Question

What would be the expected frequencies of the homozygous dominant, heterozygous, and homozygous recessive (in that order) after 100 generations, assuming that no selection or other evolutionary processes are operating?

Answer 1

Answer: If no forces act on a population in Hardy-Weinberg equilibrium, proportion of genotypes will stay the same.

Explanation: The Hardy-Weinberg law provides an equation to relate the genotype frequencies and allele frequencies in a randomly mating population.

For two alleles, p and q, p + q = 1 and following mating, p² + 2pq + q² = 1 where p = homozygous dominant, pq = heterozygous and q = homozygous recessive.

Population in which allele frequencies do not change are in genetic equilibrium (zero evolution).

Hardy-Weinberg assumes five conditions;

1. Large population

2. Random mating

3. No immigration or emigration

4. No selection

5. No mutation