Evidence for a SE Asian component in the ancestry of Ryukyuans.

To test various hypotheses concerning the origin of the Ryukyu Islanders, data on two systems of traits – craniometric and cranial non-metric – were integrated using multivariate statistical methods. The results indicate that the Ryukyuans are a hybrid group which formed from at least three components. The first two, associated with the Jomon and Yayoi cultures, are also ancestral for other modern Japanese groups. The specificity of Ryukyuans may be due to Southern Mongoloid admixture.
https://www.academia.edu/3542820/ON_...NONMETRIC_DATA