Origin: Anc Greek
The term was proposed by Ernst Mayr (1904 –2005) based on his work on birds . Previously British evolutionary biologist and entomologist Sir Edward Bagnall Poulton, (1856 –1943) had coined the term “sympatric”.
Mayr in his book Systematics and the Origin of Species (1942) he outlined the concept of "biological species." He defined for first time, that species are a group whose members can interbreed only with one another. When populations within a species become isolated eg by geography as on isolated islands, they may start to differ from other populations leading to a speciation through genetic drift and natural selection.
(biology) Allopatric concerns a type of speciation in which an isolated population of a given species experiences different environmental factors than creatures of the same species in another location.