For those who say that evolution is statistically impossible.?

What creationists such as the Discovery Institute say is that it is statistically impossible for RNA to form directly from amino acids. Which is probably correct. The first metabolic molecules were much simpler than RNA; RNA came along fairly late in the game. So the creationists are technically correct, it's just that the point they are correct in is utterly irrelevant to the actual mechanisms of abiogenesis. Abiogenesis itself is not statistically impossible or even improbable; under some conditions it may even be inevitable.