What is heterozygote advantage?

Heterozygote advantage refers to the phenomenon where individuals who are heterozygous for a particular gene have a higher fitness and greater success in survival and reproduction compared to individuals who are homozygous for either allele. This often occurs in cases where having both alleles provides a benefit, such as increased resistance to diseases. A classic example is seen in sickle cell anemia, where individuals with one sickle cell allele and one normal allele are more resistant to malaria than those with two normal alleles or two sickle cell alleles.

The concept is crucial to understanding how genetic diversity is maintained in populations, as it suggests that having a mix of different alleles can confer advantages that single alleles don't provide. Thus, heterozygous individuals often have better survival prospects, leading to increased reproductive success, which helps sustain genetic variation within the population.