A Geographical Cline in Metrical Characteristics of Kofun Skulls from Western Japan

Abstract

Geographic variations in metrical characteristics of Kofun skulls were examined, using the principal component analysis. The genetic influence of immigrants in northern Kyushu appeared as a geographical cline in the cranial measurements obtained by the method of MARTIN and SALLER (1957). We considered that the cline originated from the migration and gene mixture, since the Yayoi period. The following three clinal forms were determined from the relationship between the distance and the score of the first principal component in each series: 1) abrupt fall-off curve, 2) gentle fall-off curve, and 3) linear or irregular type. These three types seemed to show different rates of gene flow. The direction of diffusion to the east may represent local migration to obtain favorable land for cultivation.