Hybrid Speciation - Hybrid Speciation Ecology

Hybrid Speciation Ecology

A hybrid may have a distinct trait (phenotype). This phenotype may in very rare cases be better fitted to the local environment than the parental lineage and as such natural selection may favor these individuals. If reproductive isolation subsequently is achieved, it will lead to a separate species. The reproductive isolation may be genetic, ecological, behavioural or spatial, or a combination.

If reproductive isolation fails to establish, the hybrid population may breed back and finally merge with either or both parent species. This will lead to an influx of foreign genes in the parent population, a situation called an introgression. Introgression is a source of genetic variation, and can in itself facilitate speciation. There is evidence that introgression is a ubiquitous phenomenon in plants, animals, and even humans, in which it may have introduced the microcephalin D allele from a few cases of hybridization between early modern humans and Neanderthals.