why was cannibalism practised? ancient man was surrounded by plants and game, why did men hunt men? the answer lies in the forbidden fruit. the one substance in all of god's garden that was forbidden, believed to make the person more intelligent. seduced by the snake, these creatures tasted the flesh of their own kind, specifically the brain, specifically for the purpose of enhancing their sexual prowess. the increased intelligence is what we might call a "side effect". what evolutionary advantage is there in losing a coat of fur? why does human hair grow so long that it needed to be bitten off or sheared off with a rock? why does man, alone among animals, suffer delusions, and such a tremendous sense of guilt? these are the truly negative effects of this act, creating a new freak species who evolved from four foot hominid apes into eight foot super-intelligent men in little over a million years. when this line of questioning is followed, the gaping holes in our accepted story of human history become obvious. these are not my ideas, but the words of oscar kiss maerth. his book: The Beginning Was The End details this vision, including how humans became estranged from the rest of nature as well as our deviation from cosmic order. away from spirit, and towards material possessios, since matter is the only substance perceptible to us now.
Desmond Morris's book, "The Naked Ape", may answer some of your queries. Many first year university biology texts have a chapter or two on evolution. I suppose cannibalism is always an option, but so far as I know most primitive tribes don't bother with it, since there are other adequate food sources. It has been known to occur in New Guinea, Micronesia and Easter Island. I'm not sure about Africa and South America, but it wouldn't surprise me. As for man being a freak, yes, definitely, there are no known parallels to us. You may be aware we're headed for a massive herd crash in the near future, also known as Malthusian disaster.
Interesting take on the "forbidden fruit" (although forbidden meat might have been a more appropriate metaphor. Antropologists have found evidence of cannibalism among a variety of people from Neanderthals to various primitive tribes closer to our own time. In some cases, the reason for it has been food shortage resulting from some disaster, like the situation in the movie Alive, where people are forced to eat each other to survive. But as you say, another motive seems to be incorporation or spiritual union with the victim--a la Jeffrey Dahmer. Some people have practiced mortuary cannibalism, where they eat deceased relatives as a means of retaining them in the tribe, so to speak. Others eat enemy captives as a way of taking over their powers, or conveying those powers as gifts to the gods. Fiji islanders gained a powerful sacrament, Vakatoga, by cutting off the victim's limbs and eating them before him. Aztecs believed that the gods required tonali (spiritual energy) from human blood contained in the beating human heart. The bodies were then consumed as a sacrifical feast uniting the celebrants with their gods. The Iroquois likewise flayed and ate enemy captives as a sacrifice to Aireskoi, the war god.
It unlikely that a cannibalistic society would worship a god that forbade eating human flesh. The eating of people would not be forbidden to them. The eating of forbidden flesh was done not by ancient primitive homophages. It's situations like the Donner party or Alfred Packer where people eat flesh that is forbidden.
the structured religion would have come much later since the first apes to eat brain were still indistinguishable from other animals. the feeling of guilt comes from this very act, for a vegetarian ape does not normally eat flesh, and does not kill its own kind without reason. the story of genesis was told later, after men had realized the dangers of eating brain (disease, inadequate skull capacity, etc.) and the perception of gods as we imagine them came later as well.
no, we evolved from cryptoporcines. we only flatter ourselves to call apes our ancestors. these proto-crypto-porcines though, were not today's pigs and wart hogs. they weren't canabals either, at least not in any sort of premeditated sense. =^^= .../\...
Apparently there is a scientific basis for the idea: according to one study, all human beings contain a very specific cell (or it could be a gene :-S) which prevents certain extremely rare brain diseases from occuring. The ultra-rare brain diseases are one danger that comes with eating brains. ...So it follows that our ancestors at some stage practised cannibalism and it would appear to have made us what we are today. Far out.
We didn't evolve from apes. The latest myth about mans origin ridiculous and unsupported by evidence. It's much more likely that we are a genetic experiment or alien monkey hybrid.