Sterility is associated with loss of function (LOF) alleles at a gene Z. The gene has 5000 bases where LOF mutations can occur. Assuming the human mutation rate is 2 × 1 0 − 8 2×10 −8 per generation. Homozygotes for LOF alleles at Z are completely sterile, and heterozygotes have mild sterility issues. The heterozygotes for LOF alleles at Z have 20% fewer children than an individual with two functional Z genes but suffer no other ill effects.
A) What is the frequency of the Z allele under mutation-selection balance?
B) What proportion of the individuals in the population are sterile due to being homozygous for a LOF mutation at Z?