Question

Fully explain how a polymorphism of a human heterozygote can be fitter than any of the two homozygotes of the particular characteristics, by referring to sickle cell anaemia

Answer 1

Heterozygotes are therefore more resistant to the debilitating effects of malaria than the normal homozygotes. This heterozygote advantage in many sickle-cell carriers outweighs the severe reproductive disadvantage of the rarer sickle-cell homozygotes.