The Skulls of Ubayama Shell-mounds II. An Analysis of Intra- and Inter-regional Variation of the Jomon Population

Abstract

Inter-regional comparative studies of cranial morphology depend upon composite specimens constructed according to the standards chosen by the writers. Although there have been many reports about variations within the so-called “Jomon population, ” very few have taken up the issue of the validity of the regional classification. In this study, Mahalanobis' D²s are calculated from metric and non- metric data to evaluate the intra- and inter-regional variation of Jomon crania, mainly from two regions-northern Chiba and the Atsumi Peninsula. The samples of both districts cannot be regarded as a homogeneous unit with morphological peculiarity by the D²s and bootstrap derived probabilities. The heterogeneities of the intra-regional variation are as large as those of inter-regional variation. This may indicate that, at least in the samples used for this study, morphological differences are not parallel to regional ones and thus, for what has been called the “Jomon population, ” the regional classification is not valid.