So the best guess we can make based on archaeological and genetic evidence is that a population of herders from the southern or central Zagros region, speakers of Proto-Elamite or a related language, migrated to south Asia sometime after 7000 BCE, mixed with the First Indians and this new, mixed population sparked an agricultural revolution in the north-western region of India and then went on to create the Harappan Civilization over the next few millennia.
