A Darwinian macro-evolutionary perspective on the development of hunter-gatherer systems in Northwestern North America

Abstract

The archaeological record of western North American hunter-gatherers is characterized by long periods of socio-economic homogeneity interrupted by short bursts of variation. This pattern of punctuated equilibrium is best understood using a macro-evolutionary model like that employed in paleontology. We offer such a Darwinian framework, focusing on methods for recognizing distinct socioeconomic systems archaeologically and addressing processes that maintain systemic stasis and enable change. We apply this model to the prehistory of Northwestern North America, explaining a region-wide transition from highly residentially mobile foragers to semi-sedentary, logistically mobile, storage-dependent collectors between 3750 and 3000 cal. bp. Archaeological and paleoecological evidence shows that the collector Bauplan arose first along the northern Northwest Coast under conditions of relaxed competition that permitted multiple distinct Baupläne to develop. These systems coexisted from 5000 to 4200 cal. bp, when a marked temperature decline and a growing population altered the selective equation and heightened competition. Offering selective advantage under cooler conditions, the collector model spread by a combination of ethnic expansion and inter-ethnic transmission to become the sole Bauplan in the region by 3000 cal. bp.