For a population in Hardy-Weinberg equilibrium, genotype frequencies can be calculated from allele frequencies using Mendelian principles of segregation and simple probability. Here the frequency of the A allele is 0.7, and the frequency of the a allele is 0.3. The genotype frequencies in the next generation are:
  • AA: 0.49
  • aa: 0.09
  • Aa: 0.21 x 2 = 0.42 Under Hardy-Weinberg equilibrium, allele frequencies in the next generation should remain constant. For example, the A allele should be 0.49 + (0.5 x 0.42) = 0.7.