For each question, select the best answer from the four alternatives.
1. Harmful mutations include those that cause (a) Huntington's disease (b) cystic fibrosis (c) reduced reproductive success (d) all of the above (7.1) K/U
2. From the perspective of a pest species, what type of mutation confers resistance to a pesticide? (7.1) K/U A (a) harmful mutation (b) neutral mutation (c) beneficial mutation (d) none of the above
3. Artificial selection requires which of the following? (7.1) K/U (a) hypothesis (b) independent variable (c) dependent variable (d) all of the above
4. Most fossils are in the form of (a) impressions in rock (b) impressions in soft clay (c) impressions in soft lake sediment (d) impressions in sand (7.2) K/U
5. Which of the following organisms is most likely to become a fossil over time? (7.2) K/U A (a) clam (b) jellyfish (c) land animal (d) land plant
6. Which of the following statements support(s) the assertion that fossils are remains of very ancient organisms? (7.2) K/U (a) There are many of fossils of organisms that no longer exist. (b) There are no fossils of most existing species. (c) Fossils are often buried deep within rock formations. (d) all of the above
7. Which of the following describes Charles Darwin's observations from the Galapagos Islands? (7.4) K/U A (a) no unique species (b) many native amphibians and land mammals (c) many species of plants, birds, insects, and some reptiles (d) all of the above
8. Biogeography is (a) the study of fossil organisms in order to learn about earlier forms of life (b) the observed geographic patterns of the distribution of species (c) the idea that global catastrophes have caused the widespread extinctions of species (d) the idea that Earth and all living things have been created in their present forms and are unchangeable (7.4) K/U
9. Which of the following pairs are homologous features? (7.4) K/U (a) horse hind leg and human arm (b) human arm and bat wing (c) mouse skull and giraffe skull (d) porpoise paddle and whale skull
10. Vestigial features include (a) the gills of a fish (b) the larynx of a giraffe (c) goose bumps on a wolf (d) the hip bones of a snake (7.4) K/U
11. A scientific theory such as evolution must be able to (a) explain observations (b) predict outcomes (c) be tested (d) all of the above (7.5) K/U
12. Since pseudogenes no longer serve a useful purpose in a species, they can be compared to (a) homologous features (b) analogous features (c) vestigial features (d) none of the above (7.6) K/U A
13. The increased oxygen-carrying capacity of the blood of native Tibetans is an example of (a) directional selection (b) stabilizing selection (c) disruptive selection (d) all of the above (8.1) K/U
14. According to Darwin's theory of natural selection, a struggle for survival is a result of which one of the following? (8.1) K/U (a) many species competing with one another (b) the large number of offspring born in each generation (c) the occurrence of mutations (d) the environment constantly changing
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15. Which of the following is most likely to occur when a small number of individuals establish a new population? (8.1, 8.2) K/U (a) Hardy-Weinberg principle (b) genetic bottleneck (c) founder effect (d) mechanical isolation
16. Prezygotic mechanisms of reproductive isolation include (a) ecological isolation (b) hybrid infertility (c) zygotic mortality (d) none of the above (8.2) K/U
17. Convergent evolution is exhibited most clearly by which of the following animal pairs? (8.3) K/U A (a) whales and elephants (b) sharks and dolphins (c) flying squirrels and porcupines (d) lions and tigers
18. Throughout the history of life, the rate of speciation compared to the rate of extinction has generally been (a) greater (b) less (c) about the same (d) unrelated (8.4) K/U A
19. The study of abiogenesis is an effort to explain (a) why the dinosaurs became extinct (b) how life began (c) when life began (d) why the extinction rate is increasing (8.5) K/U
20. A cladogram shows (a) when groups of organisms arose (b) evolutionary relationships among groups (c) mass extinctions (d) gaps in the fossil record (8.5) K/U
21. Human success can be attributed to which of the following abilities? (8.7) K/U (a) complex reasoning and learning (b) complex tool making and use (c) communication through complex symbolic language (d) all of the above
Indicate whether each statement is true or false. If you think the statement is false, rewrite it to make it true.
22. Count Buffon, Carl Linnaeus, and Erasmus Darwin all proposed that life changed over time. (7.2) K/U
23. Cuvier's theory of catastrophism is consistent with Charles Darwin's theory of evolution. (7.2, 7.4, 7.5) K/U A
24. Charles Darwin finalized his theory of evolution during his voyage on the HMS Beagle. (7.3, 7.4, 7.5) K/U
25. The hypotheses that Charles Darwin proposed based on his observations of the Galapagos Islands have been supported by observations of life in the Hawaiian Islands. (7.4) K/U A
26. The eyes of flying insects and the wings of flying insects are analogous features. (7.4) K/U
27. Charles Darwin's reading of Malthus led him to wonder if the environment favoured certain individuals due to competition between species. (7.4) K/U A
28. Charles Darwin described natural selection as the way in which the environment favours the reproductive success of certain individuals. (7.5) K/U A
29. Darwin's theory of natural selection explained how and why species evolve. (7.6) K/U
30. The most common forms of sexual selection are female mate choice and male-versus-male competition. (8.1) K/U
31. Adaptive radiation is the evolution of a number of species each occupying different niches from an ancestral species. (8.3) K/U
32. Large-scale evolutionary changes are called endosymbiosis. (8.5) K/U
33. Derived traits are recently evolved traits. (8.5) K/U
34. Neither gradualism nor punctuated equilibrium play a significant role in evolutionary changes. (8.5) K/U
35. The discovery of Tiktaalik by Neil Shubin's team is a great success in the field of molecular biology (8.6) K/U
36. Primate features include large brains compared to body size, side-facing eyes, flexible hands and feet, and arms that can rotate fully. (8.7) K/U
37. To date, the hominid fossil record has revealed two species. (8.7) K/U
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UNIT 3 REVIEW *Do all MC,T/F and Matching questions.
For #34-137 choose 5 questions from from the following to answer (1 K/U, 2 T/I, 2 A). Write a short answer to each chosen question.
Knowledge
For each question, select the best answer from the four alternatives.
1. Artificial selection (a) reduces the genetic diversity of a population (b) increases the genetic diversity of a population (c) reduces the number of harmful mutations (d) rapidly produces new species (7.1) K/U
2. After his visit to the Galapagos Islands, Darwin concluded that all the species that lived in the Galapagos must have (a) crossed land bridges to the islands (b) arrived by air or water (c) no relation to animals on the mainland (d) none of the above (7.3) K/U
3. All vertebrate embryos have (a) gill slits (b) five finger bones (c) short forelimbs (d) none of the above (7.4) K/U
4. Which of the following four hammerhead sharks would be considered the most fit in terms of natural selection? (7.5) K/U (a) 10-year-old shark that has broken free from several fishing lines; no offspring (b) 15-year-old shark that has died from ingestion of trash in the ocean; five live offspring (c) 25-year-old shark; 15 offspring (all eaten while young) (d) 20-year-old shark with internal parasites; 10 live offspring
5. Selective pressures may result from (a) diseases (b) climatic conditions (c) food availability (d) all of the above (8.1) K/U
6. Biologists often describe evolution as a change in (a) the number of alleles in a population (b) the frequency of alleles in population (c) mutation rate (d) the immutability of nature (8.1) K/U
7. The many species of cichlid fishes in Africa present an excellent example of which pattern of evolution? (8.3) K/U (a) adaptive radiation (b) divergent evolution (c) convergent evolution (d) none of the above
8. In Figure 1, which species is the common ancestor for all groups except Species T? (8.5) K/U (a) A (b) B (c) C (d) E
Figure 1 Image: An illustration of how common ancestors can be had for various species.* see mynelson.com text p.382 for cladogram*
9. In Figure 1, which two species are most closely related? (8.5) K/U (a) U and V (b) U and T (c) X and Y (d) V and W
Indicate whether each statement is true or false. If you think the statement is false, rewrite it to make it true.
10. Most mutations are beneficial and give individuals a better chance of survival. (7.1) K/U
11. Neutral mutations do not play an important role in the evolution of a species. (7.1) K/U
12. Most species exhibit genetic variation. (7.1) K/U
13. In 1838, the Reverend Thomas Malthus claimed that the size of animal populations is limited by the availability of food. (7.2) K/U
14. To Chevalier de Lamarck, the excellent night vision of African bush babies would have been an example of the use and disuse principle. (7.2) K/U
15. The conditions required for fossil formation happen frequently. (7.2) K/U
16. Reverend Thomas Malthus believed that populations can continue to grow indefinitely. (7.4) K/U
17. On remote islands, animals are typically very scared of people. (7.4) K/U
18. The observation that "individuals within all populations vary" leads to the inference that some individuals will inherit characteristics that give them a better chance of surviving and reproducing. (7.5) K/U
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19. A gamete that receives a chromosome with duplicated genes has a low chance of survival. (7.6) K/U
20. Often a small amount of interbreeding still occurs between populations that are gradually becoming reproductively isolated. (8.2) K/U
21. Convergent evolution can result in similar features evolving in very distantly related organisms. (8.3) K/U
22. A species is least likely to undergo adaptive radiation when there is very little competition for a variety of resources. (8.3) K/U
23. Coevolution is most pronounced in symbiotic relationships. (8.3) K/U
24. The fact that many species of fish and waterfowl are darker on top and lighter underneath is most likely a result of coevolution. (8.3) K/U
25. Over Earth's history, the rate of species formation has been, on average, less than the rate of extinction. (8.4) K/U
26. Eukaryotes have existed on Earth for at least 3.5 billion years. (8.5) K/U
27. For more than 100 million years, dinosaurs were the dominant vertebrate herbivores and carnivores on land. (8.5) K/U
28. A cataclysmic event is not needed to cause a species to go extinct. (8.5) K/U
29. Abiogenesis is the study of how life appears on island chains that were previously barren. (8.5) K/U
30. The hominid fossil record from 3.7 million years ago shows that our human ancestors evolved the ability to walk upright only after they had large brains. (8.7) K/U
Match the term on the left with the most appropriate description on the right.
(i) relatively rare but are favoured by natural selection (ii) relatively low for individuals but can be numerous in populations overall (iii) often neutral and so do not immediately benefit the individual (iv) are selected against and therefore have no influence on populations (7.6) K/U
(i) occurs when the most common phenotype within a population is favoured by the environment (ii) favours individuals with a more extreme variation of a trait (iii) favours reproductive success of individuals with certain traits over others (iv) favours individuals with variations at opposite extremes of a trait over individuals with intermediate variations (8.1) K/U
33. (a) natural selection (b) small population size (c) mutation (d) immigration or emigration (e) horizontal gene transfer
(i) the gaining of new alleles from a different species (ii) introduces new alleles to a population (iii) increases the likelihood of genetic drift (iv) favours the passing on of some alleles over others (v) introduces or removes alleles in a population (8.1) K/U
(i) even very similar species may prefer occupying different habitats in a region (ii) male gametes may not recognize and fertilize an egg of a different species (iii) different species use different courtship and other mating clues to find and attract a mate (iv) different species breed at different times of the year (v) differences in morphological features may make two species incompatible (8.2) K/U
(i) hybrid offspring remain healthy and viable but sterile (ii) a hybrid individual develops but either dies before birth or, if born alive, does not survive (iii) mating and fertilization are possible, but genetic differences result in a zygote that is unable to develop properly (8.2) K/U
(i) the large-scale evolution of a group into many different forms (ii) the relatively rapid evolution of a single species into many new species, filling a variety of formerly empty ecological niches (iii) the evolution of similar traits in distantly related species (8.3) K/U
Choose 5 questions from from the following to answer (1 K/U, 2 T/I, 2 A). Write a short answer to each chosen question.
37. In science, what is the difference between a hypothesis and a scientific theory? (7.5) K/U
38. Why would unusually wide feet be defined as a beneficial adaptation for snowshoe hares? Give an example of an environment in which the hare's wide feet would have little to no benefit, and explain why. (7.1) K/U
39. Provide an example of the principle of "inheritance of acquired characteristics." (7.2) K/U
40. Explain why Darwin was surprised by the species he found in the Galapagos. (7.3) K/U
41. Provide a piece of evidence suggesting that moles and humans evolved from a common ancestor. (7.4) K/U
42. Define the term "adaptation" as it is used in the theory of evolution. (7.5) K/U
43. How do paleontologists use radioisotopes? (7.6) K/U
44. Define genetic bottlenecks and the founder effect. (8.1) K/U
45. Define genetic drift and provide a circumstance in which it occurs. (8.1) K/U
46. Provide one example of the consequences of human selective pressure and the matching evolutionary change and consequences. (8.1) K/U
47. "Why does allopatric speciation prevent beneficial mutations arising in one population from being shared with another population? (8.2) K/U
48. Define sympatric speciation, and explain how human actions can result in sympatric speciation. (8.2) K/U
49. The Mountain bluebird lives at high elevations, while the Eastern bluebird prefers lower elevations. Which type of reproductive isolating mechanism is at work here? (8.2) K/U
50. Define macroevolution and list some of the large-scale processes associated with macroevolution. (8.5) K/U
51. Based on the fossils of ancestral whales such as Pakicetus, and a modern whale, how has the location of the whale's nostrils changed over time (Figure 2)? What selective advantage does the change provide? (8.5) K/U A
Figure 2 (a) Skulls of Pakicetus and (b) a modern whale
52. Describe how Neil Shubin used fossils to predict when the transition was made between fish and land vertebrates. (8.6) K/U
53. What makes humans unique as a species? (8.7) K/U
Understanding
54. Every year, millions of people worldwide receive seasonal flu shots. As a result, they build immunity against the human influenza virus. Why, then, are health organizations so concerned about the possibility of a deadly epidemic caused by the human influenza virus? (7.1) K/U
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55. Wild tomato plants produce nutritious fruit of variable size. Plant breeders have now bred tomatoes with less variation. Why would uniformity in size be important in the modern food distribution system? (7.1) K/U
56. Why would maintaining genetic diversity in a population help breeders in their quest to produce dramatic changes in a population? (7.1) K/U
57. Paleontologists have observed that rock layers contain fossils of many species that do not occur in layers above or below them. Explain how this observation supports the theory of evolution. (7.2) K/U
58. Explain the roles that Lamarck believed inheritance and the environment played in evolution. (7.2) K/U
59. Describe the steps by which fossils are formed. List environmental conditions that are conducive to fossil formation. (7.2) K/U
60. Cave fish in the family Amblyopsidae that live in perpetual darkness have no eyes or tiny vestigial eyes. Lamarck might argue that this proves his principles of use and disuse. Why is that argument incorrect? What other explanation could there be for the loss of the fish's eyesight? (7.4) K/U
61. Explain why a dew claw is an example of a vestigial feature. (7.4) K/U
62. Do animals face greater competition from members of their own species or from other species in the ecosystem? Defend your opinion with examples. (7.4) K/U
63. Neither amphibians nor terrestrial flightless birds are capable of reaching a remote island by crossing the ocean. Amphibians are strictly freshwater species and terrestrial birds are not capable swimmers. If this is the case, why are large remote islands populated with many native species of flightless birds but not a single species of native amphibians? (7.4) T/I
64. As a scientist, why is it important to consider alternative explanations that might account for your findings when you test hypotheses? (7.4) K/U
65. Which of Darwin's observations support the inference that individuals of all species are in competition for resources? (7.5) K/U
66. Which of Darwin's observations support the inference that individuals inherit characteristics that increase their chance of reproductive success? (7.5) K/U
67. Explain how fossils provide evidence of relationships between primitive and modern species. (7.6) K/U
68. Dolphins have 1000 genes associated with a strong sense of smell, but they do not have a strong sense of smell. Explain why most of these smell genes are examples of pseudogenes. (7.6) K/U
69. The mushrooms of fungi like those shown in Figure 3 have a number of interesting features. Comment on how each of the following might have influenced their evolutionary success. (8.1) K/U A (a) They are able to produce trillions of spores. (b) They have surprisingly little energy content when eaten. (c) Many species are highly toxic.
70. When individuals from a single species become separated by a geographical barrier such as a mountain range, they become less and less alike. Describe at least two reasons why this happens. (8.2) K/U
71. Explain how the process of speciation is analogous to the formation of a new language. (8.2) K/U
72. Explain how new species can evolve within a population either gradually or suddenly. (8.2) K/U
73. Explain the circumstances in which polyploid individuals can produce fertile offspring. (8.2) K/U
74. Explain how mechanical isolation could come into play during the mating flights of dragonflies or damselflies, shown in Figure 4. (8.2) K/U
Figure 4 Male and female migrant hawker dragonflies (Aeshna mixta) mating
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75. Many marine animals, including corals and clams, release their sperm and eggs in open water. Which reproductive isolating mechanism would help ensure the right sperm and eggs combine? How might this work? (8.2) K/U
76. Why would the seemingly small difference of mating at different times of the day foster speciation? (8.2) K/U
77. Explain how Darwin's finches provide an excellent example of adaptive radiation. (8.3) K/U
78. Explain why sharks and dolphins provide a good example of convergent evolution. (8.3) K/U
79. What two outcomes can be predicted based on divergent evolution? (8.3) K/U
80. What two outcomes can be predicted based on convergent evolution? (8.3) K/U
81. What kinds of mass extinction events have occurred on Earth in the past, and why were they so biologically traumatic? (8.4) K/U
82. Although a crocodile would never be mistaken for a bird, scientists are convinced that birds are the closest living relatives of the crocodilians. What evidence supports this assertion? (8.5) K/U
83. It took billions of years for multicellular organisms to evolve from single-celled organisms on Earth. Why was this transition so important for the development of a huge variety of species on Earth? (8.5) K/U
84. What types of evidence (for example, fossils) are used to build phylogenies? Explain why each type of evidence would help to build these diagrams. (8.5) K/U
85. Explain the relationship between the terms "derived trait" and "synapomorphy." (8.5) K/U
86. When evolutionary biologists working with cladograms discuss a "primitive trait" or a "primitive condition:' what does this mean? Are these traits crude relative to current capabilities? (8.5) K/U
87. Compare and contrast two theories used to explain patterns of evolution that occur over long periods of time. (8.5) K/U
88. How does Neil Shubin's work help other paleontologists to make predictions? (8.6) K/U
Analysis and Application
89. While in South America, Charles Darwin found fossilized armadillos and sloths. How did his observations about these species (both living and fossilized) support his theory of evolution? (7.3) T/I A
90. Charles Darwin spent a considerable amount of time observing marine iguanas (Figure 5). A special gland in its snout filters out salt from its blood, and the iguana then "sneezes" that salt out of its body. How did this adaptation allow the marine iguana to fill an available ecological niche in the Galapagos? What other adaptations would help this lizard take advantage of an underwater seaweed food supply? (7.3) T/I A
91. Provide examples to compare analogous and homologous features. Which features provide evidence of evolution? Explain. (7.4) T/I A
92. According to the theories of island biogeography, remote islands share many characteristics with land ecosystems that are surrounded by very different ecosystems (such as a park surrounded by areas inhabited by humans). There are, however, also some significant differences between "island" ecosystems on land and on actual islands. Describe two of these differences. (7.4) T/I A
93. Cane toads are giant poisonous toads from the Amazon rainforest. They were introduced into Australia in the 1930s to eat beetles that were causing crop damage. However, many native frog-eating species, such as snakes, are now dying from the cane toad's poison as the species spreads across Australia. Hypothesize how a toad from the Amazon could, over the course of a few decades, be flourishing in difficult desert terrain in Australia. (7.4) T/I A
94. Baby Burmese pythons are thought to have escaped during Hurricane Andrew from a breeding facility in Florida and ended up in the Everglades. Why would these snakes find this environment so inviting? (7.4) T/I A
95. Scientific theories such as cell theory, atomic theory, and the theory of evolution allow scientists to make accurate and precise predictions. Provide an example of such a prediction from any field of biology. (7.5) T/I A
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96. Polar bears are thought to have evolved from brown bears several hundred thousand years ago. Hypothesize how this might have happened. (7.5) T/I A
97. Some antibiotics that are available only by prescription in the United States and Canada are available over the counter in parts of Asia. Why could this pose a problem in terms of quickly mutating bacteria? (7.5) T/I A
98. According to some evolutionary biologists, predators are extremely important to the health of an ecosystem. There is more biological diversity in ecosystems where top predators (such as wolves, sharks, or tigers) exist, and prey populations are far healthier. Hypothesize why the existence of predators might help, not hurt, prey populations. (7.5) T/I A
99. Scientists gain confidence in their theories when they find more than one kind of supporting evidence for them. What different types of evidence did Charles Darwin find for his theory of evolution? Given these different sorts of evidence, why do you think Darwin waited 20 years to publish his theory? (7.5) T/I A
100. Compare the speed with which advantageous and disadvantageous characteristics spread in populations. (7.5) T/I A
101. Scientific theories must, in principle, have the potential to be falsified. In other words, a theory is not scientific if there is no way to test it. (7.5) T/I A (a) How does dropping an apple "test" the scientific theory that explains gravity? (b) How does discovering a new fossil test the theory of evolution? (c) Describe what you might expect to happen in (a) and (b) if these theories were wrong.
102. Explain how half-lives of radioisotopes are used to obtain precise estimates of the age of rocks. (7.6) T/I A
103. Apply your knowledge of evolution to explain why antelope have eyes on the sides of their heads, with a broad radius of vision (Figure 6). (7.6) T/I A
104. There are approximately 100 remaining Florida panthers in the Everglades. Florida panthers are a subspecies of mountain lions. Would bringing mountain lions into the Everglades from the Rockies help or hurt the Florida panther gene pool? Support your opinion. (7.6) T/I A
105. Consider the wings of penguins and emus. Which is a vestigial feature? Why? (7.6) T/I A
106. The leafy sea dragon (Figure 7) is one of the most bizarre-looking animals on Earth. Use your understanding of evolution to (a) predict the type of habitat in which the sea dragon lives (b) name another animal to which it is closely related (c) describe a possible scenario to explain how natural selection resulted in the evolution of its unusual appearance (8.1) T/I A
107. In the South Pacific, Papua New Guinea is home to only 7 million people. However, over 850 languages have developed in this country. How could this happen? (8.2) T/I A
108. Imagine a circumstance in which a large forest is fragmented into smaller areas due to agricultural and urban expansion and the construction of roads. Explain how such changes could lead to speciation and also threaten the survival of the populations. (8.2) T/I A
109. Why does adaptive radiation often come into play when a population is isolated in an environment with no competition other than members of the same species? (8.3) T/I A
110. The principles of convergent and divergent evolution allow scientists to make predictions, such as that different species will develop similar traits when placed under similar selective pressure. How do these predictions help scientists test the validity of the theory of evolution? (8.3) T/I A
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111. Draw a cladogram based on Table 1 of derived characteristics. Then interpret your cladogram to answer the following: (8.5) T/I A C
(a) Which species represents the outgroup? (b) To which species are walruses most closely related? (c) To which two species are rhinoceroses least closely related? (d) Which derived characteristic provides no useful information for drawing this cladogram? Explain your reasoning. (e) Were you surprised by the evolutionary relationships of these species? What does this suggest about the ability of species to change over time?
Evaluation
112. Examine Figures 4 and 5 on page 283 (Section 7.1). Based on their appearances, which two dogs appear to be most different? Is their degree of difference more or less than the difference between the wolf and the German shepherd (middle dog)? Does this evidence support the possibility that all dogs belong to the same species as wolves (Canis lupus)? (7.1) T/I A
113. On rare occasions, large snakes are born with tiny hind limbs. Using this fact, defend the conclusion that snakes are descended from an ancestor that walked on four legs. (7.4) C A
114. The theory of evolution is supported by many different kinds of evidence, including fossil evidence, anatomy, genetics, biogeography, and experimental results. How does this fact influence the confidence scientists have in the theory? (7.4) T/I A
115. Why did Darwin consider the ability to make predictions important to his theory? Provide examples to illustrate the predictive power of his theory. (7.5) T/I A
116. Paleontologists recently unearthed the first fossil of an extinct species of penguin. The bird, which lived 36 mya, was twice the size of Emperor penguins—the largest living species. The fossil was discovered in Peru, South America. Refer to Figure 7 on page 312 (Section 7.6). (7.6, 8.6) A (a) Today's 17 penguin species can be found living in South America, Africa, Antarctica, Australia, and southern oceans, but none live in North America, Europe, or Asia. Why would this information not be surprising to evolutionary biologists? (b) How might this fossil discovery be similar to that of Tiktaalik?
117. The spread and formation of human languages is sometimes used as an analogy for evolutionary change and even the formation of new species. Consider each of the following descriptions related to human languages and explain how they model processes or situations that occur in evolution. (8.2) A (a) When people move to a new environment they create new words to describe their surroundings. For example, the Inuit have many words to describe snow while people living in the Amazon have none. (b) When a small group of people are tested, they have a smaller vocabulary than that of the large population to which they belong. (c) Canada seems to be the only country in the world where people are often heard to say "eh." (d) A number of Canadians moved to Australia to live. It was noticed that after a few years they had all "picked up" Australian expressions and many even developed a slight Australian accent. (e) Indigenous peoples of the world that are separated by very long distances all speak different languages and can not verbally communicate with each other. (f) New research shows that human languages often change in rapid "bursts" rather than slowly and steadily.
118. What are some of the reasons why people are concerned by the increasing rate of species extinction? What are humans potentially losing as a result? (8.4) C A
119. From what you know of evolution, how can both gradualism and punctuated equilibrium play significant roles in evolution? What kinds of forces or events would result if each type of evolution came into play? (8.5) C A
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Reflect on Your Learning
120. Like scientists, we all look for patterns in the world around us. How do patterns help us make sense of and live in our environments? K/U A
121. Assume that you are an entomologist, or insect scientist, and you have observed a female praying mantis eating a male praying mantis. Also assume you have looked in the scientific literature and found no description of this behaviour. Describe five steps you might take to help you develop and test a hypothesis regarding your praying mantis observation. T/I A
122. People breed both plants and animals to meet specific needs. Do you think there are significant differences in how plants and animals are bred? Think about the processes used for selective breeding, or the types of characteristics that are considered desirable in plants versus animals. Defend your answer with examples. K/U A
123. Lamarck's theories of evolution were both flawed and correct. If you were a scientist in his day, what kind of data would you collect to try to separate the truth from fallacy? And what would you do now, given the tools available to modern scientists? K/U A
124. In 1971, paleontologists in Mongolia found a fossilized velociraptor and protoceratops locked together in combat. The velociraptor had a claw in the throat of the protoceratops, and the protoceratops was biting down on the forelimb of the velociraptor. Hypothesize what happened to these animals. T/I A
125. Darwin began studying the role of earthworms in turning over soil and improving agriculture very early in his career. He came back to this pursuit later on in life. Some of these experiments involved placing stones on the ground, leaving them for decades, and then investigating whether worm action had caused them to sink. At the time, earthworms were considered pests. What conclusions can you draw about Darwin from this earthworm research? And what can young scientists in any field learn from this work? A
126. Does the theory of plate tectonics support the prediction that additional isolated island chains such as the Galapagos and Hawaii will be formed in the future? Why or why not? K/U A
127. How large a role do you think humans have had in the current rapid rate of extinctions on Earth? K/U A
128. What actions, if any, are you willing to take to educate others about the rate of mass extinction or to advocate for protection of Earth's species? Explain your answer. C A
129. How different do you think people's lives will be in 100 years, when many scientists predict that half of all living animal species will be extinct? A
Research GO TO NELSON SCIENCE
130. Jason Gibbs, a York University doctoral student, recently published a study on "sweat bees" These tiny metallic-coloured insects are extremely similar and a nightmare to tell apart. In his painstaking research, Gibbs identified 19 new species, including one he collected on his commute from downtown Toronto to York University. Go online to find out the following: [Go To Nelson Science] T/I (a) Why are these bees considered important to ecosystems? (b) How rapidly have sweat bees evolved? (c) Exactly where and how did Gibbs collect the new species in Toronto? (d) Is this new species of sweat bee rare? (e) How was Gibbs able to tell one species from another?
131. A very interesting outcome of evolution is the formation of “ring species!” Go online to find out more about ring species formation. Research the distribution of Ensatina eschscholtzi salamanders in California. How has their geographic distribution influenced their evolution? [Go To Nelson Science] T/I A
132. In September 2010, scientists reported the discovery of an astonishing new fossil deposit high in the Canadian Rockies. Research this important discovery and report back on the following: [Go To Nelson Science] A C (a) Why is this discovery considered special? (b) How is it related to the famous Burgess Shale fossil site? (c) What types of fossilized animals have been found at the site?
133. During the past 50 000 years, well over half of large mammal species have become extinct. The two most likely causes are climate change and human action. Research the latest evidence in support of these two possible causes. Which one seems to have played the greater role? How might this information be valuable in our present situation? [Go To Nelson Science] T/I A
134. The human appendix has been described as a vestigial feature. Explain why. Research the human appendix and briefly describe one to two hypotheses regarding the function it once played in human anatomy. [Go To Nelson Science] T/I A
SELF-QUIZ
For each question, select the best answer from the four alternatives.
1. Harmful mutations include those that cause
(a) Huntington's disease
(b) cystic fibrosis
(c) reduced reproductive success
(d) all of the above (7.1) K/U
2. From the perspective of a pest species, what type of mutation confers resistance to a pesticide? (7.1) K/U A
(a) harmful mutation
(b) neutral mutation
(c) beneficial mutation
(d) none of the above
3. Artificial selection requires which of the following? (7.1) K/U
(a) hypothesis
(b) independent variable
(c) dependent variable
(d) all of the above
4. Most fossils are in the form of
(a) impressions in rock
(b) impressions in soft clay
(c) impressions in soft lake sediment
(d) impressions in sand (7.2) K/U
5. Which of the following organisms is most likely to become a fossil over time? (7.2) K/U A
(a) clam
(b) jellyfish
(c) land animal
(d) land plant
6. Which of the following statements support(s) the assertion that fossils are remains of very ancient organisms? (7.2) K/U
(a) There are many of fossils of organisms that no longer exist.
(b) There are no fossils of most existing species.
(c) Fossils are often buried deep within rock formations.
(d) all of the above
7. Which of the following describes Charles Darwin's observations from the Galapagos Islands? (7.4) K/U A
(a) no unique species
(b) many native amphibians and land mammals
(c) many species of plants, birds, insects, and some reptiles
(d) all of the above
8. Biogeography is
(a) the study of fossil organisms in order to learn about earlier forms of life
(b) the observed geographic patterns of the distribution of species
(c) the idea that global catastrophes have caused the widespread extinctions of species
(d) the idea that Earth and all living things have been created in their present forms and are unchangeable (7.4) K/U
9. Which of the following pairs are homologous features? (7.4) K/U
(a) horse hind leg and human arm
(b) human arm and bat wing
(c) mouse skull and giraffe skull
(d) porpoise paddle and whale skull
10. Vestigial features include
(a) the gills of a fish
(b) the larynx of a giraffe
(c) goose bumps on a wolf
(d) the hip bones of a snake (7.4) K/U
11. A scientific theory such as evolution must be able to
(a) explain observations
(b) predict outcomes
(c) be tested
(d) all of the above (7.5) K/U
12. Since pseudogenes no longer serve a useful purpose in a species, they can be compared to
(a) homologous features
(b) analogous features
(c) vestigial features
(d) none of the above (7.6) K/U A
13. The increased oxygen-carrying capacity of the blood of native Tibetans is an example of
(a) directional selection
(b) stabilizing selection
(c) disruptive selection
(d) all of the above (8.1) K/U
14. According to Darwin's theory of natural selection, a struggle for survival is a result of which one of the following? (8.1) K/U
(a) many species competing with one another
(b) the large number of offspring born in each generation
(c) the occurrence of mutations
(d) the environment constantly changing
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15. Which of the following is most likely to occur when a small number of individuals establish a new population? (8.1, 8.2) K/U
(a) Hardy-Weinberg principle
(b) genetic bottleneck
(c) founder effect
(d) mechanical isolation
16. Prezygotic mechanisms of reproductive isolation include
(a) ecological isolation
(b) hybrid infertility
(c) zygotic mortality
(d) none of the above (8.2) K/U
17. Convergent evolution is exhibited most clearly by which of the following animal pairs? (8.3) K/U A
(a) whales and elephants
(b) sharks and dolphins
(c) flying squirrels and porcupines
(d) lions and tigers
18. Throughout the history of life, the rate of speciation compared to the rate of extinction has generally been
(a) greater
(b) less
(c) about the same
(d) unrelated (8.4) K/U A
19. The study of abiogenesis is an effort to explain
(a) why the dinosaurs became extinct
(b) how life began
(c) when life began
(d) why the extinction rate is increasing (8.5) K/U
20. A cladogram shows
(a) when groups of organisms arose
(b) evolutionary relationships among groups
(c) mass extinctions
(d) gaps in the fossil record (8.5) K/U
21. Human success can be attributed to which of the following abilities? (8.7) K/U
(a) complex reasoning and learning
(b) complex tool making and use
(c) communication through complex symbolic language
(d) all of the above
Indicate whether each statement is true or false. If you think the statement is false, rewrite it to make it true.
22. Count Buffon, Carl Linnaeus, and Erasmus Darwin all proposed that life changed over time. (7.2) K/U
23. Cuvier's theory of catastrophism is consistent with Charles Darwin's theory of evolution. (7.2, 7.4, 7.5) K/U A
24. Charles Darwin finalized his theory of evolution during his voyage on the HMS Beagle. (7.3, 7.4, 7.5) K/U
25. The hypotheses that Charles Darwin proposed based on his observations of the Galapagos Islands have been supported by observations of life in the Hawaiian Islands. (7.4) K/U A
26. The eyes of flying insects and the wings of flying insects are analogous features. (7.4) K/U
27. Charles Darwin's reading of Malthus led him to wonder if the environment favoured certain individuals due to competition between species. (7.4) K/U A
28. Charles Darwin described natural selection as the way in which the environment favours the reproductive success of certain individuals. (7.5) K/U A
29. Darwin's theory of natural selection explained how and why species evolve. (7.6) K/U
30. The most common forms of sexual selection are female mate choice and male-versus-male competition. (8.1) K/U
31. Adaptive radiation is the evolution of a number of species each occupying different niches from an ancestral species. (8.3) K/U
32. Large-scale evolutionary changes are called endosymbiosis. (8.5) K/U
33. Derived traits are recently evolved traits. (8.5) K/U
34. Neither gradualism nor punctuated equilibrium play a significant role in evolutionary changes. (8.5) K/U
35. The discovery of Tiktaalik by Neil Shubin's team is a great success in the field of molecular biology (8.6) K/U
36. Primate features include large brains compared to body size, side-facing eyes, flexible hands and feet, and arms that can rotate fully. (8.7) K/U
37. To date, the hominid fossil record has revealed two species. (8.7) K/U
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UNIT 3 REVIEW
*Do all MC,T/F and Matching questions.
For #34-137 choose 5 questions from from the following to answer (1 K/U, 2 T/I, 2 A). Write a short answer to each chosen question.
Knowledge
For each question, select the best answer from the four alternatives.
1. Artificial selection
(a) reduces the genetic diversity of a population
(b) increases the genetic diversity of a population
(c) reduces the number of harmful mutations
(d) rapidly produces new species (7.1) K/U
2. After his visit to the Galapagos Islands, Darwin concluded that all the species that lived in the Galapagos must have
(a) crossed land bridges to the islands
(b) arrived by air or water
(c) no relation to animals on the mainland
(d) none of the above (7.3) K/U
3. All vertebrate embryos have
(a) gill slits
(b) five finger bones
(c) short forelimbs
(d) none of the above (7.4) K/U
4. Which of the following four hammerhead sharks would be considered the most fit in terms of natural selection? (7.5) K/U
(a) 10-year-old shark that has broken free from several fishing lines; no offspring
(b) 15-year-old shark that has died from ingestion of trash in the ocean; five live offspring
(c) 25-year-old shark; 15 offspring (all eaten while young)
(d) 20-year-old shark with internal parasites; 10 live offspring
5. Selective pressures may result from
(a) diseases
(b) climatic conditions
(c) food availability
(d) all of the above (8.1) K/U
6. Biologists often describe evolution as a change in
(a) the number of alleles in a population
(b) the frequency of alleles in population
(c) mutation rate
(d) the immutability of nature (8.1) K/U
7. The many species of cichlid fishes in Africa present an excellent example of which pattern of evolution? (8.3) K/U
(a) adaptive radiation
(b) divergent evolution
(c) convergent evolution
(d) none of the above
8. In Figure 1, which species is the common ancestor for all groups except Species T? (8.5) K/U
(a) A
(b) B
(c) C
(d) E
Figure 1
Image: An illustration of how common ancestors can be had for various species.* see mynelson.com text p.382 for cladogram*
9. In Figure 1, which two species are most closely related? (8.5) K/U
(a) U and V
(b) U and T
(c) X and Y
(d) V and W
Indicate whether each statement is true or false. If you think the statement is false, rewrite it to make it true.
10. Most mutations are beneficial and give individuals a better chance of survival. (7.1) K/U
11. Neutral mutations do not play an important role in the evolution of a species. (7.1) K/U
12. Most species exhibit genetic variation. (7.1) K/U
13. In 1838, the Reverend Thomas Malthus claimed that the size of animal populations is limited by the availability of food. (7.2) K/U
14. To Chevalier de Lamarck, the excellent night vision of African bush babies would have been an example of the use and disuse principle. (7.2) K/U
15. The conditions required for fossil formation happen frequently. (7.2) K/U
16. Reverend Thomas Malthus believed that populations can continue to grow indefinitely. (7.4) K/U
17. On remote islands, animals are typically very scared of people. (7.4) K/U
18. The observation that "individuals within all populations vary" leads to the inference that some individuals will inherit characteristics that give them a better chance of surviving and reproducing. (7.5) K/U
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19. A gamete that receives a chromosome with duplicated genes has a low chance of survival. (7.6) K/U
20. Often a small amount of interbreeding still occurs between populations that are gradually becoming reproductively isolated. (8.2) K/U
21. Convergent evolution can result in similar features evolving in very distantly related organisms. (8.3) K/U
22. A species is least likely to undergo adaptive radiation when there is very little competition for a variety of resources. (8.3) K/U
23. Coevolution is most pronounced in symbiotic relationships. (8.3) K/U
24. The fact that many species of fish and waterfowl are darker on top and lighter underneath is most likely a result of coevolution. (8.3) K/U
25. Over Earth's history, the rate of species formation has been, on average, less than the rate of extinction. (8.4) K/U
26. Eukaryotes have existed on Earth for at least 3.5 billion years. (8.5) K/U
27. For more than 100 million years, dinosaurs were the dominant vertebrate herbivores and carnivores on land. (8.5) K/U
28. A cataclysmic event is not needed to cause a species to go extinct. (8.5) K/U
29. Abiogenesis is the study of how life appears on island chains that were previously barren. (8.5) K/U
30. The hominid fossil record from 3.7 million years ago shows that our human ancestors evolved the ability to walk upright only after they had large brains. (8.7) K/U
Match the term on the left with the most appropriate description on the right.
31.
(a) beneficial mutations
(b) harmful mutations
(c) duplication mutation
(d) mutation rates
(i) relatively rare but are favoured by natural selection
(ii) relatively low for individuals but can be numerous in populations overall
(iii) often neutral and so do not immediately benefit the individual
(iv) are selected against and therefore have no influence on populations (7.6) K/U
32.
(a) directional selection
(b) stabilizing selection
(c) disruptive selection
(d) sexual selection
(i) occurs when the most common phenotype within a population is favoured by the environment
(ii) favours individuals with a more extreme variation of a trait
(iii) favours reproductive success of individuals with certain traits over others
(iv) favours individuals with variations at opposite extremes of a trait over individuals with intermediate variations (8.1) K/U
33.
(a) natural selection
(b) small population size
(c) mutation
(d) immigration or emigration
(e) horizontal gene transfer
(i) the gaining of new alleles from a different species
(ii) introduces new alleles to a population
(iii) increases the likelihood of genetic drift
(iv) favours the passing on of some alleles over others
(v) introduces or removes alleles in a population (8.1) K/U
34.
(a) behavioural isolation
(b) temporal isolation
(c) mechanical isolation
(d) gametic isolation
(e) gametic isolation
(i) even very similar species may prefer occupying different habitats in a region
(ii) male gametes may not recognize and fertilize an egg of a different species
(iii) different species use different courtship and other mating clues to find and attract a mate
(iv) different species breed at different times of the year
(v) differences in morphological features may make two species incompatible (8.2) K/U
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35.
(a) zygotic mortality
(b) hybrid inviability
(c) hybrid infertility
(i) hybrid offspring remain healthy and viable but sterile
(ii) a hybrid individual develops but either dies before birth or, if born alive, does not survive
(iii) mating and fertilization are possible, but genetic differences result in a zygote that is unable to develop properly (8.2) K/U
36.
(a) adaptive radiation
(b) divergent evolution
(c) convergent evolution
(i) the large-scale evolution of a group into many different forms
(ii) the relatively rapid evolution of a single species into many new species, filling a variety of formerly empty ecological niches
(iii) the evolution of similar traits in distantly related species (8.3) K/U
Choose 5 questions from from the following to answer (1 K/U, 2 T/I, 2 A). Write a short answer to each chosen question.
37. In science, what is the difference between a hypothesis and a scientific theory? (7.5) K/U
38. Why would unusually wide feet be defined as a beneficial adaptation for snowshoe hares? Give an example of an environment in which the hare's wide feet would have little to no benefit, and explain why. (7.1) K/U
39. Provide an example of the principle of "inheritance of acquired characteristics." (7.2) K/U
40. Explain why Darwin was surprised by the species he found in the Galapagos. (7.3) K/U
41. Provide a piece of evidence suggesting that moles and humans evolved from a common ancestor. (7.4) K/U
42. Define the term "adaptation" as it is used in the theory of evolution. (7.5) K/U
43. How do paleontologists use radioisotopes? (7.6) K/U
44. Define genetic bottlenecks and the founder effect. (8.1) K/U
45. Define genetic drift and provide a circumstance in which it occurs. (8.1) K/U
46. Provide one example of the consequences of human selective pressure and the matching evolutionary change and consequences. (8.1) K/U
47. "Why does allopatric speciation prevent beneficial mutations arising in one population from being shared with another population? (8.2) K/U
48. Define sympatric speciation, and explain how human actions can result in sympatric speciation. (8.2) K/U
49. The Mountain bluebird lives at high elevations, while the Eastern bluebird prefers lower elevations. Which type of reproductive isolating mechanism is at work here? (8.2) K/U
50. Define macroevolution and list some of the large-scale processes associated with macroevolution. (8.5) K/U
51. Based on the fossils of ancestral whales such as Pakicetus, and a modern whale, how has the location of the whale's nostrils changed over time (Figure 2)? What selective advantage does the change provide? (8.5) K/U A
Figure 2 (a) Skulls of Pakicetus and (b) a modern whale
52. Describe how Neil Shubin used fossils to predict when the transition was made between fish and land vertebrates. (8.6) K/U
53. What makes humans unique as a species? (8.7) K/U
Understanding
54. Every year, millions of people worldwide receive seasonal flu shots. As a result, they build immunity against the human influenza virus. Why, then, are health organizations so concerned about the possibility of a deadly epidemic caused by the human influenza virus? (7.1) K/U
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55. Wild tomato plants produce nutritious fruit of variable size. Plant breeders have now bred tomatoes with less variation. Why would uniformity in size be important in the modern food distribution system? (7.1) K/U
56. Why would maintaining genetic diversity in a population help breeders in their quest to produce dramatic changes in a population? (7.1) K/U
57. Paleontologists have observed that rock layers contain fossils of many species that do not occur in layers above or below them. Explain how this observation supports the theory of evolution. (7.2) K/U
58. Explain the roles that Lamarck believed inheritance and the environment played in evolution. (7.2) K/U
59. Describe the steps by which fossils are formed. List environmental conditions that are conducive to fossil formation. (7.2) K/U
60. Cave fish in the family Amblyopsidae that live in perpetual darkness have no eyes or tiny vestigial eyes. Lamarck might argue that this proves his principles of use and disuse. Why is that argument incorrect? What other explanation could there be for the loss of the fish's eyesight? (7.4) K/U
61. Explain why a dew claw is an example of a vestigial feature. (7.4) K/U
62. Do animals face greater competition from members of their own species or from other species in the ecosystem? Defend your opinion with examples. (7.4) K/U
63. Neither amphibians nor terrestrial flightless birds are capable of reaching a remote island by crossing the ocean. Amphibians are strictly freshwater species and terrestrial birds are not capable swimmers. If this is the case, why are large remote islands populated with many native species of flightless birds but not a single species of native amphibians? (7.4) T/I
64. As a scientist, why is it important to consider alternative explanations that might account for your findings when you test hypotheses? (7.4) K/U
65. Which of Darwin's observations support the inference that individuals of all species are in competition for resources? (7.5) K/U
66. Which of Darwin's observations support the inference that individuals inherit characteristics that increase their chance of reproductive success? (7.5) K/U
67. Explain how fossils provide evidence of relationships between primitive and modern species. (7.6) K/U
68. Dolphins have 1000 genes associated with a strong sense of smell, but they do not have a strong sense of smell. Explain why most of these smell genes are examples of pseudogenes. (7.6) K/U
69. The mushrooms of fungi like those shown in Figure 3 have a number of interesting features. Comment on how each of the following might have influenced their evolutionary success. (8.1) K/U A
(a) They are able to produce trillions of spores.
(b) They have surprisingly little energy content when eaten.
(c) Many species are highly toxic.
70. When individuals from a single species become separated by a geographical barrier such as a mountain range, they become less and less alike. Describe at least two reasons why this happens. (8.2) K/U
71. Explain how the process of speciation is analogous to the formation of a new language. (8.2) K/U
72. Explain how new species can evolve within a population either gradually or suddenly. (8.2) K/U
73. Explain the circumstances in which polyploid individuals can produce fertile offspring. (8.2) K/U
74. Explain how mechanical isolation could come into play during the mating flights of dragonflies or damselflies, shown in Figure 4. (8.2) K/U
Figure 4 Male and female migrant hawker dragonflies (Aeshna mixta) mating
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75. Many marine animals, including corals and clams, release their sperm and eggs in open water. Which reproductive isolating mechanism would help ensure the right sperm and eggs combine? How might this work? (8.2) K/U
76. Why would the seemingly small difference of mating at different times of the day foster speciation? (8.2) K/U
77. Explain how Darwin's finches provide an excellent example of adaptive radiation. (8.3) K/U
78. Explain why sharks and dolphins provide a good example of convergent evolution. (8.3) K/U
79. What two outcomes can be predicted based on divergent evolution? (8.3) K/U
80. What two outcomes can be predicted based on convergent evolution? (8.3) K/U
81. What kinds of mass extinction events have occurred on Earth in the past, and why were they so biologically traumatic? (8.4) K/U
82. Although a crocodile would never be mistaken for a bird, scientists are convinced that birds are the closest living relatives of the crocodilians. What evidence supports this assertion? (8.5) K/U
83. It took billions of years for multicellular organisms to evolve from single-celled organisms on Earth. Why was this transition so important for the development of a huge variety of species on Earth? (8.5) K/U
84. What types of evidence (for example, fossils) are used to build phylogenies? Explain why each type of evidence would help to build these diagrams. (8.5) K/U
85. Explain the relationship between the terms "derived trait" and "synapomorphy." (8.5) K/U
86. When evolutionary biologists working with cladograms discuss a "primitive trait" or a "primitive condition:' what does this mean? Are these traits crude relative to current capabilities? (8.5) K/U
87. Compare and contrast two theories used to explain patterns of evolution that occur over long periods of time. (8.5) K/U
88. How does Neil Shubin's work help other paleontologists to make predictions? (8.6) K/U
Analysis and Application
89. While in South America, Charles Darwin found fossilized armadillos and sloths. How did his observations about these species (both living and fossilized) support his theory of evolution? (7.3) T/I A
90. Charles Darwin spent a considerable amount of time observing marine iguanas (Figure 5). A special gland in its snout filters out salt from its blood, and the iguana then "sneezes" that salt out of its body. How did this adaptation allow the marine iguana to fill an available ecological niche in the Galapagos? What other adaptations would help this lizard take advantage of an underwater seaweed food supply? (7.3) T/I A
91. Provide examples to compare analogous and homologous features. Which features provide evidence of evolution? Explain. (7.4) T/I A
92. According to the theories of island biogeography, remote islands share many characteristics with land ecosystems that are surrounded by very different ecosystems (such as a park surrounded by areas inhabited by humans). There are, however, also some significant differences between "island" ecosystems on land and on actual islands. Describe two of these differences. (7.4) T/I A
93. Cane toads are giant poisonous toads from the Amazon rainforest. They were introduced into Australia in the 1930s to eat beetles that were causing crop damage. However, many native frog-eating species, such as snakes, are now dying from the cane toad's poison as the species spreads across Australia. Hypothesize how a toad from the Amazon could, over the course of a few decades, be flourishing in difficult desert terrain in Australia. (7.4) T/I A
94. Baby Burmese pythons are thought to have escaped during Hurricane Andrew from a breeding facility in Florida and ended up in the Everglades. Why would these snakes find this environment so inviting? (7.4) T/I A
95. Scientific theories such as cell theory, atomic theory, and the theory of evolution allow scientists to make accurate and precise predictions. Provide an example of such a prediction from any field of biology. (7.5) T/I A
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96. Polar bears are thought to have evolved from brown bears several hundred thousand years ago. Hypothesize how this might have happened. (7.5) T/I A
97. Some antibiotics that are available only by prescription in the United States and Canada are available over the counter in parts of Asia. Why could this pose a problem in terms of quickly mutating bacteria? (7.5) T/I A
98. According to some evolutionary biologists, predators are extremely important to the health of an ecosystem. There is more biological diversity in ecosystems where top predators (such as wolves, sharks, or tigers) exist, and prey populations are far healthier. Hypothesize why the existence of predators might help, not hurt, prey populations. (7.5) T/I A
99. Scientists gain confidence in their theories when they find more than one kind of supporting evidence for them. What different types of evidence did Charles Darwin find for his theory of evolution? Given these different sorts of evidence, why do you think Darwin waited 20 years to publish his theory? (7.5) T/I A
100. Compare the speed with which advantageous and disadvantageous characteristics spread in populations. (7.5) T/I A
101. Scientific theories must, in principle, have the potential to be falsified. In other words, a theory is not scientific if there is no way to test it. (7.5) T/I A
(a) How does dropping an apple "test" the scientific theory that explains gravity?
(b) How does discovering a new fossil test the theory of evolution?
(c) Describe what you might expect to happen in (a) and (b) if these theories were wrong.
102. Explain how half-lives of radioisotopes are used to obtain precise estimates of the age of rocks. (7.6) T/I A
103. Apply your knowledge of evolution to explain why antelope have eyes on the sides of their heads, with a broad radius of vision (Figure 6). (7.6) T/I A
104. There are approximately 100 remaining Florida panthers in the Everglades. Florida panthers are a subspecies of mountain lions. Would bringing mountain lions into the Everglades from the Rockies help or hurt the Florida panther gene pool? Support your opinion. (7.6) T/I A
105. Consider the wings of penguins and emus. Which is a vestigial feature? Why? (7.6) T/I A
106. The leafy sea dragon (Figure 7) is one of the most bizarre-looking animals on Earth. Use your understanding of evolution to
(a) predict the type of habitat in which the sea dragon lives
(b) name another animal to which it is closely related
(c) describe a possible scenario to explain how natural selection resulted in the evolution of its unusual appearance (8.1) T/I A
107. In the South Pacific, Papua New Guinea is home to only 7 million people. However, over 850 languages have developed in this country. How could this happen? (8.2) T/I A
108. Imagine a circumstance in which a large forest is fragmented into smaller areas due to agricultural and urban expansion and the construction of roads. Explain how such changes could lead to speciation and also threaten the survival of the populations. (8.2) T/I A
109. Why does adaptive radiation often come into play when a population is isolated in an environment with no competition other than members of the same species? (8.3) T/I A
110. The principles of convergent and divergent evolution allow scientists to make predictions, such as that different species will develop similar traits when placed under similar selective pressure. How do these predictions help scientists test the validity of the theory of evolution? (8.3) T/I A
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111. Draw a cladogram based on Table 1 of derived characteristics. Then interpret your cladogram to answer the following: (8.5) T/I A C
Table 1
Species: elephant
Derived characteristics
A: -
B: -
C: -
D: -
E: +
Species: rhinoceros
Derived characteristics
A: +
B: -
C: +
D: -
E: +
Species: rabbit
Derived characteristics
A: +
B: -
C: -
D: +
E: +
Species: monkey
Derived characteristics
A: +
B: -
C: -
D: +
E: +
Species: walrus
Derived characteristics
A: +
B: +
C: +
D: -
E: +
Species: platypus
Derived characteristics
A: -
B: -
C: -
D: -
E: -
(a) Which species represents the outgroup?
(b) To which species are walruses most closely related?
(c) To which two species are rhinoceroses least closely related?
(d) Which derived characteristic provides no useful information for drawing this cladogram? Explain your reasoning.
(e) Were you surprised by the evolutionary relationships of these species? What does this suggest about the ability of species to change over time?
Evaluation
112. Examine Figures 4 and 5 on page 283 (Section 7.1). Based on their appearances, which two dogs appear to be most different? Is their degree of difference more or less than the difference between the wolf and the German shepherd (middle dog)? Does this evidence support the possibility that all dogs belong to the same species as wolves (Canis lupus)? (7.1) T/I A
113. On rare occasions, large snakes are born with tiny hind limbs. Using this fact, defend the conclusion that snakes are descended from an ancestor that walked on four legs. (7.4) C A
114. The theory of evolution is supported by many different kinds of evidence, including fossil evidence, anatomy, genetics, biogeography, and experimental results. How does this fact influence the confidence scientists have in the theory? (7.4) T/I A
115. Why did Darwin consider the ability to make predictions important to his theory? Provide examples to illustrate the predictive power of his theory. (7.5) T/I A
116. Paleontologists recently unearthed the first fossil of an extinct species of penguin. The bird, which lived 36 mya, was twice the size of Emperor penguins—the largest living species. The fossil was discovered in Peru, South America. Refer to Figure 7 on page 312 (Section 7.6). (7.6, 8.6) A
(a) Today's 17 penguin species can be found living in South America, Africa, Antarctica, Australia, and southern oceans, but none live in North America, Europe, or Asia. Why would this information not be surprising to evolutionary biologists?
(b) How might this fossil discovery be similar to that of Tiktaalik?
117. The spread and formation of human languages is sometimes used as an analogy for evolutionary change and even the formation of new species. Consider each of the following descriptions related to human languages and explain how they model processes or situations that occur in evolution. (8.2) A
(a) When people move to a new environment they create new words to describe their surroundings. For example, the Inuit have many words to describe snow while people living in the Amazon have none.
(b) When a small group of people are tested, they have a smaller vocabulary than that of the large population to which they belong.
(c) Canada seems to be the only country in the world where people are often heard to say "eh."
(d) A number of Canadians moved to Australia to live. It was noticed that after a few years they had all "picked up" Australian expressions and many even developed a slight Australian accent.
(e) Indigenous peoples of the world that are separated by very long distances all speak different languages and can not verbally communicate with each other.
(f) New research shows that human languages often change in rapid "bursts" rather than slowly and steadily.
118. What are some of the reasons why people are concerned by the increasing rate of species extinction? What are humans potentially losing as a result? (8.4) C A
119. From what you know of evolution, how can both gradualism and punctuated equilibrium play significant roles in evolution? What kinds of forces or events would result if each type of evolution came into play? (8.5) C A
Print Page 389
Reflect on Your Learning
120. Like scientists, we all look for patterns in the world around us. How do patterns help us make sense of and live in our environments? K/U A
121. Assume that you are an entomologist, or insect scientist, and you have observed a female praying mantis eating a male praying mantis. Also assume you have looked in the scientific literature and found no description of this behaviour. Describe five steps you might take to help you develop and test a hypothesis regarding your praying mantis observation. T/I A
122. People breed both plants and animals to meet specific needs. Do you think there are significant differences in how plants and animals are bred? Think about the processes used for selective breeding, or the types of characteristics that are considered desirable in plants versus animals. Defend your answer with examples. K/U A
123. Lamarck's theories of evolution were both flawed and correct. If you were a scientist in his day, what kind of data would you collect to try to separate the truth from fallacy? And what would you do now, given the tools available to modern scientists? K/U A
124. In 1971, paleontologists in Mongolia found a fossilized velociraptor and protoceratops locked together in combat. The velociraptor had a claw in the throat of the protoceratops, and the protoceratops was biting down on the forelimb of the velociraptor. Hypothesize what happened to these animals. T/I A
125. Darwin began studying the role of earthworms in turning over soil and improving agriculture very early in his career. He came back to this pursuit later on in life. Some of these experiments involved placing stones on the ground, leaving them for decades, and then investigating whether worm action had caused them to sink. At the time, earthworms were considered pests. What conclusions can you draw about Darwin from this earthworm research? And what can young scientists in any field learn from this work? A
126. Does the theory of plate tectonics support the prediction that additional isolated island chains such as the Galapagos and Hawaii will be formed in the future? Why or why not? K/U A
127. How large a role do you think humans have had in the current rapid rate of extinctions on Earth? K/U A
128. What actions, if any, are you willing to take to educate others about the rate of mass extinction or to advocate for protection of Earth's species? Explain your answer. C A
129. How different do you think people's lives will be in 100 years, when many scientists predict that half of all living animal species will be extinct? A
Research GO TO NELSON SCIENCE
130. Jason Gibbs, a York University doctoral student, recently published a study on "sweat bees" These tiny metallic-coloured insects are extremely similar and a nightmare to tell apart. In his painstaking research, Gibbs identified 19 new species, including one he collected on his commute from downtown Toronto to York University. Go online to find out the following: [Go To Nelson Science] T/I
(a) Why are these bees considered important to ecosystems?
(b) How rapidly have sweat bees evolved?
(c) Exactly where and how did Gibbs collect the new species in Toronto?
(d) Is this new species of sweat bee rare?
(e) How was Gibbs able to tell one species from another?
131. A very interesting outcome of evolution is the formation of “ring species!” Go online to find out more about ring species formation. Research the distribution of Ensatina eschscholtzi salamanders in California. How has their geographic distribution influenced their evolution? [Go To Nelson Science] T/I A
132. In September 2010, scientists reported the discovery of an astonishing new fossil deposit high in the Canadian Rockies. Research this important discovery and report back on the following: [Go To Nelson Science] A C
(a) Why is this discovery considered special?
(b) How is it related to the famous Burgess Shale fossil site?
(c) What types of fossilized animals have been found at the site?
133. During the past 50 000 years, well over half of large mammal species have become extinct. The two most likely causes are climate change and human action. Research the latest evidence in support of these two possible causes. Which one seems to have played the greater role? How might this information be valuable in our present situation? [Go To Nelson Science] T/I A
134. The human appendix has been described as a vestigial feature. Explain why. Research the human appendix and briefly describe one to two hypotheses
regarding the function it once played in human anatomy. [Go To Nelson Science] T/I A