In the Hardy-Weinberg principle, the variable p represents the frequency of the dominant allele in a given population. This principle is used in genetics to predict the genetic variation of a population under certain idealized conditions where no evolution is taking place—meaning factors such as mutation, selection, and migration are absent.
In this equation, p² refers to the frequency of individuals that are homozygous for the dominant allele, 2pq is the frequency of heterozygous individuals, and q² is the frequency of individuals that are homozygous for the recessive allele. Understanding what p represents is crucial for studying genetic compositions and making predictions about future generations.