The Guardian reports: Monkeys have been observed producing sharp stone flakes that closely resemble the earliest known tools made by our ancient relatives, proving that this ability is not uniquely human.

Previously, modifying stones to create razor-edged fragments was thought to be an activity confined to hominins, the family including early humans and their more primitive cousins. The latest observations re-write this view, showing that monkeys unintentionally produce almost identical artefacts simply by smashing stones together.

The findings put archaeologists on alert that they can no longer assume that stone flakes they discover are linked to the deliberate crafting of tools by early humans as their brains became more sophisticated.

Tomos Proffitt, an archaeologist at the University of Oxford and the study’s lead author, said: “At a very fundamental level – if you’re looking at a very simple flake – if you had a capuchin flake and a human flake they would be the same. It raises really important questions about what level of cognitive complexity is required to produce a sophisticated cutting tool.”

Unlike early humans, the flakes produced by the capuchins were the unintentional byproduct of hammering stones – an activity that the monkeys pursued decisively, but the purpose of which was not clear. Originally scientists thought the behaviour was a flamboyant display of aggression in response to an intruder, but after more extensive observations the monkeys appeared to be seeking out the quartz dust produced by smashing the rocks, possibly because it has a nutritional benefit. [Continue reading…]