On the Pleistocene Population History in the Japanese Archipelago

This paper provides a current understanding of human population history in the Pleistocene Japanese Archipelago, particularly with respect to the routes and timing of hunter-gatherer migrations, by incorporating multiple lines of evidence from the records of archaeology, human paleontology, and genetic studies. The human fossil remains are concentrated on the Ryukyu Islands in southwestern Japan, suggesting that there may have been a northward migration via the Ryukyu Islands. In contrast, studies of ancient mitochondrial DNA demonstrate genetic continuity among Holocene hunter-gatherer populations in the Paleo-Sakhalin-Hokkaido-Kurile Peninsula, whereas the Pleistocene genetic history is little explored. Although it is largely supported, the assumed population continuity from the Pleistocene to the Holocene inside the Japanese Archipelago is also challenged by an examination of the Paleolithic record and a comparison of the short-and long-term chronologies of the Japanese Paleolithic, implying that the Japanese Paleolithic record was created by hunter-gatherer population migrations from the north and south with substantial time lag and endemic technological invention and transformation during the Late Pleistocene.