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: sympatric speciation by vicariance. sympatric speciation by dispersal. peripatric speciation by vicariance. allopatric speciation by vicariance. allopatric speciation by dispersal.

Allopatric speciation by vicariance.

Explanation:

Allopatric speciation by vicaria occurs when two populations of a species are separated by a geographical barrier. This geographical barrier, which can be a gorge, for example, as shown in the question above. This barrier causes a spatial separation. In this case, we say that a geographic isolation has occurred.

When these populations separate, they may come under different pressures as they are in different areas. These pressures, over time, lead to genetic divergence and, consequently, possible reproductive isolation. Many consider this kind of speciation as the main model of speciation.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely