Also known as: geographic speciation
This theory is most often associated with ERNST MAYR (1904-2005), an evolutionary biologist at Harvard University (although many other biologists have theorized on the subject. It asserts that new species arise among sexually reproducing organisms because geographic isolation enables a small subgroup to diverge genetically from the larger, established population.
This isolated subgroup may diverge owing to particular environmental pressures, mutations or GENETIC DRIFT. For this subgroup to become a new species, its unique characteristics must allow it to survive in its isolated location, and its gene pool must be protected from mixing with that of other species.
Also see: ALLOPARAPATRIC SPECIATION, ALLOPATRIC SPECIATION, COHESION SPECIES CONCEPT, GENETIC REVOLUTION, PARAPATRIC SPECIATION, SALTATION SPECIATION, species essentialism, STASIPATRIC SPECIATION, SYMPATRIC SPECIATION
M Ereshefsky, The Units of Evolution: Essays on the Nature of Species (Cambridge, Mass., 1992)