The discovery of hundreds of skilfully crafted stone blades at Jaljulia, a site situated in modern day Israel, suggests human ancestors were communicating complex ideas and employing conceptual thinking up to 500,000 years ago, far earlier than usually proposed by scientists.
In November 2017, Israeli archaeologists announced the discovery of an ancient rock tool manufacturing ‘school’ at Qesem Cave, 12 kilometres east of Tel Aviv. The scientists found compelling evidence that techniques for sculpting perfect stone blades were being passed on to new students by older adepts. The oldest layers at the site suggested the local population of archaic humans were present at the site perhaps as early as 400,000 years ago, and some of the fossil teeth from the cave suggest these may have been very early members of the Homo sapiens species.
Schooling of the sort revealed at Qesem suggests some degree of higher cognition, forward-thinking and complex communication among a firmly bonded population group. All being traits we tend to think of as being very modern in respect to human ancestors. The latest revelation from the region pushes the dates back even further, by another 100,000 years.
Hundreds of thousands of artefacts have been excavated from an old riverbed at Jaljulia since archaeologists stumbled on the site as part of standard exploration before any residential construction projects.
“It was a perfect spot for humans,” says Ran Barkai, an archaeologist from Tel Aviv University. “The water brought flint nodules from the hills, which were used to make tools on the spot, and it attracted animals, which were hunted and butchered here. They had everything that prehistoric people needed.”
Examination of the stone tools and experimental testing of the palaeomagnetism associated with the sediments in the artefact layers suggested the site was inhabited around half a million years ago. The assumption is that the hominins responsible were probably Homo erectus, a strong candidate based on the age of the site. However, although most of the artefacts are typical bifacial hand-axes that would be expected to be in the Homo erectus toolkit, a significant number of Levallois blades have also been revealed.
“It [Levallois blade] requires a conceptual leap that allows you to envision the desired tool in the flint core before you even start shaping it,” Barkai says.
The Levallois style of blade is far more complicated to manufacture than merely banging a rock into shape and is generally considered to be beyond the cognitive abilities of Homo erectus. It is hoped that the extremely early habitation dates at Jaljulia will be confirmed by the more accurate dating process known as optically stimulated luminescence (calculation of the last time grains of sediment were exposed to light). Confirmation of the dating may well indicate that some form of archaic Homo sapiens or Homo heidelbergensis (ancestral Neanderthals) were present in the Levantine region long before scientists thought.
There is the intriguing possibility that the blades manufactured at Jaljulia were the work of the direct ancestors of modern humans living between the time of the first recognisable Homo sapiens and the divergence from the last common ancestor shared with Neanderthals and Denisovans – a split now believed to have taken place around 750,000 years ago.
What precisely our direct ancestors living 500,000 years ago would have looked like, and what name we should call them, remains unclear, but it seems likely they were intelligent and able to utilise the same conceptual thinking modern humans rely on today.