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Evolutionary biology. Reinforcement is a process of speciation where natural selection increases the reproductive isolation (further divided to pre-zygotic isolation and post-zygotic isolation) between two populations of species. This occurs as a result of selection acting against the production of hybrid individuals of low fitness.
The types of barriers that can cause this isolation include: different habitats, physical barriers, and a difference in the time of sexual maturity or flowering. [ 6 ] [ 7 ] An example of the ecological or habitat differences that impede the meeting of potential pairs occurs in two fish species of the family Gasterosteidae (sticklebacks).
Hence, prezygotic reproductive barriers to gene flow may be environment dependent. Postzygotic isolating barriers have also been shown to be important in a variety of hybrid lineages. Work on Helianthus sunflowers has revealed that intrinsic postzygotic factors can cause reproductive isolation against the parent species.
Hybrid inviability is a post-zygotic barrier, which reduces a hybrid 's capacity to mature into a healthy, fit adult. [1] The relatively low health of these hybrids relative to pure-breed individuals prevents gene flow between species. Thus, hybrid inviability acts as an isolating mechanism, limiting hybridization and allowing for the ...
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Reinforcement assists speciation by selecting against hybrids. Reinforcement is a process within speciation where natural selection increases the reproductive isolation between two populations of species by reducing the production of hybrids. [1][2] Evidence for speciation by reinforcement has been gathered since the 1990s, and along with data ...
The Bateson–Dobzhansky–Muller model, [1] also known as Dobzhansky–Muller model, is a model of the evolution of genetic incompatibility, important in understanding the evolution of reproductive isolation during speciation and the role of natural selection in bringing it about. The theory was first described by William Bateson in 1909, [2 ...
Secondary contact is the process in which two allopatrically distributed populations of a species are geographically reunited. This contact allows for the potential for the exchange of genes, dependent on how reproductively isolated the two populations have become. There are several primary outcomes of secondary contact: extinction of one ...