Assessing Population Dynamics in the Spread of Agriculture in the Mediterranean Iberia Through Early Warning Signals Metrics

Abstract

Several studies indicate that ecosystem resilience exhibits decreased signals before regime shifts. Considering human dynamics, the Neolithic constitutes a techno-economic revolution that implies a significant increase in population according to SPDs from calibrated radiocarbon dates as a relative demographic proxy. The use of SPD methods in several European regions has revealed periods of boom followed by collapse in a non-linear model.Following the previous work published by Downey, Randal Haas and Shennan (2016), we have applied a generic test known as early warning signals (EWSs) to the reconstruction of population trends in the regions of the Iberian Peninsula in order to explore the EWS statistics (autocorrelation, variance and skewness) before the Neolithic bust is detected.In accordance with the dual model proposal, we assume that an initial foreign expansion constituted the driving force of the subsequent spread in Iberia. In recent works we have used SPD methods as a relative demographic proxy to explore socioecological dynamics regarding the Neolithisation process in Iberia. The results obtained in some regions exhibit an initial boom regarding the introduction of the agricultural way of life followed for a bust pattern at the end of the early Neolithic. The observed regional variability reinforces this conclusion and highlights differences between the Mediterranean corridor (where a quick Neolithic expansion is well documented) and the Ebro valley, where acculturation processes could have a greater opportunity.