Malayan Paleosociology: Implications for Patterns of Genetic Variation among the Orang Asli / Alan G. Fix

The traditional explanation for biological and cultural diversity among Malayan Orang Asli has been separate waves of migration of already differentiated populations. According to this view, the original colonizers of the peninsula were Semang Negrito nomadic hunter-gatherers, followed by Senoi swiddeners, and later by trading and farming Melayu Asli groups. Geoffrey Benjamin has proposed an alternative model stressing in situ differentiation from a common ancestral population, and implying different causes for biological variation. In the present article, the author examines the interplay of environmental, historical, and sociocultural factors suggested by the in situ model. The differentiation of subsistence modes structured the amounts and patterns of gene flow through associated marriage patterns and the opportunities for genetic drift. Similarly, the differing ecologies of foragers and farmers affected malaria incidence and consequently the frequency, distribution, and pattern of spread for malarial protective genes such as hemoglobin E and ovalocytosis.