Ust'-Ishim man is the term given to the 45,000-year-old remains of one of theearly modern humans to inhabit westernSiberia.[1] The fossil is notable in that it had intact DNA which permitted the completesequencing of itsgenome, one of the oldest modernhuman genomes to be so decoded.[1][2]
The remains consist of a single bone—left femur—of a malehunter-gatherer, which was discovered in 2008[3] protruding from the bank of theIrtysh River by Nikolai Peristov, a Russian sculptor who specialises in carvingmammoth ivory.[1] Peristov showed the fossil to a forensic investigator who suggested that it might be of human origin.[1] The fossil was named after theUst-Ishimsky District of Siberia where it had been discovered.[1]
Ust'-Ishim man belongs toY-DNA haplogroupK-M2308.[4] Initially, he was classified only asK(xLT). However, research by Poznik et al. (2016) found that he was K2(xK2b,K2c,K2d,K2e): positive for some but not all SNPs ofK2a as it was then defined, such as M2308.[4][5][6][7] Prior to this particular research, it was assumed that haplogroups K2a andNO were synonymous; however, some Y-DNA trees have since reflected Poznik's discovery that K-M2308 is the direct ancestor of NO.[4] Other studies show that Ust’-Ishim's haplogroup most likely belongs to the NO clade rather than the more diverged K2 clade.[8][9]
Both of these haplogroups and descendantsubclades are now found among populations throughoutEurasia,Oceania andThe Americas, although no direct descendants of Ust Ishim man's specific lineages are known from modern populations.
Examination of the sequenced genome indicates that Ust'-Ishim man lived at a point in time between thefirst wave ofanatomically modern humans (270,000 years ago) that migrated out of Africa and the divergence of that population into distinct populations (45,000 years ago), in terms ofautosomal DNA in different parts of Eurasia.[3] Consequently, Ust'-Ishim man is not more closely related to the first two major migrations ofHomo Sapiens eastward from Africa into Asia: a group that migrated along the coast ofSouth Asia, or a group that moved north-east throughCentral Asia.[10] When compared to other ancient remains, Ust'-Ishim man is more closely related, in terms of autosomal DNA toTianyuan man, found near Beijing and dating from 42,000 to 39,000 years ago;Mal'ta boy (or MA-1), a child who lived 24,000 years ago along theBolshaya Belaya River near today'sIrkutsk in Siberia, or;La Braña man – a hunter-gatherer who lived inLa Braña (modernSpain) about 8,000 years ago.[11][12][13]
Analysis of modern human genomes reveals that humans interbred withNeanderthals between 86,000 and 37,000 years ago,[14] resulting in the DNA of modern humans outside Africa containing between 1.5 and 2.1 percent DNA of Neanderthal origin.[15] Neanderthal DNA in modern humans occurs in broken fragments; however, the Neanderthal DNA in Ust'-Ishim man occurs in clusters, indicating that Ust'-Ishim man lived in the immediate aftermath of the genetic interchange.[11] The genomic sequencing of Ust'-Ishim man has led to refinement of the estimated date of mating between the two hominin species to between 52,000 and 58,000 years ago.[11]
No relationship betweenDenisovans and the Ust'-Ishim man has been checked, although Denisovans have some descendants in Oceania and Asia.
Genetic proximity of Ust'-Ishim toAncient North Eurasian populations (Yana,Mal'ta andAfontova Gora), within a principal component analysis of ancient and present-day individuals from worldwide populations.[16]
Ust'-Ishim was equally related to modernEast Asians,Oceanians and certain ancientWest Eurasian populations, such as theGoyet specimen.[17][11] Modern Europeans are more closely related to other ancient remains.[18] "The finding that the Ust’-Ishim individual is equally closely related to present-day Asians and to 8,000- to 24,000-year-old individuals from western Eurasia, but not to present-day Europeans, is compatible with the hypothesis that present-day Europeans derive some of their ancestry from a population that did not participate in the initial dispersals of modern humans into Europe and Asia."[19]
Phylogenetic position of ancient Upper Paleolithic Eurasian specimens.
In a 2016 study, modernTibetans were identified as the modern population that has the most alleles in common with Ust'-Ishim man.[20] According to a 2017 study, "Siberian and East Asian populations shared 38% of their ancestry" with Ust’-Ishim man.[8] A 2021 study argues that the Ust’Ishim andOase 1 individuals showed no more affinity to any modern western or eastern Eurasian populations, suggesting that they did not contribute ancestry to later Eurasian populations, as previously shown.[21]
In 2022, a study determined that the Ust'Ishim man was part of anInitial Upper Paleolithic wave (>45kya) "ascribed to a population movement with uniform genetic features and material culture" (Ancient East Eurasians), and sharing deep ancestry with theBacho Kiro,Oase and theTianyuan man, as well as ancestors of modern-dayPapuans (Australasians). The Ust’Ishim lineage is described as "near trifurcation" between West and East Eurasians, but sharing a short period of evolutionary drift with Eastern Eurasians, having diverged from their ancestor shortly after the divergence from Ancient Western Eurasians (represented by theKostenki-14 specimen).[22]
^Sümer, Arev P.; Rougier, Hélène; Villalba-Mouco, Vanessa; Huang, Yilei; Iasi, Leonardo N. M.; Essel, Elena; Bossoms Mesa, Alba; Furtwaengler, Anja; Peyrégne, Stéphane; de Filippo, Cesare; Rohrlach, Adam B.; Pierini, Federica; Mafessoni, Fabrizio; Fewlass, Helen; Zavala, Elena I.; Mylopotamitaki, Dorothea; Bianco, Raffaela A.; Schmidt, Anna; Zorn, Julia; Nickel, Birgit; Patova, Anna; Posth, Cosimo; Smith, Geoff M.; Ruebens, Karen; Sinet-Mathiot, Virginie; Stoessel, Alexander; Dietl, Holger; Orschiedt, Jörg; Kelso, Janet; Zeberg, Hugo; Bos, Kirsten I.; Welker, Frido; Weiss, Marcel; McPherron, Shannon P.; Schüler, Tim; Hublin, Jean-Jacques; Velemínský, Petr; Brůžek, Jaroslav; Peter, Benjamin M.; Meyer, Matthias; Meller, Harald; Ringbauer, Harald; Hajdinjak, Mateja; Prüfer, Kay; Krause, Johannes (20 February 2025)."Earliest modern human genomes constrain timing of Neanderthal admixture".Nature.638 (8051):711–717.Bibcode:2025Natur.638..711S.doi:10.1038/s41586-024-08420-x.PMC11839475.PMID39667410.
^Qiaomei Fu, Heng Li, Priya Moorjani, Flora Jay, Sergey M. Slepchenko, Aleksei A. Bondarev, Philip L. F. Johnson, Ayinuer Aximu-Petri, Kay Prüfer, Cesare de Filippo, Matthias Meyer, Nicolas Zwyns, Domingo C. Salazar-García, Yaroslav V. Kuzmin, Susan G. Keates, Pavel A. Kosintsev, Dmitry I. Razhev, Michael P. Richards, Nikolai V. Peristov, Michael Lachmann, Katerina Douka, Thomas F. G. Higham, Montgomery Slatkin, Jean-Jacques Hublin, David Reich, Janet Kelso, T. Bence Viola & Svante Pääbo (23 October 2014)."Genome sequence of a 45,000-year-old modern human from western Siberia".Nature.514 (7523):445–449.Bibcode:2014Natur.514..445F.doi:10.1038/nature13810.hdl:10550/42071.PMC4753769.PMID25341783.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^Fu, Qiaomei; Li, Heng; Moorjani, Priya; Jay, Flora; Slepchenko, Sergey M.; Bondarev, Aleksei A.; Johnson, Philip L. F.; Aximu-Petri, Ayinuer; Prüfer, Kay; de Filippo, Cesare; Meyer, Matthias; Zwyns, Nicolas; Salazar-García, Domingo C.; Kuzmin, Yaroslav V.; Keates, Susan G.; Kosintsev, Pavel A.; Razhev, Dmitry I.; Richards, Michael P.; Peristov, Nikolai V.; Lachmann, Michael; Douka, Katerina; Higham, Thomas F. G.; Slatkin, Montgomery; Hublin, Jean-Jacques; Reich, David; Kelso, Janet; Viola, T. Bence; Pääbo, Svante (23 October 2014)."Genome sequence of a 45,000-year-old modern human from western Siberia".Nature.514 (7523):445–449.Bibcode:2014Natur.514..445F.doi:10.1038/nature13810.PMC4753769.PMID25341783.
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