Difference in ecological niche breadth between Mesolithic and Early Neolithic groups in Iberia

Abstract

The Mesolithic settlement of Iberia was mainly concentrated along the coastal areas, which contrasts with the wide geographic distribution achieved in a relatively short time by Early Neolithic groups. However, there was a chronological delay in the arrival of agriculture in the northern latitudes of Iberia. In the current study, paleoclimate values were interpolated from the composite benthic stable oxygen and ecological niche modelling techniques were used to determine whether these differences in the geographic distributions and spread patterns are consequences of differences in the ecological niches of the last hunter-gatherers and the first farmers. Results show that Mesolithic and Early Neolithic groups were not adapted to different ecological niches, and therefore the slowdown in the incursion of Neolithic groups into the north of Iberia was not due to their incompatibility with the environmental conditions. Furthermore, the adoption of production economies entailed an ecological niche expansion, which became essential for the observed demographic trends and the settlement distribution changes in the Mesolithic–Neolithic transition. We argue that the broader ecological niche of the first farmers probably allowed them to occupy large territories, whereas the narrower ecological niche of Mesolithic groups could have made the last hunter-gatherers more vulnerable to the climatic changes that affected the coastal ecosystems in the Mid-Holocene.