"Talageri’s master key is the internal chronology of the Rg-Veda. Basing himself on two centuries of Western scholarship, from 19th-century German Veda scholar Hermann Oldenberg to present-day AIT champion Michael Witzel, Talageri compares the contents of the oldest layer, largely coinciding with books 6, 3 and 7; of the middle layer, books 2 and 4; and the youngest layer, comprising books 1, 5, 8, 9 and 10. Covering every verse and every instance of every data category considered, and comparing the three periods, he finds a shifting focus in the names of animals, plants, rivers, landscape features, technology, ancestors, ethnic groups, and in personal name types and verse forms. His finding is this: the old layer was indubitably composed in the Yamuna/Sarawati region, which was to remain the centre of gravity of Vedic culture; the middle layer’s horizon expands westwards as far as the Indus; while the youngest parts are also familiar with Afghanistan. This is exactly the opposite of what the AIT predicts. In an invasionist scenario, the oldest layer would obviously be based in Afghanistan and be as yet unfamiliar with India’s interior, which would then only be settled in the younger period."