Reductions in similarity between two populations including as resulting in reductions in potential to produce fit, hybrid offspring.
Divergence can occur between sub-populations, among subspecies, or between separate species. The cause of this divergence can be differences in terms of what mutations enter populations, the impact of additional random effects (i.e., genetic drift), or as a consequence of natural selection.
Note that populations that consist of a single gene pool, due to rampant inter-mating, tend to not diverge, though can display polymorphisms which can lead to a limited amount of distinct morphotypes (a consequence of diversifying selection, though which does not result in substantial evolutionary divergence). The consequence of migration is equivalent, that is, the movement of alleles between populations has the effect of reducing the potential for evolutionary divergence to occur between the two populations among which such "gene flow" is occurring.
For more on this topic, see Wikipedia and Google. Contact web master. Return to home.