Principles of Evolution Part 1

Answer Key Multiple Choice 1. c 2. b 3. a 4. d 5. b 1. d 2. b 3. a 4. c 5. c 1. b 2. d 3. a 4. c 5. b 1. d 2. a 3. d 4. c 5. b 1. c 2. a 3. b 4. c 5. d 1. ANS: C 2. ANS: B 3. ANS: A 4. ANS: B 5. ANS: D 6. ANS: C 7. ANS: B 8. ANS: B 9. ANS: A 10. ANS: A 11. ANS: D 12. ANS: B 13. ANS: C 15. ANS: A 16. ANS: B 17. ANS: B 18. ANS: B 19. ANS: B 20. ANS: C 21. ANS: B 22. ANS: 23. ANS: D 24. ANS: B 25. ANS: B 26. ANS: B 27. ANS: C 28. ANS: B 29. ANS: D 30. ANS: C 31. ANS: A 32. ANS: C 33. ANS: D 34. ANS: B 35. ANS: B 36. ANS: A 37. ANS: B 38. ANS: B 39. ANS: B 40. ANS: A 41. ANS: A 42. ANS: A C 43. 44. 45. ANS: D ANS: C ANS: D Modified True/False 1. ANS: T 2. ANS: F, “differ” or “are different” or “have natural variations” 3. ANS: F, Lyell 4. ANS: T 5. ANS: T 6. ANS: F, “phenotype” or “body” 7. ANS: F, Malthus 8. ANS: T 9. ANS: F, artificial selection 10. ANS: F, common descent 11. ANS: F, biogeography 12. ANS: T 13. ANS: F, homologous 14. ANS: T 15. ANS: F, “physical characteristics” or “phenotype” Completion 46. ANS: “Darwin” or “Charles Darwin” 47. ANS: “globally” or “all over the world” 48. ANS: “many millions” or “millions” 49. ANS: “Lyell” or “James Lyell” 50. ANS: acquired 51. ANS: evolution 52. ANS: “grows” or “increases” 53. ANS: “organisms” or “living things” 54. ANS: “offspring” or “progeny” or “descendants” 55. ANS: “common descent” or “common ancestors” 56. ANS: “species” or “organisms” 57. ANS: “radioactivity” or “radioactive dating” 58. ANS: homologous 59. ANS: Homologous 60. ANS: “natural selection” or “adaptation” Short Answer 91. ANS: Darwin collected many examples of similar, but not identical, modern organisms as well as fossils that were previously unknown. These specimens helped him form his theory of evolution by natural selection. 92. ANS: Darwin proposed a scientific theory of biological evolution to explain how organisms evolved over long periods of time through descent from common ancestors. 93. ANS: Darwin noticed that some of the fossils were similar to living species. 94. ANS: The tortoises varied from island to island in predictable ways, such as shell shape and neck length. The variations seemed to enable the tortoises to exploit food resources on the islands. 95. ANS: Hutton and Lyell recognized that geologic process take place over much longer periods of time than was commonly thought. Further, these processes are the same that have been acting on Earth since its formation. Hutton and Lyell’s ideas led them to conclude that Earth is millions, not thousands, of years old. 96. ANS: Lamarck thought that organisms tended toward complexity and perfection. He thought they could change their structures during their lifetimes through selective use and disuse. These acquired characteristics could then be inherited. 97. ANS: Malthus concluded that if human population growth was not “checked” by factors like disease, there would not be enough resources to sustain it. 98. ANS: Farmers bred only animals with desirable traits, which resulted in improved offspring. 99. ANS: In artificial selection, humans do the “selecting”—that is, they choose which traits they want to appear in future generations. In natural selection, the environment does the “selecting.” 100. ANS: Natural selection occurs when 1) more individuals are born than can survive, 2) natural, heritable variations among organisms are present, and 3) organisms vary in their fitness. 101. ANS: All living and extinct species are descended from a common ancestor. 102. ANS: Ancestors of modern whales probably had functional legs and lived on land. 103. ANS: It suggests that there is no disadvantage to fitness associated with the vestigial structures. If there were a disadvantage, then the structures would be selected against and you’d expect them to no longer be present. 104. ANS: The similarity of Hox genes in many types of organisms is evidence that the organisms all evolved from a common ancestor. 105. ANS: The Grants documented changes in the finch population consistent with Darwin’s ideas of natural selection. Through their work, they discovered that natural selection can occur oftzen and frequently. Other (Figures) 136. ANS: The tortoises have necks of different lengths and shells that differ in overall shape and in the size of the opening for the neck. 137. ANS: The Hood Island tortoise has the longest neck. 138. ANS: Ancestral tortoises with long necks and shells that permitted greater neck movement obtained food more easily, survived longer, and produced more offspring than other tortoises. 139. ANS: The Pinta Island tortoises would be likely to survive more successfully because they appear to be more similar to the Hood Island tortoises. 140. ANS: No. The diagram does not provide information on the ancestral species. 141. ANS: Darwin proposed that over time, natural selection made a population more fit for its environment. Sharks and dolphins both live in the ocean, where natural selection favors organisms that move efficiently through water. 142. ANS: Sharks show fitness because they are able to survive and reproduce successfully in their ocean environment. Students should give two of the following examples: (1) Sharks have an overall body shape that enables them to move rapidly through water. (2) Sharks have a large tail and fins that provide balance and enable them to steer. (3) Sharks have teeth that make them successful predators. 143. ANS: Student answer may include that the dolphin’s land-dwelling ancestors were probably made up of populations with different body shapes and limbs. Those land-dwellers began to spend more time in the ocean, perhaps because food was easier to find. In each generation, those with bodies that moved efficiently in water survived longer and produced more offspring than others. Eventually, the whole population came to resemble today’s dolphins. 144. ANS: It is not likely. Possible arguments: (1) Darwin emphasized that evolution usually requires millions, not thousands, of years. (2) The bodies of dolphins are well adapted to life in water, with little observable variation; it’s unlikely that the population’s relevant characteristics could change in just thousands of years. 145. ANS: Student answer could include that although their skeletons are made of different materials, there are likely to be homologous structures in the skull, backbone, and limbs. There may also be homologous structures among internal organs such as heart, brain, and digestive system. 146. ANS: Scientists probably used the fossil bones of ancient horses from several sites and compared them with the bodies of modern horses. 147. ANS: Body size increased in mass and volume. (The horse became taller and heavier.) 148. ANS: The head becomes larger. 149. ANS: The number of toes decreased from three to one. 150. ANS: No, this diagram shows a pattern only in horse evolution. Many other species have remained small. Biology Principles of Evolution Multiple Choice Identify the choice that best completes the statement or answers the question. _______ 1. Which of the following is a term for a group of similar organisms that can reproduce and produce fertile offspring? a. individual b. population c. species d. fossil _______ 2. Which scientist proposed that if an organism used a structure so much that it grew, the trait of that larger structure could be passed to its offspring? a. Erasmus Darwin b. Jean-Baptiste Lamarck c. Georges de Buffon d. Charles Lyell _______ 3. The “present is the key to the past” describes the theory of a. uniformitarianism. b. catastrophism. c. natural selection. d. evolution. _______ 4. Which of the following is a fossil? a. a plant that has recently died b. a group of similar organisms that can reproduce c. a structure or organ that no longer functions d. a trace of an organism that existed in the past _______ 5. The theory that landforms on Earth’s surface, such as mountains, waterfalls, and canyons, were created as the result of sudden spectacular events is called the theory of a. uniformitarianism. b. catastrophism. c. gradualism. d. evolution. _______ 1. The difference in the physical traits of an individual from those of other individuals in a group is called a(n) a. change. b. adaptation. c. species. d. variation. _______ 2. Over time, adaptations can lead populations to experience a. environmental changes. b. genetic changes. c. geologic changes. d. extinctions. _______ 3. What did Charles Darwin observe in finch populations on the Galápagos Islands off the coast of South America? a. different species on different islands b. all species on one of the islands c. identical species on all the islands d. the same species as in North America _______ 4. What did Charles Darwin learn from the fossils of a giant armadillo that he found in Argentina? a. An earthquake led to the armadillo’s extinction. b. Armadillos used to be marine organisms. c. Modern animals may be related to fossilized organisms. d. Fossils do not resemble modern animals. _______ 5. Fossils of marine organisms high in the Andes Mountains led Darwin to conclude that a. Earth is 6000 years old. b. interspecific variation had taken place. c. great change can happen over time. d. an earthquake had taken place. _______ 1. The development by scientists of a new color in a rose is the result of a. natural selection. b. artificial selection. c. descent with modification. d. overproduction. _______ 2. In natural selection, the selective agent is the a. humans. b. mutations. c. breeders. d. environment. _______ 3. All the rabbits living in a particular area would be an example of a(n) a. population. b. species. c. fossil. d. individual organism. _______ 4. A bird that can easily outcompete other birds for food and that can produce many eggs has a high a. life expectancy. b. mutation rate. c. fitness. d. adaptability. _______ 5. Which of the following describes natural selection? a. It acts on genetic material directly. b. It acts on existing physical traits. c. It forms new traits. d. It forms new genetic material. _______ 1. Which of the following is an example of a vestigial structure? a. the wings of red-tailed hawks b. the hind limbs of a house cat c. the fins of a shark d. the wings of an ostrich _______ 2. Biogeography is the study of the a. distribution of organisms around the world. b. environments around the world. c. different types of rocks around the world. d. age of fossils around the world. _______ 3. What is suggested by the similarity of early embryos of different species of vertebrates? a. no evolutionary relationship between the groups b. recent common ancestry c. similar environments in the past d. evolution from a distant common ancestor _______ 4. Some organisms that share a common ancestor have features that have different functions, but similar structures. These are known as a. vestigial structures. b. analogous structures. c. homologous structures. d. fossil structures. _______ 5. If an organism has a vestigial structure, that structure likely once had a function in a(n) a. close relative. b. early ancestor. c. unrelated organism. d. embryological stage. _______ 1. Paleontology is the study of a. ecosystems. b. genetics. c. fossils. d. rocks and minerals. _______ 2. Two organisms that are closely related would have a. very similar DNA sequences. b. exactly the same DNA sequences. c. no proteins in common. d. completely different DNA sequences. _______ 3. What are pseudogenes? a. cell structures that function like genes b. gene sequences that no longer function c. protein sequences that look like genes d. mutations in nucleotides _______ 4. Evolution is considered to be one of the most important theories in science, because it a. was developed more than 100 years ago. b. is not supported by the fossil record. c. unites the fields of biology, geology, chemistry, and ecology. d. was discovered by Charles Darwin, a famous scientist. _______ 5. Protein sequences in one organism that resemble those of another suggest a a. coincidence. b. lack of evolutionary relationship. c. great number of mutations. d. shared ancestry. ____ 1. Darwin noticed that many organisms seemed well suited to a. being preserved as fossils. b. providing humans with food. c. surviving in the environments in which they lived. d. swimming from South America to the Galápagos Islands. ____ 2. The species of finches that Charles Darwin found on different Galápagos Islands varied in certain structural adaptations. One of the most significant adaptations that Darwin noted was the a. similarities of the birds’ embryos. b. birds’ different-shaped beaks. c. length of the birds’ necks. d. number of eggs in each bird’s nest. ____ 3. Based on the adaptations Charles Darwin observed in finches and tortoises in the Galápagos, he wondered a. if species living on different islands had once been members of the same species. b. if finches and tortoises had originated from the same ancestral species. c. if all birds on the different islands were finches. d. why all tortoises on the different islands were identical.