What are the Hardy-Weinberg equilibrium equations?

The Hardy-Weinberg equilibrium equations provide a mathematical framework for understanding genetic variation in a population that is not evolving. The equations are based on the allele frequencies of two alleles, which are typically represented as "p" and "q."

The first equation, p + q = 1, states that the sum of the frequencies of the two alleles must equal one. This means that if "p" represents the frequency of one allele, "q" must represent the frequency of the other allele, and together they account for all the genetic variation in that locus.

The second equation, p² + 2pq + q² = 1, relates to the expected genotype frequencies in a population at equilibrium. Here, p² represents the frequency of the homozygous dominant genotype, 2pq represents the frequency of the heterozygous genotype, and q² represents the frequency of the homozygous recessive genotype. These equations allow researchers to predict the distribution of genotypes in a population based on allele frequencies when certain conditions are met, such as no selection, mutation, migration, or genetic drift.

Understanding these equations is crucial for assessing whether a population is in genetic equilibrium or if evolutionary forces are acting upon it.