At a Lower Paleolithic site in Israel, researchers discovered ancient stone tools that are revealing prehistoric man's taste for meat, according to a new study.
Some 2.5 million years ago, early humans survived on a paltry diet of plants. But as the human brain expanded, so did our need for more nourishment. So we turned to more substantial sustenance - namely fat and meat - to sustain it. And given that we lacked the sharp claws and teeth of carnivores, our ancestors learned to develop the skills and tools necessary to hunt animals and butcher fat and meat from large carcasses.
This adaptation is what led a team from Tel Aviv University to find prehistoric stone tools bearing 500,000-year-old animal residue in Revadim, Israel. These flint handaxes and scrapers still retained animal fat from long ago when humans cut into elephant remains, which were also found at the site.
"Archaeologists have until now only been able to suggest scenarios about the use and function of such tools. We don't have a time machine," lead author Ran Barkai explained in a statement. "It makes sense that these tools would be used to break down carcasses, but until evidence was uncovered to prove this, it remained just a theory."
They found for the first time direct proof of animal exploitation by flint tools using use-wear analysis - which means examining the surfaces and edges of the tools to determine their function - and the Fourier Transform InfraRed (FTIR) residue analysis. This uses infrared to identify signatures of prehistoric organic compounds.
Until now, researchers could only guess at the function of the handaxe and scraper. But conducting their own butchering experiment with them, the team determined that the handaxe was prehistoric man's sturdy "Swiss army knife," capable of cutting and breaking down bone, tough sinew, and hide. The slimmer, more delicate scraper was used to separate fur and animal fat from muscle tissue.
"There are three parts to this puzzle: the expansion of the human brain, the shift to meat consumption, and the ability to develop sophisticated technology to meet the new biological demands. The invention of stone technology was a major breakthrough in human evolution," Barkai said. "Fracturing rocks in order to butcher and cut animal meat represents a key biological and cultural milestone."
The results were published in the journal PLOS ONE.
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