Evolution Integrative Biology 160 Mid Term Examination Answer Key.

1. How does recombination happen? Its origin is centrally related to the evolution of sex. Give two explanations as to why it evolved and is maintained. (15 points)

2. Suppose a population is split into two parts, which do not exchangegenes. Describe the expected series of events in the differentiation of these populations, and relate concepts of lineage and genealogy to species formation. Draw on the article by Graybeal in the reader. (15 points)

Using the fictional tree of taxa shown below, use terms (e.g., symplesiomorphy, paraphyletic, etc.) to identify:

3. Character state a
4. Character state b
5. Character state d
6. Group 1-2-3
7. Group 4-5
8. Group 3-4
9. Group 1-4-5

Terms can be used more than once (14 points).

10. Explain why effective population size is more appropriate than census number when trying to assess the importance of stochastic factors in evolution. (10 points).

11. List the main tenets of natural selection. (12 points)

12. Why do researchers use indirect rather than direct methods for estimating the level of gene flow? What is a main problem with this approach? (10 points)

13. Name three important sources of genetic novelty. (15 points)

14. Why is inbreeding generally maladaptive? (4 points)

15. Heterozygosity is often used as a surrogate for what? Why are evolutionists so interested in it? (5 points).