A single population becomes separated by a geographic barrier,and each population acquires genetic differences.Which of the following could happen if this barrier is removed and the two populations interact and attempt to mate?
A)Reproductive isolating mechanisms may not have evolved and thus the two species could successfully mate.
B)Prezygotic isolating mechanisms may have evolved,thus preventing the two populations from mating.
C)Postzygotic isolating mechanisms may have evolved,thus preventing the two populations from producing viable or fertile offspring.
D)All of the above could happen.

Question

Quizplus · Accepted Answer

All three possibilities could happen depending on the genetic changes that occurred during the time that the two populations were separated. If no reproductive isolating mechanisms had evolved, the two populations could successfully mate and produce viable offspring. If prezygotic isolating mechanisms had evolved, such as differences in mating behaviors or physical incompatibilities, the two populations would not mate even if they came into contact. If postzygotic isolating mechanisms had evolved, such as hybrid inviability or sterility, the two populations could mate but not produce viable or fertile offspring. Therefore, all three possibilities could happen depending on the situation.

A Single Population Becomes Separated by a Geographic Barrier,and Each