"After all, in evolutionary terms, religion helped our species dream of the infinite, before the infinite was within our grasp. And if I were an ancient human, I would have believed in any religious system that I happened to be born within. Religion would have given me a reason to get up in the morning, and it would have comforted me from the knowledge of my own death."

How do you know this to be true? That is, how do you know that religion helped our species to dream of the infinite before the infinite was in our grasp? That sounds like a rather outlandish claim, especially given that you started this article by suggesting a profound love of evidence.

I think atheism is more likely to be the default position of ancient humans. After all, we are all born atheists. Religion is a learned phenomenon. Is there any reason to believe this would have been different in the past?

Religion, is by its very nature, is coercive. It has been constantly been used by people in positions of power as a tool to dominate others (or to obtain power in the first place). Given that this has been a constant in all nearly all religions throughout recorded history it seems much more likely that religion originated as means of control.