A large-scale genomic study published in Genome Research Quarterly has sequenced the DNA from 14,000-year-old skeletal remains found in the Ryukyu Islands of Japan. The analysis identifies a distinct, late-surviving Pleistocene lineage that diverged from mainland Asian populations over 35,000 years ago. This "ghost lineage" contributes significantly to the modern genetic makeup of Okinawan populations but is largely absent from the contemporary Japanese mainland, suggesting a period of extreme isolation during the last glacial maximum.
The research, led by the University of Tokyo, provides the first direct genetic evidence of a unique human adaptation to the insular environments of the Western Pacific during the Ice Age. The study also identifies specific genetic markers for hyper-efficient lipid metabolism, which likely allowed these hunter-gatherers to thrive on a high-protein marine diet. This finding rewrites the migratory history of the Japanese archipelago, showing that the traditional Jomon-Yayoi dual-origin model must be expanded to include this ancient Southern maritime pulse.