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A genetic isolate is a population of organisms that has little to no genetic mixing with other organisms of the same species due to geographic isolation or other factors that prevent reproduction. Genetic isolates form new species through an evolutionary process known as speciation. All modern species diversity is a product of genetic isolates ...
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.
allopatric speciation. Also called geographic speciation, vicariance, vicariant speciation, and dichopatric speciation. 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 ...
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.
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]
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.
Ecological speciation caused by habitat isolation can occur in any geographic sense, that is, either allopatrically, parapatrically, or sympatrically. [4] Speciation arising by habitat isolation in allopatry (and parapatry) is straightforward in that reduced gene flow between two populations acquire adaptations that fit the ecological ...
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 ...