Early humans used high-tech “glue” made from a local coniferous tree in Africa ago 39,000 years, according to a new study.
In the Stone Age In the Middle Ages, early Homo sapiens used adhesives made from local Podocarpus trees to attach stone tools to wooden spears.
Scientists say the substance has “excellent” adhesive properties and can only be produced through an “elaborate” process.
Dr. Patrick Schmidt and Ph.D. student Tabea Koch, from the University of Tübingen in Germany, traced the production in a joint study with Professor Edmund February from the University of Cape Town in South Africa.
The research team reported in the study published in the journal Proceedings of the National Academy of Sciences (PNAS), that the failure of early modern humans to resort to more readily available adhesives tens of thousands of years ago is a testimonial to his innovative capabilities and abilities
Dr. Schmidt said: “Adhesives have been discovered at various sites in the Middle Stone Age in South Africa, mainly as residue on scrapers or stone blades that had been glued to handles or spears”.
“Chemical analysis had shown that this glue was often extracted from the yellow woods. This is surprising because yellow sticks do not exude tree resins or any other sticky substance,” he said, adding that “yellow stick leaves contain small amounts of resin, which needs to be distilled.”
The team discovered two ways to make the glue; Dr. Schmidt said: “It is quite simple to burn the leaves directly next to the flat stones.”
He added that the second option is more difficult and requires more time. In it, the leaves have to be heated in a kind of underground still for several hours, so that the tar drips into a container. It is not known which method was used.
Schmidt said that, in any case, it was surprising that early modern humans at that time did not use plants other than yellow woods as sources of glue.
“People it could just have collected resin from trees,” Koch said. “In several species that were in their environment, it visibly flows from the trunk. And some plants release sticky latex when the leaves fall off.”
The team found the explanation with the help of standard laboratory tests, such as those used in the adhesive industry:
“Our distilled yellow wood tar had particularly good mechanical properties and proved to be stronger than all other natural adhesive substances from the Stone Age in South Africa; it was able to sustain significantly larger loads.”
Also read:
· The largest asteroid that has hit the Earth was 15 miles wide
· Jupiter will be closer to Earth, how and at what time can it be seen from the US and Mexico?
· The impact of a second asteroid on Earth would have led to the extinction of the dinosaurs