population, partially caused by the Tianshan Mountains which form a natural barrier, with gene flows from the east and west. The study identifies four major ancestral components that may have arisen from two earlier admixed groups: one West-Eurasian component, associated with European ancestry (25–37%), one South Asian ancestry component (12–20%), and two East-Eurasian components with Siberian (15–17%) and East Asian ancestries (29–47%). In total, Uyghurs on average range from 44 to 64% Siberian/East Asian, 33.2% European, and 17.9% South Asian. Western Xinjiang shows more West Eurasian components than East Asian. It suggests at least two major waves of admixture, one ~3,750 years ago coinciding with the age range of the mummies with European feature found in Xinjiang, and another occurring around 750 years ago. A 2018 study of 206 Uyghur samples from Xinjiang, using the ancestry-informative SNP (AISNP) analysis, found that the average genetic ancestry of Uyghurs is 63.7% East Asian-related and 36.3% European-related. History The history of the Uyghur people, as with the ethnic origin of the people, is a matter of contention. Uyghur historians viewed the Uyghurs as the original inhabitants of Xinjiang with a long history. Uyghur politician and historian Muhammad Amin Bughra wrote in his book A History of East Turkestan, stressing the Turkic aspects of his people, that the Turks have a continuous 9000-year-old history, while historian Turghun Almas incorporated discoveries of Tarim mummies to conclude that Uyghurs have over 6400 years of continuous history, and the World Uyghur Congress claimed a 4,000-year history in East Turkestan. However, the official Chinese view, as documented in the white paper History and Development of Xinjiang, asserts that the Uyghur ethnic group formed after the collapse of the Uyghur Khaganate in 840, when the local residents of the Tarim Basin and its surrounding areas were merged with migrants from the khaganate. The name "Uyghur" reappeared after the Soviet Union took the 9th-century ethnonym from the Uyghur Khaganate, then reapplied it to all non-nomadic Turkic Muslims of Xinjiang. Many contemporary Western scholars, however, do not consider the modern Uyghurs to be of direct linear descent from the old Uyghur Khaganate of Mongolia. Rather, they consider them to be descendants of a number of peoples, one of them the ancient Uyghurs. Early history Discovery of well-preserved Tarim mummies of a people European in appearance indicates the migration of a European-looking people into the Tarim area at the beginning of the