Humans have been growing cannabis for 12,000 years, according to new research claiming to pinpoint where the first crops were developed. Scientists writing in Science Advances add 82 whole genomes of cannabis plants to the 28 already sequenced, determining the first Cannabis sativa plant was likely domesticated not in Central Asia as commonly believed but in East Asia—probably northwestern China, near Kazakhstan and Kyrgyzstan, per Live Science. Ancient cannabis seeds have been found in pottery dating to this early Neolithic period in southern China, Taiwan, and Japan. It was then a "primarily multipurpose crop" probably used as medicine and for fiber, per the New York Times. Researchers note it wasn't until 4,000 years ago, as cannabis spread into Europe and the Middle East, that it began to be grown specifically for its mind-altering effects.
Central Asia was previously thought to be the site of domestication "because there were a lot of feral cannabis plants along the roads there," study co-author Luca Fumagalli, a geneticist at Switzerland's University of Lausanne, tells Live Science. But these tall, unbranching plants belonged to the "hemp type," ideal for producing fibers for textiles. The hemp type and two other drug types that produce higher levels of psychoactive chemicals are thought to have "diverged from an ancestral gene pool currently represented by feral plants and landraces in China," known as the "basal type," suitable for producing fibers and mild-altering effects, about 4,000 years ago, according to the study. East Asia is already known as a hotspot for domestication of various crop species, including rice and soybean, per the study, which notes the wild progenitors of C. sativa are probably extinct. (Read more cannabis stories.)