Not that I believe in both, but I don't see why you can't have both? Is it not possible that some supernatural being came up with the system of natural selection?

Is it also impossible that a creator of some sort didn't give us the BEST of everything because it wanted to see how well it's system of natural selection worked and to see how we would go about making things better than they are?

Like I said, I don't believe these things, but I don't see how they're entirely impossible. If I were a supernatural being I could imagine myself doing something similar.