Yanghai Tombs
More actions
The Yanghai Tombs are a cemetery of the late second and first millennia BCE in the Turpan basin of Xinjiang, in north-western China. Archaeologists assign the cemetery to the Subeixi culture and date its use to between about 1260 and 48 BCE.[1] One of its graves, tomb M90, held 789 grams of cannabis in a leather basket and a wooden bowl beside the remains of a man.[2] The plant material was first dated by radiocarbon to about 2500 years before present and later to about 2700 years.[3][2] Analysis of the cannabis found part of the gene for THCA synthase and cannabinol, a breakdown product of tetrahydrocannabinol (THC).[2]
Site
The cemetery lies in the Ayding Lake basin near Turpan, at the foot of the Huoyan Shan or Flaming Mountains. Its graves are 2 metres deep or more. In a climate of about 16 millimetres of rain a year and an alkaline soil, many of the bodies dried into mummies without any treatment. Formal excavation of the cemetery was completed in 2003.[2]
The graves held horse gear and crops of western Asian origin, among them capers, wheat, naked barley and grapevine.[2] Plant remains of 25 species have been identified from the cemetery, among them three cereals and two medicinal plants. From them Meiying Zhao and colleagues inferred that the people of Yanghai lived mainly by herding and grew common millet, naked barley and wheat as a supplement. They took the grapevines as evidence of a settled life.[1]
Tomb M90
Tomb M90 held the disarticulated skeleton of a man of about 45, buried with bridles, archery equipment and a harp. Ethan Russo and colleagues described him as a man of high social status whose grave goods marked him as a shaman. They suggested that he died in the highlands of the Tian Shan and that his bones were later brought to Yanghai for burial.[2]
Near the head and the foot of his bier stood a leather basket and a wooden bowl, together holding 789 grams of plant matter. It was first identified as coriander and then as cannabis.[2] The material consisted of shoots, leaves and fruits,[3] lightly pounded and without large stalks. The inside of the bowl was worn smooth, apparently from use as a mortar. No male flowers were seen in the sample.[2]
Dating
Hong-En Jiang and colleagues published the cache in 2006 with a radiocarbon date of 2500 years before present.[3] Russo and colleagues reported in 2008 that this date had been corrected to a calibrated 2700 years before present, after further analysis of the horse gear in the grave and comparison with tree-ring data from China.[2] Meng Ren and colleagues date the Yanghai find to about 500 BCE.[4] The plant remains studied from the cemetery as a whole date from about 900 to 200 BCE.[1]
Analyses
Jiang and colleagues identified the plant remains as Cannabis by comparing their form and anatomy with modern specimens.[3] An 11-gram sample of the material kept a green colour in its leafy parts and had lost the smell of cannabis. Under the microscope the leaf fragments carried intact sessile glandular trichomes with an amber tint. The fruits (achenes) were 2.2 to 3.6 millimetres long, pale and striated, with a rough attachment scar that was not concave. Russo and colleagues read these as traits of cultivated cannabis, since wild fruits are smaller and darker and have a concave scar that lets them fall easily. One hundred fruits sown in compost did not germinate within 21 days.[2]
In the chemical analysis the largest cannabinoid peak was cannabinol (CBN), the product of the oxidation of THC with age, at a concentration of about 0.007 per cent by weight. A small peak at the retention time of THC could not be confirmed by its spectrum. Cannabidiol (CBD), cannabichromene and several of their breakdown products were present in smaller amounts. From the dominance of CBN, Russo and colleagues concluded that THC had been the main cannabinoid of the original plants. They suggested that the low concentrations might reflect a sample rich in leaf and twig rather than plants of low potency.[2]
DNA from the pounded leaves confirmed Cannabis sativa. It also yielded part of the gene for THCA synthase, the enzyme that makes the acid form of THC, in two sequences: one identical to published sequences and a variant with two single-base differences, entered in GenBank as EU839988. No gene for the enzyme that makes CBD was found. DNA could not be amplified from the seeds.[2]
Interpretations
Jiang and colleagues held that the cannabis was used for ritual or medicinal purposes, given the shamanistic setting of the burial.[3] Russo and colleagues concluded that the people of Yanghai most probably cultivated cannabis "for pharmaceutical, psychoactive or divinatory purposes". They took the selection of a THC-dominant material and the absence of male flowers as signs of human choice.[2] Zhao and colleagues concluded that cannabis at Yanghai served both in medicine and in shamanic practice.[1]
How the plant was taken is not known. No implement for smoking or inhaling it has been excavated in the area.[2] Ren and colleagues observed that nothing in the tomb points to burning. In their view the plant may have been taken by mouth after it was ground in the bowl.[4]
No hemp artefacts were found in the tombs. The people of Yanghai wore wool and made their ropes of reed fibre.[2] Russo and colleagues linked the cemetery with the Gushi (or Jushi), a people named in the Chinese Hou Hanshu,[2] while Zhao and colleagues assign it to the Subeixi culture.[1]
At Jiayi, another cemetery near Turpan, a grave of about 2800 to 2400 years ago held 13 nearly whole cannabis plants laid over a man's body. The team that studied it grouped the Jiayi plants with the finds from Yanghai and from the Altai Mountains as evidence that the peoples of Central Eurasia used cannabis for ritual or medicinal purposes in the first millennium BCE.[5]
See also
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Zhao, Meiying; Jiang, Hongen; Grassa, Christopher Joel (2019). "Archaeobotanical studies of the Yanghai cemetery in Turpan, Xinjiang, China". Archaeological and Anthropological Sciences. 11 (4): 1143–1153. doi:10.1007/s12520-018-0719-2.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 Russo, Ethan B.; Jiang, Hong-En; Li, Xiao; et al. (2008). "Phytochemical and genetic analyses of ancient cannabis from Central Asia". Journal of Experimental Botany. 59 (15): 4171–4182. doi:10.1093/jxb/ern260. PMC 2639026.
- ↑ 3.0 3.1 3.2 3.3 3.4 Jiang, Hong-En; Li, Xiao; Zhao, You-Xing; Ferguson, David K.; Hueber, Francis; Bera, Subir; Wang, Yu-Fei; Zhao, Liang-Cheng; Liu, Chang-Jiang; Li, Cheng-Sen (2006). "A new insight into Cannabis sativa (Cannabaceae) utilization from 2500-year-old Yanghai Tombs, Xinjiang, China". Journal of Ethnopharmacology. 108 (3): 414–422. doi:10.1016/j.jep.2006.05.034.
- ↑ 4.0 4.1 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.
- ↑ Jiang, Hongen; Wang, Long; Merlin, Mark D.; Clarke, Robert C.; Pan, Yan; Zhang, Yong; Xiao, Guoqiang; Ding, Xiaolian (2016). "Ancient Cannabis burial shroud in a Central Eurasian cemetery". Economic Botany. 70 (3): 213–221. doi:10.1007/s12231-016-9351-1.