My point wasn't about the specific evolutionary advantage granted by this piece of biology, but rather that atheists would explain it in exactly the ways you all are doing, while fundamentalists would go the second route and completely discount the first, while a discerning theist will take both explanation types as equally and simultaneously valid.
The advantages of any evolved trait must be many - especially in the brain where it takes so much energy to develop. You could pick just about any region of the brain that is unique to a species (or genus, or phylum, or whatever) and come up with a laundry list of all the ways it may be advantageous. The God Module is a little bit unique, though, in that it forces one to consider that religion itself is important to a species even if one doesn't believe in it. It's existence indicates that either it is useful for an entire species to suffer from delusions, or that there is a cosmic intelligence of some sort. I'll admit that it's possible that delusions grant some sort of advantage (and I fully expect atheists to justify it that way and give examples of useful delusion, and I'll think nothing less of them for it), but my personal opinion is that it is far more likely that this little piece of wetware is an intentional design feature.
One argument I can foresee is that foreign stimulation to just about any part of the brain can cause delusions of one sort or another. But that is through the misfiring of neurons in a brain region normally responsible for something else more useful. This region, though, has no known function other than to grant religious experience. If it's just a biological coincidence, then it has evolved not only for the express purpose of deluding us, but of doing so in a very specific way. I have a hard time seeing that as a logical conclusion.
w
