In human populations in Africa, two common alleles affect the structure of hemoglobin, the protein that carries oxygen on red blood cells. What is regarded as the normal allele (the allele common in European populations) is usually labeled A, and the sickle-cell allele is designated S. There are three hemoglobin genotypes, and the phenotypes associated with these genotypes can be distinguished in a variety of ways. In one African population of 10,000 adults, for example, there are 3,000 AS individuals, 7,000 AA individuals, and 0 SS individuals.
(a) Suppose that these individuals were to mate at random. What would be the frequency of the A and S alleles among the gametes that they produced?
(b) What would be the frequency of the three genotypes that resulted from random mating?
(c) Is the original population of adults in Hardy–Weinberg equilibrium?