The human b-globin gene has two alleles,H^S and H^A,individuals that are homozygous for H^S have sickle-cell anemia and a lower fitness.Individuals that are heterozygotes (H^SH^A)do not show sickle-cell symptoms and have a resistance to malaria.Individuals that are homozygous for H^A have the highest fitness but are susceptible to malaria.In areas where malaria is prevalent the H^S allele is maintained in the population.Which type of selection is occurring with the b-globin gene?

Question

Quizplus · Accepted Answer

Balancing selection is occurring with the b-globin gene because heterozygotes have a higher fitness than either of the homozygotes. This means that both alleles are maintained in the population at relatively high frequencies. The presence of malaria is likely driving this balancing selection as each allele confers a different advantage in response to the disease.

The Human B-Globin Gene Has Two Alleles,HS and HA,individuals That

The Human B-Globin Gene Has Two Alleles,H^S and H^A,individuals That