A macroarchaeological view of mobility

Abstract

Archaeological evidence of mobility is often analyzed using ethnographic-scale models of individual foraging trips and residential moves as a point of reference. Due to site formation processes and the limitations of geochronology, the archaeological record rarely offers the kind of fine-grained resolution needed to identify mobility events at this scale. Here we explore an alternative, macroarchaeological approach that asks how site occupation patterns in a region balance the evolutionary tradeoff between exploration and exploitation. We use a statistical point process model that equates independent-in-time occupations with mobility-driven exploration and dependent-in-time occupations with mobility-driven exploitation. We evaluate the theoretical expectations against the archaeological record of North America using radiocarbon dates from multi-occupation sites. We find strong clustering at short waiting-time intervals of less than under 1000 years, consistent with a model of mobility-driven exploitation at those scales. At longer time scales, waiting times are consistent with a model of mobility-driven exploration. Implications for social learning and niche construction models are explored.