Many linguists have commented that these proposed dates of separation are 'too early,' but how . . . do they know this, or judge this? - Colin Renfrew

All the migrations postulated by Renfrew ultimately stem from a single catalyst: the crossing of Anatolian farmers into Greece… For all practical purposes, Renfrew's hypothesis disregards Tocharian and Indo-Iranian.

It is difficult to see what is particularly non-Aryan about the Indus Valley Civilization.

This hypothesis that early Indo-European languages were spoken in north India with Pakistan and on the Iranian plateau at the sixth millennium ec has the merit of harmonizing symmetrically with the theory for the origin of the Indo-European languages of Europe. It also emphasizes the continuity in the Indus Valley and adjacent areas from the early Neolithic through to the floruit of the Indus Valley Civilization~ point that Jarrige has recently stressed. Moreover the continuity is seen to follow unbroken from that time across the Dark Age succeeding the collapse of the urban centres of the Indus Valley, so that features of that urban civilization persist, across a series of transformations, to form the basis for later Indian civilization. A number of scholars have previously developed these ideas of continuity.