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You've fixated on a particular date (1 MYA) and understood "major component of diet" / "majority calories in some groups" to be "all of our ancestors ate mostly
by AlotOfReading 6y ago
You've fixated on a particular date (1 MYA) and understood "major component of diet" / "majority calories in some groups" to be "all of our ancestors ate mostly plants". Neither is what I said.
First the date: 1 MYA was the time of H. erectus, not the AMH I was referencing. That's fine, but you'll probably be unsatisfied with the evidence from the period because it's notoriously thin. Regardless, by this time our ancestors had shifted to include megafaunal hunting and harder, diverse plant foods in their diet, so H. erectus populations were likely eating both. See [1]. For a good (slightly outdated) overview of the evidence problems, see [2]. In later periods, we can discuss things like dental microwear patterns, archaeobotany, optimal foraging models, and coprolite analysis as the evidentiary bases are so much better.
Secondly, you have to understand the difference between "plants were a large component of the diet" and "carnivores". All the former means is that meat was only about 30-70% of the diet, not upwards of 90%. The exact amount would have varied hugely by group, environment, and even the season or year. The diversity of the plants eaten would also have varied for the same reasons. For instance, some groups in the Mediterranean basin in the later Upper Pleistocene were sedentary foragers who would transition to nomadic hunter-gatherers at other times.
[1] http://doi.org/10.1126/science.1236828 http://doi.org/10.1126/science.1236828
[2] http://doi.org/10.1086/666700 http://doi.org/10.1086/666700
edit: overview of the elements of "forager diets" and the various viewpoints. There's also a large body of literature on archaeobotany, especially from temperate regions.
[3] http://doi.org/10.1002/ajpa.23148 http://doi.org/10.1002/ajpa.23148
- chlodwig 6y agoYou've fixated on a particular date (1 MYA) and understood "major component of diet" / "majority calories in some groups" to be "all of our ancestors ate mostly plants". Neither is what I said. My working hypothesis is that from a few million years ago to 100,000 years ago, our ancestors primarily ate megafauna (80% to 100% of calories) and so that is the diet we are most evolved to thrive off of. In the last 100,000 years, with the rise of agriculture and the extinction of many megafauna, there has been rapid selection pressure for humans to tolerate grains and dairy (and also breeding of tubers and grains to make them much more nutrition for humans). Toleration of plant and dairy food by modern people varies by race and by individual; but everyone can thrive by eating a lot of megafauna. I am interested in evidence that contradicts this hypothesis -- particularly whether there is evidence that from 100kya to 3mya our ancestors were eating 30% or 50% or 70% or 95% or 100% plants. It doesn't seem like the links you gave me have such evidence. Got anything more convincing? The evidence from dental collagen and brain size energy requirements arguing for an ancestral diet of 80%+ animals seem more convincing to me.