Allopatric speciation 3. Parapatric speciation Sympatric speciation - the subdividing of a gene pool even though members of the daughter species are not physically separated during the process. An example is habitat selection among animals. Allopatric speciation - speciation that results when a population is divided by a barrier. It is also called geographic speciation.
Barriers can be water, land, or mountains.
Parapatric speciation - when reproductive isolation develops among adjacent members of a population in the absence of a geographic barrier. An example is a plant species that flowers at different times due to contaminated soil. Reproductive Isolating Mechanisms 1. Prezygotic reproductive barriers 2. Postzygotic reproductive barriers Prezygotic reproductive barriers - reproductive isolating mechanisms that operate before mating.