Gradually, the frequency of the sickle cell allele in East Africa rose from ... History provides the evidence that links PKU heterozygosity to protection against a fungal toxin.

The Hardy-Weinberg theorem characterizes the distributions of genotype frequencies in populations that are not evolving, and is thus the fundamental null model for population genetics. Under the ...

Even if conservation efforts boost population growth, low heterozygosity ... the deleterious allele will remain at an intermediate equilibrium frequency that reflects the balance between gene ...