Ape-made stone slabs cast doubt on ancient human ‘tools’

Apes use rocks to crack nuts, creating sharp spikes that coincidentally resemble the tools believed to have been used by our earliest human relatives.

The discovery casts doubt on whether all the stone chips found in archaeological digs are actually early hominin tools — and that they could be the accidental result of striking objects with stones, he said. Lydia Luncz at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

In the year In 2016, Luncz and her colleagues discovered that Brazilian capuchins produce stone chips from rocks that they use to punch food, dig, and watch sexual displays without meaning to. The flakes were essentially the same as those found in hominin settlements dating to at least 3 million years ago. It made the team question whether the artifacts actually reflected any technical planning by those early humans.

Since then, Lunci and her colleagues have been studying tool use in long-tailed macaques.Macaca fascicularis) on the islands of Phang Nga Bay in Thailand. In the jungles there, Luncz stumbles upon places where nut cracking takes place – surprising, since long-tailed macaques have not previously been known to crack open nuts.

The team set up motion-sensing cameras to study the behavior of wild macaques. In 100 hours of footage, the team watched as the monkeys pounded nuts between the stones, used as hammerstones and anvils – and accidentally created mice as they left the broken stones in search of new, whole stones.

This is almost exactly what Capuchins did in earlier research, says Luncz, showing that flake making is not a one-time event. “This happened on the other side of the planet, in a different ecosystem and in a different species,” she said. “So it was very clear that this was the first thing. This is a grazing behavior that we assume also occurred in early hominins.

So far, capuchins, chimpanzees and long-tailed deer are the only non-human primates known to use stone tools in the wild — and all of these have now been confirmed to produce flakes that coincidentally resemble ancient hominin tools, she says.

The team then compared 1,119 stone fragments from macaque nut collection sites with artifacts from hominin sites in Ethiopia, Kenya and Tanzania. Measuring between 1.3 and 7.9 centimeters long, the apes’ thin, flat, broad skulls were “almost indistinguishable” from the fliers associated with early humans 3.3 million years ago, he says. Thomas the ProphetAnother research group member at the Max Planck Institute for Evolutionary Anthropology.

Despite a few trends – the ape flakes were on average smaller and thicker than hominin flakes – they were so similar that they could have replaced up to 70 percent of the tools of early humans.

The findings could challenge current understanding of early stone technology, says Prof. “I wouldn’t go so far as to say that everything in the past was intentional,” he said. But our research shows that we cannot be 100 percent sure that every particle in the Paleolithic archaeological record was intentionally made. There may be an unintended component in this record.

b Seed recovery At the University of Chicago, the research largely points to the gradual development of cognitive evolution in primates. “Is what we find in the archaeological record the result of an intentional process?” He says. “I don’t think we have an answer, but the important point in this article is that stone tool making and stone tooling have a much deeper history both in time and in the ancient world. That’s what’s becoming clearer.”