What must happen for hardy-weinburg equilibrium to occur?

For Hardy-Weinberg equilibrium to occur, five key conditions must be met: a large population size to minimize genetic drift, random mating to ensure that all individuals have an equal chance of mating, no mutations to prevent changes in allele frequencies, no migration to avoid gene flow from outside populations, and no natural selection so that all alleles confer equal fitness. When these conditions are satisfied, allele and genotype frequencies remain constant from generation to generation.