Genetic characteristics of Yayoi people in Northwestern Kyushu

We conducted nuclear genome analyses of two Yayoi-period human skeletal remains excavated from the Shimomotoyama Rock Shelter site in Sasebo City. Based on the site’s geographic location and prior morphological studies, these remains had been considered members of the Northwestern-Kyushu Yayoi population descending from the Jomon lineage. However, DNA analyses using next-generation sequencing revealed that both individuals possess genomic components from both Jomon-related and immigrant Yayoi lineages. The remains date to the late Yayoi period. Our results indicate that by this time substantial admixture between indigenous groups and incoming peoples had already progressed even in the coastal regions of Kyushu. This finding suggests that the previously rigid view of the relationship between immigrant Yayoi and Northwestern-Kyushu Yayoi needs to be reconsidered. The study also demonstrates that nuclear genome data from ancient human remains are effective for capturing such admixture processes. Further genome analyses of Yayoi remains from northern Kyushu are expected to refine the scenario for the formation of the Japanese people.