Biologist Rob Dunn argues in Scientific American (the oldest continuously published monthly magazine in the United States!) that our ancestors were (mostly) vegetarian. Dunn says that “[o]ur guts are remarkably similar to those of chimpanzees and orangutans … which are, in turn, not so very different from those of most monkeys” and since most monkeys are mostly herbivorous, our ancestors must have been mostly herbivorous, too. He then adds, “If you want a justification for eating a meaty ‘paleodiet’ … the search should be for evidence that some aspect of our bodies evolved in such a way as to be better able to deal with extra meat…. It could be there, as of yet undetected.”
Such evidence, as it so happens, is undetected, but only by Rob Dunn. As a recent article points out, our high stomach acidity, low insulin sensitivity, long small intestines, small colons, and adaptations to spear-throwing, endurance running, and lengthy fasting—among other things—are adaptations to carnivory. Not only were our ancestors not vegetarians, they were hypercarnivores for hundreds of thousands of years. In fact, they ate so much fatty meat that they hunted many animals to extinction.
You may ask how all this biological evidence was “undetected” by a professional biologist. The simplest answer is: You can’t trust the experts.