Acorns are edible if you boil them several times to remove the tannins that make them bitter.................Or you run them through a pig first.............
Oh for sure. But do you see ancient man knowing this? A few rhousand years ago yes, not cavemen 50.000 years ago. I could br wrong.
Personally I go heavy on animal food, light on plant. For me the carbohydrate content of plant food is a bit much, for others it could be the opposite. But yeah we need both, I think the carnivore types are a bit extreme.