Wednesday, June 01, 2011

The Arabian Middle Paleolithic and the southern route of human dispersal

In a comment on my last post, Maju who's a regular commenter on this blog, pointed out that recent finds in the Arabian Peninsula and the Persian Gulf suggest that modern humans might have been present in the Middle East by the time Shanidar 3 was killed. Some of the specific evidence in support of this that has come out in the past year include that presented by Armitage et al. (2011) and Rose (2011), and a more recent paper by Petraglia et al. (in press), which he briefly discussed in a post of his own. Here, I just want to provide some additional thoughts about this series of papers, and what they tell us about the modern human population dynamics in the region.

Armitage et al. (2011) report a series of three stratified assemblages from the site of FAY-NE1, in the Jebel Faya in SW Arabia, near the Straits of Hormuz. The interesting thing about these assemblages is their age, and the fact that their typology suggests affinities - or lack thereof - to assemblages from other regions. The oldest assemblage dates to ca. 125kya (dated through single-grain OSL), and the authors argue it shows affinities to assemblages of similar age in East Africa. On that basis, they argue for an early dispersal of modern humans out of Africa along the so-called 'southern route', which comprises the southern coast of the Arabian Peninsula and Indian subcontinent. They link this, in turn, to a potential early population of modern humans in Indian prior to the Toba super-eruption ca. 74kya (Petraglia et al. 2011 and references therein). The later assemblages from FAY-NE1 are older than ca. 40kya, and show little to no affinities to either the MSA/LSA or the Levantine Paleolithic. Armitage and co. interpret this as evidence of their not having been made by Neanderthals, but don't really explore this issue in great depth. They conclude that human occupation of FAY-NE1 and Arabia more broadly would have been tethered to humid periods that made it hospitable to humans, who would have disappeared from the interior of the peninsula during arid periods.

Rose (2010), on the other hand, argues that one area that humans might have found refuge in during these hyper-arid periods would have been the Persian Gulf. Because it is comparatively shallow, arid periods (which correspond with colder periods associated with decreased sea level) would have effectively exposed much of the gulf, which would have been associated with perennial sources of water, which would have acted as a drawing force for human populations from surrounding areas. In a nutshell, the 'Gulf Oasis' would have provided something of a safe haven for humans at times where both Arabia and parts of Iran would have been too inhospitable for humans to occupy. If modern humans were present in the region by 125kya, it stands to reason that the people who would have congregated in the 'Gulf Oasis' would have been modern humans, who could have in turn recolonized the areas to the E and W of the Gulf during wetter periods. The prolonged isolation of people in the Gulf Oasis during prolonged (multi-millennial) episodes of dessication would have lead to cultural drift, perhaps explaining the unique configuration of Assemblages A and B from FAY-NE1 (Armitage et al. 2011).

While these new data are very interesting, they still concern the potential presence of humans mainly along the coasts. What this means is that they tell us little about whether or not humans ventured far inland and/or northwards, and what this implies about their interactions with other, putatively 'archaic' human populations in those areas. A new paper by Petraglia et al. (in press), however, helps shed some light on this situation. These authors present a preliminary report on the site of Jebel Qattar 1, located near Jubbah, Saudi Arabia, on the shores of a paleo-lake. This places the site smack-dab in the center of northern Saudi Arabia, hundreds of kilometers from any coastal area. The site dates to ca. 75kya (OSL), which associates it with comparatively moist conditions that would have made the region habitable by humans.

Overall, the presence of JQ1 agrees with the scenario for human occupation of inland Arabia proposed in the previous two papers. Namely, it shows that people would have ventured far inland only during comparatively moist periods. What is really interesting here, however, is that the assemblage found at JQ1, in contrast to those from FAY-NE1 (Armitage et al. 2011), fits well within what Petraglia and Alsharekh (2003) have described as the Arabian Middle Paleolithic, which shows some affinities to the Levantine Mousterian. However, as the authors state

"Given the current absence of pre-Holocene hominin fossils in Arabia, and the fact that Levantine Mousterian assemblages are associated with both early modern humans and Neanderthals, caution is warranted in attributing a maker to the JQ1 and other Arabian Middle Paleolithic assemblages." (Petraglia et al. 2011: 4)

Here, I just want to point the contrast between this assemblage, and those from FAY-NE1, who show affinities either to the MSA or to no other known industries to the West. What this means for the presence of modern humans in the northern Zagros, close to Shanidar, remains an open question. It may well be, however, that what was happening along the coast of the Indian Ocean during the Late Pleistocene may have been quite different from what was happening in the interior of the landmasses it borders on, with attendant implications for scenarios about modern human dispersals. I close with words by Petraglia et al. (2011:4, references excised) to that effect:

"If modern humans were responsible for the early Arabian toolkit, then our findings contradict the argument that the dispersal of Homo sapiens out of Africa was accompanied by a microblade technology 60 ka ago. Furthermore, the presence of JQ1 in the interior of northern Arabia, 500 km from the nearest coast, indicates that an exclusive coastal corridor for hominin expansion out of Africa can no longer be assumed."

Hat tip: For what they were... we are.

PS: I should also mention here that Michael Petraglia and his team have a blog, Ancient Indian Ocean Corridors, where they post about the Indian and Arabian Paleolithic , issues related to their ongoing research in those areas.

References

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 (6016), 453-456 DOI: 10.1126/science.1199113

Petraglia, Michael D., & Alsharekh, Abdullah (2003). The Middle Palaeolithic of Arabia: Implications for modern human origins, behaviour and dispersals Antiquity, 77 (298), 671-684

Petraglia, M., Alsharekh, A., Crassard, R., Drake, N., Groucutt, H., Parker, A., & Roberts, R. (2011). Middle Paleolithic occupation on a Marine Isotope Stage 5 lakeshore in the Nefud Desert, Saudi Arabia Quaternary Science Reviews DOI: 10.1016/j.quascirev.2011.04.006

Rose, J. (2010). New Light on Human Prehistory in the Arabo-Persian Gulf Oasis Current Anthropology, 51 (6), 849-883 DOI: 10.1086/657397