Razib @ the ever excellent Gene Expressions links to a story on the genetic structure of the Kannada-speaker - Gene Expression: Genetics of Karnataka populations

For South Asians readers, Genetic structure of four socio-culturally diversified caste populations of southwest India and their affinity with related Indian and global groups:


The microsatellite study divulges a common ancestry for the four diverse populations of Karnataka, with the overall genetic differentiation among them being largely confined to intra-population variation. The practice of consanguineous marriages might have attributed to the relatively lower gene flow displayed by Gowda and Muslim as compared to Iyengar and Lyngayat....


Standard caveat, don't read too much into one study!

Consanguineous was word of the day a little while back. ;-)