Genetic study of scheduled caste populations of Tamil Nadu

The present study aims to describe the genetic structure ofthe scheduled caste populations in Tamil Nadu state, and toassess their relationships with contemporary people of dif-ferent socio-economic groups of the state. We have stud-ied eight human-specific indels (insertion/deletion polymor-phisms) in DNA samples from five Tamil Nadu caste groupsusing phylogeneticand principal component analysis (PCA),and compared the data with earlier data on the three othercaste groups of the state. The results indicate that scheduledcastes are genetically heterogenous, but show closeness withother socio-economic groups of the state.The social structure of India is dominated by the Hinducaste system. Caste refers to a rigid system of ranked socialinequality with significant barriers to mobility or to intimateassociations between different strata. ‘Caste’ comes from thePortuguese word