Did religion evolve?

One of the hot topics now among evolutionary biologists is the existence and survival of religion among human beings. Is religion and belief part of our wiring? In Darwinian theory a trait that evolved and survived did so for a reason. Did it evolve in order to give the species some survival advantage? If so, what about it modern times? The plethora of religious beliefs as far back as recorded history, and its existence everywhere, is fascinating. That people are drawn to faith is certain, but why?
One school of reasoning is that faith is indeed an adaptive evolved trait. It gave groups a survival advantage, whose members organized around a group of similar believers, giving them a social structure and primitive organized society. To the individual, faith gives strength, comfort, community support and predictability.
Others argue that religion logically is maladaptive, in that the person believes in imagined beings and false explanations. So how could that be a survival advantage? Seemingly, the most "logical" rational intelligence would have an advantage over others. According to this school, religion is considered a "spandrel" (literally, the unplanned space between two arches). In evolutionary theory, a spandrel is an "unintended" byproduct of another trait that is in fact, advantageous to survival. A classic example, which Dawkins gives, is the moth, which uses the angle of incidence from the sun to navigate in a straight line. Since the sun is at an infinite distance, this angle doesn't change. But a close artificial light source, like a lamp, is close, so the angle changes, causing the moth to spiral into the light.
Man's large cortex and intelligence gave him an advantage over other species. Part of this intelligence includes determination of cause and effect. Certainly a creature who could learn well from mistakes and figure out the causes for things would do better than a creature who couldn't. Yet ancient man didn't have to tools to really understand the cause of many natural phenomena around him. So his drive to understand these things lead him to find hidden, unseen causes for these experiences. So the basic intellectual trait, which is adaptive, went "awry" with religion.

Both explanations seem plausable. My sense is that by observing how people today are drawn to religion that even now it has adaptive value in helping people living a meaningful and healthy life.