Map courtesy of Wikimedia Commons, will be replacing with my own map soon.
Age: 2100-1700 BC (Early-Middle Bronze Age [EMBA]) |
Associated Populations: Ancient North Eurasians, Ancient Northeast Asians , Bronze-Age Dzungarians |
Associated Culture: Xiaohe Horizon |
Associated Maternal Haplogroups: C4, R1b1 |
Associated Sites: Xiaohe, Gumugou, Beifang |
Associated Paternal Haplogroups: R1, R1b1c |
The origins of the naturally-preserved mummies of the Bronze Age Tarim Basin, dating from 4000 ya to 1800 ya, have long been a subject of contention among academics. Discovered in the 1990s, the supposedly atypical appearance of these mummies, along with their ostensibly pastoralist lifestyle, have engendered much discussion about the significance of the population which these mummies belonged to. Due to evidence of Tarim populations relying on a pastoralist lifestyle and consuming dairy, it has been hypothesized that the Tarim mummies were a population derived from Steppe pastoralists of the Afanasievo culture. Other origins for the Tarim populations have been hypothesized, such as the agricultural Bactria-Margiana Archaeological Complex (BMAC) population to the west.
In 2021, 13 EMBA Tarim individuals belonging to the Xiaohe Horizon were genetically sequenced, and their admixture was analyzed using qpAdm. Two genetic clusters (groups) were found within the Tarim population, the first comprising individuals from Xiaohe and Gumugou, and the second comprising individuals from Beifang.
The first cluster, composed of individuals from Xiaohe and Gumuguo, was modeled as a two-way mixture between Ancient North Eurasians (represented by AG3 of the Afontova Gora site), and Ancient Northeast Asians (represented by Early Bronze Age [EBA] populations of the Baikal region). Approximately three quarters of the ancestry of this cluster was derived from Ancient North Eurasians, with the rest being derived from Ancient Northeast Asians. As such, the first cluster of the Tarim population can be described as a remnant of the Ancient North Eurasian population.
The second cluster, composed of individuals from Beifang, was modeled as a two-way mixture between Tarim Cluster 1 and Ancient Northeast Asians (represented by Early Bronze Age [EBA] populations of the Baikal region). This means that the second Tarim cluster received additional genetic input from Ancient Northeast Asians (11%). The admixture of the second cluster can also be described as 64% Ancient North Eurasian-derived and 36% Ancient Northeast Asian-derived. As such, the second cluster of the Tarim population can also be described as a remnant of the Ancient North Eurasian population, although they received additional Ancient Northeast Asian ancestry compared to the first cluster.
Despite the slight differences in admixture and hundreds of kilometers of desert that separate the two Tarim clusters, the two clusters comprise a significantly homogenous population. The high genetic affinity between Tarim individuals and homogeneity of maternal and paternal haplogroups that occur within the EMBA Tarim population indicate that the population underwent a substantial population bottleneck (meaning that they experienced a significant reduction in population size, resulting in limited genetic diversity). Furthermore, the Tarim population was an isolated remnant of an ancient, indigenous genetic lineage (Ancient North Eurasians). Notwithstanding this genetic isolation, the Tarim population adopted the lifestyles of various neighboring populations, such as pastoralism, the cultivation of wheat, barley, and millet, and the burial of the deceased with ephedra twigs.
Sources
Zhang, F., Ning, C., Scott, A. et al. Supplementary Data