited characteristics. Survival of the Fittest: mechanism of natural selection. Individuals that are better equipped for their environment are more likely to survive and pass on their traits to their offspring Artificial Selection: process by which humans breed other animals and plans for particular traits Selectively neutral: the mutations have no effect on the phenotype of the individual that possess the mutation. Saltational evolution: an abrupt variation in the appearance of an organism, species, etc, usually caused by genetic mutation Synthetic Theory of Evolution: the modern theory of evolution, incorporating Darwinian thinking, Mendelian genetics, and an understanding of genes and genetic change at the molecular level. Gradualism: small genetic changes occur slowly within a population. Darwin’s original description of evolution Natural Selection: process where organisms that are better adapted to their environment tend to survive and produce more offspring than other organisms Population: group of organisms living in the same habitat that are also of the same species Species: group of living organisms that consist of similar individuals that are capable of breeding Vestigial Structure: it is a genetically determined structure or attributes that have apparently lost most if not all of their ancestral function in any given species but it has been retained through evolution Analogous Structure: structure that have similar functions but not common structure or common ancestor Variation: different or distinct form or versions within any species Coevolution: evolution of two species that are dependent on one another Competition: a contest between organisms for territory, a niche, or a location of resources, for resources and goods, mates, for prestige, recognition, awards, or group or social status, for leadership needed for survival. Gene pool: collection of all genes within a population at any given time Natural Selection Main Points: 1. There is variation within a population 2. Some variations are favorable 3. Not all young produced in each generation can survive 4. Individuals that survive and reproduce are those with favorable variations Habitat: place where an organism population lives Speciation: evolutionary process by which new biological species come Morphology: study of the form and structures of organisms Convergent evolution: the independent evolution of similar features in species that have different ancestors Evolution: a change in the genes over time Adaptation: inherited characteristic of a species that develops over time in response to an environmental factor, enabling the species to survive Punctuated Equilibrium: populations stay stable for long period of times, interrupted by brief period of rapid chance. Caused by environmental change or increased mutation rate. Supported by fossil record. Mutation: permanent change of the nucleotide sequence of DNA Divergent Evolution: Accumulation of difference between different populations which can lead to the formation of a new species Homo sapien: translates to “wise man” it is the modern human Homo habilis: translates to “Handy man”, this specimen was discovered in 1964. Homo habilis used and made tools, it is the direct ancestor to Homo sapiens Neanderthal: the closest extinct human relative. Fossils of Neanderthals were found in Neader Valley Germany. They lived in the Middle East, Europe and Asia. They were adapted for cold weather conditions. They buried their dead, hunted, used tools and had social structure. Australopithecus afarensis: commonly known as “Lucy”, this specimen was dubbed as the “Missing Link,” this is the longest living hominin species. They are shorter and more closely similar to chimpanzees Homo erectus: translates to "upright Man," Homo erectus had migrated out of Africa to Asia and Europe. Taller with a larger brain. Built fires, wore animal skin clothing, lived in caves, made stone tools. Homologous Structures: structures that are similar due to a common ancestor however they do not necessarily have a common function Cladogram: diagram that is used to illustrate the evolutionary relationships between species
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'