W ell, it makes a BIG difference.
T ake corn, wheat, and rice, for instance.
Over many generations we can change them into things that serve us better. Nowadays we do it very systematically and on purpose. We've done it more haphazardly for thousands of years. But corn, for instance, is still being improved, and still has enemies. One way we could improve it is to find its wild ancestor, the native grass that our ancestors started cultivating.