File:Upper Paleolithic expansion (Western Eurasian).jpg

English: Upper Paleolithic expansion (Western Eurasian): The UP branch would have then emerged from a putative OoA population Hub well after 45 ka, a scenario that finds support in previous hypotheses on the appearance of UP techno-complexes (e.g. Aurignacian) in Europe, although the role of migrations and exchange between Europe, Western Asia, and the Levant is still debated (Conard 2002; Mellars 2006; Teyssandier 2006; Davies 2007; Hoffecker 2009; Le Brun-Ricalens et al. 2009; Nigst et al. 2014; Zilhão 2014; Hublin 2015; Bataille et al. 2020; Falcucci et al. 2020). The origin and spatiotemporal development of later UP techno-complexes (e.g. Gravettian) are also still debated, and are currently interpreted as the outcome of mixed processes involving regional adaptation, functional convergence, and exchange between populations that took place in Europe (Pesesse 2010; Moreau 2012; Otte 2013, 2017; Kozłowski 2015) after the putative split from the OoA Hub. As far as Northern Asia and the reported Ancestral Northern Eurasian ancestry is concerned, the UP legacy may be responsible for the West Eurasian components already reported in ancient Siberian samples dated between 34 (Salkhit [Massilani et al. 2020]), 31 (Yana1 [Sikora et al. 2019]), and 24 ka (Mal’ta [Raghavan et al. 2014]). A tree featuring admixture events in varying proportions between sister groups of Kostenki14 and Tianyuan is supported, and can indeed explain this observation (fig. 1A, purple leaves; Supplementary fig. S5 and Section 3.6, Supplementary Material online). This is further supported by the younger chronology for these two sites which is compatible with a stepwise arrival of West Eurasian components in Siberia following the UP exit from the Hub sometimes before 38 ka. The lack of West Eurasian components in Tianyuan and in subsequent East Asian individuals may provide clues on the resistance of those groups to the incoming UP population movements, or on subsequent reexpansion from a genetically IUP-like population reservoir.