In Hardy–Weinberg equilibrium, genotype frequencies stabilize after
When allele frequencies deviate from Hardy-Weinberg proportions due to prior nonrandom mating, a single round of random mating reshuffles gametes and restores genotype frequencies to p squared, two pq, q squared predicted by allele frequencies. If sexes have equal allele frequencies and locus is autosomal, equilibrium is achieved in one generation because genotype proportions derive directly from product of male and female gamete pools. No gradual convergence is required, unlike linkage disequilibrium decay. Persistent deviation after one generation signals ongoing evolutionary forces such as
Ref: Hartl & Clark, Principles of Population Genetics, Chapter 2: Attainment of Hardy-Weinberg Equilibrium
