Dairy and Evolution

Via Marginal Revolution, a very interesting Slate piece on the evolution of lactase-tolerance.  An excerpt:

Milk, by itself, somehow saved lives. This is odd, because milk is just food, just one source of nutrients and calories among many others. It's not medicine. But there was a time in human history when our diet and environment conspired to create conditions that mimicked those of a disease epidemic. Milk, in such circumstances, may well have performed the function of a life-saving drug.

You can't be a dairy farmer and deny evolution.