Another convincing proof is the fact that there are similarities between species, which would be expected if they were all designed by the same Designer. If evolution is the great unifying principle in biology, why don't we see the evolution of species today? (The sort of massive change that would be necessary for Darwinism to be true. Imagine. Mammals becoming whales, reptiles becoming birds, etc.) In the absence of such evidence, the proof is strong that one intelligent designer is responsible for whatever similarities exist in nature.