Disruptive selection is described in the text with the case of british land snails.
a) in the grassy fields, the light-banded snails escape bird predators.
b) in the darker forest, the dark snails survive and the light-banded snails are eaten.
c) as long as the snails continue to cruise across the british landscape mating at the same season and having access to each other,
why doesn't this "disruptive selection" eventually lead to two separate species?