By sequencing genetic samples from the plant, they found that the species had likely been domesticated in the early Neolithic period. They said their conclusion was supported by pottery and other archaeological evidence from the same period that was discovered in present-day China, Japan, and Taiwan.
But Professor Purugganan said he was skeptical about the conclusions that the plant was developed for drug or fiber use 12,000 years ago, as archaeological evidence shows that the use or constant presence of cannabis for those purposes began around 7,500 years ago. years.
“I would like to see a much larger study with a larger sample,” he said.
Luca Fumagalli, an author of the study and a biologist in Switzerland who specializes in conservation genetics, said the Central Asian origin theory was largely based on observational data from wild samples in that region.
“It is easy to find samples from wild animals, but these are not wild types,” Dr. Fumagalli said. “These are plants that escaped captivity and readapted to the wild.”
“By the way, that’s why you call it marijuana, because it grows anywhere,” he added.
The study was led by Ren Guangpeng, a botanist at Lanzhou University in western China’s Gansu Province. Dr. Ren said in an interview that the original site of cannabis domestication was likely Northwest China, and that the find could help with current efforts in the country to produce new types of hemp.
To conduct the study, Dr. Ren and his colleagues collected 82 samples, either seeds or leaves, from around the world. The samples included strains that had been selected for fiber production and others from Europe and North America that were bred to produce large amounts of tetrahydrocannabinol (THC), the plant’s most mood-altering compound.
Dr. Fumagalli and his colleagues then extracted genomic DNA from the samples and sequenced them in a laboratory in Switzerland. They also downloaded and re-analyzed the sequencing data for 28 other samples. The results showed that the wild varieties they analyzed were in fact “historical escapes of domesticated forms” and that the existing strains in China, cultivated and wild, were their closest descendants of the ancestral gene pool.