Solutions For An Introduction to Genetic Analysis Chapter 18 Problem 27P

(a)

The rules that have to be followed by a population to be in Hardy-Weinberg equilibrium are as follows:

1) If the sum of the homozygous dominant (), homozygous recessive () and heterozygous genotype frequencies () is equal to one (1), then the population is said to be in Hardy-Weinberg equilibrium.

2) If the sum of the homozygous dominant () and recessive () allele frequencies is equal to one (1), then the population is said to be in Hardy-Weinberg equilibrium.

3) The genotypic frequency of offspring that are produced after random mating should be equal to the parental genotypic frequencies then the population is said to be in Hardy-Weinberg equilibrium. In case of Hardy-Weinberg population, the genotypic frequencies remain unchanged over generations after random mating.

Therefore, the populations are not in Hardy-Weinberg equilibrium.

(b)

The formula for calculation of dominant allele frequency is as follows:

The formula for calculation of recessive allele frequency is as follows:

Thus,

(c)

The calculation is as follows:

Substitute the given values in the above equation:

The fitness of is calculated as follows:

Thus, the fitness of at equilibrium is

(d)

In population 6, the allele is deleterious while the A allele is incompletely dominant. The genotype of A/A is perfectly fit, A/a has a fitness of 0.8 and a/a has a fitness of 0.6. To find out what each genotype contributes to the next generation, we can calculate the following:

Substituting the values:

Thus, the p allele frequency in the next generation is

The formula for calculation of recessive allele frequency is as follows:

Thus, the q allele frequency in the next generation is