||This article has multiple issues. Please help improve it or
discuss these issues on the talk page. The Hardy–Weinberg
principle (also known as the Hardy–Weinberg "Equilibrium",
"Model", "Theorem", or "Law") states that allele and genotype
frequencies in a population will remain constant from generation
to generation in the absence of other evolutionary influences.
These influences include non-random mating, mutation, selection,
genetic drift, gene flow and meiotic drive. Because one or more
of these influences are typically present in real populations,
the Hardy–Weinberg principle describes an ideal condition
against which the effects of these influences can be analyzed.
In the simplest case of a single locus with two alleles denoted
A and B with frequencies freq(A) = p and freq(B) = q,
respectively, the expected genotype frequencies are freq(AA) =
p2 for the AA homozygotes, freq(BB) = q2 for the BB homozygotes,
and freq(AB) = 2pq for the heterozygotes. The genotype
proportions p2, 2pq, and q2 are called th