A morphometric analysis of the Late Pleistocene Human Skeleton from the Moh Khiew Cave in Thailand.

Few Late Pleistocene human remains have been found in Southeast Asia and the morphological features of the people of that age are still largely unknown due to the virtual lack of human remains in the area. Recent excavations at the Moh Khiew Cave in Thailand resulted in the discovery of a Late Pleistocene human skeleton in a relatively good state of preservation. An AMS radiocarbon date on the charcoal sample gathered from the burial gave a result of 25,800 +/- 600 BP, implying that the inhabitants of Moh Khiew Cave resided in a part of Sundaland during the last glacial age. In debates on the population history of Southeast Asia, it has been repeatedly advocated that Southeast Asia was occupied by indigenous people akin to present-day Australo-Melanesians prior to an expansion of migrants from Northeast Asia into this area. Morphometric analyses were undertaken to test the validity of this hypothesis. In the present study, cranial and dental measurements recorded from the Moh Khiew remains are compared with those of early and modern samples from Southeast Asia and Australia. These comparisons demonstrate that the Moh Khiew specimen resembles the Late Pleistocene series from Coobool Creek, Australia in both cranial and dental measurements. These results suggest that the Moh Khiew skeleton, as well as other fossil remains from the Tabon, Niah and Gua Gunung sites, represents a member of the Sundaland population during the Late Pleistocene, who may share common ancestry with the present-day Australian Aborigines and Melanesians.

Recent origin and cultural reversion of a hunter-gatherer group.

Contemporary hunter-gatherer groups are often thought to serve as models of an ancient lifestyle that was typical of human populations prior to the development of agriculture. Patterns of genetic variation in hunter-gatherer groups such as the Kung and African Pygmies are consistent with this view, as they exhibit low genetic diversity coupled with high frequencies of divergent mtDNA types not found in surrounding agricultural groups, suggesting long-term isolation and small population sizes. We report here genetic evidence concerning the origins of the Mlabri, an enigmatic hunter-gatherer group from northern Thailand. The Mlabri have no mtDNA diversity, and the genetic diversity at Y-chromosome and autosomal loci are also extraordinarily reduced in the Mlabri. Genetic, linguistic, and cultural data all suggest that the Mlabri were recently founded, 500-800 y ago, from a very small number of individuals. Moreover, the Mlabri appear to have originated from an agricultural group and then adopted a hunting-gathering subsistence mode. This example of cultural reversion from agriculture to a hunting-gathering lifestyle indicates that contemporary hunter-gatherer groups do not necessarily reflect a pre-agricultural lifestyle.

Anthropological implication of the SDF1-3'A allele distribution in Southeast Asia and Melanesia.

The distribution of the SDF1-3'A allele among 1848 individuals in Southeast Asia and Melanesia was studied with the polymerase chain reaction-restriction fragment length polymorphism assay. The SDF1-3'A allele frequency in the populations of mainland Southeast Asia ranged from 0.0 to 0.355, whereas in the populations of insular Southeast Asia and Melanesia, it ranged from 0.233 to 0.733, with an increasing cline from west to east. Correlation between SDF1-3'A frequency and longitude values was highly significant for the populations in the Pacific region (r = 0.867, P < 0.001). The geographic distribution of the SDF1-3'A frequencies in the Pacific region was interpreted by an admixture of Austronesians with the aboriginal people in situ. In addition, this study found high proportions of SDF1-3'A/3'A homozygous individuals in several populations, which will enable us to evaluate roles of the SDF1 genotypes in SDF-1 expression.