Those Ancient Stone Tools — Did Humans Make Them, Or Was It Really Monkeys? : The Two-Way Capuchin monkeys in Brazil have been seen making sharp stone flakes. It was previously thought that only humans and their ancestors had flaking skills.
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Those Ancient Stone Tools — Did Humans Make Them, Or Was It Really Monkeys?

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Those Ancient Stone Tools — Did Humans Make Them, Or Was It Really Monkeys?

Those Ancient Stone Tools — Did Humans Make Them, Or Was It Really Monkeys?

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  • <iframe src="https://www.npr.org/player/embed/498421284/498582246" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
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ROBERT SIEGEL, HOST:

One of the things that humans and our ancestors are known for is our ability to make tools, but a discovery in a Brazilian forest suggests that a tool commonly associated with early humans might not be unique to humans. NPR's Christopher Joyce has this story about monkey flakes.

CHRISTOPHER JOYCE, BYLINE: A flake is about as important a tool as humans have ever made. You whack two rocks together - a certain kind of rock in a certain way - and you get a sharp flake shaped kind of like a scallop shell. Hold it carefully, and voila, you've got a knife.

The oldest toolmaking by our ancestors dates back 3.3 million years. But anthropologists in Brazil have filmed Capuchin monkeys doing this very thing easily, gleefully. Tomos Proffitt from Oxford University watched them do it. He was expecting to see them crack nuts with the rocks.

TOMOS PROFFITT: Capuchins do nut-cracking. They crack open palm nuts all the time, and so we were looking for this.

JOYCE: But instead they were whacking rocks together.

PROFFITT: And then they started doing this, this stone-on-stone percussion. And that was quite exciting. And then looking at the material that they produced was - yeah, it was a bit of a, you know, a jaw-dropping moment.

JOYCE: Jaw-dropping because they were chipping off flakes. No one had ever seen a monkey doing that. Sure, they use rocks to whack nuts open but stone tools - well, actually not tools. Here's the thing. The monkeys have no idea what to do with the flakes. They're breaking those quartz rocks so they can lick the insides.

PROFFITT: We hypothesize that it's something to do with getting minerals from the quartz because they lick the dust. They ingest it.

JOYCE: Or another possibility - there's a lichen growing on these rocks. Maybe the Capuchin monkeys are going after that. Whatever the case, they ignore the flakes. So we can all breathe a sigh of relief knowing that monkeys are not as smart as our early ancestors were.

However, writing in the journal Nature, Proffitt says the monkey flakes should put scientists on notice - not to be confused by monkey flakes that might look like human-made ones.

PROFFITT: They're still more complex than what we see with the Capuchins. However, they do share the same basic characteristics.

JOYCE: There are usually clues found along with ancient tools that suggest that unlike the monkey flakes, they were actually used - cut marks on bones, for example. The discovery does reinforce other research showing that non-human primates do use tools if only occasionally. But anthropologists say the profound difference is that humans use them all the time. Tools defined our lives. Christopher Joyce, NPR News.

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