An Arabian perspective on the dispersal of Homo sapiens out of Africa

Abstract

The privileged position of Africa in human evolution has long been hypothesised and was largely confirmed, after many years of often heavily polarised debate, in the later twentieth century (e.g., Willoughby 2007). Recent developments have shown that the later stage of this process, the evolution of Homo sapiens in Africa and their subsequent dispersal into Eurasia, was a spatially and temporally complex process, involving, for instance, interbreeding with ‘archaic’ hominin species (e.g., Green et al. 2010; Reich et al. 2010). The rapidity with which such changes to our understanding of the dispersals of H. sapiens out of Africa have taken place suggests a need for interpretative caution, the development of a solidified interdisciplinary approach, and a move towards nuanced and explicit models of the dispersal process (see Blinkhorn & Petraglia, this volume). A large body of research from the interlinking disciplines of Palaeolithic archaeology, genetics and palaeontology – contextualised in terms of palaeoenvironmental variation and biogeography – addresses the character of Upper Pleistocene dispersals out of Africa into Asia. In this chapter we describe four main models for this process (Table 5.1). We focus on the evidence from the Arabian Peninsula as a means of testing the four models, placing particular emphasis on the archaeological record. Given that Arabia may have been the first place dispersing African H. sapiens encountered in Eurasia, the peninsula has a special position, in that it was here that the genetic and behavioural foundations of populations that would go on to populate the rest of the world were assembled, tested and altered by natural and cultural selection. Quaternary Arabia saw dramatic environmental oscillations, and these most likely played a pivotal role in determining the timing and character of H. sapiens dispersals. Although the prehistoric record of Arabia remains understudied compared to many other areas, recent years have seen significant advances (see, e.g., Petraglia & Rose 2009; Groucutt & Petraglia 2012). The time has come for the rich Arabian record to play a more central role in debates on hominin dispersals out of Africa.