June 2013, Cover Stories, Daily News
"Diet Change After 3.5 Million Years Ago a Gamechanger for Human Ancestors, Say Scientists"
The most significant findings indicate that human ancestors expanded their menu 3.5 million years ago, adding tropical grasses and sedges characteristic of a savannah-like environment to the typical ape-like diet of leaves and fruits from trees and shrubs of a forest environment. This, suggests the scientists, may have set the stage for our modern diet of grains, grasses, and meat and dairy from grazing animals.
"We don't know exactly what they ate. We don't know if they were pure herbivores or carnivores, if they were eating fish [which leave a tooth signal that looks like grass-eating], if they were eating insects or if they were eating mixes of all of these."
He says this because the isotope method used in the new studies cannot distinguish what parts of grasses and sedges human ancestors ate – leaves, stems, seeds and/or underground elements of the plants such as roots or rhizomes. The method also cannot determine when human ancestors began getting much of their grass indirectly by eating grass-eating insects or meat from grazing animals.
May I leap in before this goes any further? Take that opening sentence; it says that early humans added “tropical grasses and sedges characteristic of a savannah-like environment to the typical ape-like diet of leaves and fruits from trees and shrubs of a forest environment.”
That seems pretty unambiguous. It implies we typically ate leaves and fruits before adding grasses and sedges. I didn’t know that we were leaf eaters prior to diverging from our fellow simians—I thought it was primarily, nuts; fruits; and small game, like insects—but I’m a little dubious about us moving over to include the grasses and sedges. To begin with, can one tell the difference between grasses and sedges in the diet of proto-humans, or do they both have the same signature? As they stand, sedges provide a very minimal addition to the human diet in any culture, so it’s hard to imagine that they were once very popular but then died out.
I’d also question the signature difference between what parts of the grass were eaten, a difference we can't yet discern. The way the sentence is written, it’s implied that grasses were used much like a cow would, the entire plant eaten, as if we suddenly had become a grazing animal, only to abandon the practice later on. That, too, doesn’t seem likely to me. It doesn’t seem likely that we began to use any but the seed heads from grasses; and even those, it’s easier to imagine that we started to consume grain after we’d domesticated herding animals and tended to have stockpiles of grain on hand that we might, in desperation, try eating in times of privation. Most importantly, it’s easier to imagine grain consumption after the advent of cooking, as it’s nutritionally much more accessible to us after it has been cooked.
All in all, it seems unlikely that humans ever were large consumers of sedges and grass blades any more than they are now. That doesn’t mean that their data are wrong, though. Instead, the answer lies in a succeeding paragraph, where it added, that their analytical “method… cannot determine when human ancestors began getting much of their grass indirectly by eating grass-eating insects or meat from grazing animals.”
Well, okay then. Is it likely that people were harvesting grass eaters 3.5 million years ago? You can bet your bottom dollar on that. It’s a hell of a lot more likely that we were hunting grazing animals 3.5 mya than we were doing the grazing ourselves. A hell of a lot more.
I’ve seen this error made before with precisely the same kind of evidence, evidence that our diet of grasses and sedges increased, but in that case, too, they couldn’t tell whether it came from direct or indirect consumption. For some reason, primarily related to our own obsession with fad diets and the heavy PC status of vegetarianism and veganism among the young creatives, etc., the nod is always given to a vegetarian interpretation of our probable early diet history, despite evidence to the contrary.
The profession of archaeology, also, poorly interprets early dietary data because they’ve yet to understand how early it was that hunting tools, including stones, were used by our ancestors, millions of years prior to the first flaked stone tool; nor do they recognize the strong probability that standing up to carry hunting tools and game was the only reason we stood up in the first place. Much of that error comes, of course, from the impossible assumption that it was a dwindling forest cover that drove us to bipedalism. As any reader of this blog is well aware, evolution only goes towards a goal, not away from a danger. If we stood up, it was because we were harvesting a new food source that required us to stand up; and I can guarantee you that a diet of grasses and sedges does not require one to stand up.
Stand up to hunt? Sure, the chimps do it all the time. They just don’t do it enough to make a habit of us, like we do. And if I were you, I wouldn’t give them any ideas.
The good news is that we now have evidence for hunting going back 3.5 million years. You can be sure it goes back twice that far, but this is a good leap in that direction.