Differences in Mandibular Morphology of the Jomon People from Kanto and the Yayoi People from Northern Kyushu and Yamaguchi
Differences in mandibular morphology were investigated among three Japanese populations, the Neolithic Jomon from the Kanto region and two Aeneolithic Yayoi series from the northern Kyushu region and Yamaguchi Prefecture. The Jomon and Yayoi are considered to represent two major ancestral populations of the modern Japanese. Differences between the two male Yayoi samples were so small that they could be considered as having nearly identical mandibular morphology. Considerable differences were detected between the males of the Yayoi populations and the Jomon. In comparison to the Jomon males, mandibles of the male Yayoi populations are characterized by having (1) a larger overall size, (2) a higher symphyseal height, (3) corpus heights consistently decreasing posteriorly, (4) a relatively lower least coronial height, (5) a deeper sigmoid notch, (6) a thicker angular region, and (7) a larger mandibular angle. In contrast, corpus heights at the premolar region of the Jomon mandibles were approximately equivalent to the symphyseal height. A similar tendency was recognized in the females with minor exceptions.