<P> (5) </P> <P> These frequencies define the Hardy--Weinberg equilibrium . It should be mentioned that the genotype frequencies after the first generation need not equal the genotype frequencies from the initial generation, e.g. f (AA) ≠ f (AA). However, the genotype frequencies for all future times will equal the Hardy--Weinberg frequencies, e.g. f (AA) = f (AA) for t> 1 . This follows since the genotype frequencies of the next generation depend only on the allele frequencies of the current generation which, as calculated by equations (1) and (2), are preserved from the initial generation: </P> <Dl> <Dd> f 1 (A) = f 1 (AA) + 1 2 f 1 (Aa) = p 2 + p q = p (p + q) = p = f 0 (A) f 1 (a) = f 1 (aa) + 1 2 f 1 (Aa) = q 2 + p q = q (p + q) = q = f 0 (a) (\ displaystyle (\ begin (aligned) f_ (1) ((\ text (A))) & = f_ (1) ((\ text (AA))) + (\ tfrac (1) (2)) f_ (1) ((\ text (Aa))) = p ^ (2) + pq = p (p + q) = p = f_ (0) ((\ text (A))) \ \ f_ (1) ((\ text (a))) & = f_ (1) ((\ text (aa))) + (\ tfrac (1) (2)) f_ (1) ((\ text (Aa))) = q ^ (2) + pq = q (p + q) = q = f_ (0) ((\ text (a))) \ end (aligned))) </Dd> </Dl> <Dd> f 1 (A) = f 1 (AA) + 1 2 f 1 (Aa) = p 2 + p q = p (p + q) = p = f 0 (A) f 1 (a) = f 1 (aa) + 1 2 f 1 (Aa) = q 2 + p q = q (p + q) = q = f 0 (a) (\ displaystyle (\ begin (aligned) f_ (1) ((\ text (A))) & = f_ (1) ((\ text (AA))) + (\ tfrac (1) (2)) f_ (1) ((\ text (Aa))) = p ^ (2) + pq = p (p + q) = p = f_ (0) ((\ text (A))) \ \ f_ (1) ((\ text (a))) & = f_ (1) ((\ text (aa))) + (\ tfrac (1) (2)) f_ (1) ((\ text (Aa))) = q ^ (2) + pq = q (p + q) = q = f_ (0) ((\ text (a))) \ end (aligned))) </Dd>

Reasons why a population may not be in hardy-weinberg equilibrium