Unit III Evolution and Population genetics Study Guide 1 a What is the biological meaning of the term evolution b Contrast microevolution with macroevolution a The biological meaning of the term evolution is the idea that species change over time and the new species arise by the modification of their ancestral species b Microevolution is the gradual evolution of traits within a population of a species over time populations evolve not individuals Macroevolution is the evolution of an entirely new species 2 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 can be created from a common ancestor via selective breeding by humans i Example Humans intentionally creating different breeds of dogs by artificial selection selective breeding for particular traits which leads to many different breeds of dogs b Comparative anatomy the anatomy of different organisms could be similar because that descended from a common ancestor i Example The same bones having the same relative position in the forelimbs of all mammals suggest that mammals evolved from a common ancestor who had this basic forelimb ground plan c Paleontology the study of fossils i Exam ple the The forelimbs to the left of different mammals are homologous they share similarities because of common ancestry Homology similarity cause by shared ancestry Analogy structures that appear similar due to having a similar function NOT because of shared ancestry patterns of fossils in the rock layers in the Grand Canyons suggests that organisms change over time d Comparative embryology early embryos of different vertebrates share many general features But as development proceeds similarity persists only among more closely related vertebrates This is turn makes the early embryos more similar than later developed embryos 3 a How can molecular biology provide evidence for evolution b Provide two examples a Molecular biology provides evidence for evolution when the more recent of two species share a common ancestor the more similar their proteins DNA b 1 Humans and Rhesus monkeys and 2 Rhesus monkeys and mice 4 Distinguish between a homologous b analogous and c vestigial structures providing at least ONE EXAMPLE of each a Homologous the forelimbs of different mammals are homologous they share similarities because of common ancestry i Example the limbs of humans cats whales and bats b Analogous appear similar due to having a similar function NOT because of shared ancestry i Example an insect wing and a bird wing are analogous because they serve the same function NOT because they both evolved from a common ancestor with wings c Vestigial structures remnants of once functional ancestral structures The vestigial hind limbs of whales and snakes indicate common ancestry with vertebrates that had limbs i Example modern whales evolving from a 4 leggeed mammal 5 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 hypothesized that 14 endemic found nowhere else species of finches evolved from a common mainland ancestor each adapted to different lifestyles conditions on the various islands b The Galapagos finches might have helped Darwin formulate his theory of natural selection because it helped him understand that the different species of finches descended from a common ancestor 6 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 1 More offspring are born than can survive to reproduce so there is competition for limited resources Parent Offspring Parent 2 There is phenotypic variation among individuals in a population of a particular species Some are genetically blue some are genetically red but Darwin was unaware of genetics 3 The phenotypic variation among individuals in a population must be heritable so they must have a genetic basis Offspring 4 Individuals with more adaptive phenotypes survive better and therefore leave more offspring than others in a particular environment Parents pass their blue and red alleles on to their offspring Offspring 5 Traits alleles that enhance survival reproduction gradually become more common each generation Those with red alleles survive better reproduce more their red offspring also survive better If the red allele enhances survival more than the blue allele then over time the red allele appears with greater frequency in the population Parent Generation 1 Offspring Generation 1 Parent Generation 2 Parent Generation 2 b Genetic variation is required for evolution by natural selection so that it will make an individual more adapted to its environment and it is a basis for natural selection 7 Lamarck thought that evolution was the best explanation for life s diversity as did Darwin How did Darwin s view differ from Lamarck s a Lamarck s view differed from Darwin s view in that Lamarck had the right idea about species evolving in response to their environment but he had the wrong mechanism His mechanism stated that the inheritance is from acquired characteristics is false 8 Explain what is meant by the phrase populations evolve not individuals a Populations evolve not individuals essentially states through microevolution that evolution takes places within a population over time not just one specific individual s 9 Define describe a gene pool b allele frequency c genotype frequency d phenotype frequency e gene fixation Give an example for c and d a Gene pool the stock of different genes in an interbreeding population b Allele frequency is the proportion of a particular allele among all allele copies being considered c Genotype frequency is the frequency or proportions of genotypes in a population i Example out of a population of 100 colored plants 49 red flowered plants with genotype AA 42 pink flowered plants with genotype Aa and 9 white flowered plants with genotype aa d Phenotype frequency is the frequency or proportions of phenotypes in a population i Example out of a population of 100 colored plants 49 red flowered plants 42 pink flowered plants and 9 white flowered plants e Gene fixation fixation is the change in a gene
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