Question

If A single population of butterflies is separated into two populations by the emergence of a mountain range. How genetic drift, natural selection, and gene flow might affect the evolutionary fates of the two resulting populations?

Answer 1

The two resulting populations will evolve and adapt differently over time to the different ranges as the conditions change in both ranges.

Their color, size, lifespan, and consumption choices may change with that.

After all of this takes place, you're left with 2 new breeds/species of butterflies.

Hope I helped :)