Ainu, Japanese, their ancestors and neighbours: cranioscopic data

Seven sutural and two foraminal non-metric characters were studied in ancient and recent skulls from Japan and surrounding areas. Variation of threeprincipal traits in most groups can be best explained by a mixture of two components, Jomon and Mongoloid, the latter one increasing in the following order: West Jomon people-East Jomon people-Hokkaido Ainu-Sakhalin Ainu-Ryukyuans -Yayoi people-Kofun people-West Japanese-Tokyo Japanese. In theJapanese and their ancestors beginning from the Yayoi period, the Mongoloid component is very similar to the one represented in modern Chinese. Its introduction to Japan in Yayoi times was abrupt and obviously caused by massive immigration.The further increase of Mongoloid traits from Yayoi to modem times was slow. Traces of Jomon (or Ainu) substratum are seen in all modern Japanese groups which is probably due to an early shift of West Jomon populations to agriculture and their mixture with the immigrants. The Okhotsk group of Hokkaido shows an unusual combination of Tunguso-Manchurian and Ainu features.