Ancestry of Modern Indian Populations

Abstract

An analysis of mitochondrial DNA (mtDNA) restriction fragment length polymorphisms (RFLPs) was done with the primary goal of clarifying the relationship of the Indian population to world populations. Phylogenetically informative RFLP sites were amplified, restricted and scored for 187 Indian-descended individuals. This sample collectively represented a geographically wide distribution, the three main religions present in the subcontinent, and three main caste groups. Thirteen haplotypes were found in the Indian population, and when combined with world population data obtained from the literature, 41 different haplotypes were found. India was found to be significantly different from all world populations under study. In agreement with previously reported results, the Indian population was found to be more similar to European populations than south-east Asian populations, with all Indian populations sharing the European-associated haplotypes 14 and 15 at high frequencies. However, high frequencies of haplotype 30 implied similarity with the Evenk population of Siberia, suggesting a possible north-central Asian origin for the Dravidian and/or Indo-Aryan migration into India. Significant geographical differentiation within India was found, with north-western India having significantly higher frequencies of haplotypes 14 and 15 than Southern India, and lower frequencies of the Evenk-associated haplotype 30. The northwest was also significantly more diverse than other regions of India, most likely due to its location on the main routes of repeated migration into India. Significant differences between religious groups were found to have a geographical basis, while caste groups were undifferentiated from each other and the main religious groups.