In a study published in the journal Vegetation History and Archaeobotany, the Berlin team, led by Tengwen Long and Pavel Tarasov, writes that cannabis was used in Europe and East Asia as early as 10,000 years ago. Then, around 5,000 years ago, consumption and trade increased markedly. New Scientist sums up the findings in a memorable headline: “Founders of Western civilization were prehistoric dope dealers.”
Most scholars generally agree that the plant originated in central Asia. As Robert Clarke and Mark Merlin write in their 2013 book Cannabis: evolution and ethnobotany, “Hypothetical early human contact with cannabis and the subsequent discovery and application of its useful resources took place during the distant past in one of the more temperate and well-watered areas of ancient Central Asia.”
The Berlin Freie Universität team, however, found that cannabis first appeared in historical records 11,500 to 10,200 years ago, towards the end of the last ice age, in two separate regions: Asia and Europe.
Even more striking than the multiregional origin of the plant is the sharp rise in cannabis use that occurred in East Asia around 5,000 years ago, after the start of the Bronze Age. The researchers associate the spike with the establishment of a trans-Eurasian exchange and migration network through the Mongolian steppe. Nomadic tribes on the Eurasian steppe had recently mastered horse riding and could cover vast distances. They forged trade routes that thousands of years later would become famous as the Silk Road.
The Yamna or Yamnaya people of Central Asia, one of three tribes believed to be the ancestral founders of European civilization, dispersed eastward to Asia at the same time cannabis was first distributed. In their study, the Berlin researchers suggest that the independent use of European and Asian cannabis led to the creation of cannabis as a cash crop. It may even have been a driving factor behind transcontinental trade.
“It’s a hypothesis that requires more evidence to test,” Tengwen Long told New Scientist, pointing out that the high value of cannabis would have made it an ideal exchangeable good — a “cash crop before cash”.
It remains difficult to establish for certain whether cannabis was used just for food and fiber or also for its psychoactive properties. David Anthony, who studies the Yamnaya at Hartwick College in Oneonta, N.Y., told New Scientist that the Yamnaya may have consumed cannabis on special occasions. “The expansion of cannabis use as a drug does seem to be linked to movements out of the steppe,” he said. “Cannabis might have been reserved for special feasts or rituals.”
An abstract of the 15-page study, Cannabis in Eurasia: origin of human use and Bronze Age trans-continental connections, is available online.