A scenario of human dispersal in the northwestern Mediterranean throughout the Early to Middle Pleistocene

Throughout the Early to Middle Pleistocene several origination and extinction bioevents led to a progressive rebuilding of the structure of the Mediterranean mammalian communities. Understanding whether faunal dispersal and turnovers developed on a backdrop of climatic changes or intrinsic biotic factors exerted a more important control, it is an outstanding interest in elucidating the ecological scenario, enabling humans to disperse towards and across the Mediterranean region. Although a link between human dispersal and climate change possibly exists, many archaeologists continue to reject environmental determinism. The first dispersal of some human groups towards the Mediterranean was undoubtedly part of the Early Pleistocene faunal renewal triggered by climate changes, but the increase of suitable prey and limited competition with other predators would have been beneficial to human peopling. To contribute to the debate, the Early to Middle Pleistocene fossil record of large Mediterranean mammals has been analysed with the aim of delineating the main biological events and processes which affected the evolution of faunal complexes, in turn enabling humans to disperse throughout the Mediterranean region. The results of this study confirm that the most important renewals of large Mediterranean mammalian fauna (due to both originations/dispersals and extinctions) are connected to major global climatic changes that, via migrations and dispersal events, altered palaeocommunity equilibrium, leading to new intra- and inter-guild dynamics. Changes in the richness and crop biomass of principal prey, as in the relative abundance of forest and open environment dwellers, possibly had an important role in opening favourable windows to human dispersal during the late Early Pleistocene. Nonetheless, a significant peopling occurred only after the faunal renewal of the Early to Middle Pleistocene transition and at the time of functional turnovers throughout the beginning of the Middle Pleistocene. (C) 2009 Elsevier Ltd and INQUA. All rights reserved.