Allele frequency
= Allele frequency
{title2=$p_A$}
The allele frequency is the proportion of gene copies at a specified <genetic locus> carrying an <allele>. Two unrelated copies can have the same observed allele without being <identical by descent>; under independent sampling their matching probability is the sum of squared allele frequencies. Pedigree <autozygosity> instead traces copies to the same ancestral copy.