Abstract
In this study, a cranial sample of the Hokkaido Ainu was compared with 10 samples from the Japanese archipelago ranging from prehistoric to recent times and with three prehistoric and recent samples from continental Northeast Asia and Sakhalin, using nine nonmetric cranial traits that were confirmed to have few interobserver errors in terms of presence or absence. Statistical treatments such as Smith’s mean measure of divergence (MMD) and principal coordinate analysis revealed that the Okhotsk people, who thrived from the fifth to twelfth centuries CE along the Okhotsk Sea coast of Hokkaido, are situated between the Hokkaido Ainu and the Amur/Nivkh/Neolithic Baikal and are fairly close to the Hokkaido Ainu, as are the Jomon in the main islands of Japan. In contrast, the Yayoi people of continental East Asian lineage, as represented by Doigahama and Kanenokuma, are far distant from the Hokkaido Ainu. Although the core physical makeup of the Hokkaido Ainu was derived from the Jomon and Epi-Jomon lineage in Hokkaido, the Okhotsk people are considered to have exerted a certain amount of genetic influence on the ethnogenesis of the Hokkaido Ainu. These views were also confirmed by an analysis based on 20 nonmetric cranial traits performed on 12 samples from the Japanese archipelago and Sakhalin.
