Cultural diffusion of Indo-Aryan languages into Bangladesh: A perspective from mitochondrial DNA.

Although both linguistic and historical studies indicated only a small group of Aryans had been involved into the diffusion of Indo-Aryan languages into Bangladesh, no genetic studies had been carried out to prove this notion. By studying mitochondrial DNA variants of 240 Bengali speakers in Bangladesh, among which 23 mitogenomes are completely sequenced, we found a high proportion of South Asian components in this group. By contrast, only a small proportion of lineages can be traced back to western Eurasia, which could be attributed to recent gene flow. Our results implied a cultural diffusion of the Indo-Aryan languages into Bangladesh.