Blue Arabia, green Arabia: Examining human colonisation and dispersal models

The dispersal of hominins (our species and our closely related bipedal ancestors) out of Africa is a major topic in human evolutionary studies. As a geographic cross-road between continents, the Arabian Peninsula has a significant role to play in understanding the movement of hominin populations and the effect of climate change in shaping demographic history throughout the Pleistocene. However, the Palaeolithic evidence in Arabia has often been marginalized in prominent Out of Africa models, with the assumption that hominins would have avoided the hyper-arid desert belt, and utilized coastlines for their movement, especially along the Indian Ocean rim. Two interdisciplinary archaeological projects, named DISPERSE and PALAEODESERTS, have been conducted in Saudi Arabia in recent years in order to address dispersal models, and to improve our understanding of the hominin occupation history of the Red Sea coastline (``Blue Arabia'') and the interior of the peninsula, especially during wet periods (``Green Arabia''). While acknowledging the importance of the Red Sea region as a potential zone for hominin occupation in the Pleistocene, we emphasize the crucial significance of the terrestrial environments for repeated hominin expansions during ameliorated periods in the Pleistocene, when a mosaic of ecosystems and plentiful rivers, wetlands and lakes were present