Allopatric speciation

Allopatric speciation

Allopatric speciation, also known as geographic speciation, is the phenomenon whereby biological populations are physically isolated by an extrinsic barrier and evolve intrinsic (genetic) reproductive isolation, such that if the barrier breaks down, individuals of the populations can no longer interbreed. Evolutionary biologists agree that allopatry is a common method by which new species arise. (The word is derived from the ancient Greek "allos", "other" + Greek "patrā", "fatherland".) By contrast, the frequency of other types of speciation, such as sympatric speciation, parapatric speciation, and heteropatric speciation, is debated.

Evolution of reproductive isolation is generally thought to be an incidental by-product of genetic divergence of other traits, particularly adaptive changes that evolve through natural selection in response to different environmental conditions in separate geographic areas. Ernst Mayr, an evolutionary biologist and famous proponent of allopatric speciation, hypothesized that adaptive genetic changes that accumulate between allopatric populations cause negative epistasis in hybrids, resulting in sterility or inviability.

Allopatric speciation may occur when a species is subdivided into two large populations (dichopatric or vicariant speciation), or when a small number of individuals colonize a novel habitat on the periphery of a species' geographic range (peripatric speciation). Because natural selection is a powerful evolutionary force in large populations, adaptive evolution likely causes the genetic changes that results in reproductive isolation in vicariant speciation. In peripatric speciation, however, the genetic changes that are thought to occur within the peripheral isolate are more controversial.

Proponents of peripatric speciation contend that small population size in the peripheral isolate (sometimes referred to as a "splinter population") allows genetic drift, which can be a more powerful force than natural selection in small populations, to deconstruct complex genotypes, allowing the creation of novel gene combinations. Both forms need not be mutually exclusive; in practice, passive isolation or fragmentation as well as active dispersal seem to play a role in many cases of speciation.

A famous example of allopatric speciation is that of Charles Darwin's Galápagos Finches, another one involves the Asian Elephantcite journal
author = Fickel, J.
coauthors = Lieckfeldt, D.; Ratanakorn, P.; Pitra, C.
year = 2007
title = Distribution of haplotypes and microsatellite alleles among Asian elephants (Elephas maximus) in Thailand
journal = European Journal of Wildlife Research
volume = 53
issue = 4
pages = 298–303
url =
accessdate = 2008-04-14
doi = 10.1007/s10344-007-0099-x
] .


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  • allopatric speciation — allopatric speciation. См. аллопатрическое видообразование. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • allopatric speciation — Speciation occurring at least in part because of geographic isolation …   Glossary of Biotechnology

  • allopatric speciation —   Differentiation and attainment of reproductive isolation of populations that are geographically separated.   Cf. sympatric speciation …   Expanded glossary of Cycad terms

  • Speciation — Part of a series on Evolutionary Biology …   Wikipedia

  • allopatric — adjective Etymology: all + Greek patra fatherland, from patēr father more at father Date: 1942 occurring in different geographical areas or in isolation < allopatric speciation > compare sympatric • allopatrically adverb …   New Collegiate Dictionary

  • allopatric — /æləˈpætrɪk/ (say aluh patrik) adjective of or relating to species occurring in different geographical areas although descended from a common ancestor: allopatric speciation. Compare sympatric. {allo + Greek patria fatherland} –allopatry… …  

  • allopatric — adjective (of biological species or speciation) occurring in areas isolated geographically from one another • Ant: ↑sympatric • Derivationally related forms: ↑allopatry • Topics: ↑biology, ↑biological science …   Useful english dictionary

  • Heteropatric speciation — is a special case of sympatric speciation that occurs when different ecotypes or races of the same species geographically coexist but exploit different niches in the same patchy or heterogeneous environment. Thus heteropatric speciation is a… …   Wikipedia

  • 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… …   Wikipedia

  • Parapatric speciation — is a form of speciation that occurs due to variations in mating frequency of a population within a continuous geographical area. In this model, the parent species lives in a continuous habitat, in contrast with allopatric speciation where… …   Wikipedia

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