S38-4

Diachronic Changes in Human Diet in the Ryukyu Islands, Japan: A Meta-analysis of Carbon and Nitrogen Stable Isotope Ratios

Takumi Tsutaya1 & Minoru Yoneda2

1Graduate University for Advanced Studies, Japan

2University of Tokyo, Japan

The Ryukyu Islands, which stretch for over 1000 km in southern Japan, consist of 160 islands. Each island generally covers a relatively small land area of less than 1200 km2. The Ryukyu’s have been occupied by people from the Late Pleistocene onwards. Due to their relative isolation and small size, the Ryukyu Islands make excellent examples to investigate long-term sustainability of human populations in island settings. This paper investigates the diachronic changes in the human diet over the past several millennia in the Ryukyu Islands by analysing the previously published and newly measured results of carbon and nitrogen stable isotope ratios in 194 ancient human skeletons from palaeolithic to pre-modern periods, and 25 modern human hair samples. The results of the meta-analysis indicate that human diet in the Ryukyu Islands changed significantly during three recognizable phases: at the time of reef formation, the introduction of agriculture, and modernization. Also, dietary breadth was broader in the past. This suggests that the ancient humans of the Ryukyu Islands depended on a greater variety of food resources for resilient lifeways in a resource-restricted island setting.