Review questions for Ch. 22

Practice questions for Ch. 22 The questions will not be exactly the same as exam questions. Students need to review the whole Chapter 22 for Exam I. I. Review the following terms and concepts of Ch. 22: fossil, stratum/strata, catastrophism, paleontology, trait, natural selection, artificial selection, adaptation, Darwin’s theory of evolution, Lamarck’s theory of evolution, homology, analogy, vestigial structure, convergent evolution, unity in life, “tree thinking”, continental drift, endemic species, evidence for Darwin’s theory. II. Read the explanation for each question 1. Which of the following statements about Darwin following the voyage of HMS Beagle is incorrect? a) Darwin thought individuals varied. b) Darwin thought the Earth was a few thousand years old. c) Darwin thought fossils in a given area were similar to the animals that were still living there. d) Darwin thought organisms produced many offspring. e) Darwin thought few offspring of a pair survived. Answer: Darwin knew species varied (option a), that fossils in a given area were similar to living species in that area (option c), and that many offspring were produced (option d) but few survived (option e). However, from reading Lyell’s Principles of Geology , Darwin realized that Earth cannot be just a few thousand years old. Therefore, the only correct answer is b). 2. Imagine a species of bird in which females prefer to mate with brightly colored males. However, males with bright backs are more often preyed upon by hawks. Assuming that a wide variety of genetic variation exists in the species, which do you think is the most likely evolutionary outcome? a) Males will be selected to be brightly colored. b) Females will be selected to choose drab males. c) Males will be selected to have bright chests and dull backs. d) Females will not mate. e) The species will go extinct because the hawks catch all the males. Answer: This question presents a scenario designed to be analogous to the guppy example in the textbook. You would expect hawks to select against birds with brightly colored backs and females to select for males with bright colors. Option a) is likely if only female choice is considered but not with the effect of hawk predation. Option b) is a possibility if males contribute parental care (i.e., if males help care for young and they have a high mortality rate, females who mate with drab males may have a higher probability of fledging their offspring). Option c) is the most likely scenario (assuming the genetic variation is available) because males with dull backs will not be preyed upon as much by hawks, and females will see and choose

males with bright chests. Options d) and e) are not likely because females will probably mate even if males are rare and hawks are not likely to catch all the males immediately. 3. Imagine two species that are thought to have a recent common ancestor. If this idea is correct, these two species most likely have a) no morphological similarities. b) few biochemical similarities. c) some genes with identical amino acid sequences. d) very different habits. e) similar embryological development. Answer: Again, this question is designed to help students understand what phylogenetic trees show. They show evolutionary branching points and indicate how closely related different species are. Furthermore, if you make a phylogeny based on one set of characteristics, you would predict that a phylogeny based on another set of characteristics would yield the same results. Based on this reasoning, you would expect e), similar embryological development, and c) for at least some genes should still have identical sequences, but not a lot of differences (as in options a, b, and d). 4. Imagine that you have discovered a new lizard that lives in a foggy desert in southwestern South America. As fog rolls in, this lizard stands on its head and lets water condense on its back and roll in grooves to its mouth. Considering the Namibian beetle in the figure below, this trait is an example of which of the following? a) convergent evolution b) inheritance of acquired characteristics c) homology Answer: This question is designed to make students think about adaptations and how they arise. The imaginary lizard in this question should remind students of the “headstander beetle” in the

5. Charles Darwin was the first person A. to propose that the earth is more than a few thousand old. B. to propose that evolution occurs. C. to propose a theory in explaining the cause of evolution. D. to propose that natural section caused evolution. E. to study fossils in strata. 6 . Natural selection is based on all of the following except A. Genetic variation exists within populations. B. Organism acquire genetic characteristics from their parents C. Individuals adapt to their environments can change their own genetic makeup, Therefore their offspring acquire better characteristics. D. Organisms tend to reproduce more offspring than the environment can support. E. Individuals who can acquire more resource tend to leave more offspring than those who cannot. 7 . Bats and birds both have wings. _____________________ A. They both have wings because they share a recent ancestor. B. They both have the wings because are closely related species. C. Their structural similarity is an example of analogy in evolution. D. Their structural similarity is an example of homology in evolution. E. Because they lived in the same area. 8. What must be true of any organ that is described as vestigial ? A. It must be analogous to some feature in an ancestor. B. It must have lost its original function C. It must have no function in the animal’s ancestor. D. It must be the same as in the animal’s ancestor. 9. Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities? I. by identifying the bones as being homologous structures II. by comparing the function of these structures III. by the principle of convergent evolution IV. by proposing that humans, bats, and dolphins share a common ancestor A. Biologists used both I and II. B. Biologists used both II and III. C. Biologists used both I and IV. D. Biologists think all of the statements above are correct. 10. Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? A. Natural selection cannot account for losses, only for innovations.

B. Natural selection accounts for these losses by proposing that animals benefit from not developing these organs in their unique living environment. C. Natural selection accounts for these losses by the principle of use and disuse. D. Natural selection accounts for these losses by Catastrophism. IV. Short answer question 1. According to Charles Darwin, how did giraffes evolve their long neck? Try to use all the concepts or observations you learned in Ch. 22 to answer this question. 2. What is the major difference between Darwin’s theory of evolution and Lamarck’s theory of evolution? The major difference between Darwin’s theory of evolution and Lamarck’s theory of evolution is that Darwin proposed that natural selection is the main mechanism of evolutionary change, whereas Lamarck proposed that inheritance of acquired characteristics is the main mechanism of evolutionary change 1 3. What did Darwin learn from Lyell and Cuvier? Darwin used Lyell’s ideas to support his theory of evolution by natural selection, which required a long-time span for species to adapt and diversify. He also used Cuvier’s evidence of extinctions to explain why some species were no longer present, and why some living species resembled extinct ones. 4. With your own wards, describe the major observations and inferences that led to Darwin’s theory of natural selection. Why are these observations and inferences so important for Darwin’s explanation of evolution? These observations and inferences are important for Darwin’s explanation of evolution because they provide a natural mechanism for how species change and diversify over time, without requiring any supernatural intervention or guidance. Darwin’s theory also explains how organisms become adapted to their environments, and how new traits and features can arise through a gradual accumulation of small changes. 5. In Ch. 22, we learned 4 types of evidence biologists collected in support of Darwin’s theory (evolution is caused by natural selection, all species evolved from one common ancestor). Think of one example for each types of evidence. How does it show that evolution is caused by natural selection or unity of life? Answer of Section III: 1. D 2. C 3. B 4. A 5. D 6. C 7. C 8. B 9. C 10. B About question IV – 1