Question

if the dam is removed, which statement best describes if the two populations could produce fertile offspring?
a. the two populations can produce fertile offspring because they have a common ancestor.
b. the two species cannot produce fertile offspring because they have different appearances.
c. the two populations can produce fertile offspring because they have the same resources available.
d. the two populations cannot produce fertile offspring because they have become two different species.

Explanation:

When a population is separated (by a dam in this case), over time, they can undergo speciation. Speciation is the process by which one species splits into two or more species. If the two populations have become different species, they cannot produce fertile offspring. Having a common ancestor (A) doesn't mean they can still interbreed - speciation can occur. Different appearances (B) aren't the key factor - it's reproductive isolation. Having the same resources (C) after the dam is removed doesn't ensure they are the same species.

Answer:

D. The two populations cannot produce fertile offspring because they have become two different species.