“This is where the debate between contingency and determinism becomes personal. If we can predict not only when rapid evolution will occur, but what form it will take, we will be able to derive general principles and thus be better positioned to respond effectively. But if each case of rapid evolution is contingent on the specific circumstances, then we'll have to start from scratch each time we face a new weed, pest, or disease, figuring out how our evolutionary foe is adapting and what we can do about it.”