GENETICS × PEOPLING
The Mal'ta Boy Genome
~24,000 years ago
Palaeolithic · Upper Palaeolithic · Last glacial · Last Glacial Maximum
Mal'ta is an Upper Palaeolithic site on the Belaya River near Lake Baikal, in south-central Siberia, excavated between 1928 and 1958; among its finds are some thirty female figurines of the type known as Venuses, rare in Siberia, and the skeleton of a juvenile, a boy, buried about 24,000 years ago. His genome, sequenced in 2014, was then the oldest genome of a modern human ever read. Its lesson lies in what it does not resemble: the boy shows no close affinity to East Asians; his mitochondrial DNA belongs to haplogroup U, common among the Ice Age hunter-gatherers of Europe, and his Y chromosome, like his nuclear genome, sits at the base of the lineage of present-day western Eurasians. Populations related to western Eurasians therefore lived far to the north-east 24,000 years ago, in a lineage now called the Ancient North Eurasians; and that same genome is, at the same time, closely related to those of present-day Native Americans.
Why it matters
Dual ancestry means the first Americans were not simply East Asians who crossed Beringia: their genome is a mixture, and one of its two parts came from this northern Eurasian lineage, an estimated 14 to 38 per cent. The mixing came after the ancestors of Native Americans had separated from East Asians and before they diversified in the Americas; the Anzick child, buried in Montana with Clovis tools about 12,600 years ago, already carries it. The same lineage contributed to Europeans, so part of the western Eurasian ancestry of Native Americans today is ancient, not a post-Columbian legacy alone.
Dating & uncertainty
The age of ~24,000 years is the boy's calibrated radiocarbon date; the bounds of 24,500 and 23,500 years retained here reflect the rounding of the published 'approximately 24,000'. The date matters less than the timing of the mixture, placed after the split between the ancestors of Native Americans and East Asians and before 12,600 years ago, the age of the Anzick child; a later Upper Palaeolithic genome from the Baikal region already carries the combined ancestry, so the mixed population lived in Siberia. Were the mixture later than the crossing, the northern Eurasian ancestry would have had to enter America separately, which the Anzick genome, already carrying it, makes unlikely.
Sources
- Raghavan et al. (2014), Nature · Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americansdoi:10.1038/nature12736
- Yu et al. (2020), Cell · Paleolithic to Bronze Age Siberians Reveal Connections with First Americans and across Eurasiadoi:10.1016/j.cell.2020.04.037
- Rasmussen et al. (2014), Nature · The genome of a Late Pleistocene human from a Clovis burial site in western Montanadoi:10.1038/nature13025
- Lazaridis et al. (2014), Nature · Ancient human genomes suggest three ancestral populations for present-day Europeansdoi:10.1038/nature13673
Our species’ history as one day
22:10:171 h 50 min before midnight
if the 315,000 years of Homo sapiens were compressed into a single day