Ward: >microscope studies show that australopithecus (roughly 2.5 to > 3.7 millionyears ago) and homo habilis (dating to roughly 2 million > y.a.) were largely frugivorous, but they also show that they ate some meat. And I would add that this is precisely the same with modern chimps (who eat about 2/3rds fruit), so it looks like diet has not changed all that much & there has been a remarkable consistency in homonid diet for a long time. This would not have been the case unless there were strong arguments in favor of this evolutionarily, & the question needs to be answered just what is it in RAF that is beneficial? Is it simply an adaptation designed to grant survival during times when plant foods were scarce, or is it also designed to provide specific nutrients? Are we having trouble answering these questions because there are one or more undiscovered nutrients? These questions are reminiscent of the sorts of things being asked back in the years prior to the discovery of the vitamins. But I suspect that this is probably not true, & what all this is designed for is to insure the intake of essential minerals and/or fats. It may be that both are more concentrated in animal than in plant foods, & certainly there is a possibility of mineral deficiencies in any local soil. By eating animals there is a greater chance of taking in minerals picked up by animals (especially fish or birds & their eggs) which had traveled into a region from afar, even if they are several animals removed from the final animal you eat. This meshes well with Weston Price's work, in which he pointed out how some inland peoples went to great efforts to insure they had a little seafood to insure sufficient minerals. --Doug Schwartz [log in to unmask]