Domestication
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The domestication of cannabis is the process by which Cannabis sativa became a crop, grown and selected by people for fibre, seed and drugs.[1] Where and when it began are open questions. A review of 2022 called them "still a matter of debate between contrasting views".[2]
Genome studies, plant remains from excavations and pollen give different answers. A genome study by Guangpeng Ren and colleagues (2021) placed the first domestication in East Asia. The study dated the split between the ancestors of today's hemp and drug plants and a group of Chinese feral plants and landraces to about 12,000 years before present, with a 95% confidence interval of 6,458 to 15,728 years.[3]: 1, 3 Later studies question its grouping of the plants and its sampling.[4][5] Hemp fruits from the Okinoshima site in Japan were dated directly by radiocarbon to about 10,000 calibrated years before present. The team that dated them called them the oldest known fruits of the plant and wrote that hemp "may have been cultivated and utilized" there from the earliest Jōmon period.[6]: 27 In Europe, syntheses of pollen cores and archaeological finds by John McPartland and colleagues place the start of cultivation in the Copper Age and the Bronze Age.[7][8]
Botanists of the 19th and early 20th centuries looked for the crop's origin where hemp grew outside fields, in the steppes and mountains of Central Asia and Siberia.[9][10] Ren and colleagues set their East Asian result against that older view.[3]: 3
Wild, feral and domesticated plants
Nikolai Vavilov set out how wild hemp differs from the crop in 1926, from plants he had studied in Saratov and Astrakhan provinces since 1920. The hemp growing outside fields there shed its fruits as they ripened. Its fruits were about one and a half times smaller than those of cultivated hemp, with a thicker shell and an elongated outgrowth at the base, which he compared with the base of the wild oat, where the fruit broke away. Sown beside cultivated hemp, they lay for weeks or months before sprouting unevenly, while the crop came up together within a few days. On these grounds Vavilov treated the plants as truly wild and named them C. sativa var. spontanea. Dmitri Janischewsky described the weedy hemp of south-eastern Russia in 1924 as Cannabis ruderalis.[10]: 110–111 The cultivated forms Vavilov had studied held their fruits and as a rule lacked the perianth that the wild races kept around the fruit.[10]: 114
A wild population is hard to tell from a feral one, descended from escaped crops. Alphonse de Candolle accepted hemp as wild "beyond a doubt" south of the Caspian Sea, near the Irtysh and beyond Lake Baikal. He doubted the reports from southern and central Russia and south of the Caucasus, "seeing that these are populous countries, and that the seeds of the hemp are easily diffused from gardens".[9] Ren and colleagues found that all the feral plants in their sample, Central Asian ones among them, were "historical escapes from domesticated forms". They suggested that the pure wild ancestors of the species had died out, while calling for more sampling of feral plants in those regions.[3]: 3 John McPartland and Ernest Small wrote that the "aboriginal populations" of several of the world's major crops do not seem to have survived, and that Cannabis may be one of them. The plant changes form quickly, they noted, which makes truly wild plants hard to tell from cultivated ones that have reverted to a wild type.[11]: 86 Small had earlier judged it "impossible to determine" whether any unaltered ancestral populations survive.[12] A pangenome study of 2025 judged that wild relatives probably exist in Asia. The one wild genome from Tibet available to it stood apart from all the domesticated and feral lines it compared.[13]
Robert C. Clarke and Mark D. Merlin write that people carried the plant from its "Eurasian homelands" across much of the world. Natural and farmer selection made landraces with "few apparent signs of domestication". Most modern drug cultivars, in contrast, are "completely domesticated, and thus are entirely dependent on humans for their survival".[1]
Ideas of a centre of origin
De Candolle set the wild range of hemp beside its history and the names people gave it. He read the antiquity of hemp growing in China as a sign that the wild range reached further east than botanists had yet shown.[9] He thought it "probable" that the Scythians carried the plant west from Central Asia and Russia about 1500 BC.[9]
Vavilov opened his 1926 chapter on hemp by stating that the time it was first grown, the peoples who first grew it and the country where they did so were not known. He held that the process could still be traced, perhaps more clearly in hemp than in any other old crop.[10]: 107 On his account wild and weedy hemp is a plant of manured, loose ground. It gathers on rubbish heaps beside villages and on the camps of herders, where livestock manure the soil through the winter. It followed people and their dwellings without their intending it. In times of hunger, people gathering wild seed would have taken the plants that kept their large, oily fruits. In this way, he wrote, the crop arose apart from human will. Citing E. N. Sinskaya's observations, he wrote that every stage of the process could still be seen in the Altai, where wild, weedy and cultivated hemp grew together and crossed.[10]: 115–121 McPartland and Small write that Vavilov named and mapped eight centres of diversity in 1935, two of which, the Central Asiatic and the Indian, he gave for Cannabis indica.[11]: 103
By 2021 a region "ranging from West Asia through Central Asia to North China" had often been proposed as the place where cultivation began, on the plant's distribution and on archaeobotanical finds.[3]: 1 Ren and colleagues called the Central Asian centre "a widely accepted view" and wrote that it rested mostly on where feral plants grow.[3]: 3
Where the genus itself evolved is a separate question. From 155 studies of fossil pollen in Asia, McPartland and colleagues placed the centre of origin of Cannabis on the north-eastern Tibetan Plateau, near Qinghai Lake. In the same synthesis they found pollen of the genus in India by 32,600 years ago.[14]
Genome studies
Ren and colleagues sequenced the whole genomes of 110 accessions from around the world. Their sample took in feral plants, landraces, old cultivars and modern hybrids of both hemp and drug types, with most attention to central and eastern Asia.[3]: 1–2 The plants fell into four groups. The first, which they called "Basal cannabis", held 14 feral plants and landraces from China and two feral plants from the United States. It stood at the base of the family tree. The others were a hemp group, a group of mostly feral drug plants from southern China and from India and Pakistan south of the Himalayas, and a group of drug cultivars.[3]: 3 They concluded that "C. sativa was first domesticated in early Neolithic times in East Asia" and that today's hemp and drug cultivars came from an ancestral gene pool now represented by feral plants and landraces in China.[3]: 1 Their results, they wrote, were "consistent with a single domestication origin".[3]: 3
Their date comes from a coalescent model of the genomes, the best fit among 18 alternative histories. In it the early domesticated ancestors of hemp and drug types split from Basal cannabis about 12,000 years before present, with a 95% confidence interval of 6,458 to 15,728 years. The authors read this as showing that the plant "had already been domesticated by early Neolithic times".[3]: 3 Later in the model, about 4,000 years before present, a few early domesticated lines expanded to form the hemp and drug types. From this they proposed that cannabis was first a multipurpose crop and was later selected apart for fibre or for drugs.[3]: 3–4
Other genetic studies place the origin elsewhere, or doubt that the question can yet be settled:
- Qingying Zhang and colleagues (2018), from the chloroplast DNA of 645 plants, proposed that Cannabis probably arose in a low-latitude region. They suggested that domestication "could have occurred in more than three areas in Eurasia". Their markers did not separate wild from cultivated plants. They noted that the low mutation rate of the plant's organelle DNA makes such studies difficult.[15]: 1, 9, 11
- Anna Halpin-McCormick and colleagues (2024) compared several collections and found between three and seven genetic clusters, with no consistent structure by use type. They stressed how much such results depend on sampling, above all where the passport data on a plant's origin are limited.[16]
- Manica Balant and colleagues (2025) sequenced wild-growing plants and landraces, herbarium specimens among them. They found three main groups, which they called E Asia, Paleotropis and Boreal. The groups followed where the plants came from and not their use, "contrary to what Ren et al. (2021) found". Of the six Basal cannabis samples of Ren and colleagues that they could include, only two fell in their East Asian group. They suggested that the most recent common ancestor of living cannabis "might have originated" near northern China and eastern Mongolia, a claim about the ancestry of the species and not about its domestication. Following Halpin-McCormick and colleagues, they warned that sampling bias could be driving the results.[4]
- Rita Dal Martello and colleagues (2024), writing from archaeobotany, held that "the limited sampling of wild populations and wide error bars" of the genomic date call for testing against plant remains from excavations. They noted that "there are no ancient genomic data" to calibrate such dates.[5]
A review of the plant's genomics by Igor Kovalchuk and colleagues (2020) found that only 15 of the 470 landraces and naturalised plants in three recent genotyping studies were reliably known to come from Central Asia.[17]: 732–733 The authors of the 2025 pangenome study wrote that the history of domestication will need "broader sampling of Asian and historical specimens" and a careful separation of wild from feral plants.[13]
Fruits, fibres and pollen
Plant remains from excavations show where people used cannabis at a given date. Each kind has its limits as evidence of domestication. Pollen cannot show whether a plant was wild or cultivated. The pollen of cannabis is also hard to tell from that of the hop genus, Humulus.[5] Dal Martello and colleagues call claims of hemp textiles from impressions on pottery "problematic". McPartland and Small call the identification of ancient cordage or its impressions as Cannabis "somewhat subjective".[5][11]: 82
East Asia
At the Okinoshima site in Chiba Prefecture, Japan, hemp fruits came from a layer of the earliest Jōmon period.[18]: 11 Three of them, dated together by accelerator mass spectrometry, gave 8955 ± 45 radiocarbon years before present, about 10,000 calibrated years. Yuichiro Kudo and colleagues called the find "the oldest record of the fruits of Cannabis sativa in the world at this moment". They concluded that hemp "may have been cultivated and utilized from the earliest Jomon period", without calling the fruits domesticated.[6]: 27 Dal Martello and colleagues later measured the fruits against wild cannabis. They found them too wide for wild plants and without the protruding base of wild forms. They inferred that they were "likely already a domesticated form". With large early grains from China, they took this to mean that cultivation "plausibly had begun independently in at least China and Japan".[5]
Tengwen Long and colleagues (2017) proposed "a multiregional origin of human use of the plant", since cannabis appears in Europe and in East Asia at more or less the same time. They found a marked increase in finds of cannabis fruits in East Asia between about 5,000 and 4,000 calibrated years before present, which they suggested might be linked to exchange across the steppe.[19] At Haimenkou in Yunnan, Dal Martello and colleagues read seeds of about 1600 to 1100 BCE as a crop changing from an early domesticated form towards larger-seeded fibre and oilseed varieties.[5]
Europe
McPartland, Geoffrey Guy and William Hegman (2018) used a probabilistic method to separate Cannabis from Humulus pollen in 479 European studies. They concluded that the plant was native to Europe and that its cultivation began in the Copper or Bronze Age. Their maps linked it with the Copper Age Varna–Gumelnița culture and with the Bronze Age Yamnaya and Terramare cultures.[7] In a companion review of 136 archaeological studies, McPartland and Hegman found "no robust evidence" for the use of hemp in the Neolithic of Europe. One Copper Age site of the Gumelnița–Varna culture, in south-eastern Europe, gave them "robust evidence". More came from the Bronze Age, among the Yamnaya and Catacomb cultures.[8] The authors of the pollen study note that their method takes no account of how much pollen each plant sheds and that it assumes cannabis was domesticated after the cereals.[7]
Valentí Rull (2022) compared the two lines of evidence. He put the European domestication estimated from pollen and archaeology at 7,000 to 5,000 years before present, after the European Neolithic, beside the 12,000 years that Ren and colleagues estimated for Asia from dated family trees.[2] Kovalchuk and colleagues wrote that a multiregional origin of domestication "would also be supported by fossil data", which would mean that people domesticated the plant independently from stocks that had already diverged. They added that a genomic data set sampled across the whole range is needed to test this.[17]: 732
Hemp and drug types
Whether the plant was first a single crop with many uses, or was domesticated separately for fibre and for drugs, is also unsettled.[17]: 715 Ren and colleagues favour the first: in their model one early domesticated crop served many purposes until about 4,000 years before present, when selection drove hemp and drug types apart.[3]: 4
McPartland and Small classed the high-THC landraces of Asia as C. sativa subsp. indica. They traced the plants known in vernacular use as "Sativa" to South Asia and those known as "Indica" to Central Asia (Afghanistan, Pakistan and Turkestan). In their view natural selection under the climates of South and Central Asia began the divergence. Domestication then carried the chemical divergence further. Their study leaves aside the European subspecies, subsp. sativa.[11]: 81, 86 McPartland had earlier argued from fossil pollen that Cannabis reached Europe by 1.8 to 1.2 million years ago and that genetic drift there began the split between European C. sativa and Asian C. indica. He set this against the "conventional wisdom" that the two differ because of human selection.[20]
At the Jirzankal Cemetery in the Pamirs, residues in wooden braziers of the first millennium BCE show the burning of plants with more THC. Meng Ren and colleagues concluded that "the earliest targeted use of cannabis with higher levels of THC originated in western China or the broader Central Asia region". The braziers show the use of such plants, not where they were domesticated.[21]
See also
References
- ↑ 1.0 1.1 Clarke, Robert C.; Merlin, Mark D. (2016). "Cannabis domestication, breeding history, present-day genetic diversity, and future prospects". Critical Reviews in Plant Sciences. 35 (5–6): 293–327. doi:10.1080/07352689.2016.1267498.
- ↑ 2.0 2.1 Rull, Valentí (2022). "Origin, early expansion, domestication and anthropogenic diffusion of Cannabis, with emphasis on Europe and the Iberian Peninsula". Perspectives in Plant Ecology, Evolution and Systematics. 55 125670. doi:10.1016/j.ppees.2022.125670.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 Ren, G.; Zhang, X.; Li, Y.; Ridout, K.; Serrano-Serrano, M.L.; Yang, Y.; Liu, A.; Ravikanth, G.; Nawaz, M.A.; Mumtaz, A.S.; Salamin, N.; Fumagalli, L. (2021). "Large-scale whole-genome resequencing unravels the domestication history of Cannabis sativa". Science Advances. 7 (29) eabg2286. doi:10.1126/sciadv.abg2286.
- ↑ 4.0 4.1 Balant, M.; Vitales, D.; Wang, Z.; Barina, Z.; Fu, L.; et al. (2025). "Integrating target capture with whole genome sequencing of recent and natural history collections to explain the phylogeography of wild-growing and cultivated cannabis". Plants, People, Planet. 7 (6): 1771–1788. doi:10.1002/ppp3.70043.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Dal Martello, Rita; Min, Rui; Stevens, Chris J.; Qin, Ling; Fuller, Dorian Q. (2024). "Morphometric approaches to Cannabis evolution and differentiation from archaeological sites: interpreting the archaeobotanical evidence from bronze age Haimenkou, Yunnan". Vegetation History and Archaeobotany. 33 (4): 503–518. doi:10.1007/s00334-023-00966-6.
- ↑ 6.0 6.1 Kudo, Yuichiro; Kobayashi, Makiko; Momohara, Arata; Noshiro, Shuichi; Nakamura, Toshio; Okitsu, Susumu; Yanagisawa, Seiichi; Okamoto, Tozo (2009). 千葉県沖ノ島遺跡から出土した縄文時代早期のアサ果実の14C年代 [Radiocarbon dating of fossil hemp fruits in the earliest Jomon period excavated from the Okinoshima site, Chiba, Japan]. Japanese Journal of Historical Botany (in 日本語). 17 (1): 27–31. doi:10.34596/hisbot.17.1_27.
- ↑ 7.0 7.1 7.2 McPartland, John M.; Guy, Geoffrey W.; Hegman, William (2018). "Cannabis is indigenous to Europe and cultivation began during the Copper or Bronze age: a probabilistic synthesis of fossil pollen studies". Vegetation History and Archaeobotany. 27 (4): 635–648. doi:10.1007/s00334-018-0678-7.
- ↑ 8.0 8.1 McPartland, John M.; Hegman, William (2018). "Cannabis utilization and diffusion patterns in prehistoric Europe: a critical analysis of archaeological evidence". Vegetation History and Archaeobotany. 27 (4): 627–634. doi:10.1007/s00334-017-0646-7.
- ↑ 9.0 9.1 9.2 9.3 de Candolle, Alphonse. Origin of Cultivated Plants. Retrieved 14 October 2026 – via Project Gutenberg.
- ↑ 10.0 10.1 10.2 10.3 10.4 Vavilov, N.I. (1926). Центры происхождения культурных растений [Studies on the origin of cultivated plants] (in русский). Leningrad: Всесоюзный институт прикладной ботаники и новых культур. pp. 107–121 – via Internet Archive.
- ↑ 11.0 11.1 11.2 11.3 McPartland, J.M.; Small, E. (2020). "A classification of endangered high-THC cannabis (Cannabis sativa subsp. indica) domesticates and their wild relatives". PhytoKeys. 144: 81–112. doi:10.3897/phytokeys.144.46700.
- ↑ Small, E. (2015). "Evolution and classification of Cannabis sativa (marijuana, hemp) in relation to human utilization". Botanical Review. 81 (3): 189–294. doi:10.1007/s12229-015-9157-3.
- ↑ 13.0 13.1 Lynch, R.C.; Padgitt-Cobb, L.K.; Garfinkel, A.R.; Knaus, B.J.; Hartwick, N.T.; et al. (2025). "Domesticated cannabinoid synthases amid a wild mosaic cannabis pangenome". Nature. 643 (8073): 1001–1010. doi:10.1038/s41586-025-09065-0. PMC 12286863.
- ↑ McPartland, J.M.; Hegman, W.; Long, T. (2019). "Cannabis in Asia: its center of origin and early cultivation, based on a synthesis of subfossil pollen and archaeobotanical studies". Vegetation History and Archaeobotany. 28 (6): 691–702. doi:10.1007/s00334-019-00731-8.
- ↑ Zhang, Q.; Chen, X.; Guo, H.; Trindade, L.M.; Salentijn, E.M.J.; Guo, R.; Guo, M.; Xu, Y.; Yang, M. (2018). "Latitudinal adaptation and genetic insights into the origins of Cannabis sativa L." Frontiers in Plant Science. 9 1876. doi:10.3389/fpls.2018.01876.
- ↑ Halpin-McCormick, Anna; Heyduk, Karolina; Kantar, Michael B.; Batora, Nicholas L.; Masalia, Rishi R.; Law, Kerin B.; Kuntz, Eleanor J. (2024). "Examining population structure across multiple collections of Cannabis". Genetic Resources and Crop Evolution. 71 (8): 4705–4722. doi:10.1007/s10722-024-01928-1.
- ↑ 17.0 17.1 17.2 Kovalchuk, I.; Pellino, M.; Rigault, P.; van Velzen, R.; Ebersbach, J.; Ashnest, J.R.; Mau, M.; Schranz, M.E.; Alcorn, J.; Laprairie, R.B.; McKay, J.K.; Burbridge, C.; Schneider, D.; Vergara, D.; Kane, N.C.; Sharbel, T.F. (2020). "The genomics of Cannabis and its close relatives". Annual Review of Plant Biology. 71: 713–739. doi:10.1146/annurev-arplant-081519-040203.
- ↑ Kobayashi, Makiko; Momohara, Arata; Okitsu, Susumu; Yanagisawa, Seiichi; Okamoto, Tozo (2008). 千葉県沖ノ島遺跡から出土した縄文時代早期のアサ果実 [Fossil hemp fruits in the earliest Jomon period from the Okinoshima site, Chiba Prefecture, Japan]. Japanese Journal of Historical Botany (in 日本語). 16 (1): 11–18. doi:10.34596/hisbot.16.1_11.
- ↑ Long, Tengwen; Wagner, Mayke; Demske, Dieter; Leipe, Christian; Tarasov, Pavel E. (2017). "Cannabis in Eurasia: origin of human use and Bronze Age trans-continental connections". Vegetation History and Archaeobotany. 26 (2): 245–258. doi:10.1007/s00334-016-0579-6.
- ↑ McPartland, J.M. (2018). "Cannabis systematics at the levels of family, genus, and species". Cannabis and Cannabinoid Research. 3 (1): 203–212. doi:10.1089/can.2018.0039.
- ↑ Ren, Meng; Tang, Zihua; Wu, Xinhua; Spengler, Robert; Jiang, Hongen; Yang, Yimin; Boivin, Nicole (2019). "The origins of cannabis smoking: chemical residue evidence from the first millennium BCE in the Pamirs". Science Advances. 5 (6) eaaw1391. doi:10.1126/sciadv.aaw1391.