Let me clarify. Milton K was NOT recommending a vegetarian diet. Indeed, she is on record as saying (1998) "I am not advocating a vegetarian diet". She even wrote an entire paper (1999) arguing that animal food played an essential role in human evolution and that "the routine inclusion of animal foods in the diets of weaned children seems mandatory". I quoted her at length to prove that there was no consensus amongst scientists as to the actual percentage of animal food in Homo's diet. Our ancestors left Africa about 50 Ky ago, at which time our evolution as a species was largely complete. So the diet of those of our ancestors who migrated to high latitudes, on which Cordain's 70% estimate was based, is much less relevant than the diet of our African ancestors who lived 50 Ky ago. What do we know of the diet of our African ancestors 50 Ky ago? Well, we have the example of the present day !Kung San, who eat 33% animal food. But do they occupy their original lands? They do not. In the past 2000 years they have been driven to marginal lands by Bantu-speaking farmers who have seized the most fertile soils for their crops. Is this push to marginal lands likely to have increased or decreased the San's intake of animal food? I do not know. More fertile lands support both a richer plant life and a more abundant animal life. But we certainly cannot deduce that it was 33%. In short, the study of present-day hunter-gatherers gives us insufficient data from which to deduce the proportion of animal food in Homo's primitive diet. Milton's point was that it is unsafe to draw conclusions. Rick asks that we not "get picky with percentages". But percentages are the whole point. Our early ancestors almost certainly ate SOME animal foods, just like present-day apes & baboons. The question is, how much and what? Cordain makes a plausible case that early man relied heavily on animal brains and bone marrow, scavenged from the leftovers of carnivores who lacked the weaponry to crack open skulls and large bones. Brains are high in omega-3 fats and bone-marrow is high in mono-unsaturated fat. Fortunately, for those of us who do not relish raw brains & marrow, our gut is flexible enough to source the nutrients elsewhere. I agree that this would be difficult on a purely vegetarian diet. I also agree that we can thrive on 70% animal food. But I find no scientific consensus that 70% is either the dominant historical percentage or the ideal one. Cheers Lance