Accepted Panels

The ethnic groups inhabiting the lowland and highland terrain in far northern Pakistan have recently been suggested to have served as middlemen in an interregional exchange network between Turkestan and the Indus Valley—an exchange network that may have involved populations at the northern terminus of the Inner Asian Mountain Corridor or populations of the Bactrian Margianan Archaeological Complex (BMAC) of southern Central Asia. Alternatively, it may be that waves of Pathan immigration into northern Pakistan introduced such extensive gene flow from the west that all trace of contacts north has been eliminated. Patterning of morphological trait frequencies of the permanent tooth crown are known to correlate closely with DNA patterns and are largely free of natural selection making them ideal for tracing patterns of past gene flow and genetic drift. A contrast of trait frequencies among archaeologically derived samples from the Indus Valley and southern Central Asia with 16 samples of members of living ethnic groups from the lowlands of Hazarewal and the highlands of Chitral (n= 2576 individuals) reveals a striking absence of evidence for interactions with populations to the north but does yield some, albeit meager, evidence of Pathan-related gene flow from the west. These results not only provide a low-cost diachronic perspective on the population dynamics characterizing northern Pakistani ethnic groups only dimly illuminated by DNA studies, but also call long-held theories of Aryan invasions into South Asia across the Hindu Kush-Karakoram Mountains seriously into question.