Question

a squirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of
a) differential speciation.

b) allopatric speciation.

c) penultimate speciation.

d) sympatric speciation.

Explanation:

Allopatric speciation occurs when a physical barrier (like the canyon formed by the river here) separates a population, preventing gene flow between the two groups. Over time, they evolve into distinct species. Differential speciation is not a standard term. Penultimate speciation is not a recognized concept. Sympatric speciation happens without a physical barrier, within the same geographic area, so it doesn't fit here.

Answer:

B) allopatric speciation.