Genome of an early Okhotsk individual reveals ancient admixture between Jomon and Kamchatka lineages

The prehistoric Okhotsk culture was distributed along the southern coastal regions of the Sea of Okhotsk during the late first millennium AD. A previous study that performed whole-genome sequencing of a late Okhotsk individual suggested two migration waves from the Russian Far East to northern Japan. The first wave is estimated to have originated from the Kamchatka Peninsula around 2000 years before present (BP), and the second from the Amur Basin around 1600 BP. These findings suggest the past existence of an admixed hypothetical population between the Kamchatka and indigenous Jomon lineages in northern Japan between 2000 and 1600 BP, although direct genetic evidence has not yet been obtained. Here, we present the genome data of an early Okhotsk individual (NAT004) excavated from northern Japan. Admixture modelling reveals that the genome can be explained as a mixture of Kamchatka and Jomon ancestries, providing direct support for the existence of the previously hypothesized hypothetical population. This result offers new insights into the prehistoric population dynamics of northern Japan and contributes to the broader understanding of its archaeological and anthropological history.