Reinforcement (speciation)

Reinforcement is a process in speciation in which natural selection increases the reproductive isolation between two populations of a species, acting against the production of low fitness hybrid offspring. The idea was originally developed by Alfred Russel Wallace and is sometimes called the Wallace effect; the modern concept traces to Theodosius Dobzhansky, who envisioned two allopatrically separated populations that come into secondary contact and produce hybrids of lower fitness. Because members of one population that avoid mating with the other have greater reproductive success, natural selection favors the evolution of stronger prezygotic isolation. Reinforcement is one of the few documented cases in which selection directly favors an increase in prezygotic isolation, and so bears directly on the process of speciation itself. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/