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This is the left hemi-maxilla with teeth. Photo: Rolf Quam

Humans emerged from our cradle of evolution in Africa, and spread to the corners of the globe. Scientists are pretty sure of those earliest steps – but they’re unsure of when they were taken. The oldest modern human remains were previously dated to between 90,000 and 120,000 years ago, in the Middle East.

But a jawbone with intact teeth found high in a mountain cave in Israel has potentially upended that timeline, placing modern humans outside Africa as much as 100,000 years earlier than previously believed – approximately 220,000 years ago, according to a new paper in the journal Science.

“This finding changes our view on modern human dispersal and is consistent with recent genetic studies, which have posited the possibility of an earlier dispersal of Homo sapiens around 220,000 years ago,” they write. “The Misliya maxilla is associated with full-fledged Levallois technology in the Levant, suggesting that the emergence of this technology is linked to the appearance of Homo sapiens in the region, as has been documented in Africa.”

The find was made at Misliya Cave, on the western slopes of Mount Carmel, and about 12 kilometers south of Haifa.

The upper jaw bone (maxilla) and several teeth were unearthed in the upper part of the Early Middle Paleolithic layer of the site, they report.

The fossil includes part of the palate and nasal floor, and the complete left row of teeth from a broken root of the first incisor all the way to the third molar, they add.

Three dating methods were employed at three different laboratories, they explain. One was a U-series, another was a complete uranium series and electron spin resonance series, and the third was a thermoluminescence series. The latter method was also employed on nine burnt flints near the fossil.

Analysis of the jaw itself was made with 3-D geometric morphometric analysis (micro-computed tomography), which indicated the remains were most similar to modern humans, and most dissimilar to Neanderthals and other ancient hominids, they report.

Some of the features were visually characteristic of modern humans, as well: they included a flat labial surface and a lingual groove, and no lingual tubercle, among other features, they report.

“Indeed, the combination of features in the incisor and canine appears to occur only in H. sapiens,” they add.

The archaeological layers of the cave also offer some clues, they report. The Levallois stone toolmaking processes are shown in the artifacts. The humans who lived in the high cliff (some 90 meters elevation) could hunt large game and manipulate fire, the scientists contend.

“It provides the clearest evidence yet that our ancestors first migrated out of Africa much earlier than we previously believed,” said Rolf Quam, an anthropologist at Binghamton University, and one of the authors. “While all of the anatomical details in the Misliya fossil are fully consistent with modern humans, some features are also found in Neanderthals and other human groups.”

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