The Red Sea, Coastal Landscapes, and Hominin Dispersals

Blue Arabia: Palaeolithic and underwater survey in SW Saudi Arabia and the role of coasts in Pleistocene dispersals

“…However, as we have also shown elsewhere (Bailey et al, 2007, Bailey, 2009Lambeck et al, 2011), this crossing would have been much narrower for long periods of the Pleistocene, at almost any time when sea level was lower than about -40m in relation to the present day, forming a long and narrow channel and the shortest crossing point in the vicinity of the Hanish Sill, with intermediate islands that would have facilitated sea crossings over distances no greater than about 3-4 km. Of course, even without sea crossings the SW Arabian region could have been reached from Africa via the Nile Valley and the Sinai Peninsula to the North, albeit by a much longer route.…”

“…The Dhahaban coastal site is of particular interest, given uncertainties about earlier claims for association between Palaeolithic artefacts and beach deposits in the region (Bailey, 2009), and suggests a parallel with the Abdur site in Eritrea (Walter et al, 2000). However, the fossilised coral and beach deposits on the Arabian coast are heavily weathered, bone is not preserved, and shells, though present in small numbers, are not demonstrably food remains as opposed to natural death assemblages.…”

“…Climatic changes associated with the glacial-interglacial cycle may have modified the pattern in some regions because of changes in ocean currents, but these changes are not relevant to the Arabian region, and the broad pattern of relative differences between ocean basins at a world scale is thought to be valid throughout the period under discussion here. Reduction in the extent of the shallow shelf at low sea level and restriction of inflow from the Indian Ocean possibly had some local and small-scale effects on Red Sea fertility particularly in the North (for further discussion see Bailey, 2009). From the point of view both of climate and of complex topography, the SW region of the Arabian Peninsula is one that we would expect to be very high on the list of regions that first attracted hominin populations expanding out of Africa, an attraction further reinforced by its proximity to the Ethiopian Rift. We should expect early dates, long archaeological sequences indicating continuous settlement, and relatively high population densities, regardless of whether or not marine resources were part of the subsistence economy.…”

Dynamic landscapes and human dispersal patterns: tectonics, coastlines, and the reconstruction of human habitats

“…One side effect of this hypothesis has been to deter consideration of the Arabian Peninsula as a region of any significance in early human settlement and dispersal, a neglect reinforced by the difficulties of working in the region, the absence of well-dated early finds, and an assumption of persistent climatic aridity during the Pleistocene. However, recent interest in the 'southern corridor' across the southern end of the Red Sea as a potential alternative pathway of human expansion, particularly in relation to anatomically modern humans (Lahr and Foley, 1994), and the demonstration of an abundant Palaeolithic archaeological record of obvious (if not well dated) time depth and episodes of Pleistocene climate wetter than at present (Petraglia and Rose, 2009), has focussed attention on the Red Sea region as a whole as a potentially suitable habitat for human settlement and dispersal, particularly with respect to its potential marine resources (Stringer, 2000;Walter et al, 2000;Bailey, 2009). Our discussion of tectonic models and methods of mapping provides a useful point of entry into the evaluation of these ideas and the potentials of the region more generally for human settlement and dispersal.…”

“…Modelling of palaeoshorelines taking account of isostatic adjustment suggests that the Straits would have narrowed considerably but not closed completely at maximum sea level regression (Lambeck et al forthcoming;Bailey et al, 2007), and this is consistent with isotope data from deep sea cores, which show continuous water flow between the Indian Ocean and the Red Sea over the past 450,000 years (Siddall et al, 2003). However, at low sea levels the sea channel would have been long and narrow, and detailed consideration of the duration of these episodes and the associated channel geometry suggests that crossing by swimming or rafting could have occurred without difficulty over many thousands of years during the glacial cycle (Bailey et al, 2007;Bailey, 2009).…”