The Arabian peninsula: Gate for Human Migrations Out of Africa or Cul-de-Sac? A Mitochondrial DNA Phylogeographic Perspective

Abstract

The reconstruction of the origin and spread of modern humans has been a multidisciplinary enterprise. Archaeological records and genetic inferences (Stringer and Andrews, 1988), have given strong support to the model of a single recent origin of modern humans in Africa around 200 ka (McDougall et al., 2005). Subsequent dispersals out of Africa replaced, in relatively short time, the archaic humans living in Eurasia (Pääbo et al., 2004). However, the dates of this exit and the routes taken to spread out of Africa are currently debatable topics. On the basis of modern human fossils in the Levant, dated around 120 ka (Valladas et al., 1988), a northern route by land across the Sinai peninsula was proposed. The lack of fossil continuity in the area prompted researchers to consider it as an unproductive exit. A later successful exit around 45 ka using the same corridor has received stronger archaeological support (Lahr and Foley, 1994). A second, maritime, southern route across the Bab al Mandab strait and afterwards coasting Arabia, India, Southeast Asia to reach the Sahul has also been proposed as a complementary or alternative exit gate (Stringer, 2000). Recent archaeological findings in coastal Eritrea dated about 125 ka (Walter et al., 2000) have been taken as support of an earlier exit age for the southern route (Stringer, 2000).