A population of mountain goats are split because of the formation of a glacier.After 500 years the glacier melts and the two goat populations are free to move between the two areas.Under what conditions might the populations be able to occasionally interbreed?
A)Both pre- and post-zygotic isolating mechanisms have arisen.
B)Reproductive isolation is incomplete.
C)Pre-zygotic isolating mechanisms have arisen.
D)Post-zygotic isolating mechanisms have arisen.
E)Gene flow between the two populations does not occur.

Question

Quizplus · Accepted Answer

If reproductive isolation is incomplete, then it is possible for the two goat populations to occasionally interbreed. This means that some individuals from one population may mate with individuals from the other population, producing viable offspring. However, it may not occur consistently enough to result in the full merging of the two populations. Pre- and post-zygotic isolating mechanisms would prevent interbreeding altogether, while lack of gene flow would prevent any interbreeding from occurring at all.

A Population of Mountain Goats Are Split Because of the Formation