Cavemen ate grains, and other reasons the "paleo diet" is a work of fiction

Zuk detects an unspoken, barely formed assumption that humanity essentially stopped evolving in the Stone Age and that our bodies are “stuck” in a state that was perfectly adapted to survive in the paleolithic environment. Sometimes you hear that the intervention of “culture” has halted the process of natural selection. This, “Paleofantasy” points out, flies in the face of facts. Living things are always and continuously in the process of adapting to the changing conditions of their environment, and the emergence of lactase persistence indicates that culture (in this case, the practice of keeping livestock for meat and hides) simply becomes another one of those conditions.

“Paleofantasy”: Stone Age delusions [Salon]