2007/01/01 by Takashi Toma, Tsunehiko Hanihara, Hajime Sunakawa +2 · 5 citations
Arts and Humanities · Biochemistry, Genetics and Molecular Biology · Health Professions · #Forensic Anthropology and Bioarchaeology Studies #Forensic and Genetic Research #Indigenous Studies and Ecology #Geography #Population #Range (aeronautics) #Pacific islanders #Demography #Biology #Polynesians
paper · pdf · doi:10.1537/ase.061219
openalex publication_date 2007/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Mesiodistal and buccolingual crown diameters were examined to describe and compare patterns of metric dental variation in five modern samples from the Ryukyu Island chain (Miyako, Ishigaki, Tokunoshima, and two samples from Okinawa Island). Principal component analysis applied to two separate datasets, raw measurement and standardized (C-score) data, for 32 Asian and Pacific samples, including the five Ryukyu Islander series, produced an overall size factor and three shape factors (relative size of mesiodistal diameters versus buccolingual diameters and two kinds of front-back polarity). Ryukyu Islanders have similar crown dimensions as those of the predominant eastern Asian groups, characterized by mesodont dentition. In terms of shape factors, Ryukyu Islanders are distinctive among eastern Asian population groups on the one hand, and show diversity among themselves on the other hand. The inter-regional variation of Ryukyu Island groups estimated by Fst falls within the range of 4–6% of the total variance, which is greater than those of Arctic population samples (Aleuts and Eskimos). The average within-group variance of the Ryukyu Island series measured by the R-matrix method (intra-regional variation) is compatible with those of East and Northeast Asians, Micronesians, and Polynesians. These findings suggest that differential patterns of long-term gene flow from an outside source, geographical isolation, and genetic drift in each island of the Ryukyu Island chain has produced the morphological diversification of modern Ryukyu Islanders.