Interesting program today on NPR's On Point. The guest was a Harvard primatologist who postulates that cooking was the pivotal event in evolution of homo sapiens (increased food quality):
http://www.onpointradio.org/2009/06/...uman-evolution
He doesn't seem to espouse a paleo-diet for modern humans, however. He makes a comment to a self-described "raw food vegan" that the ancestral diet isn't necessarily the optimal diet.