British land snails are an example of disruptive selection.In the grassy fields,the light-banded snails escape bird predators.In the darker forest,the dark snails survive and the light-banded snails are eaten.As long as the snails continue to cruise across the British landscape mating at the same season,why doesn't this "disruptive selection" eventually lead to two separate species?

Question

Quizplus · Accepted Answer

Disruptive selection alone is not enough to lead to the formation of two separate species unless there is some kind of reproductive isolation that prevents gene flow between the light-banded and dark snails. Without reproductive isolation, the light-banded and dark snails will continue to mate and exchange genetic material, preventing them from evolving into two separate species.

British Land Snails Are an Example of Disruptive Selection