1. Department of Anatomy, Faculty of Medicine, University of the Ryukyus, Nishihara
2. Transdisciplinary Research Organization of Subtropics and Island Studies, University of the Ryukyus, Nishihara
3. Department of Anthropology, University of Washington, Seattle
4. Center for Studies in Demography and Ecology, University of Washington, Seattle
5. Center for Statistics and the Social Sciences, University of Washington, Seattle