I apparently missed this one when it came out last year. The existence of this ancient DNA was paradigm confirming as Tibetan modern DNA shows that high altitude adaptations in the region were introgressions from Denisovans.
Two archaic lineages overlapped with modern humans outside of Africa: the well-studied Neanderthals and their more mysterious cousins, the Denisovans. Denisovan remains are rare, being limited to Denisovan Cave in Siberia and a putative, undated jaw from Tibet. However, there is evidence for multiple introgressions from Denisovans into modern-day humans, especially in Australasian populations. By examining the sediment of Baishiya Karst Cave located on a high plateau in Tibet, Zhang et al. identified ancient mitochondrial DNA from Denisovans indicating their presence at about 100 thousand, 60 thousand, and possibly 45 thousand years ago. This finding provides insight into the timing and distribution of Denisovans in Asia and extends the time of occupation of the Tibetan plateau by hominins.
A late Middle Pleistocene mandible from Baishiya Karst Cave (BKC) on the Tibetan Plateau has been inferred to be from a Denisovan, an Asian hominin related to Neanderthals, on the basis of an amino acid substitution in its collagen. Here we describe the stratigraphy, chronology, and mitochondrial DNA extracted from the sediments in BKC. We recover Denisovan mitochondrial DNA from sediments deposited ~100 thousand and ~60 thousand years ago (ka) and possibly as recently as ~45 ka. The long-term occupation of BKC by Denisovans suggests that they may have adapted to life at high altitudes and may have contributed such adaptations to modern humans on the Tibetan Plateau.
Dongju Zhang, et al., "Denisovan DNA in Late Pleistocene sediments from Baishiya Karst Cave on the Tibetan Plateau" 370 (6516) Science 584-587 (October 30, 2020).