July 15, 2008

Craniometry of the Ainu

American Journal of Physical Anthropology

Craniometric variation of the Ainu: An assessment of differential gene flow from Northeast Asia into Northern Japan, Hokkaido

Tsunehiko Hanihara et al.


In and after the latest Neolithic period in Japan (B.P. 2,300 years), there were two distinct waves of migration from eastern Asia. One is well known as successive episodes in which indigenous inhabitants of main-island Japan were intruded on by new arrivals with advanced technology, and of a different genetic stock. Another migration of people and culture, identified as the Okhotsk culture, reached the northeastern part of Hokkaido. As opposed to main-island Japan, the morphological continuity from the Neolithic to recent inhabitants in Hokkaido (Ainu) is notable, so that the evidence of admixture easily could have escaped notice. In this study, the effects of gene flow from an outside source on the pattern of among-group variation of Hokkaido Ainu are examined by means of two models. One is the R-matrix model comparing observed and expected craniometric variation for estimating differential external gene flow into a region. The other is a simple simulation model that estimates admixture in a population with two parental populations. The two approaches give similar results. The results suggest the possibility of admixture between the migrants from Northeast Asia, the Okhotsk culture people, and the indigenous inhabitants in Hokkaido during the 5th to 12th centuries A.D., at least in northeastern Hokkaido. Such gene flow may have a certain degree of effect on the genetic structure of recent Ainu. The findings further suggest morphological heterogeneity in Northeast Asia during the Holocene that has relevance for understanding the morphological heterogeneity seen through time in the New World.



UncleTomRuckusInGoodWhiteWorld said...

This is probably how Ainu got a significant amount of C3 Haplogroup (same as Ghengis Khan) which is pretty absent in ethnic Japanese.

Ainu have the highest rate of D Y haplogroup...and I believe Ryuku Islanders are second in Japan...this is believed to be the marker for the Japanese aboriginals (Jomon).

25% C3...whereas Kyushu Japanese were only 7.5%...and in central Japan it is even lower...(likely Kyushu people have more genes in common with people of the Ryuku islands than Honshu Island Japanese). Since there is a negative relationship of between C3 and distance from Mongolia, I would imagine the C3 came into Japan from the North, not through Korea...and since the Ainu live in the North...well...this is not rocket science.

UncleTomRuckusInGoodWhiteWorld said...

Also from the 7th-12th century...Emishi (thought to be proto-Ainu, semi Japanified barbarians) were pushed out of Honshu or absorbed into the Japanese population of Northern Honshu.

Many of these people ran off to Hokkaido and merged with the Ainu...no one knows anything about them genetically...not there language or where they came from. They are assumed to be related to the Ainu.

terryt said...

Dragon Horse. That's what I think too. C1 is a much earlier arrival than C3.