[The population history of the Japanese].

This paper introduces a "dual structure model" that explains the population history of the Japanese population including the Okinawa islanders (Ryukyus) and Ainu under a single hypothesis. The model assumes that the first occupants of the Japanese Archipelago came from somewhere in Southeast Asia in the Upper Palaeolithic age and gave rise to the people in the Neolithic Jomon age, or Jomonese; then the second wave of migration from North Asia took place in and after the Aeneolithic Yayoi age; and the populations of both lineages gradually mixed with each other. The "dual structure model" also assumes that the population intermixture is still continuing and the dual structure of the Japanese population is maintained even today.

Fourier analysis of shape changes in the Japanese skull: occipital view.

Photographs (norma occipitalis) of Japanese adult skulls (n = 171) were mathematically described with Fourier analysis to assess shape changes over time. The materials used were adult male skulls excavated from the Kanto District and covered four age-periods; Jomon (2000-1000 BC). Kamakura (14C.

Elevated lead concentrations in Japanese ribs of the Edo era (300-120 BP).

Nineteen elements (Al, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V and Zn) were analyzed in excavated bone (rib) of the Edo era (a Japanese historical era, 300-120 BP (before present] from different burial conditions in Tokyo, and in contemporary Japanese bone (rib) obtained from autopsy cases. The elemental composition of the excavated bones varied according to their burial conditions. The concentration of soil-related elements such as Fe, Mn, Co and Ti in the bone was lowest in the samples in the "wooden coffin in a stone room", next lowest in the "funeral urn with mud", and highest in the "wooden coffin full of mud".

Elemental composition of ancient Japanese bones.

Excavated bones (rib) obtained from 50 sites in Japan were measured by ICP atomic emission spectrometry and atomic absorption spectrometry for concentration of 19 elements, including Al, B, Ca, Cd, Cr, Co, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V and Zn. One hundred and forty-one specimens were classified into five groups according to Japanese prehistoric and historic eras (Jomon, Yayoi, Kofun, Kamakura and Muromachi, and Edo). The elements, with concentrations which showed no significant change with era were Al, B and Cr.

Origins and affinities of Japanese viewed from cranial measurements.

The origins and affinities of Japanese were analysed by means of cluster analysis using nine cranial measurements which were statistically selected as those representing a large proportion of the variance. As a result, the following hypotheses are proposed: Japanese are basically descendants of Jomon people, a fairly large amount of admixture between migrants from the Korean Peninsula and Jomon people took place during the Yayoi and protohistoric ages, particularly in western Japan, the migrants were close to north Asians in cranial morphology, Ainu and Ryukyus (Okinawan people) seem to be direct descendants of Jomon people without any or with very little influence of the migrants and geographical variations in modern Japanese quite likely are the result of differences in the magnitude of admixture.

Estimation of age from the pubic symphysis by means of multiple regression analysis.

This study has been carried out to assess the age from the pubic symphysial surface employing a multiple regression analysis and a quantification theory model I analysis. Using partial regression coefficients and/or normalized scores obtained from the analyses, ages of skeletal remains can be quantitatively estimated with a fairly high reliability. The use of this method is, however, limited to the samples between 18 and 38 years of age, because age changes in the symphysial surface show large variations after about 40 years.

Additional features of Ainu dentition. V. Peopling of the pacific.

Crown morphology of 85 plaster dental casts from skeletal and living Ainus of less than 1/8 non-Ainu admixture is described and compared for microevolutionary and origins considerations. There is no significant sex dimorphism and few inter-sample differences through time. Inter-observer differences occur where observation standards are poorly established.