Archaeological evidence in the form of stone tools discovered from Jebel Faya, a site close to Sharjah in United Arab Emirates and about 50 km from the Persian Gulf, suggests that modern humans migrated out of Africa 100,000 to 125,000 years ago. The tools include small hand axes and two-sided blades. The conclusions of a paper published online in Science (“The Southern Route ‘Out of Africa': Evidence for an Early Expansion of Modern Humans into Arabia” by Simon J. Armitage et al., January 28, 2011) are contrary to the generally accepted view on two counts — the time and the route. It turns out that the migration of modern humans out of Africa took place about 55,000 years earlier than used to be believed. Secondly, they took a southern route to reach Arabia from east Africa, not a northern route to reach the Mediterranean region. The hostile desert conditions of Arabia, the Red Sea, and the Straits of Hormuz were previously regarded as the three natural barriers that prevented migration into this region. But the interglacial period that started about 130,000 years ago would probably have transformed Arabia from an arid region into a more hospitable, wetter region with savannah grass, lakes, and rivers. Crossing the narrower and shallower Red Sea would have been possible at the start of the interglacial period; water locked up in ice sheets during the preceding glacial period was yet to melt and raise the local sea level.
Evidence of human inhabitation about 50,000 years ago has been discovered in Australia. Artefacts and bones of anatomically modern humans dating back between 30,000 and 40,000 years have been discovered at sites along the Don River, about 400 km south of Moscow. Modern humans reaching such faraway places can be explained only if an earlier wave of modern humans migrating out of Africa had taken place more than 60,000 years ago. Stone tools become a reliable source for studying the inhabitation of modern humans for a period that goes back more than 100,000 years; the preservation of human fossils from that time is quite unlikely. The sophisticated stone tools recovered from Jebel Faya bear a strong resemblance to the tools used by people in east Africa. Although the possibility of other hominins traversing Arabia and occupying the site of discovery during the interglacial period cannot be completely ruled out, it becomes more than a coincidence that they and modern humans in east Africa used nearly identical tools. There is a need to find similar tools from more sites at or near Jebel Faya to confirm an earlier exodus of our species.