Study Questions - Deviations from HWE
Relevant Readings: chapter 6
1) Consider a population with p = 0.8, q = 0.2, and a mutation rate of a-->A of 0.00003. What will the new gene frequencies be after one generation of mutation?
2) Suppose there was also mutation of A--> a at a rate of 0.00004? What would delta-q be? At what frequency would q equilibrate? Prove this by plugging that gene frequency in and testing for delta-q... what do you get? Is that right?
3) Consider two populations. 1: p = 0.8, q= 0.2..... 2: p = 0.4, q = 0.6. Suppose migration occurs from 1 to 2, such that migrants represent 10% of the population... what will the new gene frequencies be in Pop 2?
What is the Genetic Distance between these populations?
4) Consider a population, p = q = 0.5, in HWE. Suppose there is exclusive positive assortative mating for this trait. How will the genotypic frequencies change over 2 generations?
5) How do the effects of positive assortative mating and inbreeding differ?
6) List the effects that inbreeding has on a population.
7) Calculate F for the following population:
| p=0.3 q = 0.7 | AA | Aa | aa | |
| parental zygotes | 0.18 | 0.24 | 0.58 | = 1.00 |
8) Define genetic drift. How does sample size affect the relationship between the sample and the population, and between repeated samples of a given size?
9) List 5 reasons why a reproductive population may act, genetically, as a population much smaller than the total population.
10) Explain how selection at one locus can cause drift at another locus.
11) What is coalescence, and why does it occur? What is the consequence of coalescence in terms of relatedness among mates?
12) Why does inbreeding necessarily increase as time passes - include the effects of drift and coalescence.
13) What's the exact probability that a given allele becomes fixed in the population?
14) What is the probability that a brand new allele will be come fixed in a population? How long will this take, on average, if drift is the only agent of change?
15) How are heterozygosity and variation related? When is a population most variable (and most heterozygotic if in HWE?). How will drift affect the variation within a population?
16) Explain the Wahlund Effect.
17) Why can we measure the effects of drift by measuring the decline in heterozygosity of subdivided populations?