"I agree that a plausible explanation has yet to be given as to how the newcomers could have completely eradicated the pre-existing language of the entire North of the subcontinent in the short interval normally allotted between their arrival and the composition of the Rg Veda, in which the local topography is Indo-Aryan. ... Kazanas has a right to wonder how and why would the Indus Valley dwellers have so thoroughly and completely adopted the language of these illiterate herdsmen if the latter were not invaders – a status denied them by archaeology?"