You're going about this all wrong. You see, you're being the agressor in this argument asking the question "Where is the proof God exists?"
However, through proposing the argument that there is no God, you are obliged to support your statement with more than a simple "there's variety therefore no God", as this could be explained away quite easily through some minor thinking such as "Oh, God invented a variety gene that allowed man to adapt a little to his current surroundings, whilst remaining within the species barrier" or something similar.
You seem to be suggesting, though, that simply by asking forcefully whether or not there is proof of a God, that you have defeated the existance of one, when in fact a common feature of most rational debate is the premise "lack of proof for does not constitute proof against".
Just to throw in my personal view, though, I'm an atheist. I like to see arguments proposed correctly, though.
============================
The Watchtower, April 15, 1928, p. 126 "As every one knows, there are mistakes in the Bible "
