Evidence of specialized resource exploitation by Modern Humans in Western Iberia associated to Pleistocene and Holocene extreme environmental conditions

Abstract

Throughout prehistory, landscapes were repeatedly subjected to both global and localized climatic fluctuations that changed the regional environments where human groups lived. This instability demanded constant adaptation and, as a result, the functionality of some sites changed over time. In this light, the western coast of Iberia represents an exceptional case study due to the proximity between at least some oceanic cores and archaeological sites, which should facilitate an accurate reconstruction of the relationships between paleoenvironmental conditions and the coeval patterns of human behavior. This region, and in particular the valley of the River Lis, is marked by wide exposed plateaus cut by narrow and deep canyons. In this paper we present the stratigraphic, archaeometric, technological and archaeobotanical record of Poço Rock Shelter, located in one of these canyons, which hints at the human responses to such changes, and discuss the link between its Solutrean and Epipaleolithic occupations to specific activities. During the coldest part of the Last Glacial Maximum, we hypothesize that there was intensive exploitation of a chert outcrop above the roof to produce blades and Solutrean tips. Later, during Bond Event 6, after that outcrop had been exhausted, there was intensive consumption of shellfish gathered between the mouth of the canyon and the sea. We hypothesize that these strikingly different roles demonstrate how hunter-gatherers adapted to local conditions, and exploited specific resources, promising to provide a better understanding about its functional role during specific extreme climate events.