Evolutionary Human Sciences (2020), 2, e6, page 1 of 13 doi:10.1017/ehs.2020.6 REVIEW The evolving Japanese: the dual structure hypothesis at 30 Mark J. Hudson1* , Shigeki Nakagome2 and John B. Whitman3 1Eurasia3angle Research Group, Max Planck Institute for the Science of Human History, Kahlaische straße 10, 07745 Jena, Germany, 2School of Medicine, Trinity College Dublin, 150-162 Pearse Street, Dublin, Ireland and 3Department of Linguistics, Cornell University, 203 Morrill Hall, Ithaca, NY 14853, USA *Corresponding author. E-mail:
[email protected] Abstract The population history of Japan has been one of the most intensively studied anthropological questions anywhere in the world, with a huge literature dating back to the nineteenth century and before. A growing consensus over the 1980s that the modern Japanese comprise an admixture of a Neolithic population with Bronze Age migrants from the Korean peninsula was crystallised in Kazurō Hanihara’s influential ‘dual structure hypothesis’ published in 1991. Here, we use recent research in biological anthropology, historical linguistics and archaeology to evaluate this hypothesis after three decades. Although the major assump- tions of Hanihara’s model have been supported by recent work, we discuss areas where new findings have led to a re-evaluation of aspects of the hypothesis and emphasise the need for further research in key areas including ancient DNA and archaeology. Keywords: Agricultural dispersals; Bronze Age migrations; Japanese; Ainu; national identity Media summary: The ‘dual structure hypothesis’ of two genetic layers in the population history of the Japanese archipelago still remains widely accepted after three decades, but new research is starting to suggest more complex social relations between Neolithic (Jōmon) and Bronze Age (Yayoi) peoples.