| Abstract: |
South Asia has a complex cultural and genetic history of great time depth. But relatively little is known of the cause of genetic variability in South Asian populations. Dental morphological traits are a useful resource for interpretation of South Asian biohistory because they are genetically inherited, exhibit little environmental influence, are evolutionarily conservative, and lack sexual dimorphism. Thus, dental data were used to suggest potential microevolutionary processes at work within the region, and to assess the role played by South Asians in the peopling of the world by modern humans. Dental morphological data from 22,875 individuals were utilized in multivariate statistical analyses (Mean Measure of Divergence, multi-dimensional scaling, cluster methods), with all data standardized to the Arizona State University Dental Anthropology System. Ten Early South Asian groups (late Pleistocene to Iron Age/Early Historic) and 16 Late South Asian samples (historic, primarily 18$/sp[/rm th]$-19$/sp[/rm th]$ Century AD) consisted of data collected by a single observer (DEH) for 1,622 individuals, with the remainder (n = 2,576) extracted from available literature. Dental data (n = 18,677) for 14 Early World (prehistoric) and 24 Late World (historic) groups were also obtained from published sources. All Early and Late South Asian samples are more similar to one another than to any Early/Later World group, suggesting that gene drift, rather than gene flow, played a substantial role in regional biohistory. People of the Indus civilization and Iron/Megalithic period also appear to have indigenous origins, and were not the result of massive, non-Asian genetic influence. Minimum MMD divergence values and similarities in dentition suggest an early dental pattern shared by South Asians (Indodont) and early populations of Southeast Asia (Sundadonts). Additional affinities between Early South Asia and Early Eurasia (Ukrainian Black Sea region) suggest two possibilities. (1) This early dental pattern (Indo-Sundadont) was once widely distributed geographically. (2) The Indo-Sundadont pattern diverged into two subsequent patterns, with Indodonts more similar to Early Near-Mid East/Eurasia/Europe, and Sundadonts with North Asia (Sinodonts). Affinities of early Sri Lankan populations with modern Melanesians and Australian Aborigines also suggest possible colonization of the Sahul region by peoples of South/Southeast Asia.
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