Theory of speciation (18TH CENTURY).
Also called geographic speciation, this theory is most often associated with Ernst Mayr (1904- ), 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
Source:
M Ereshefsky, The Units of Evolution: Essays on the Nature of Species (Cambridge, Mass., 1992)
Table of Contents
Last update 2020-06-17. Price and product availability may change.