Comparative studies of the Ainu, their ancestors, and neighbors: assessment based on metric and nonmetric dental data

Abstract

Using Mahalanobis' generalized distance for odontometric data and Smith's mean measure of divergence for nonmetric dental data, interpopulation similarities between four local Ainu groups from Sakhalin Island and Hokkaido, as well as their supposedly ancestral and neighboring populations, were analyzed. In this study, multidimensional scaling and multidimensional plots by Andrews were applied to the distance matrices to visualize the intergroup relationships. The results obtained reconfirm the dental association between the prehistoric Jomon and the recent Ainu. However, the diversity of the recent Ainu in Hokkaido is not necessarily accommodated in a single regional populational lineage, the Jomon. The present findings also suggest that admixture between the immigrants from Northeast Asia as represented by the Okhotsk culture people and the indigenous inhabitants in Hokkaido during the 5th-12th centuries AD may in part have contributed to the formation of the physical characteristic of the recent Ainu. In particular, the female Okhotsk culture sample shows closer affinity to the northeastern Hokkaido and the Sakhalin Ainu in some of the analyses presented in this study. Such findings are compatible with those obtained by craniometric analyses, supporting the hypothesis of higher migration rates among females than among males due to patrilocality or the shorter matrilineal generation interval.

Mandibular tooth root size in modern Japanese, prehistoric Jomon, and Late Pleistocene Minatogawa human fossils

“…However, the timing, extent, and nature of admixture are regionally and temporally complex and the subject of continued study (e.g. Suzuki et al, 2004;Nakahashi and Iizuka, 2008;Adachi et al, 2009;Hanihara and Ishida, 2009;Ishida et al, 2009;Kawakubo et al, 2009;Matsumura and Dodo, 2009;Sato et al, 2009;Fukumoto and Kondo, 2010;Kaburagi et al, 2010).…”

The Ainu and their neighbors as seen from the perspective of nonmetric cranial trait variation

“…， 北海道アイヌの母体となった集団は北 海道や本州の縄文人と北海道の続縄文人であることを再 確認した。 しかし， 近年の研究が明らかにしたように (近 藤， 2005;Hanihara et al, 2008;Sato et al, 2009;Adachi et al, 2011a (Ishida, 1995(Ishida, , 1996石田，1996;Ishida and Kondo, 1999;Shigematsu et al, 2004;Komesu et al, 2008) (山口， 1974;菊池， 1978;Ishida, 1988Ishida, , 1996Kozintsev, 1992 山口，1974, 1991Ishida, 1988Ishida, , 1996Shigematsu et al, 2004;Komesu et al, 2008;Matsumura et al, 2009;Kaburagi et al, 2010) (Kodama, 1970;Yamaguchi, 1973;Kozintsev, 1990;Ishida and Kida, 1991;Ishida, 1995;石 田，1996;Hanihara et al, 2008;Kaburagi et al, 2010 2002Cranial affinities of the Epi-Jomon inhabitants in Hokkaido, Japan. Anthropological Science, 110: 1-32.…”

Jomon genome sheds light on East Asian population history

“…This could be an influence of the Hokkaido Ainu who are likely to be direct descendants of the Jomon people. The ancestor of the Ainu people could have admixed with the Okhotsk people [54] who were morphologically close related to Ulchi and Nivkh currently inhabit in the the Primorye region [55][56][57] , which are supported by mtDNA [58,59] and genome-wide SNP data (Matsumae et al, unpublished data). The second explanation is that the track of the earliest-wave was erased in the inland but left over in the coastal region.…”