Wonderist, you're talking my language. Meme-driven genes don't have to be god related. A good example is the ability-to-copy meme. For early evolving hominids, learning how to make a spear was certainly beneficial to survival. We can see in kids who believe in Santa Claus how strong it is. The kid who disregards mama’s warning that there are alligators in the stream didn’t last long. Kids are wired to copy and obey.
I agree with the out-of-Africa theory, and Homo erectus speciating into H. neanderthalensis and Homo sapiens. There’s evidence that Neanderthals buried their dead and placed trinkets and talismans in the grave. To me, that the first sign of an “outside agency” as you put it.
It’s not the god meme that’s carried from hominids (especially the immediate ancestor of H. erectus, H. habilus) but the copy-meme. This meme-driven gene made madkind easy prey for the god meme.
It was the agricultural revolution that really changed humanity. The tribal system broke down in favor of the family system. Private property, especially land ownership, brought on specialization of labor. Here’s where the god meme really took off. You can bet the first specialized profession was soldier/policeman, then came scribe/lawyer/cleric.
Sam Harris makes a great point that almost every early human culture had human sacrifice. Babylonians, Egyptians, Romans, Aztecs, etc. all liked to make sure the crops come up next year by sacrificing a few young ladies. It took to Christians to put a new twist on this by sacrificing the Son of God perpetually through the mass to keep the Sky God happy and appeased.