Dynamics without selection

Case 2: Individuals mate and these mating pairs produce offspring.

Will Hardy-Weinberg frequencies still obtain?

Again, to calculate offspring frequencies we use mating tables.

Individual Mating Table

This shows that x'=p^2: Hardy-Weinberg equilibrium is reached after only one generation of random mating.

Since the allele frequency of A in the parents is x+y/2=p (by definition), and since the allele frequency of A in the offspring equals x'+y'/2 = p^2 + 2 p q/2 = p (p+q) = p , the allele frequencies again remain constant.