What in the study of evolution convinced you that God could not be responsible for evolution? In a mechanical universe such as ours, if God created it one would expect a mechanical force such as evolution to create life. Sure, evolution takes the mystery out of life and puts a real damper on those who wish to use that mystery as a rational for God's existence. However, it still doesn't kill God.
It's just not necessary to postulate a God when there's a perfectly reasonable naturalistic explanation.
No, it's not even as simple as that. There are entire voluminous books written on this subject (a great one to mention if you are interested in doing some research is
The Blind Watchmaker by Richard Dawkins), but I'll briefly elaborate on how evolution puts the idea of an intelligent creator under an intense microscope at the least, and in the trash can of history at the most:
First a rudimentary lesson in evolutionary education. Evolution by natural selection states that life moves on a one-way street: from simplicity to complexity over a very long period of time. One can trace fossils through ancestors to find that many share common ancestors. Take homo sapiens for example; they have a common ancestor with the chimpanzee (which
is not to say that humans evolved from monkeys, unlike the embarrassingly inaccurate Creationist argument; "If we evolved from monkeys, then why doesn't a monkey today have a human baby? HMM?"), which can be traced back to an even grander common ancestor, back to less complex organisms, back further even to single celled organisms, back all the way to the first catalysts of life, amino acids.
Okay, so now let's address your question. You may ask, "Well what came before the amino acid? And still, what came before that? And that? AND THAT?! Eventually, you have to stumble upon God, otherwise there is no other explanation." This, as we can see, directly contradicts the very fundamental and solid statement of evolution; to regress to more and more simplicity and then erect a Creator God who has to be immensely complex directly betrays what the fundamental behaviors of this universe would have you conclude. However you end that infinite regression of "what came before?", it's going to be something simple and easy to understand. By retreating into a God answer, you've in essence, answered nothing concerning our above question; you've only provided more to explain, and what an explanation it would require for a God so intricate, he has been actively involved in even the thought life of every individual ever to walk upon the earth!
You may be quick to point out that science does not answer this question either. I agree, it doesn't. Neither alternatives are very satisfying. Science
does however provide grounds for an educated guess (and I would also point out you the countless times in history where a scientific answer to a then apparent impossible mystery has come swiftly after such a off-limits declaration). Thus, we have in the realm of speculation, a significant favor of there being no God.
Once again, this is a very brief explication, if you have more questions, you should pick up the book I recommended above for a much more educated and well written argument.