ap lectureguide23


AP Biology: CHAPTER 23- THE EVOLUTION OF POPULATIONS

1. How does the “modern synthesis” theory of evolution differ from Darwin’s Theory of Natural

Selection?

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2. Population genetics puts a mathematical approach to the study of microevolution. Define

each of the terms commonly used in population genetics.

a. population: _____________________________________________________________

b. gene pool: ______________________________________________________________

c. gene frequency: _________________________________________________________

3. What are the gene frequencies for the red and white flowers?

a. p = ____________________________________________________________________

b. q = ____________________________________________________________________

4. List the five condition that must be met by a populations to insure stability (no evolution).

a. ______________________________________________________________________

b. ______________________________________________________________________

c. ______________________________________________________________________

d. ______________________________________________________________________

e. ______________________________________________________________________

5. Assuming Hardy-Weinberg distribution of genes in a population, write the equation that

describes genotype frequencies.

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6. Define the following:

a. p2 = ___________________________________________________________________

b. 2pq = __________________________________________________________________

c. q2 = ___________________________________________________________________

7. Work out these practice problems. Find both the gene and genotype frequencies:

a. In Drosophilia, the allele for normal length wings is dominant over the allele for vestigial

wings. In a population of 1,000 individuals, 160 show the recessive phenotype.

b. The allele for the hair pattern called "widow’s peak" is dominant over the allele for no

"widow’s peak." In a population of 1,000 individuals, 360 show the dominant phenotype.

8. What is the H-W assumption that is broken when genetic drift occurs? Explain

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9. How does genetic drift apply to each of the following? Give an example of each.

a. Founders effect: _________________________________________________________

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b. Bottleneck effect _________________________________________________________

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10. How do each of the following break H-W assumptions?

a. natural selection: ________________________________________________________

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b. gene flow: ______________________________________________________________

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c. mutation: _______________________________________________________________

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d. selective mating: _________________________________________________________

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11. Why is genetic variation important to evolution?

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12. How can populations vary along a geographic axis compared to isolated populations?

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13. What is the role of mutations to forming variation?

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14. What factors of sexual reproduction lead to variations within a population?

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15. How does diploidy preserve variation?

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16. What is “balanced polymorphism?”

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17. How can parasites contribute to balanced polymorphism?

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18. In a biological sense, what is fitness?

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19. Label the following graphs of variation in color with the type of selection.

20. What is the effect of sexual selection?

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21. For each of the following, give an example or describe what is meant by the statement.

a. Natural selection cannot fashion perfect organisms: _____________________________

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b. Evolution is limited by historical constraints: ___________________________________

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c. Adaptations are often compromises: _________________________________________

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d. Not all evolution is adaptive: _______________________________________________

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e. Selection can only edit existing variations: ____________________________________

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