Researchers at Eberhard Karls University of Tübingen, Germany, challenge our understanding of Neanderthal ingenuity. Their analysis of ancient birch tar used as an adhesive on tools reveals a far more complex manufacturing process than previously thought.
The ability to create synthetic materials has long been considered a hallmark of human intelligence. However, the Tübingen team’s findings, published in “Archaeological and Anthropological Sciences” under the title “Production method of the Königsaue birch tar documents cumulative culture in Neanderthals,” push back the timeline for this cognitive leap by a staggering 100,000 years.
Neanderthal tools, predating any known adaptation by modern humans, utilized birch tar as a water-resistant and durable adhesive. While the creation of birch tar was previously considered a basic process, perhaps even accidental, the new research paints a different picture.
Through a meticulous comparison of chemical signatures on ancient tools and birch tar produced using various Stone Age techniques, the researchers discovered that Neanderthals employed a surprisingly sophisticated method. Unlike simpler above-ground techniques, the Neanderthal method involved a multi-step, oxygen-restricted distillation process achieved through underground heating.
“This level of complexity suggests the technique wasn’t invented overnight,” the authors explain. It likely began with simpler methods and gradually evolved through experimentation, showcasing a capacity for problem-solving and innovation.
To validate their theory, the researchers recreated five different birch tar extraction techniques – two above ground and three below ground – using experimental archaeology methods. Advanced analysis techniques like infrared spectroscopy and micro-computed tomography then compared the experimental tars with the ancient artifacts.
The presence or absence of oxygen during extraction left a distinct chemical fingerprint on the tar. This fingerprint clearly differentiated above-ground from below-ground methods, and the ancient artifacts matched the signature of the below-ground process. Both the artifacts and the recreated below-ground tar also showed interaction with soil minerals and lacked traces of soot, further solidifying the findings.
This discovery adds to the growing body of evidence suggesting a more cognitively complex Neanderthal society. Many technological advancements previously attributed solely to modern humans are now being found in the Neanderthal repertoire. The authors conclude by stating, “Neanderthal birch tar making seems to be the first documented instance of its kind in human evolution,” highlighting their claim that Neanderthals possessed a level of intelligence previously underestimated.