Excerpt from the linked summary^1 by Dyani Lewis, about research^2 by Hongru Wang et al.:

>The Tibetan Plateau extends from the northern edge of the Himalayas across 2.5 million square kilometres. It is a high-altitude, dry and cold region.

>Despite its inhospitable environment, humans have been present on the plateau since prehistoric times. Denisovans, extinct hominins that interbred with both Neanderthals and the ancestors of modern humans, lived on the northeastern edge of the plateau 160,000 years ago.

>Stone tools made 30,000–40,000 years ago are further signs of an early human presence in the region.

>But when people established a permanent presence on the plateau — and where they came from — has been a matter of debate, says Qiaomei Fu, an evolutionary geneticist at the Chinese Academy of Sciences in Beijing, who led the study.

> 

>Fu and her team sequenced ancient genomes from the remains of 89 individuals, dated to 5,100–100 years ago, unearthed from 29 archaeological sites.

>Their study confirms that permanent occupation of the region pre-dates historical records.

>It also paints a complex picture of where early Tibetans migrated from, and how their interactions in the region and with their lowland neighbours shaped their heritage.

>Analysis of the genomes reveals that the ancient occupants of the Tibetan Plateau have strong genetic links to the Tibetan, Sherpa and Qiang ethnic groups that live on or near the plateau today.

>Comparisons of the oldest genomes with ancient and living people across Asia suggest that the ancestors of modern Tibetans arrived on the plateau from the east.

>By contrast, India and the rest of the Asian subcontinent were populated by immigrants from eastern Eurasia and central Asia.

^1 Dyani Lewis, Nature, 17 Mar. 2023, https://www.nature.com/articles/d41586-023-00742-6

^2 Hongru Wang et al. Human genetic history on the Tibetan Plateau in the past 5100 years. Science Advances 9, eadd5582 (2023) https://doi.org/10.1126/sciadv.add5582