CANNABIS

A wide-ranging study of the evolution, chemistry, and allure of marijuana.

“As a full-time evolutionary biologist, part-time botanist, recreational user, and more than likely a future medicinal user, I find cannabis one of the most fascinating of all plants on our planet,” writes DeSalle, a curator of molecular systematics at the American Museum of Natural History. It’s fascinating indeed: A flowering plant, cannabis is a distant cousin of the grape (thus pairing nicely with a glass of wine) but is more closely related to hops (thus also pairing nicely with a pint of ale). The divergence from the latter took place about 28 million years ago, meaning that cannabis was known to early animal forms, including our ancestral primates, who, by DeSalle’s account, preferred the booze that they found in fallen fruit—thus becoming evolutionarily “preadapted” to getting high, a trait they passed along to their human kin. As the author notes, the earliest attested use of cannabis dates to about 12,000 years ago on the Tibetan Plateau, but soon after the plant spread all over Eurasia, so that “it is more than likely that any human group in those occupied areas was using cannabis in some way.” The author writes with an occasional winking reference, as when he titles one section of a chapter “Light Up or Leave Me Alone,” but in the main his text is rigorously scientific; it helps to have some background in botany and chemistry, as well as a tolerance for terms such as “xerostomia” and “cannabidiolic acid synthase.” Read on, though, and DeSalle sneaks in some popular culture, venturing that the Coen brothers’ film The Big Lebowski deserves the “highest” (wink, wink) rank of films about weed and recommending that the medical establishment take a more relaxed attitude toward cannabis and allow it into “our medical toolbox.”

Everything you ever wanted to know about pot. Just don’t try to read it when you’re baked.