Question

Assume that you just calculated baseline allele frequencies for this population So at time TO. Suppose these flies were allowed to mate and produce offspring for the next two weeks. The population is large, rates of mutation at the body color locus are low, and flies cannot enter or leave the source population If the allele frequencies were: f(e)=0.55 and f(E)=0.45, and you waited 2 weeks (one fly generation) to take another sample of flies (S1 flies at T1), what genotype frequencies would you expect to see? To calculate expected genotype frequencies for S1 and T1, use a Prout Square (for populations). Place the observed allele frequencies in each of the marginal squares (see the table below), then multiply them together to fill in the center four values (A, B, C, and D). Do this in your lab manual (page 125). What are the expected genotypic frequencies under the hypothesis of no evolution? (Do not leave answers as fractions)

please help me out in Q24 and Q25!! all info is given. thank you

Answer 1

24. If the population is large, rates of mutation at the body colour locus are low and flies can not enter or leave the source population, then we can say the population are in Hardy-Weinberg equilibrium. So, according to Hardy-Weinberg equilibrium, P²+2PQ+Q²=1, here P, Q represents the allelic frequencies.

And P²= genotypic frequency of homozygous dominant allele

Q²= genotypic frequency of homozygous recessive allele

2PQ= genotypic frequency of heterozygous allele

As the population are in Hardy-Weinberg equilibrium, so the allelic frequency will be same in the next generation of the flies. So the expected genotypic frequency will be:

The allelic frequency is given that is P (E= 0.45) and Q (e=0.55)

Frequency of EE= P² = (0.45)² = 0.2025

Frequency of ee= Q² = (0.55) ² =0.3025

Frequency of 2Ee= 2PQ= 2*0.45*0.55= 0.495

25. To answer it would be better if I could see the question 22. But one basic concept is true for every population which are in Hardy-Weinberg equilibrium that is if there is no mutation, no gene flow between population and if the population is large and the mating is random then the allelic frequency will be same for each and every generation.