Which type of selection is responsible for the high frequency of the 'sickle cell allele' in some populations?

Question

Quizplus · Accepted Answer

Balancing selection is responsible for the high frequency of the sickle cell allele in some populations. This is because individuals who carry one copy of the sickle cell allele are less susceptible to malaria, while individuals who carry two copies of the allele (and therefore have sickle cell disease) are more severely affected. In areas where malaria is prevalent, having one copy of the sickle cell allele provides a selective advantage, while having two copies of the allele is detrimental. This results in the maintenance of the sickle cell allele at a relatively high frequency, as both the sickle cell and normal hemoglobin alleles are maintained in the population through balancing selection.

Which Type of Selection Is Responsible for the High Frequency