"Stone ‘tools’ may not have been made by human ancestors, research finds"
https://cosmosmagazine.com/palaeontology/stone-tools-may-not-have-been-made-by-human-ancestors-research-finds
Monkey business forces a rethink on human evolution, reports paleoanthropologist Darren Curnoe.
When did a human-like mind first emerge, setting its owner on a path distinct to that of other apes?
We paleoanthropologists have long looked to tool use as the marker – particularly the appearance of a cutting tool known as a flake. It now seems we were wrong.
Recent research published in Nature by a team led by Tomos Proffitt at the University of Oxford shows that capuchin monkeys regularly produce sharp-edged flakes indistinguishable from those made by early hominins.
As it turns out, no. The flakes are produced by accident when the monkeys smash rocks together. Nonetheless, the capuchins have thrown a spanner in the works for archaeologists. Since the flakes they make are not tools at all, we can no longer assume the flakes found in the archaeological record are tools either.
So what these clever monkeys show us is that, if we find ancient flakes, we can no longer assume they were a tool made by a human ancestor.
The discovery of flakes at the Lomekwi archeological site in Kenya, which dates to 3.3 million years ago, led researchers to propose in 2015 that early humans appeared about 700,000 years earlier than previously thought. Now, however, without other evidence, such as cut marks on bones, we can no longer assume the flakes are evidence of a human presence.