Monkey Tools and Early Human Ingenuity

Wild capuchin monkeys in Brazil produce sharp stone flakes by accident, causing some researchers to suggest a rethink of the beginnings of human tool use.

Written byBob Grant
| 2 min read

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A male capuchin monkey in Brazil's Serra da Capivara National ParkWIKIMEDIA, TIAGO FALOTICOFlaked stone tools have long held a special place in the concept of humanity’s rise from just another animal to one that would evolve to conquer the biosphere. But our ancestors may have struck upon this important innovation quite by accident, according to researchers studying wild capuchin monkeys in Brazil. Those monkeys use large rocks to crack nuts, dig for roots, and attract mates in their forest home. Scientists working in northeastern Brazil’s Serra da Capivara National Park found that the primate labors often result in stone flakes that bear a striking resemblance to knapped stone pieces that are commonly thought to be critical implements of early human technology. The findings, which may challenge claims of millennia-old human tool use at archaeological sites scattered across the globe, were published last week (October 20) in Nature.

The findings “help illuminate capabilities of our primate brethren that we thought only we and our immediate ancestors had,” Florida Atlantic University’s James Adovasio, who wasn’t involved with the study, told Scientific American. “They make us rethink how special we are.”

While other primates, such as chimpanzees, are known to use rocks as nut crackers, the stone flakes produced from their industrious activity are not quite as human-tool–like as the flakes produced by capuchins. “You would think that they are indeed made by hominins,” Tomos Proffitt, a University of Oxford postdoc and coauthor on the paper, told The Verge. “That’s what’s impressive about the material.” The Brazilian monkeys do not use the stone flakes they inadvertently produced, the researchers reported, whereas many early human archaeological ...

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Meet the Author

  • From 2017 to 2022, Bob Grant was Editor in Chief of The Scientist, where he started in 2007 as a Staff Writer. Before joining the team, he worked as a reporter at Audubon and earned a master’s degree in science journalism from New York University. In his previous life, he pursued a career in science, getting a bachelor’s degree in wildlife biology from Montana State University and a master’s degree in marine biology from the College of Charleston in South Carolina. Bob edited Reading Frames and other sections of the magazine.

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