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Encyclopedia > Peripatric speciation

Peripatric speciation (also known as Parapatry) is a type of speciation in the theory of natural selection. It occurs when the zones of two species with a similar ecological niche abut but do not overlap. The two species may have contact at the common boundary of their zones. The concept of parapatry is necessary to satisfy the postulate of natural selection that two species cannot co-exist in the same location over the longer term with the same ecological niche. It suggests that there may be some factor apart from distance or ecological role which keeps the two species apart.

It contrasts with allopatry where different species are geographically isolated from each other, and sympatry where different species evolve in the same area by finding different ecological roles. If there is a zone where hybridisation occurs providing gene flow between the two base populations, then it is questionable whether they are indeed distinct species. Parapatry is relatively uncommon in temperate areas, but can be seen more often in tropical areas. Examples of the boundaries between two species include a change in elevation or a crossable river.

The distinction between this and allopatric speciation is that that these species stop changing after becoming self sustaining.

  Results from FactBites:
Punctuated Equilibria (3019 words)
This pattern includes the characteristically abrupt appearance of new species, the relative stability of morphology in widespread species, the distribution of transitional fossils when those are found, the apparent differences in morphology between ancestral and daughter species, and the pattern of extinction of species.
Peripatric speciation states that a population of an ancestral species in a geographically peripheral part of the ancestral range is modified over time until even when the ancestral and daughter populations come into contact, there is reproductive isolation.
The adaptations of newly speciated daughter populations are forever excluded from the ancestral population because of reproductive isolation (2 above).
Peripatric speciation - Wikipedia, the free encyclopedia (128 words)
Peripatric speciation is a form of speciation, the formation of new species through evolution.
In this form, new species are formed in isolated peripheral populations; this is similar to allopatric speciation in that populations are isolated and prevented from exchanging genes.
Peripatric speciation was originally proposed by Ernst Mayr, and is related to the concept of a Founder effect, since small populations often undergo bottlenecks.
  More results at FactBites »



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