BIO 440: Population Genetics and Evolution

Study Questions - The Neutral and Nearly Neutral Models

1) Differentiate between hard and soft selection.

2) All genetic variation is NOT of selective value. Give two obvious examples.

3) Through equations, show why the rate of substitution = the mutation rate.

4) What predictions does the neutral model make abou the rates of molecular evolution in: codon positions, exons vs. introns, functional vs. non-functional regions of proteins, and vital vs. non-vital proteins?

5) How can these differences in rate be explained from a selectionist perspective?

6) Should neutral substitution rates follow a generational or absolute clock?

7) How does Ohta's nearly neutral model, which looks at the relative effects of weak selection and drift, explain this discrepancy between an expected difference based on genration time, and the observed susbstitution rate that is constant and independent of generation time?

8) Does the rate of molecular evolution vary in lineages with different rates of morphological change? Why or why not?