Question

Sickle cell anemia evolved in Africa. Though homozygotes of this allele have the anemia, the sickle cell allele of β-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____________.

Answer 1

Answer:

Balancing selection

Explanation:

Balancing selection is a type of natiral selection that maintains different alleles (i.e. sickle cell allele and normal allele) at frequencies larger than expected. This can happen for example, when the heterozygotes for the alleles under consideration have a higher fitness than the homozygote -as is the case of the sickle cell anemia-.