Hardy-Weinberg Equilibrium

∞ generated and posted on 2016.09.05 ∞

Genetic description of a hypothetical population that is not evolving.

Hardy-Weinberg Equilibrium – named after G. H. Hardy and Wilhelm Weinberg – is how evolutionary biologists describe a species if that species is not evolving.

Specifically, when there is no mutation, no migration, no selection, infinite (or last very large) population sizes, and random mating then the frequency of genotypes making up that population will be not only not change over time but will be fully specified by the frequency of the alleles within the population (which also will not change over time).

See also Hardy-Weinberg theorem.

Hardy-Weinberg equilibrium is the default assumption that one makes in terms of a population's evolution, that is, that evolution is not occurring until deviation from Hardy-Weinberg equilibrium has been demonstrated. Note that many populations do indeed approximate Hardy-Weinberg equilibrium and this occurs particularly when large populations found in relatively unchanging environments are subject to stabilizing selection, that is, selection for those alleles that in fact the population already consists of.

Video (Absolutely hilarious take, sort of, on Hardy-Weinberg equilibrium; terribly silly)