New research on the diet of Australopithecus Sediba has revealed another beautiful fact undermining the ugly Paleo DietTM theory. This recently discovered possible human ancestor that lived about 2 million years ago appears to have eaten an "almost exclusively" plant-food diet:
"Almost two million years after their last meals, two members of a prehuman species in southern Africa left traces in their teeth of what they had eaten then, as well as over a lifetime of foraging. Scientists were surprised to find that these hominins apparently lived almost exclusively on a diet of leaves, fruits, wood and bark."This NYT article discussing the research contains an interesting comment from Benjamin H. Passey, a geochemist at Johns Hopkins University, who conducted the tests determining the high ratio of carbon isotopes indicating a diet mostly of plant foods:
"“One thing people probably don’t realize is that humans are basically grass eaters,” Dr. Passey said in a statement. “We eat grass in the form of the grains we use to make breads, noodles, cereals and beers, and we eat animals that eat grass. So when did our addiction to grass begin? At what point in our evolutionary history did we start making use of grasses? We are simply trying to find out where in the human chain that begins.”"[Emphasis added]
It doesn't look like anyone presenting at the upcoming 2012 Ancestral Health Symposium will be discussing the reality that humans evolved as primarily plant- and probably, grass-product eaters. In fact, it looks like someone there considers plants "A Little Shop of Horrors." Sigh.
Science like this shows that so-called "Paleo diet" advocates are way off track if they still think that grains, i.e. seeds of grasses, are only a recent addition to the diet of humans. The idea that an almost purely carnivorous species with no experience eating grass seeds just suddenly adopted a grain-based diet only 10K years ago, after more than 2 millions of years completely grain-free, simply strains credulity.
Put otherwise, the agricultural revolution must have been preceded by a long, increasingly symbiotic relationship between human ancestors and seed-bearing grasses. Although ancestral humans did consume variable quantities of meat, meat-consumption probably did not provide the key to human brain expansion or significantly alter human physiology from its baseline adaptation to a plant-based diet.
This new research reminds me of my June 19, 2011 post entitled "Gathering Wild Grains," wherein I wrote
"Put this together with evidence that Paranthropus boisei, a human relative dating to 1.4 to 1.9 million years ago, grazed on grass . Paranthropus and humans both descended from Australopithecus, but the Paranthropus went extinct. To several scientists working with this information, this new data on Paranthropus suggests a reinterpretation of previously collected data on Australopithecine diet, i.e. that Australopithecus may also have eaten grasses.
"Perhaps we can start to put together a plausible path for the incorporation of cereal grains--grass seeds--into human diets. Perhaps human ancestors used grasses as food more than 2 million years ago. Human evolution might look something like this: the grass-eaters went extinct, but the grass-seed eaters thrived."