Genetic Diversity and Affinities among Indian Populations: An Overview

Abstract

One of the primary objectives of the study of human biology is to understand the nature and extent of biological variation among human populations. Genetic characters are commonly used for this purpose. Genetic diversity among Indian populations is large (Table 1). From Table 1 it is seen that the variation in gene frequencies among populations of South Asia (comprising primarily the Indian subcontinent) is the highest compared to the populations resident in the other Asian regions. Using gene frequency data on ten polymorphic loci, Roychoudhury (1983) obtained relationships among some castes and tribes of India and some neighbouring populations. He found that the south Indian castes are genetically very close to the Sinhalese of Sri Lanka. This is because of past large-scale migrations of Tamil-speaking south Indian people to Sri Lanka; the linguistic and cultural similarities of Sinhalese with the south Indian people (especially those of Tamilnadu) has also resulted in a good deal of genetic admixture. On the whole, the caste groups of India were found to be closer to the Iranians and Afghans than to Mongoloid populations of Malaya and China. The south Indian tribal groups were found to be genetically close to the tribal Veddahs of Sri Lanka. He also found the tribal groups of Malaya and the aborigines of New Guinea and Australia to be genetically unrelated to the south Indian tribes. Using data on four polymorphic loci (Tf, Gc, Gm and Km), Walter (1986) arrived at similar conclusions, and additionally found that the east Indian populations are more similar to the Mongoloid populations of Nepal, Japan and China.