Question

Please show work so I can get a full understanding.Thank you! :)

1. Consider the equation ∆p = p(1/2 − p)(1 − p) Find all of its equilibria and classify them in terms of stability.

2. What is the equilibrium frequency of a recessive gene arising with a mutation rate of 4×10−6 and a reproductive fitness in homozygotes of 0.8? What would it be if the gene were partially recessive with h = 0.05? How different are these two equilibrium frequencies? Explain the difference. Calculate and compare the genetic loads under these two conditions (use the full equation for ¯w).

3. The fitness of the A1A1, A1A2, and A2A2 genotypes are 1.2, 0.9, and 1.0, respectively. Calculate the selection coefficient and heterozygous effect. What kind of selection is this? Where will the population ultimately end up in terms of allele frequencies?

Answer 1

ans)

2.

3. Relative fitness = individual allelic fitness / the fitness of A1A1

the relative fitness of A1A1 (homozygotes) = 1.2 /1.2 = 1

= 0.9/1.2 = 0.75

= 1.0/1.2 = 0.83

if the relative fitness of fittest homozygotes is defined as 1, then we define s as the difference between that and the relative fitness of the other homozygotes

s = 1- 0.83

= 0.17

the heterozygous effect can be found from the fitness of the heterzygotes:

0.75 = 1 - hs

hs = 1- 0.75 = 0.25

h = 3 x 0.25

h = 0.75