Question

Even if the environmental conditions are similar for each population, why might the populations become different from each other over time?

Answer 1

See below.

Explanation:

If the two groups are geographically isolated from each other, even if they have equal environmental conditions, then the two populations would become more and more different from each other over time. This is because geographic isolation would prevent the two populations from mingling and interbreeding, which would result in the creation of two separate gene pools for each population (rather than just one for the two combined populations).

I hope that helps!