has created some stir in the paleo diet community and of course among paleo diet opponents. The abstract of this article:
The nature and causes of the disappearance of Neanderthals and their apparent replacement by modern humans are subjects of considerable debate. Many researchers have proposed biologically or technologically mediated dietary differences between the two groups as one of the fundamental causes of Neanderthal disappearance. Some scenarios have focused on the apparent lack of plant foods in Neanderthal diets. Here we report direct evidence for Neanderthal consumption of a variety of plant foods, in the form of phytoliths and starch grains recovered from dental calculus of Neanderthal skeletons from Shanidar Cave, Iraq, and Spy Cave, Belgium. Some of the plants are typical of recent modern human diets, including date palms (Phoenix spp.), legumes, and grass seeds (Triticeae), whereas others are known to be edible but are not heavily used today. Many of the grass seed starches showed damage that is a distinctive marker of cooking. Our results indicate that in both warm eastern Mediterranean and cold northwestern European climates, and across their latitudinal range, Neanderthals made use of the diverse plant foods available in their local environment and transformed them into more easily digestible foodstuffs in part through cooking them, suggesting an overall sophistication in Neanderthal dietary regimes.
It seems that whenever any evidence arises for grain consumption by prehistory hominins in the Upper Paleolithic age, someone asserts or wonders if this constitutes evidence (no matter how slim) that, contrary to the widely accepted paleo principle, humans have adapted to eating grains. But before I get to that, let me comment on a part of this abstract.
Henry et al imply in this abstract that some people think that the Neanderthals went extinct because of "the apparent lack of plant foods in Neanderthal diets." The idea that lack of plant foods caused nutritional deficiencies that wiped out the Neanderthals got entertained by a CNN reporter, Samira Said:
Researchers found starch granules from plant grains in their teeth, leading them to believe the early humans did not -- as previously thought -- have an exclusively meat-based diet. It also debunks the theory that Neanderthals became extinct because of dietary deficiencies.
Let's have some fun unraveling the non-sequitors in this passage. So you find some starch on the teeth of some Neanderthal remains, which shows that those individuals definitely ate some plants. Now you leap to the conclusion that "early humans did not....have an exclusively meat-based diet." This is like finding some starch granules on the teeth of some domestic cats fed commercial cat foods, then concluding that earlier wild cats did not have a carnivorous diet. It is entirely possible that these particular Neanderthals were at that point in time eating some plant foods (out of desperation), while earlier Neanderthals, or Neanderthals in richer ecosystems, ate an almost exclusively meat diet.
By the way, what does Said mean by the phrase "exclusively meat-based diet"? Strictly speaking, "meat-based" means just that, based on, or composed primarily of, meat. To wit, a diet that is 80% meat certainly is "meat-based." It does not mean exclusively meat, any more than "plant-based" means "exclusively plants." Thus, "exclusively meat-based" means "only based on meat" which means that the "exclusively" is not even redundant, just plain unnecessary.
I really don't know how any anthropologist could seriously entertain the idea that dietary deficiencies due to lack of plant foods would cause the extinction of Neanderthals, who according to unrefuted stable isotope studies were almost exclusively carnivorous and apex predators. Just for the record, in their report on their isotopic studies, Richard et al stated that the Neanderthals "occupied the top trophic level, obtaining nearly [italics mine] all of their dietary protein from animal sources." See that "nearly"? To refresh the memories of Henry et al, "nearly" means "almost." In other words, from isotopic studies we already knew that Neanderthals ate some plant foods.
Further, previous researchers had already previously established that Neanderthals consumed grass seeds, legumes, and other plant foods, as discussed by Dr. BG in her blog post Neanderthals Consumed Grains and Legumes. However, these previous researchers also established that "cereal grains were an insignificant food source" for Neanderthals; making me wonder why these three researchers presented their findings as if it established that grains were a mainstay and hedge against nutritional deficiencies for the Neanderthals. Do they have an axe to grind?
Back to those who entertain the idea that dietary deficiencies due to lack of plant foods would cause the extinction of Neanderthals. Have they no knowledge of the Inuit? Inuit people clearly show that humans can live indefinitely and reproduce successfully for millenia eating almost nothing but animal products. How could lack of plant foods kill off a species that obviously can obtain all its nutritional requirements from consumption of the various parts of animals? Its like believing that the lions could go extinct for lack of salads and goji berries. It could only happen indirectly i.e. not enough plants for their prey.
Henry et al are referring to Neanderthal remains found in Shanidar cave in Iraq, and Spy, Belgium.
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| Shanidar Cave. Source: Wikipedia |
The Shanidar III remains they examined date to 60K to 80K years before present (YBP), and the Spy specimens are dated to about 36K YBP. This means they lived in the Middle to Upper Paleolithic.
Now for a little prehistory lesson. Humans have been evolving for more than 2 million years. Most of that time the Earth maintained an ice age environment. According to Wikipedia:
The current ice age, the Pliocene-Quaternary glaciation, started about 2.58 million years ago during the late Pliocene when the spread of ice sheets in the Northern Hemisphere began. Since then, the world has seen cycles of glaciation with ice sheets advancing and retreating on 40,000- and 100,000-year time scales called glacial periods, glacials or glacial advances, and interglacial periods, interglacials or glacial retreats. The earth is currently in an interglacial, and the last glacial period ended about 10,000 years ago.
During that 2.6 million years, periods of glacial advance exceeded interglacial periods, which typically lasted only 12K years, although some lasted up to 30K years. During periods of glacial advance, the cold, dry climate favored the growth of grasses but not other plants; and thus it favored the survival of animals that could eat grass, or animals that could eat grass-eating animals. Isotopic studies such as I cited above, and discussed here as well, clearly show that humans belong among the latter group. As reported in "A brief review of the archaeological evidence for Palaeolithic and Neolithic subsistence" published here:
There have only been two studies of Palaeolithic modern humans, Homo sapiens sapiens. A study of the isotope values of humans from the late Upper Palaeolithic (ca 13 000 years old) site of Gough's and Sun Hole Cave in Southern England (Richards et al, 2000a) indicated, again by the15N values, that the main source of dietary protein was animal-based, and most likely herbivore flesh. The second study (Richards et al, 2001) was a survey of isotope values of humans from Gravettian and later (approximately 30 000-20 000 years old) Eurasian sites. The
Between 50K and 21K years before present (YBP), the earth entered a period of full glaciation, during which the climate became colder and drier. As reported by Science News, between 50K and 3K YBP, 65% of mammal species weighing over 44kg, together with a smaller proportion of mammals of lesser size, went extinct, and it appears that this climate change played a major role in the extinction of the large mammals previously hunted by humans.
So far, it is only during the Middle and Upper Paleolithic, that we evidence evidence of both Neanderthal and Cro Magnon humans consuming cereal grains. Given the isotopic studies cited above and known climatic and faunal changes, I would conclude that this situation reflects humans choosing between starving to death and trying to live on previously unexploited plant foods, not a choice of "more balanced, healthier diet," nor what Henry et al decided in their abstract to call "an overall sophistication in Neanderthal dietary regimes."
That line about made me laugh. So Henry et al think that if Neanderthal people ate a diet composed almost exclusively of meat, then the Neanderthal diet was not "sophisticated," but since they did, they had a "sophisticated dietary regime." Its as if they think Neanderthals are more respectable if they did eat plants than if they didn't. Lions must not be "sophisticated" either since they avoid plants. Who cares about sophistication? What about adaptation?
Which brings me to my speculation. Why did Neanderthals go extinct? Maybe you could connect some dots. Climate change and the hunting prowess of migrating modern humans, equipped with more sophisticated tools, language, shamans, and domesticated dogs, resulted in rapidly declining stocks of mammals, the primary food source for the Neanderthals. They were like other carnivores supremely adapted to hunting mammals but apparently unlike the African transplant they did not know how to hunt smaller game or seafoods, and did not adapt to more diverse or plant-based diets. Cro Magnon proved to have the upper hand on hunting in the same ecosystems as Neanderthals, depleting herds rapidly or before Neanderthals could get their hands on them. Just as would any other true carnivore, they may have gone extinct for lack of meat, not for lack of plants.
In my view, the starch on their teeth is not a mark of sophistication, but of desperation.
Then Homo sapiens sapiens (my we have a high opinion of our selves) went through the same process. We think we proved smarter and more adaptable by (sort of) adapting grains to us (by cooking), but Nature always has the last laugh. We've hung on grains for 10K years, but this proves nothing; 10K years is a blink of the evolutionary eye. Extinction is more the rule than the exception, and agriculture may yet prove to put the proud one out on his ass.
Unless we come to our primal senses.
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