Two species of antelope ground squirrels are separated by the Grand Canyon. They are hypothesized to descend from a common ancestor, populations of which were separated as the canyon formed. If this hypothesis is correct, it would be an example of:
A)allopatric speciation by dispersal.
B)allopatric speciation by vicariance.
C)peripatric speciation by vicariance.
D)sympatric speciation by dispersal.
E)sympatric speciation by vicariance.

Question

Quizplus · Accepted Answer

Allopatric speciation by vicariance occurs when a geographical barrier, such as a canyon, separates a population into two or more groups, leading to the formation of different species over time. This is the best choice because it describes the scenario given in the question, in which the two antelope ground squirrel species are separated by the Grand Canyon, and are hypothesized to have descended from a common ancestor as the canyon formed.

Two Species of Antelope Ground Squirrels Are Separated by the Grand