Where Does Weed Come From? A New Study Suggests East Asia.

A group of biologists and other scientists said humans began growing cannabis about 12,000 years ago not just for food, but also for hemp and, yes, probably to get high.

People feeling the effects of marijuana are prone to what scientists call “divergent thinking,” the process of searching for solutions to a loosely defined question. Here’s one to ponder: Where did the weed come from? No, not where it was bought, but where and when was the plant first domesticated? Many botanists believe that the cannabis sativa plant was first domesticated in Central Asia. But a new study published on Friday in the journal Science Advances suggests that East Asia is the more likely source, and that all existing strains of the plant come from an “ancestral gene pool” represented by wild and cultivated varieties growing in China today.