It's full of choice gems (emphasis added):
Read the whole thing. You won't regret it.Another main objection I have to Keith’s book is that many of her arguments commit the genetic fallacy. She cites a theory which suggests that the switch to a diet of meat made it possible for hominids to develop the type of brains characteristic of modern humans, implying that if we don’t eat meat now we will not be fully human. Yet even if humans developed certain traits by eating meat, this does not mean they must now eat meat to maintain those traits. Furthermore, it should be noted that the theory Keith cites is being debated by anthropologists and that there are rival theories that Keith does not mention. A relatively recent overview of research on Paleolithic and Neolithic modes of subsistence is found in this article. She also mentions that the Neolithic Revolution and the beginnings of agriculture first resulted in a decline in health in humans, implying that lifestyles in modern agricultural societies will necessarily also result in worse health than that enjoyed by Paleolithic humans. This conclusion doesn’t follow, for technology and knowledge in agricultural societies today make possible very different diets and lifestyles from those of agriculturalists in the Neolithic.
We should be skeptical about arguments that appeal to human evolution to come up with conclusions about what we are “meant” to do. Vegetarians have often used this kind of argument to conclude that we aren’t meant to eat meat, and it is the type of argument Keith relies on in many cases to arrive at the opposite conclusion. The study of the human body as it exists today is the most useful method for figuring out what kinds of diets are best for humans to eat now. The study of the sketchy record of human evolution in the Paleolithic and Neolithic periods is primarily suited to explaining why the human body is this way.