Question

Most speciation (formation of new species) occurs allopatrically. This means
A. new species usually form when one species lives in the same location and same habitat for a long time
B. members of one species become separated geographically so that gene flow is stopped between the new populations eventually resulting in enough changes between the populations that they become different species
C. a catastrophy causes the formation of a new species by a bottleneck effect
D. gene flow between different populations in different locations prevents the gene pools of the populations from diverging
E. gene flow between different populations in different locations causes the gene pools of the populations to change.

Answer 1

Answer- B. Members of one species become separated geographically so that gene flow is stopped between the new populations eventually resulting in enough changes between the populations that the become different species.

This is exactly what allopatric speciation is. This separation maybe due to movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. The divided populations then experience different selection pressure and adapt accordingly. Over time small mutations are accumulated in the gene pool, effectively making the two populations different species altogether.