A common example of this phenomenon is the malaria resistance of individuals who are carriers for sickle cell trait.
Dobzhansky noted this effect in Drosophila pseudoobscura while studying ST-CH inversions. Older theories ascribed this phenomenon to dominance or overdominance, though linkage and epistasis are now thought to account for most of its effects. Determining mutation rates with the Hardy-Weinberg equation fails with loci affected by this phenomenon, as novel mutation rates appear to be anomalously high. Inbreeding depression is the inverse of this effect, which affects the chloride transporter that is mutated in cystic fibrosis because Salmonella typhi binds most efficiently to the wild-type protein. A common example of this phenomenon is the malaria resistance of individuals who are carriers for sickle cell trait. For 10 points, name this genetic phenomenon in which being a hybrid or possessing two different alleles of a gene confers greater fitness.
Dobzhansky noted this effect in Drosophila pseudoobscura while studying ST-CH inversions.
heterosis [or heterozygote advantage; or hybrid vigor; or outbreeding advantage]