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Allopatric speciation (from Ancient Greek ἄλλος (állos) 'other' and πατρίς (patrís) 'fatherland') – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model [1]: 86 – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow.
A mode of speciation where the evolution of reproductive isolation is caused by the geographic separation of two or more populations of a single species. [5] allopatric taxa Specific species that are allopatrically distributed. allopatry The phenomenon by which two or more populations of a single species exist in geographic isolation from one ...
Speciation ultimately results due to the reproductive isolation between two populations. This can happen in a multitude of ways, a common mode of which is known as allopatric speciation. The geographic mode, where two species become physically isolated and unable to interbreed, allows for selection to act on both populations independently. Over ...
There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric, peripatric, parapatric, and sympatric. Whether genetic drift is a minor or major contributor to speciation is the subject of much ongoing discussion.
Controversy exists as to whether Charles Darwin recognized a true geographical-based model of speciation in his publication On the Origin of Species. [5] In chapter 11, "Geographical Distribution", Darwin discusses geographic barriers to migration, stating for example that "barriers of any kind, or obstacles to free migration, are related in a close and important manner to the differences ...
In biogeography, geodispersal is the erosion of barriers to gene flow and biological dispersal (Lieberman, 2005.; [1] Albert and Crampton, 2010. [2]). Geodispersal differs from vicariance, which reduces gene flow through the creation of geographic barriers. [3]
In ecotypes, it is common for continuous, gradual geographic variation to impose analogous phenotypic and genetic variation, a situation which leads to the emergence of clines. [1] A well-known example of a cline is the skin color gradation in indigenous human populations worldwide, which is related to latitude and amounts of sunlight.
The patterns of species distribution across geographical areas can usually be explained through a combination of historical factors such as: speciation, extinction, continental drift, and glaciation. Through observing the geographic distribution of species, we can see associated variations in sea level, river routes, habitat, and river capture.