A recent reexamining of artifacts from the Boker Tachtit archaeological excavation site in Israel’s central Negev desert has found that humans likely coexisted with neanderthals around 50,000 years ago.
The study also found that Boker Tachtit is the earliest known migration point from Africa for early Homo Sapiens (humans) in the Levant region.
The study, which was published on Monday in the Proceedings of the National Academy of Sciences scientific journal, was led by researchers from the Weizmann Institute of Science and the Max Planck Society, Prof. Elisabetta Boaretto, together with Dr. Omry Barzilai of the Antiquities Authority (IAA).
“Boker Tachtit is the first site outside of Africa, which modern man penetrated on his way to the rest of the world, hence the importance of the site, as well as the importance of dating it accurately,” Dr. Barzilai, director of excavation at the Boker Tachtit site on behalf of the IAA, said in a statement.
“The age of the site as dated in the study – 50,000 years – indicates that modern man existed in the area of the Negev at the same time as the Neanderthal man, who is known to have lived in it during this period,” he said. “There is no doubt that the two species, who lived and roamed the Negev, were aware of each other’s existence.”
“Our research Boker Tachtit site places an important and unequivocal point of reference on the timeline of human evolution,” he concluded.
According to the “recent African origin” theory, Homo sapiens originated in Africa as early as 270,000 years ago and at different times took either the northern route to Eurasia, passing through the Levant, or several possible southern routes to remote corners of Asia and even Oceania – reaching as far as Australia by land.
DNA research shows that the migration of modern human groups began from Africa to Asia and Europe, and from there to the rest of the world about 60,000 years ago, caused Neanderthals to disappear and assimilate into the modern human population.
During the Middle Paleolithic period (50,000-250,000 years ago), two different species of man lived in the world at the same time: Neanderthal man and modern man.
Neanderthal man lived in Europe and Central Asia, while modern man lived in Africa. The Middle East and Israel in particular were the distribution limits of these species, so they also contain remnants of the two populations at different time periods.
Boker Tachtit, which is located in the Wadi Zin basin in what today is known as the Ein Avdat National Park, is considered a key site for tracing this migration out of Africa.
It is considered a major site in the Levant for documenting an important period in humankind’s prehistory: the transition from a predominantly Neanderthal prehistorical culture to the beginning of modern humans’ reign (Middle to Upper Paleolithic).
This transition was marked by technological innovations such as blade production and the introduction of standardized tools made from bones and antlers.
American archaeologist Anthony Marks, who first excavated and published his analysis of Boker Tachtit in the early 1980s, defined the site as a transitional industry from the Middle to the Upper Paleolithic and, based on a single radiocarbon date, concluded that it dates to 47,000 years ago.
The problem was, however, that additional dates obtained from the site, some reaching as late as 34,000 years ago, made the timing of the transition very problematic.
“If we are to follow this timeline, then the transitional period could have lasted more than 10,000 years, and yet artifacts excavated from northern sites in Israel, Lebanon and even Turkey suggest that the transition occurred much faster,” says Boaretto, who heads D-REAMS – The Dangoor Research Accelerator Mass Spectrometry – Laboratory at the Weizmann Institute, which specializes in advanced archaeological dating methods.
“Marks managed to date only a few specimens from Boker Tachtit, owing to the limitations of radiocarbon dating then, and the range of his proposed dates is not consistent with evidence gathered from other – old and new – excavation sites in the region,” Boaretto says. “Radiocarbon dating, the method that he used in his study, has evolved tremendously since his time,” she said.
To resolve these questions, Boaretto, Barzilai and their multidisciplinary team performed advanced dating methods on specimens obtained from Boker Tachtit during the new excavations that they performed in 2013–2015.
These methods included the latest techniques, such as high-resolution radiocarbon dating of single charcoal pieces found at the site and optically stimulated luminescence-dating of quartz sand grains, performed at the Weizmann Institute and at the Max Planck Institute, respectively.
The researchers also integrated detailed studies of the sediments, using micro-archaeological methods to understand how the site was formed physically, and to contribute necessary data for the construction of its chronological framework.
“We are now able to conclude with greater confidence that the Middle-to-Upper Paleolithic transition was a rather fast-evolving event that began at Boker Tachtit approximately 50-49,000 years ago and ended about 44,000 years ago,” says Boaretto.
This dating allows for a certain overlap between the transition that occurred at Boker Tachtit and that of the Mediterranean woodland region (Lebanon, Turkey) between 49,000 and 46,000 years ago.
“The dating results prove – for the first time in prehistoric research – the hypothesis that there was indeed an overlap in space between the late Mostar culture, identified with Neanderthal man, and the Emirite culture, linked to the emergence of modern man in the Middle East,” Barzilay said.
Still, it shows that Boker Tachtit was the earliest site for this transition in the Levant, and that, based on the materials found, is a testimony to the last dispersal event of modern humans from Africa.
According to the new dating scheme, the early phase at Boker Tachtit also overlaps with the locally previous, Middle Paleolithic culture in the region – that of the Neanderthals. “This goes to show that Neanderthals and Homo sapiens in the Negev coexisted and most likely interacted with one another, resulting in not only genetic interbreeding, as is postulated by the ‘recent African origin’ theory, but also in cultural exchange,” Boaretto and Barzilay conclude.