Temporal changes in morphometric features of human cranial remains from the late Jomon period (1500 B.C.-300 B.C.) to the Modern period (1900-1950 A.D.) in western Japan are examined. The results of univariate and multivariate analysis indicate that the Yayoi people (300 B.C.-300 A.D.), characterized by high faces and tall stature, show morphological discontinuity with the earlier Jomon people, who exhibit lower faces and shorter stature. This discontinuity contrasts with the relatively continuous changes among populations after the Yayoi. Comparing these changes with those documented in the Kanto region of eastern Japan indicates there are significant regional differences in the degree and rate of transformation in certain cranial features, especially facial height, between the two regions. Differences in cranial shape between the two regions become apparent during the Yayoi period and these differences tend to diminish thereafter. The most plausible explanation for these observed changes is the introduction of new genes, coinciding with the arrival of new immigrants from the Asian continent in the northern Kyushu-Yamaguchi region at the beginning of the Yayoi period. Further testing of this hypothesis will be necessary before definitive conclusions can be reached regarding the appearance of modern Japanese.

No abstract

A rare case of a short radiocarpal flexor (M. flexor carpi radialis brevis vel profundus of Wood) was found on the right forearm of a 47-year-old Japanese male corpse. The muscle arose from the anterior surface of the radius, ran distally in the deep layer of the flexor region to enter deeply into the carpal tunnel, and then interconnected with the subtendon of the extensor carpi radialis brevis at the gap between the bases of the second and third metacarpal bones. This muscle was supplied by a branch of the anterior interosseous nerve.

To determine the sex of fragmentary human skeletal remains, discriminant function analysis using 18 measurements on relatively preserv-able parts of the skeleton was made on samples from western Japan, of recent, medieval and aeneolithic Yayoi periods. A total of over 150 dis-criminant functions based on one to eight variables were applied to recent samples and the sex could be determined with over 90% accuracy, using combinations of only two to three measurements. When the discriminant function coefficients calculated from measurements on the recent Japanese were applied to the excavated skeletal remains, they proved to be useful in sexing the samples from the Yoshimo-hama site (15-16C.). In case of the Yayoi population (300 B. C.-A. D. 300), a suitable selection of the discriminant functions containing the variables which showed relatively small differences among the populations studied made feasible sex determination at a high rate of accuracy. When the discriminant functions were calculated for each population respectively, the measurements were found to be highly useful for sex determination in all the populations studied. Furthermore, the combination method of midpoints between the male and female mean measurements also showed a sufficiently high accuracy in sexing the samples. Since the methods we used are not so influenced by the degree of bone preservation, these approaches can be used to determine the sex of excavated human skeletons containing poorly preserved materials.

No abstract