BSC2011 UNIT III STUDY GUIDE PART A Unit III Evolution and Population Genetics 1 2 Terebelski omits a What is the biological meaning of the term evolution a species change over time and new species may arise by the modification of their ancestral species descent with modification b Contrast microevolution with macroevolution MICROEVOLUTION gradual evolution of TRAITS within a population populations evolve not individuals MACROEVOLUTION evolution of an entirely NEW SPECIES scientists vs creationists 3 Describe explain how each of the following serves as evidence that evolution could be a means by which life s diversity arose a artificial selection b comparative anatomy c geology d paleontology and e comparative embryology a Artificial Selection new forms created from a common ancestor via selecting breeding by humans microevolution i Ex wild mustard flower ii Ex 2 breeding of dogs for particular traits but still same species Canis Familaris b Comparative Anatomy the anatomy of different organisms could be similar because they descended from a common ancestor i Ex all mammals have the same relative position of bones of forelimbs because their common ancestor had a basic forelimb ground plan later evolves to different functions in different mammal groups c Geology Terebelski omits d Paleontology the study of fossils pattern in rock layers suggest organisms have evolved over time in close layers more similar e Comparative Embryology early embryos of difference vertebrates share many general features as development proceeds similarity persists only among more closely related vertebrates Von Baer s Law i Ex Reptile and human early embryos are similar but pig and human later embryos look similar 4 a How can molecular biology provide evidence for evolution a Molecular biology provides evidence for evolution in that the more recently two species shared a common ancestor the more similar their proteins and DNA b Provide two examples Ex 1 in a phylogenic tree a node represents the common ancestor and can compare protein DNA sequences such as the mitochondrial cytochrome C gene Ex 2 compare the percentages of amino acids that are identical to the amino acids in human hemoglobin polypeptide pattern goes monkey mouse chicken frog lamprey 5 Distinguish between a homologous b analogous and c vestigial structures providing at least ONE EXAMPLE of each HOMOLOGOUS comparative anatomy similar because of shared ancestry ex forelimbs of mammals ANALOGOUS comparative anatomy similar because of similar function ex insect wing bird wing VESTIGIAL comparative anatomy remnants of once functional ancestral structures homologous ex human appendix no function to humans but does for other mammals ex2 goose bumps no function to humans but warms up animals 6 a What did Darwin find intriguing about the finches on the Galapagos Islands a The 14 endemic species came from a common mainland ancestor but each adapted to different lifestyles and conditions on the various islands b Explain why how the Galapagos finches might have helped Darwin formulate his hypothesis of evolution by natural selection Species evolved due to traits that helped adapt to specific environment superior traits and thus finches that possess those traits survive 7 a Describe the process by which populations evolve via natural selection a More offspring produced than can survive to reproduce leads to competition for limited resources b Phenotype variation exists and is heritable genetic c Variation affects ability to survive and reproduce d fittest individuals survive better and produce more offspring then contribute more of their genes to the next generation e change in allele composition with favorable adaptive alleles accumulating evolution in its most basic form b Why is it said that genetic variation is a prerequisite is required for evolution by natural selection because variation causes some alleles to be better in adapting than other the better ones survive and reproduce among generations 8 Lamarck thought that evolution was the best explanation for life s diversity as did Darwin How did Darwin s view differ from Lamarck s DARWIN species evolve to better adapt environment better traits made certain individuals survive and those better adaptive traits were passed on weak traits gone LAMARCK species evolve to better adapt environment Use Disuse Inheritance of acquired characteristics differs from survival of the fittest believed weak traits could improve or be Survival of the fittest adapted over development and this would pass on to offspring 9 Explain what is meant by the phrase populations evolve not individuals Represents microevolution and how the evolution of traits influence the variation among a species but the species individuals themselves do not change 10 Define describe a gene pool b allele frequency c genotype frequency d phenotype frequency e gene fixation Using actual letters and descriptive terms Give an example for b c d and e a Gene Pool all the alleles in a population each diploid individual has 2 alleles for each gene i Total of alleles in gene pool 2 x of individuals b Allele Frequency the proportion of how often an allele shows up in a population i Ex if 15 total organisms total of alleles 30 c Genotype Frequency the proportion of how often a genotype shows up in A 20 30 67 a 10 30 33 a population i Ex if 15 total organisms AA 8 15 53 Aa 4 15 27 aa 3 15 20 expressed in a population i Ex if 15 total organisms d Phenotype Frequency the proportion of how often a phenotype is Red aa 3 15 20 Green AA Aa 12 15 80 e Gene Fixation when there is only 1 kind of allele for a trait in the population so all individuals are homozygous genetic variation is the opposite of this i Ex population fixed for the a allele So all species are aa for that trait 11 a Explain the Hardy Weinberg theorem a The Hardy Weinberg theorem states that there are five conditions under which a population will not evolve allele frequencies will remain the same and no evolution will occur b Provide all of the conditions that are required for a population to remain in HW equilibrium 1 The population is large 2 There is no mutation 3 There is no immigration or emigration 4 Mating is random 5 All individuals survive and reproduce equally well no natural selection c How is the HW theorem useful in the study of evolution It allows you to predict allele frequencies in a population that is not evolving If a population s actual observed frequencies do not match HW
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