The aim of this study is to examine and assess the nonmetric dental trait evidence for the population history of East and Southeast Asia and, more specifically, to test the two-layer hypothesis for the peopling of Southeast Asia. Using a battery of 21 nonmetric dental traits we examine 7,247 individuals representing 58 samples drawn from East and Southeast Asian populations inhabiting the region from the late Pleistocene, through the Neolithic, Bronze Age, Iron Age, and into the historic and modern periods. The chief data reduction technique is a neighbor-joining tree generated from the triangular matrix of mean measure of divergence values. Principal findings indicated a major dichotomization of the dataset into (1) an early Southeast Asian sample with close affinities to modern Australian and Melanesian populations and (2) a very distinct grouping of ancient and modern Northeast Asians. Distinct patterns of clinal variation among Neolithic and post-Neolithic Mainland Southeast Asian samples suggest a center to periphery spread of genes into the region from Northeast Asia. This pattern is consistent with archaeological and linguistic evidence for demic diffusion that accompanied agriculturally driven population expansion in the Neolithic. Later Metal Age affinities between Island and Mainland coastal populations with Northeast Asian series is likely a consequence of a South China Sea interaction sphere operating from at least 500 BCE, if not from the Neolithic. Such results provide extensive support for the two-layer hypothesis to account for the population history of the region.
The authors expresses sincere gratitude to the following for permission to access comparative dental specimens and/or helpful assistance for newly recorded samples (abbreviations in parentheses are affiliations given in the foot notes of Table 1); Wang Daw‐Hwan (AST); Chris Stringer, Margaret Clegg, Robert Kruszynski (BMNH); Robert Foley, Jay Stock, Maggie Bellati (CAM); Nguyen Viet (CSPH); Rachanie Thosarat, Sahawat Naenna, Amphan Kijngam, Suphot Phommanodch (FAD); Nguyen Giang Hai, Nguyen Lan Cuong, Nguyen Kim Thuy (IAH); Le Chi Huong, Nguyen Tam (KHPM); Bui Phat Diem, Vuong Thu Hong (LAPM); Philippe Mennecier (MHO); Wilfred Ronquillio (NMP); John de Vos (NNML); Tsai Hsi‐Kue (NTW); Zhang Chi (PKU); Korakot Boonlop (SAC); Michael Pietrusewsky (UHW); Denise Donlon (USYD); Gen Suwa (UTK); Bernardo Arriaza, Vicki Cassman (UNLV); Charles Higham, Nancy Tayles, University of Otago; Bui Chi Hoang, Southern Institute of Social Sciences, Ho Chi Minh; Hsiao Chun Hung, Australian National University; Mariko Yamagata, Kanazawa University.
- clinal variation
- demic diffusion
- two-layer model