Further Thought

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Further Thought

Use the questions at the end of the chapter to explore concepts and connections in greater depth through application and synthesis.

1. In everyday English, the word adaptation means "an adjustment to environmental conditions." How is the evolutionary definition of adaptation different from the everyday English sense? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

2. Think about how the finch bill data demonstrate Darwin's postulates. What would figure 3.6 have looked like if bill depth was not variable? What would figure 3.10 look like if bill depth was variable, but the variation was not heritable? In figure 3.7, why is the line drawn from the 1978 data, after the drought, higher on the y axis than the line drawn from the 1976 data, before the drought? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

3. According to the text, it is legitimate to claim that most finches died from starvation during the 1977 drought because "there was a strong correspondence between population size and seed availability." Do you accept this hypothesis? If so, why don't the data in Figure 3.8 show a perfect correspondence between when seed availability started declining and when population size started declining? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

4. Suppose that you are starting a long-term study of a population of annual, flowering plants isolated on a small island. Reading some recent papers has convinced you that global warming is real and will lead to significant, long-term changes in the amount of rain the island receives. Outline the observations and experiments you would need to do in order to document whether natural selection occurs in your study population over the course of your research. What traits would you measure, and why? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

5. At the end of an article on how mutations in variable number tandem repeat (VNTR) sequences of DNA are associated with disease, Krontiris (1995, p. 1683) writes: the VNTR mutational process may actually be positively selected; by culling those of us in middle age and beyond, evolution brings our species into fighting trim. This researcher proposes that natural selection on humans favors individuals who die relatively early in life. His logic is that the trait of dying from VNTR mutations is beneficial and should spread, because the population as a whole becomes younger and healthier as a result. Can this hypothesis be true, given that selection acts on individuals? Explain. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

6. Many working scientists are relatively uninterested in the history of their fields. Did the historical development of Darwinism, reviewed in Section 3.6, help you understand the theory better? Why or why not? Do you think it is important for practicing scientists to spend time studying history? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

7. Recently, the Alabama School Board, after reviewing high school biology texts, voted to require that this disclaimer be posted on the inside front cover of the approved book (National Public Radio 1995):
This textbook discussed evolution, a controversial theory some scientists present as a scientific explanation for the origin of living things, such as plants, animals, and humans. No one was present when life first appeared on Earth; therefore, any statement about life"s origins should be considered as theory, not fact.

Do you accept the last sentence in this statement? Does the insert"s point of view pertain to other scientific theories, such as the Cell Theory, the Atomic Theory, the Theory of Plate Tectonics, and the Germ Theory of Disease? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

8. A 1991 Gallup poll of U.S. adults found that 47 of the respondents believed that God created man within the last 10,000 years (Root-Bernstein, 1995). Given the evidence for evolution by natural selection, comment on why so few people in the United States accept it. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.




1.	In everyday English, the word adaptation means "an adjustment to environmental conditions." How is the evolutionary definition of adaptation different from the everyday English sense? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



2.	Think about how the finch bill data demonstrate Darwin's postulates. What would figure 3.6 have looked like if bill depth was not variable? What would figure 3.10 look like if bill depth was variable, but the variation was not heritable? In figure 3.7, why is the line drawn from the 1978 data, after the drought, higher on the y axis than the line drawn from the 1976 data, before the drought? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



3.	According to the text, it is legitimate to claim that most finches died from starvation during the 1977 drought because "there was a strong correspondence between population size and seed availability." Do you accept this hypothesis? If so, why don't the data in Figure 3.8 show a perfect correspondence between when seed availability started declining and when population size started declining? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



4.	Suppose that you are starting a long-term study of a population of annual, flowering plants isolated on a small island. Reading some recent papers has convinced you that global warming is real and will lead to significant, long-term changes in the amount of rain the island receives. Outline the observations and experiments you would need to do in order to document whether natural selection occurs in your study population over the course of your research. What traits would you measure, and why? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



5.	At the end of an article on how mutations in variable number tandem repeat (VNTR) sequences of DNA are associated with disease, Krontiris (1995, p. 1683) writes: the VNTR mutational process may actually be positively selected; by culling those of us in middle age and beyond, evolution brings our species into fighting trim. This researcher proposes that natural selection on humans favors individuals who die relatively early in life. His logic is that the trait of dying from VNTR mutations is beneficial and should spread, because the population as a whole becomes younger and healthier as a result. Can this hypothesis be true, given that selection acts on individuals? Explain. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



6.	Many working scientists are relatively uninterested in the history of their fields. Did the historical development of Darwinism, reviewed in Section 3.6, help you understand the theory better? Why or why not? Do you think it is important for practicing scientists to spend time studying history? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



7.	Recently, the Alabama School Board, after reviewing high school biology texts, voted to require that this disclaimer be posted on the inside front cover of the approved book (National Public Radio 1995): This textbook discussed evolution, a controversial theory some scientists present as a scientific explanation for the origin of living things, such as plants, animals, and humans. No one was present when life first appeared on Earth; therefore, any statement about life"s origins should be considered as theory, not fact. Do you accept the last sentence in this statement? Does the insert"s point of view pertain to other scientific theories, such as the Cell Theory, the Atomic Theory, the Theory of Plate Tectonics, and the Germ Theory of Disease? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



8.	A 1991 Gallup poll of U.S. adults found that 47 of the respondents believed that God created man within the last 10,000 years (Root-Bernstein, 1995). Given the evidence for evolution by natural selection, comment on why so few people in the United States accept it. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.

Chapter 3: Darwinian Natural selection

Further Thought