Because God did not create the world in seven days does not mean that he couldn't. What did, or did not, happen is not an indication of what could, or could not, have happened. All evidence suggests that evolution is the way things happened. Regardless of what could have happened, the evidence would still point to evolution. Evolution and Proof Q9.
Nobody can really prove anything anyway.
Except, of course, in mathematics. However, science does not require absolute proof, otherwise science textbooks would be empty. Evolution has passed thousands of tests, many of which separated it from theories indistinguishable to non-biologists. Few people are aware, for instance, that Darwin's original hypothesis predicted the existence of genetic information. As said before, even if the theory is not correct in every detail, it is very close to the truth.