BSC 2011 UNIT III STUDY GUIDE PART A UNIT III Evolution and Population Genetics The purpose of this study guide is to encourage you to review your notes and text material and to integrate numerous facts and terms into broad but meaningful concepts Please try and work on your own at first but don t hesitate to ask for assistance from me or your TAs Dr Spears 1 Discuss the following various views people held about life s diversity how it arose and the age of the earth old young before evolution was suggested a essentialism idealism b natural theology c catastrophism d uniformitarianism 2 a What is the biological meaning of the term evolution b Contrast microevolution with macroevolution Species change over time and new speices arise by the modification of earlier species Microevolution gradual evolution of traits within a population of a species over time populations evolve not individuals Macroevolution evolution of an entirely new species 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 species are created from a common ancestor via selective humans created different breeds of dog by artificial selection and selective breeding b Comparative anatomy anatomy of different organisms could be similar because they same bones have same relative positions suggesting they had a common ancestor breeding by humans for particular traits descended from a common ancestor with this basic groundplan d Paleontology study of fossils the pattern of fossils in rock layers suggest that organisms have changed over time organisms in close recent layers are similar yet still different organisms far apart are less similar separated by longer time new species appear that didn t exist in lower layers species in older lower layers don t exist today e comparative embryology early embryos of different vertebrates share many general features as development proceeds similarity persists among more closely related vertebrates 4 a How can molecular biology provide evidence for evolution b Provide two examples Molecular biology provides evidence for evolution by explaining that the more recently two species shared a common ancestor the more similar their proteins and DNA Protein and DNA sequence comparisons 5 Distinguish between a homologous b analogous and c vestigial structures providing at least ONE EXAMPLE of each a homologous share similarities because of common ancestry forelimb of different vertebrates b analogous have similar function but not due to common ancestry insect wing and bird wing c vestigial structures remnants of once functional ancestral structures hind limbs of whales and snakes 6 a What did Darwin find intriguing about the finches on the Galapagos Islands b Explain why how the Galapagos finches might have helped Darwin formulate his hypothesis of evolution by natural selection a Darwin found that the species of finches evolved from a common mainland ancestor and each species had adapted to different lifestyles and conditions on the various islands b He was able to formulate his hypothesis of natural selection because of adaptive radiation He discovered that when ancestors move into a new environment they adapt to the habitat and eventually become a new species 7 a Describe the process by which populations evolve via natural selection b Why is it said that genetic variation is a prerequisite is required for evolution by natural selection a Within a population the more offspring produced than can survive to reproduce lead to competition for limited resources and struggle for existence Phenotypic variation exists in all organisms and much of this variation is heritable Some of the variation affects the individual s ability to survive and reproduce The fittest individuals survive better and produce more offspring and contribute more of their genes for the next generations generation the more favorable characteristics are accumulated over time and passed on to next b Variation is required for evolution because it enhance the individuals chance of survival and continuation of the population 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 Lamarck stated that traits acquired during an organism s life could be passed on to its offspring Darwin s theory was survival of the fittest or natural selection Genetic mutations occur in every species and sometimes these are beneficial Also the survivors get to reproduce and leave more offspring that share their parents traits 9 Explain what is meant by the phrase populations evolve not individuals Microevolution states this the gradual evolution of traits within a population of a species over time 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 alleles in a population b allele frequency total number of alleles in a population Each diploid individual has 2 alleles for each gene A 20 30 67 a 10 30 33 c genotype frequency number of AA Aa aa in a population d phenotype frequency kind of trait being expressed in a population 3 15 red and 12 15 are green e gene fixation when a population has one kind of allele for a trait Homozygous 11 a Explain the Hardy Weinberg theorem b provide all of the conditions that are required for a population to remain in HW equilibrium and c how is the HW theorem useful in the study of evolution a allows you to predict allele frequencies in a population that is not evolving b 1 Population is large 2 No mutation 3 No immigration or emigration 4 Mating is random 5 All individuals survive and reproduce equally well i e no natural selection c allows you to see if the population is evolving or not and why 12 Describe how each of the following mechanisms of evolution affect allele and genotype frequencies in populations a genetic drift b mutation c population bottleneck d founder effect e gene flow f non random mating and g natural selection Please describe a possible real life example for cases a through g a genetic drift alleles change due to chance events such as a disaster b mutation creates new alleles that may increase survival or be lethal Can only affect evolution if they are heritable c
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