Friday, 28 January 2011

Modern Humans in Arabia 125,000 years ago?

Stone tools have been recovered from a site in the United Arab Emirates. The tools are reported to be 125,000 years old and it is claimed by British archaeologist Simon Armitage in the journal Science that they were made by modern humans. This date is 40,000 to 60,000 years before modern humans are generally thought to have reached the Arabian Peninsula.

The tools were found at a rock shelter on Jebel Faya, a 350m (1,200ft) mountain equidistant from the Gulf of Oman and the Persian Gulf and lying due south of the Straits of Hormuz. The rock shelter itself is 180m (600ft) above sea level. It contains archaeological layers dating from the Iron and Bronze Ages all the way back to the Palaeolithic. Artefacts from the latter have been found in three layers, the oldest of which, Layer C, has been dated by optical stimulated luminescence methods to the Eemian Interglacial, 125,000 years ago. The artefacts were manufactured using a number of different reduction strategies including Levallois, volumetric blade, and simple parallel methods. The tools include small handaxes, foliates, end scrapers, side scrapers, and denticulates. It has been suggested that they have more in common with contemporary artefacts from North and Northeast Africa than with those known from other Arabian sites. Since the African artefacts were made by modern humans, it is proposed that the Eemian Jebel Faya artefacts were too.

The Eemian Interglacial was warm period between the last and penultimate ice ages during which “humid corridors” opened up in the Sahara Desert. Modern humans reached the Levant, probably via the “humid corridors”, but they are not generally thought to have reached further into Asia. The general view is at that time, the Levant was effectively a north-eastern extension of Africa. After conditions worsened 91,000 years ago, modern humans disappeared from the Levant, which was subsequently re-occupied by Neanderthals.

Armitage believes that humans crossed the Bab Al Mandab Strait at the southern end of the Red Sea at the onset of the Eemian, when sea-levels were fairly low and it could readily be crossed. Once in Arabia, the colonists benefitted from reduced competition for resources and exploit both the coast and interior for food. Groups occupied the southern coast and pushed inland, taking advantage of the warm wet conditions. Armitage suggests that it is these rather than technological innovation that provided the stimulus for the expansion. The more recent Palaeolithic artefacts suggests that the colony survived the harsher conditions that set in at the end of the Eemian, although it was probably cut off from groups living further south.

It cannot be ruled out that the tools were of Neanderthal origin, although co-author Anthony Marks rejects this view and in an article in Science claimed that Neanderthals did not use this combination of tools. Archaeologist Michael Petraglia noted that the site was out of the Neanderthal habitat range. But archaeologist Sir Paul Mellars was quoted as being “totally unpersuaded”. He does not believe that there is any evidence that the tools were made by modern humans and does not see the tool style as African.

I will personally admit to being sceptical and think it is far more likely that these tools were made by Neanderthals. Petraglia’s comments notwithstanding, it was reported last year that modern humans interbred with Neanderthals soon after leaving Africa. Assuming they left via the Bab Al-Mandab Strait, as is widely believed, they must have encountered Neanderthals in Arabia.

Armitage, S., Jasim, S., Marks, A., Parker, A., Usik, V., & Uerpmann, H. (2011). The Southern Route “Out of Africa”: Evidence for an Early Expansion of Modern Humans into Arabia. Science , 331, 453-456.

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