Dietary shifts and the European Upper Palaeolithic transition

Abstract

High-latitude modern humans with traditional diets must maintain a critical ratio of dietary fat to protein. An analysis of 15 New World Arctic groups reveals that the abundance and predictability of dietary fat affects eight social variables. Assuming that the physiology of extinct Palaeolithic humans resembles that of anatomically modern humans and that dietary carbohydrates were limited, constraints to their behavior must have existed. These constraints were determined by the physiological necessity of maintaining a critical ratio of dietary fat to protein. At the end of the European Middle Palaeolithic, a relatively subtle dietary shift occurred; an initial increase in dietary fat would have increased population size with very little lag time. Later in the Upper Palaeolithic, dietary breadth expanded. These dietary shifts may have affected hominid biology and social behavior, with selection pressure being exercised principally through population growth. A relaxation of selection pressure for skeletal robusticity could have resulted in high-protein diets without intolerable calciuria. The cascading, interacting consequences of population increase would eventually have resulted in a phase change which is identified as the Upper Palaeolithic. If similar physiology is assumed, different human groups may have independently acquired traits of modernity. The effect of population expansion in temperate areas is dramatic, because dietary carbohydrates are always seasonally limited. In the eastern Canadian Arctic, the transition between the Dorset culture and the Thule culture offers a recent analogue to the European Middle Palaeolithic/Upper Palaeolithic transition. © 1987 by The Wenner-Gren Foundation for Anthropological Research. All rights reserved.