Genetic Studies in Tobishima: II. Dermatoglyphic Differentiation among the Villages

Abstract

The finger and palm prints of 328 males and 369 females from Tobishima Island in Yamagata Prefecture were examined for 16 qualitative and 7 quantitative characters, attempting to reveal a regional dermatoglyphic differentation in relation to the population structure reported previously. A high degree of dermatoglyphic differentiation was found among three villages on Tobishima, especially in finger patterns, both hypothenar and thenar/I configurations, total finger ridge counts, and a-b ridge counts. Graphic profiles summarizing variation patterns in qualitative traits were strikingly different from one village to another, suggesting that the dermatoglyphic differentia-tion was apparently of random nature. Such rare variants as hypothenar whorls, hypothenar radial arches, and accessory axial triradii showed an uneven distribution among the villages. Further, a considerable deviation of the Tobishima population from the general Japanese was found in pattern frequencies, especially in missing c triradii, accessory interdigital triradii, thenar/I patterns, and simian creases. These results indicate that, as suggested by the previous report, the regional dermatoglyphic differentiation on Tobishima has been caused mainly by random genetic drift.