"[A very recent study, not on crude skull types but on the far more precise genetic traits, confirms the absence of an immigration from Central Asia in the second millennium BC. Brian E. Hemphill and Alexander F. Christensen report on their study of the migration of genetic traits (with reference to AIT advocate Asko Parpola):] “Parpola’s suggestion of movement of Proto-Rg-Vedic Aryan speakers into the Indus Valley by 1800 BC is not supported by our data. Gene flow from Bactria occurs much later, and does not impact Indus Valley gene pools until the dawn of the Christian era.”"