A population-genetics baseline

The Hardy-Weinberg model predicts genotype frequencies from allele frequencies for an idealized population. It assumes random mating and no selection, migration, mutation, or genetic drift. Real populations may depart from these conditions. For two alleles with frequencies 0.2 and 0.8, the expected heterozygote frequency is twice their product: 0.32. The model is a baseline for comparison, not proof that a real population has no evolutionary processes.