Chapter 15 Teacher Guide and Answers Diagnostic Test Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Page 38 1. The correct answer is C. Based on student responses, use the list below to address preconceptions. • Student thinks Darwin developed the theory of evolution aboard the HMS Beagle. Direct student to the developing the theory of evolution by natural selection discussion in Section 1. • Student thinks people living during Darwin’s time accepted the theory of evolution. Direct student to the developing the theory of evolution by natural selection discussion in Section 1. • Student thinks Darwin observed evolutionary changes. Explain to student that most evolutionary changes normally occur over long periods of time and are not observable. • Student confuses evolution with natural selection. Explain to student that evolution is the theory that species change over time, but natural selection is the proposed process by which species change. • Student is confused by the idea of natural selection. Direct student to the developing the theory of evolution by natural selection discussion in Section 1. 2. The correct answer is D. Based on student responses, use the list below to address preconceptions. • Student is unaware of vestigial structures. Direct student to the comparative anatomy discussion in Section 2. • Student thinks the fossil record demonstrates clear evidence of evolutionary changes for most organisms. Direct student to the fossil record discussion in Section 2. • Student thinks breeding domesticated varieties of organisms demonstrates evolutionary change. Explain that domesticated varieties of organisms, such as dog breeds, are not separate species that demonstrate a change in a species over time. • Student thinks vertebrate embryos do not share common features. Direct student to the comparative embryology discussion in Section 2. Unit 4 3. The six species share a recent common ancestor—they possibly belonged to the same species in the past. Because of a physical or behavioral isolating mechanism they evolved into the six species present today. These species are not able to interbreed. Based on student responses, use the list below to address preconceptions. • Student does not understand that the six species of chickadees share a common ancestor. Direct student to the speciation discussion in Section 3. • Student thinks members of different species can interbreed. Direct student to the speciation discussion in Section 3. • Student thinks two species always evolve due to a physical barrier that isolates two populations. Direct student to the speciation discussion in Section 3. • Student does not understand how natural selection causes speciation. Direct student to the speciation discussion in Section 3. Launch Lab Page 39 • How does selection work? Analysis 1. Answers will vary. Square 1 is less likely to be chosen in the group with eight red squares. 2. It is less likely Square 1 from the group with eight red squares will be eaten because there are more red squares in that group that the predator can choose from. MiniLab Page 40 • Investigate Mimicry Analysis 1. The monarch butterfly is dark orange with black veins and a row of white spots on the edge of its wings. The viceroy has the same color pattern except for a black horizontal stripe across the bottom of its wings. 2. Answers may vary, but the bright colors serve as warnings to signal the toxicity to predators. CHAPTER 15 TEACHER GUIDE AND ANSWERS 151 Chapter 15 Teacher Guide and Answers BioLab Page 41 • Can scientists model natural selection? Real-World Biology: Lab Page 43 • Modeling Natural Selection Planning the Activity Use this activity to reinforce student understanding of natural selection. It can also be used to reinforce basic principles of genetics, gene frequency, and predator-prey relationships. Purpose Students develop a model to observe how natural selection can affect a population of organisms when the environment changes. Career Applications Wildlife managers perform many duties associated with conserving species of fish and wildlife. They conduct population counts, reintroduce endangered species, and evaluate the impact of state and federal programs. They might use aerial or ground 152 CHAPTER 15 TEACHER GUIDE AND ANSWERS Materials Tips Materials page of newspaper want ads, sheet of brown butcher paper of the same size, envelope with 50 butcher-paper circles and 50 newspaper want-ad circles cut out with a paper punch, stopwatch or clock • A paper punch should be used to make the butcher-paper circles and newspaper want-ad circles. • Place circles in envelopes or small film containers until needed. Have students replace the circles in the containers after the activity so you can reuse them. • When you punch out the newspaper circles, be sure there is print on both sides of each circle. • If a stopwatch is not available, a clock with a second hand can be used. Teaching Strategies • Have students read the procedure first, then ask them “Which lizards do you think will be easier to see on the black-and-white background?” “Which lizards do you think will be easier to see on the brown background?” Unit 4 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Analyze and Conclude 1. To calculate the percentage, students should divide the number of forceps/pliers that survived by the total number of forceps/pliers in the community. Answers will vary based on class data. 2. To determine the number of offspring produced in the community, students should calculate the number of offspring produced by the forceps/ pliers in each group, and then add the group members. 3. To calculate the ratio, students should write (the number of offspring forceps): (the number of offspring pliers). Answers will vary based on class data. 4. Answers will vary based on class data. If the survival percentage is low, the population will not persist. If relatively few offspring are produced, the population will likely decline over generations. 5. The population that produces the most offspring will be most likely to grow over time. Body structure variations that make it easier to obtain food are likely to be passed to offspring by surviving individuals. photography to track animals or monitor the migration of animals. Wildlife managers enforce laws and regulations that are designed to maintain wildlife populations at optimum levels. Additionally, wildlife managers are public relations specialists and educators. A career in wildlife management requires a strong interest in wildlife and the outdoors. Excellent physical and mental health is needed. Wildlife managers should like and understand people as well as wildlife because most jobs involve working with the public. A wildlife manager should have the ability to assume responsibility and work on his or her own. To be a wildlife manager, a person must have a college degree in biology or natural resources management. Studies must include courses in wildlife subjects, zoology, and botany or related plant sciences. Preparing for a career in wildlife management can begin in high school by taking courses in biology, chemistry, physics, math, and computers. Activities such as camping, hiking, hunting and fishing, bird watching, and wildlife photography will help to understand wildlife. Chapter 15 Teacher Guide and Answers • Monitor students to be sure that the circles are randomly scattered on the background and not piled up. • Turn the classroom lights down to make picking up the “lizards” more difficult. Tell students that the owl predator in this activity hunts for prey just before sunrise or just after sunset. • You might have to review with students how to calculate the percentage of survivors and the percentage of lizards that died. • Below Level: If students are having trouble with question 4, review the basics of Mendelian genetics and population genetics. • Above Level: Have students test their predictions from question 5. Have them take the surviving lizards from step 5, place them on newspaper, and repeat step 3. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers to Student Worksheet Analyze and Conclude 1. The percentage of speckled lizards that survived probably decreased when the environment changed because they would be more easily seen and picked up by the owl against the brown background. 2. The percentage of brown lizards that survived probably increased when the environment changed because they would be harder for the owl to see and pick up against the brown background. 3. If an organism has characteristics that enable it to blend in with its environment, its chances of survival will increase, and it will be more likely to reproduce than organisms that do not have such characteristics. 4. When BB and bb lizards mate, Bb lizards will be produced. When Bb lizards mate, some brown bb lizards will be produced. Because Bb lizards are likely to survive and reproduce, brown bb lizards are not likely to disappear completely from the population. 5. The fitness of speckled lizards would increase in the black-and-white rock environment; therefore, more would survive and reproduce. The number of speckled lizards in the population would gradually increase. Brown lizards would decrease in number because they would be less fit. Unit 4 6. Changing the predator would introduce another variable into the experiment. For example, partners might have different eyesight or be able to pick up the circles at different speeds. Careers in Biology Wildlife managers help conserve species of fish and wildlife. They conduct population counts, reintroduce endangered species, and evaluate the impact of state and federal programs. Enrichment Page 45 • Darwin’s Finches Student articles will vary but should be clearly written and accurate. All questions posed should be thoroughly researched, and answers should be supported by the research. All sources should be accurately cited. Drawings or photographs of the finches would be useful in student articles. Concept Mapping Page 46 • Patterns of Evolution 1. adaptive radiation 2. convergent evolution 3. more similar to unrelated species 4. change in response to each other 5. many similar but distinct species 6. unrelated species with similar characteristics 7. species with symbiotic relationships 8. Galápagos finches Study Guide Page 47 • Section 1 1. true 2. false 3. true 4. false 5. false 6. A 7. B 8. D 9. C CHAPTER 15 TEACHER GUIDE AND ANSWERS 153 Chapter 15 Teacher Guide and Answers Page 48 • Section 2 1. C 2. E 3. D 4. B 5. A 6. Homologous Structure 7. Vestigial Structure 8. Comparative Biochemistry 9. Analogous Structure 10. Vestigial Structure 11. true 12. biogeography 13. true 14. adaptations 15. harmful 16. true 17. true 18. true Page 50 • Section 3 Guía de estudio Página 51 • Sección 1 1. verdadero 2. falso 3. verdadero 4. falso 154 CHAPTER 15 TEACHER GUIDE AND ANSWERS Página 52 • Sección 2 1. C 2. E 3. D 4. B 5. A 6. Estructura homóloga 7. Estructura vestigial 8. Bioquímica comparativa 9. Estructura análoga 10. Estructura vestigial 11. verdadero 12. biogeografía 13. verdadero 14. adaptaciones 15. dañina 16. verdadero 17. verdadero 18. verdadero Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. Genetic drift 2. Disruptive selection 3. stabilizing selection 4. founder effect 5. sympatric speciation 6. Directional selection 7. allopatric speciation 8. Sexual selection 9. adaptive radiation 10. gradualism 11. the darker moth (moth B) 12. industrial melanism 5. falso 6. A 7. B 8. D 9. C Página 54 • Sección 3 1. deriva genética 2. selección disruptiva 3. selección estabilizadora 4. efecto fundador 5. especiación simpátrica 6. selección direccional 7. especiación alopátrica 8. selección sexual 9. radiación adaptiva 10. gradualismo 11. la mariposa más oscura (mariposa B) 12. melanismo industrial Unit 4 Chapter 15 Teacher Guide and Answers Section Quick Check Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Page 55 • Section 1 1. (1) Individuals in a population show differences, or variations, even among individuals of the same species. (2) Variations are inherited. (3) Animals have more young than can survive on the available resources. (4) Variations that increase reproductive success will be common in the next generation. 2. Alfred Russel Wallace’s theory was almost identical to Darwin’s theory. 3. All of today’s species are descended from one or a few ancestral species, and natural selection is the process by which ancestral species become modified into new species. 4. Artificial and natural selection both result in species changing over time. In artificial selection, humans breed a species to increase the frequency of a trait. In natural selection, species change over time according to variations that increase the reproductive success. 5. Wheat would be tested for fiber content, and only those with a high level would be planted and crossbred. The offspring of successive generations would also be tested and crossed. Eventually, the level of fiber in the offspring will increase. Page 56 • Section 2 1. An adaptation is a trait that makes individuals better able to survive or reproduce than individuals without those traits. 2. If a structure such as a wing does not increase the reproductive success of the organism, it might become a vestigial structure through evolution. This can happen when a population contains individuals that expend less energy on the development of such a structure and more energy on other activities. These individuals will probably be more successful in reproduction. As a result, these individuals will survive in greater numbers and pass on their traits to their offspring. Eventually, individuals that have smaller versions of the structure, and thus use the least energy on developing the structure, will become most prevalent in a population. Unit 4 3. Homologous structures are inherited from a common ancestor, and analogous structures are not. 4. The color pattern of the California kingsnake is mimicry, not camouflage. It makes the snake resemble a harmful species but does not help the snake blend in with its surroundings. 5. Squirrels and rabbits will have more similar DNA because squirrels are more like rabbits than like antelope. DNA is more similar in more closely related species. Page 57 • Section 3 1. Genetic bottlenecks reduce the total alleles in a gene pool, and the population that results can be unusually genetically similar. 2. relatively sudden speciation followed by long periods of stability 3. Scientists determine that evolution will not occur in a population unless the allelic frequencies are acted on by outside forces that cause change. 4. There are 60 + 60 + 30 = 150 O alleles and 30 + 10 + 10 = 50 o alleles. The total number of alleles is 150 + 50 = 200 alleles. The O allele frequency is 150/200, or 0.75. The o allele frequency is 50/200, or 0.25. 5. Sexual selection does not always result in selection of traits that are best for survival in a particular environment, so it will not always lead to better survival of a species. Chapter Test A Page 58 • Part A: Multiple Choice 1. C 2. D 3. C Page 58 • Part B: Matching Matching Set 1 1. homologous structure 2. vestigial structure 3. analogous structure 4. vestigial structure CHAPTER 15 TEACHER GUIDE AND ANSWERS 155 Chapter 15 Teacher Guide and Answers Matching Set 2 5. D 6. A 7. B Page 59 • Part C: Interpreting Graphs 1. The graph illustrates directional selection. The graph shows a shift in snail numbers away from one extreme, which is light coloration. 2. The graph illustrates disruptive selection. The graph shows a shift in number toward the extremes of a trait and away from the mean. Page 59 • Part D: Short Answer Page 60 • Part E: Concept Application 1. Darwin would have explained the many different verities of guppies as an example of artificial selection. He would have noticed that the breeders of guppies were breeding fish for certain characteristics. This is known as selective breeding today. Through artificial selection, breeders have chosen guppies with different traits such as varying colors and tail shapes. Although guppies show a wide variety of traits, all guppies are still considered one species. 2. The adaptation of the syrphid fly is an example of mimicry. Mimicry is an adaptation of body features so that one species resembles another 156 CHAPTER 15 TEACHER GUIDE AND ANSWERS Chapter Test B Page 61 • Part A: Multiple Choice 1. C 2. D 3. B 4. A Page 61 • Part B: Matching and Completion Matching 1. homologous structure 2. vestigial structure 3. analogous structure 4. vestigial structure Completion 5. artificial selection 6. adaptation 7. fitness 8. sexual selection Page 62 • Part C: Interpreting Graphs 1. The graph illustrates directional selection. The dark-colored snails can camouflage better with their natural surroundings and avoid predation more frequently than the light-colored snails. 2. The graph illustrates disruptive selection. The population probably has two primary habitats. The squirrels with light-colored fur populate a light-colored habitat, and the squirrels with dark-colored fur populate a dark-colored habitat. A squirrel with a color of fur between light and dark matches neither habitat and presents an easier target for predators. Page 62 • Part D: Short Answer 1. The peppered moth produces more offspring than can survive on the available resources, and these offspring show a variation in colors. Some moths are light colored and others are dark. These color traits are passed down from parent moths to their offspring. During the initial Unit 4 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. Animals produce more young than can survive on the available resources. Offspring of the same species show variation of traits. These traits are passed on from parents to offspring. Finally, variations that increase reproductive success will be more common in future generations. 2. Evolution is the change in a species over time. 3. The bull fur seal, a mammal, and the emperor penguin, a bird, are different animals, but both are adapted to an aquatic environment. Convergent evolution is when organisms that live in different places and are often unrelated resemble each other in shape, size, and behavior. The bull fur seal and the emperor penguin are such an example. They are different animals from different places, but have similar structures and shapes. species. The fly is harmless, but because its markings resemble the stinging yellow jacket, it is less vulnerable to predation. Chapter 15 Teacher Guide and Answers industrialization of England, air pollution darkened the trunks of trees making the darker colored moths better camouflaged from predators. More dark-colored moths survived to reproduce, and this reproductive success led to the dark-colored moths becoming more common. 2. The shared traits among vertebrate embryos, such as a tail, provide evidence of the shared ancestry of vertebrates. Physical traits that are not always apparent or present in the adults of different species can be observed in their embryos. This is why scientists often compare embryos to search for evolutionary relationships. 3. This is an example of convergent evolution. The bull fur seal, a mammal, and the emperor penguin, a bird, are different animals, but both of these animals are adapted to an aquatic environment. These organisms evolved in different places and are not closely related, but they evolved similar structures and behaviors in response to their environments. Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Page 63 • Part E: Concept Application 1. The syrphid fly is about the same size as the yellow jacket, and it has black and yellow stripes. The fly is harmless and cannot sting, but because it mimics the stinging yellow jacket, it is less desirable to predators. 2. The conditions include: random mating, no emigration or immigration, no mutations, and no natural selection. The violation is that the population is small, not large. Chapter Test C Page 64 • Part A: Multiple Choice 1. A 2. B 3. D 4. D 5. A Page 64 • Part B: Completion 1. artificial selection 2. evolution 3. comparative embryology 4. constraint Unit 4 5. bottleneck 6. gradualism Page 65 • Part C: Interpreting Graphs 1. The graph illustrates directional selection. The dark snails probably have the advantage of better camouflage against predators, but if the snails’ environment becomes lighter in color, the snails with a light coloration will have the advantage. A lighter colored environment will cause an increase in the survival rate of light-colored individuals, and the graph will shift back toward the light color extreme. 2. The population probably has two primary habitats. The squirrels with light color fur populate a light-colored habitat, and the squirrels with dark color fur populate a dark-colored habitat. This is disruptive selection—when two populations are created with extreme traits. If one of the habitats changes colors or becomes uninhabitable for squirrels, the coloration of the squirrel fur will shift toward directional selection. This means that the coloration of the squirrels would begin to tend toward the color of the unaffected environment. Page 65 • Part D: Short Answer 1. Both are morphological adaptations. Mimicry is an adaptation in which one species resembles another species, and camouflage is an adaptation in which a species resembles its surroundings. The adaptation can be combined if a species mimics the camouflage of another species. 2. Homologous structures are anatomically similar structures inherited from a common ancestor. An example would be bird wings evolved from reptile forearms. Vestigial structures, such as the human appendix, are features with a reduced function in the organism. Analogous structures have the same function, but they do not have a common ancestry. Eagle wings and bee wings would be an example. 3. Homozygous dominant: 0.525; heterozygous dominant: 0.397, homozygous recessive: 0.075. Note: Numbers are rounded to the thousandth place. CHAPTER 15 TEACHER GUIDE AND ANSWERS 157 Chapter 15 Teacher Guide and Answers Page 66 • Part E: Concept Application 158 CHAPTER 15 TEACHER GUIDE AND ANSWERS Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 1. Polar bears produce more offspring than can survive on the available resources and these offspring show a variation in fur colors. Some of the bear cubs are born with thicker fur that is lighter in color. These fur color and thickness traits are passed down from parent bears to their offspring. The snow-covered environment favored the lighter colored bears because they were better camouflaged to hunt prey. Bears with thicker fur also had a survival advantage in the cold northern temperature than thin-furred bears. More light-colored, thick-furred bears survived to reproduce, and this reproductive success led to white bears with thick fur becoming more common. The isolation of polar bears from brown bears eventually led to the evolution of two distinct species. 2. Eye color in humans is a trait, but it is presently not considered an adaptation because it does not contribute to the survival and reproductive success of an individual. Measurements of the fitness of people with different eye colors would be statistically equal. 3. They exhibit sympatric speciation because the two species evolved without being separated by any natural barriers. Presumably, the ancestor species and new species lived side by side during the speciation process. Unit 4