RetroAllele

RetroAllele is a term used in genetics to describe an allele that is found in a population at a much lower frequency than expected based on its evolutionary history. It suggests that a particular genetic variant, which was once common, has become rare over time. This can occur for several reasons, including selective pressures that disadvantage the allele, genetic drift causing its frequency to decrease, or the introduction of new alleles that outcompete it. The study of retroalleles can provide insights into past evolutionary events and the dynamics of genetic change within populations. Identifying retroalleles often involves comparing the genetic makeup of a population to related species or to inferred ancestral states. It's a concept that helps scientists understand how allele frequencies shift and what factors drive these changes in the long term.