| Abstract: |
It has been debated whether a human dispersal originating from southern mainland Asia replaced the original, late Pleistocene modern human populations inhabiting the islands of Southeast Asia or whether observed morphological changes (and cultural changes) are attributable to <italic> in situ</italic> change. It has been suggested that this transition occurred at the Mesolithic-Neolithic boundary. The migration-replacement model predicts abrupt morphological changes in a short period of time due to the influx of a southern mainland China population. The <italic>in situ</italic> model predicts no significant abrupt morphological changes at the Mesolithic-Neolithic boundary. It is the goal of this dissertation to test predictions of both models with a suite of traditional cranio-dental and geometric morphometric cranial analyses that have proven useful in studies of biological relatedness. Analyses are performed on recent human samples from the East Asia-Pacific region and prehistoric skeletal samples (i.e., Pre-Neolithic and Neolithic) from an archaeological site in northwest Borneo (West Mouth, Niah Cave). The first phase of analysis tests predictions of both models by comparing statistically the Pre-Neolithic and Neolithic group means. If the data indicate significant morphological differences between the temporal groups, then the <italic> in situ</italic> model is rejected. Conversely, if significant differences are not detected, then the <italic>in situ</italic> model cannot be rejected and the migration-replacement model remains unsupported. The second phase, statistical comparison of the prehistoric samples with modern East Asia-Pacific human samples, determines to which modern populations the prehistoric groups have the closest affinities. Results of the analyses fail to falsify the <italic>in situ</italic> model. The two West Mouth samples do not appear significantly different from each other regarding cranial and dental non-metric or upper- and mid-face shape. The Pre-Neolithic and Neolithic samples demonstrate affinities closer to Southeast Asians, Polynesians and Australians than to East Asians. Both prehistoric groups also demonstrate considerable variation and overlap in morphology. Tooth size, however, does differ significantly between the temporal samples and is most likely a result of dental reduction over time. The cultural changes evident at the Mesolithic-Neolithic boundary in island Southeast Asia, therefore, may be the result of diffusion without significant genetic contribution at this particular site.
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