You see, this is what separates science from religion, evolution from ID or creationism. With science, one can build a framework from which one can make predictions (birds will never have mammary glands). By their very nature, these predictions must be falsifiable (if a bird with mammary glands is found, the framework is crap). ID and creationism simply state "God did it the way He did it, and no one is to second guess Him." Under either of the latter there is no way to make any predictions about what one should find in nature because God might have done just about anything that caught His fancy (all those mythical half-this/half-that critters come to mind). And, because there is no way to make any predictions there is no potential falsification -- and a theory MUST be falsifiable.
The above is the assumption of evolutionists. Assumptions are not science. Assumptions are not facts. Assumptions are not proof of anything. To prove such a thing you need evidence and you have none at all.