The Jomon, hunter-gatherers who inhabited the Japanese archipelago for millennia, carry in their genomes a record of one of humanity's harshest ordeals. A team led from the University of Tokyo's Graduate School of Science combined genomes from 42 Jomon individuals, including 25 newly extracted and sequenced, to reconstruct the deep population history of East Eurasia and ask how its peoples endured the last Ice Age.
The analysis shows the ancestral Jomon population descended from a lineage that split from continental East Eurasian populations roughly 27,000 to 19,000 years ago, a window that corresponds to the Late Palaeolithic and almost exactly brackets the coldest phase of the Last Glacial Maximum. A whole-genome scan for natural selection then revealed signals of cold adaptation concentrated in gene regions linked to heat generation in brown adipose tissue, lipid metabolism and cold sensitivity.
One region, around the APOA5 gene, shows a rapid rise in mutation frequency precisely during the glacial maximum. Published in Science Advances with collaborators at Tokyo Metropolitan University and Kyushu University, the study illuminates the origins of the archipelago's people and offers a broader framework: reading ancient genomes as archives of how human populations responded to past environmental extremes.