Résumé
Palaeoenvironmental data and climatic reconstructions show that the Mediterranean ecoregion of North Africa underwent drastic ecological changes during the Pleistocene. Given its rich palaeontological record, North Africa is a pertinent region for documenting the role of climate change and human mediated-habitat changes on the demography and genetic structure of faunal species. In the present study, we collected data from this species in Morocco, Algeria, and Tunisia, and we combined molecular (mitochondrial and nuclear DNA sequences, microsatellites), fossil, palaeoenvironmental, and human context data to propose an explanation for the fluctuations of populations belonging to the Meriones shawii complex in the past. Genetic and fossil data both indicate a strong bottleneck in Moroccan populations at the Middle Holocene (last interglacial optimum) compared to the Late Pleistocene. Our mitochondrial DNA data suggest a diversification event within Morocco corresponding to the 130-125 kya interglacial optimum. Given that (1) major demographic changes in the M.shawii complex coincide with the interglacial optimums, and (2) the impact of human activities on the landscape and faunal communities was moderate during the Middle Holocene (beginnings of the Neolithic culture), our results demonstrate that climate, rather than anthropogenic influences, likely explains the M.shawii complex population decline in the Holocene.