Hardy-Weinberg (Equilibrium)

In a large random intrabreeding population, not subjected to excessive selection or mutation, the gene and genotype frequencies will remain constant overt time. The sum of p²+2pq+q² applies at equilibrium for a single allele pair where p is the frequency of the allele A, q is the frequency of a, p² is the frequency of genotype AA, q² is the frequency of aa, and 2pq is the frequency of Aa.