I would have to say a little bit o' both, God started it all, and science just took over. Who knows where the tiny organism's came from we will never know. But, those tiny organism's evolved, into microscopic things with body parts you could say. Those evolved into animals over millions(maybe TeraTrillions..??) of years into animals, and then to something, then to the caveman. Thats what I belive what happened. Who knows, no one but god himself. Look at Mars, or the moon or something like that. They have already found the TINY microscopic organism's in the ground, im thinking they are the beginning of another whole race, or maybe humans. Thats why I believe in so called "Aliens", They have just started to evolve that much before us, and are just that much ahead of us. They dont have to look the same, its just how they came about. So, I think a little of both, how could there be ANYTHING, how could there even be a universe without God.
PS: Sorry for kind of changing the subject to Extra-terrestrial beings. :/