Some of the earliest bands of modern humans who ventured out of Africa and into the Middle East 120,000 to 140,000 years ago might have met a strange-looking character with the look of a primitive Neanderthal, but a stone toolkit as modern as their own. New fossils of this individual, found over the past decade in Israel, are stirring intense debate among paleoanthropologists: Was it the earliest known Neanderthal in the Middle East, or a late remnant of a previously unknown Neanderthal ancestor?
Finding modern tools with such a primitive-looking toolmaker at this time in the main passage between Africa and Eurasia makes this “a major discovery,” writes paleoanthropologist Marta Mirazón Lahr of the University of Cambridge in an accompanying commentary.
Researchers have long known the Middle East was a busy crossroads for modern humans and Neanderthals. Although fossils of modern humans in Israel date back 130,000 years, recognizable Neanderthals don’t show up in the fossil record of the region until about 60,000 to 70,000 years ago. Both fossils and ancient DNA have suggested Neanderthals arose more than 400,000 years ago in Europe and spread later into the Middle East, where they likely met and mated with modern humans who had migrated out of Africa.
The new fossils and tools were found over the past few years in a sinkhole in a limestone quarry in central Israel, after a construction crew uncovered the first tools from the site in 2010. Over the next 5 years, a team led by archaeologist Yossi Zaidner of the Hebrew University of Jerusalem excavated the open-air site at Nesher Ramla and found pieces of an ancient skull, a nearly complete jawbone, and a molar, all likely from the same individual. They also dug up animal bones and flint tools from the same layer of sediments, which date to 120,000 to 140,000 years ago, according to one of two papers published today in Science.
The stone tools were made with a so-called Levallois method: typical of the area’s modern humans, as well as of Neanderthals who appeared later in the region. But the fossils were clearly not Homo sapiens, says Tel Aviv University paleoanthropologist Hila May. And they didn’t look like early or late Neanderthals in the Middle East or Europe, says co-author María Martinón-Torres, a paleoanthropologist at CENIEH, the national center for research on human evolution. “They didn’t fit with anything,” she says.
Instead, the fossils show a “weird” mix of archaic and Neanderthal-like traits, May says. For example, the robust jaw and molar were similar to Neanderthals, but the parietal skull bones were thicker, and more like those in archaic members of Homo, May says. Dental anthropologist Rachel Sarig, also at Tel Aviv University, says the inner structure of the molars reminds her of the teeth of archaic members of the Homo genus found at Qesem Cave in Israel, dating to about 400,000 years ago. This suggests the fossils belonged to the “late survivors” of a previously unknown population of Homo, or to another Neanderthal lineage that lived in the Middle East. They could have also belonged to a hybrid who was a mix of Neanderthal and archaic Homo, says paleoanthropologist Israel Hershkovitz of Tel Aviv University, which would add another member to the diverse cast of hominins that ranged across Eurasia and Africa during the Middle Pleistocene, some 790,000 to 130,000 years ago.
The researchers end their paper with a radical idea: They propose that the fossils, with their mix of archaic and Neanderthal-like traits, could have been late survivors of a group that was a source population in the Middle East for both late and early Neanderthals in Europe and Asia, they write today in Science.
That suggestion, however, has quickly drawn fire. Paleoanthropologist Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology says the fossils were too recent to represent the source population for Neanderthals, whose earliest known ancestors lived more than 400,000 years ago at Sima de los Huesos in Spain. “That’s an overinterpretation of the fossil evidence,” he says. Instead, he thinks the mix of archaic and Neanderthal traits may reflect regional variation, with Neanderthals living in the Middle East being different from the classic Neanderthals of Europe, or at least a hybrid mix of different groups. He adds that in his view, teeth are the most important body part for classifying a fossil, and “that tooth is like a Neanderthal tooth.”
Paleoanthropologist Mirjana Roksandic of the University of Winnipeg agrees that the Nesher Ramla specimen is too young to be “seriously considered” as evidence for the source Neanderthals. She does think, however, the new fossils show that modern humans and Neanderthals were interacting earlier than previously believed in the Middle East. That’s a pattern she has also seen at a fossil site in Europe’s Balkan Mountains, where a minimum of two Homo lineages were present and interacted. “It is exciting that they are seeing this pattern in the Levant as well.”
sciencemag.org, 24 June 2021