Principal component analysis of Y-chromosome haplogroup frequencies. (a) Comparison with Nepalese and Tibetan groups ; (b) Comparison with some Indian caste and tribal groups  where our data have been normalized to the Sengupta level of resolution. Populations: Kat, Kathmandu; New, Newar; Tam, Tamang; Tib, Tibet; DC Dravidian castes; IEC, Indo-European castes; AAT, Austro-Asiatic tribals; TBT, Tibeto-Burman tribals; DT, Dravidian tribals; IET, Indo-European tribals.
Fornarino et al. BMC Evolutionary Biology 2009 9:154 doi:10.1186/1471-2148-9-154