Contributions of Chemical Dietary Reconstruction to the Assessment of Adaptation by Ancient Highland Immigrants (Alto Ramirez) to Coastal Conditions at Pisagua, North Chile

Abstract At the latitudes of northern Chile the earliest migrants from the highlands were members of the Alto Ramirez cultural group. They arrived in the lower valleys about 1000 BC, where they transferred their highland practices of agriculture and pastoralism to those lower valley sites, acquiring only a minority of their dietary needs from the nearby sea. The unexpected archaeological finding of 11 spontaneously mummified Alto Ramirez bodies at a beach site near Pisagua, northern Chile, provided us an opportunity to evaluate the degree to which they had absorbed and adapted to the subsistence strategy of their purely maritime coastal predecessors (the Chinchorros and their immediate successors, the Quiani people). Using the methodology of chemical dietary reconstruction, supplemented by anatomic observations (external auditory canal exostoses, a "marker" for prolonged cold water exposure-diving; dental analysis), it became clear that this group's subsistence strategy was indistinguishable from that of the coastal maritime populations. This reflects a high degree of coastal adaptation by the highlanders and suggests that they may have been functioning as a subgroup of "marine specialists" for their lower valley kin.