A new genetic study has revealed that cannabis domestication began in China during the early stages of the Neolithic period. In an article just publi
A new genetic study has revealed that cannabis domestication began in China during the early stages of the Neolithic period. In an article just published in the journal Science Advances , an international team of genetic researchers reported significant progress in tracing the long history of human interactions with this medicinally potent yet highly controversial plant. Through careful analysis of cannabis DNA, they’ve demonstrated that the wild cannabis plant was first tamed and cultivated by ancient farmers in northwest China, approximately 12,000 years ago.
Until recently, genetic studies into the origin of domesticated cannabis had been few and far between. The legal penalties associated with cannabis possession and its use had inhibited science. Researchers who wanted to study cannabis had to jump through hoops to get permission to undertake such studies, and final approval was never guaranteed.
But as societal attitudes toward cannabis have changed, the situation has improved dramatically. As legal sanctions against cannabis have been lifted and the taboos against it have weakened, it has become much easier for scientists to obtain samples to analyze.
As a result, research into cannabis’s genetic properties has rapidly advanced to the point where some major questions about cannabis are now being answered.
Hemp was likely the first stage in cannabis domestication as a food source and for making rope. ( JLO_FOTO / Adobe Stock)
Cannabis Domestication: From China to the World
The cannabis genetic analysis was led by Luca Fumagalli, a biologist affiliated with the Department of Ecology and Evolution at the University of Lausanne. Fumagalli’s team included esteemed genetic researchers from China, Britain, Switzerland, India, Pakistan, and Qatar, making this ambitious research project truly an international affair.
This study to discover the true origin of domesticated cannabis was planetary in scope. Researchers collected genomic data from 110 distinct cannabis samples, found across the globe. This included both wild-growing plants and cultivated versions, sourced from different locations. It included plants used to make industrial hemp, medicinal marijuana , and recreational cannabis , which are different yet share strong genetic links.
With this extensive storehouse of genetic data in hand, the scientists were able to learn more about how cannabis had evolved, in the wild and under more controlled conditions. Putting all of the results together, they were able to identify “the time and origin of domestication, post-domestication divergence patterns and present-day genetic diversity ,” they wrote in their Science Advances article.
“We show that C. sativa [cannabis sativa] was first domesticated in early Neolithic times in East Asia,” they declared, “and that all current hemp and drug cultivars diverged from an ancestral gene pool currently represented by feral plants and landraces in China.”
Previous research suggested that the oldest ancestors of modern domesticated Cannabis sativa plants could be found in Central Asia. It wasn’t known if modern versions of the cannabis plant all came from a single ancestor, or from different varieties that had been growing in the wild in multiple locations in Central Asia .
A wooden shaft well in the Siberian Altai Mountains surrounded by wild cannabis and fleabane native grasses. Early uses of cannabis have pointed to Siberia in the past. However, the latest global genetic study shows that actual cannabis domestication began in northwest China about 12,000 years ago. ( skyNext / Adobe Stock)
The new research has clearly proven the Central Asian hypothesis false. It also shows that all cannabis did in fact come from a single ancestor, which was first domesticated 12,000 years ago and in an entirely different location in Asia.
“Our genomic dating suggests that early domesticated ancestors of hemp and drug types diverged from Basal cannabis,” the scientists wrote, adding that their research proved ” that the species had already been domesticated by early Neolithic times [approximately 10,000 BC].”
From its origins in China, domesticated cannabis spread eastward , arriving in the Middle East, Eastern Europe, and India about 3,000 years ago. From that point it may have taken another 1,500 to 2,000 years before cannabis made its way to Africa and Western Europe . It likely crossed the seas to South and Central America between the 17th and 19th centuries, before arriving in North America in the early 20th century.
Wild agricultural hemp growing in the countryside. ( johnalexandr / Adobe Stock)
When Agriculture Began, So Did Cannabis
Notably, the early Neolithic era is when the Agricultural Revolution first began. The development of farming and the domestication of animals is believed to have begun in the Fertile Crescent region of the Middle East, around 10,000 BC.
Chinese agriculture is generally thought to have started somewhat later, in approximately 9,000 BC, according to some sources . This new study will inevitably push the beginning of agricultural practices in the area back somewhat, making cannabis cultivators among the very first (if not the first) Chinese farmers.
At the time the ancestor of modern cannabis was growing in the wilds, it possessed a broad range of properties. This would have included the characteristics of both modern-day hemp, which is grown for its fiber, and recreational or medicinal cannabis plants, which are grown for their healing and/or mind-altering effects. In the earliest days of its domestication, this “Basal” type of cannabis would have been grown as a multipurpose plant, used to make clothing, rope, and building materials at the same time it was being cultivated to make medicines, or for its mind-altering impact.
A vintage engraving of hemp. ( Morphart / Adobe Stock)
For the few thousand years after its discovery and domestication, cannabis remained in this undifferentiated state. Starting about 4,000 years ago, however, cannabis growers began to actively work to create different strains that emphasized different qualities that cannabis was known to possess.
Cultures would have been selected to emphasize certain properties. Through intensive, controlled breeding over a period of time, new strains of cannabis sativa would have developed, bearing less and less resemblance to their ancestors.
Out of this process, hemp plants high in fiber but low in THC (the intoxicating ingredient in cannabis) emerged, as did marijuana plants with high concentrations of THC. Eventually, these two types of cannabis became so different that it was possible to think of them as unique species. This is the case today, where hemp for industrial use is grown separately from cannabis plants used to create medicines or recreational marijuana products.
Despite their differences, all hemp and marijuana plants share a single common ancestor, which began as a wild species growing in Neolithic period China. A few types of cannabis growing wild in China today are the direct descendants of that ancient ancestor, which makes the connection between Neolithic cannabis and its modern forms even stronger.
Top image: Cannabis landraces in Qinghai province, central China have been determined as the forerunners of cannabis domestication. A landrace refers to domesticated, locally adapted, traditional variety of a species of animal or plant that has developed over time. Source: Guangpeng Ren / Science Advances journal
By Nathan Falde