Just who were these people, how long ago did they migrate, and what route did they first take? These are some of the biggest questions in archeology. Now at last researchers seem to be closing in on concrete answers.
In a report published in the November 30 issue of the open-access journal PLoS ONE, an international research team led by Jeffrey Rose presents its analysis of recent work in southern Oman, located on the southeastern corner of the Arabian peninsula.
For years, researchers have debated with each other over the earliest migration route. Was it across the Red Sea to the Arabian boot heel (sea levels being much lower then)? Or was it north from Egypt along the Mediterranean?
Rose and his team found evidence suggesting that AMH residents of the Nile valley migrated—with their distinctive tool technology—to present day Oman. Their analysis of over 100 sites in Oman led researchers to believe that the tool culture was clearly the same in both settings. In other words, one culture spans two continents, clearly supporting the idea of human migration.
Scientists have long known about the Nile valley culture, which they call “Nubian.” The breakthrough reported here is the strong evidence that Nubian toolmakers made their way out of Africa to Arabia, bringing their characteristic stonecutting techniques with them.
The date of migration, according to the report, is at least 106,000 years ago, perhaps earlier.
No human remains were found with the stone tools. This leaves open the possibility that some other humans—“archaic” and not anatomically modern—may be responsible for the stone tools. The researchers dismiss this idea on the grounds that AMH seem to be the only form of humans present in North Africa at the time of the migration.
“After a decade of searching in southern Arabia for some clue that might help us understand early human expansion, at long last we've found the smoking gun of their exit from Africa,” according to Rose, a Research Fellow at the University of Birmingham.
Another surprise contained in the report is that the stone tools were found inland rather than right along the coast. “For a while,” remarks Rose, “South Arabia became a verdant paradise rich in resources – large game, plentiful freshwater, and high-quality flint with which to make stone tools,” according to a press release issued by PLoS One. One possibility is that the “southern route” out of Africa along the southern Arabian peninsula was not so much a coastal expressway to Asia and Europe as it was a settling of the interior of Arabia.
The report, “The Nubian Complex of Dhofar, Oman: An African Middle Stone Age Industry in Southern Arabia,” appears in the November 30, 2011 issue of PLoS ONE