In some conditions caused by mutations, it is beneficial for an individual to be a carrier of the disorder, and not have the full homozygous condition. This is known as fitness. sickle cell trait. heterozygote advantage. homozygote advantage.
A heterozygote advantage describes the case in which the heterozygous genotype has a higher relative fitness than either the homozygous dominant or homozygous recessive genotype. The specific case of heterozygote advantage due to a single locus is known as overdominance. Overdominance is a condition in genetics where the phenotype of the heterozygote lies outside of the phenotypical range of both homozygote parents, and heterozygous individuals have a higher fitness than homozygous individuals.
