Ust'-Ishim man is a 45,000-year-old modern human from western Siberia with fully sequenced genome. His Y-DNA is haplogroup K-M2308, ancestor of NO clade found in Eurasians, Oceanians, Americans. His mtDNA is R*, one mutation from root. He lived between out-of-Africa migration and Eurasian population split. Not closely related to South Asian coastal or Central Asian migrants. Genetically closest to Tianyuan man from China, Mal'ta boy from Siberia, La Braña from Spain. Neanderthal DNA appears in intact clusters, proving immediate post-interbreeding era. No Denisovan relation tested. Equally related to modern East Asians, Oceanians, and ancient West Eurasians like Goyet. Modern Europeans derive from later population not in initial dispersals. Tibetans share most alleles with him among moderns. Siberian and East Asian populations share 38% ancestry with him. Ust'-Ishim and Oase show no ancestry contribution to later Eurasians. Part of Initial Upper Paleolithic wave of Ancient East Eurasians. Shares deep ancestry with Papuan ancestors and trifurcates near West-East Eurasian split.