Parapatry

Parapatry is a combination of geographical sympatry and ecological allopatry.

Principle of parapatry

In parapatry two phylogenetically similar species occupy adjacent areas of distribution. They can therefore potentially come into contact and exchange genetic material.

However, ecological (different ecological niches), ethological (different mating rituals), or temporal isolation (different reproductive seasons) can create a reproductive barrier and block this exchange.

Although hybrids exist, the genome of the two species evolves separately and can lead to the emergence of new species.