In the comments, ashen man links to an argument I had come across long ago that the evolution of our ability to digest gluten and lactose was driven not by its nutritional value but by the shift from a free-roaming hunter-gatherer society to one of agricultural civilization that we are not cut out for and need to be drugged in order to fit in. Some of you may not feel like visiting a lycos page with its annoying ads, so by googling the authors I found this duplicate. The paper is entitled “The Origins of Agriculture: a biological perspective and a new hypothesis”, by Greg Wadley and Angus Martin from the June 1993 Australian Biologist.
As long as I’m talking about mind-altering chemicals, Robert Lindsay has a new post on marijuana and brain damage, though he also discusses shrooms and coke. Hopefully Anonymous points out an article on scientists using cognitive-enhancement drugs (or “nootropics”).