Sickle cell anemia evolved in Africa.Although homozygotes of this allele have the anemia,the sickle cell allele of $\beta$-globin has reached high frequencies because individuals with one copy of the allele have a resistance to malaria.The maintenance of both the normal and sickle cell alleles is therefore due to
A) the Hardy-Weinberg principle.
B) stabilizing selection.
C) Muller's ratchet.
D) directional selection.
E) heterozygote advantage.

Question

Quizplus · Accepted Answer

Heterozygote advantage, also known as balancing selection, occurs when individuals heterozygous for a specific allele have a higher fitness than both homozygous genotypes. In the case of sickle cell anemia, the heterozygous genotype (F1F1S1) provides resistance to malaria while also avoiding the detrimental effects of having two copies of the sickle cell allele. This results in the maintenance of both the normal and sickle cell alleles in the population.

Sickle Cell Anemia Evolved in Africa β\betaβ -Globin Has Reached High Frequencies Because Individuals with One Copy

Sickle Cell Anemia Evolved in Africa $\beta$ -Globin Has Reached High Frequencies Because Individuals with One Copy