Decades of research by scientists regarding human evolution may need to be reconsidered. A new behavior observed in monkeys found that the primate is also capable of producing tool-like flakes previously thought to have been created by humans alone.
To be specific, the monkeys that were exhibiting the behavior were wild bearded capuchins in Brazil. Researchers observed that the primates were engaging in "stone-to-stone percussion" activities, hammering rounded quartzite cobbles to extract minerals causing large flakes to chip off.
Researchers Find That Stone Flakes Aren't As Unique To Humans as Previously Thought
The flakes are thought to have been uniquely made by humans through a process called "stone-knapping," according to the Telegraph. The method is described as using stones to strike a larger rock to create sharp blade-like slivers which can then be fashioned to be used as knives, spears, or arrows.
The process has been thought by archeologists as a turning point in human evolution as it involved a level of planning, cognition and hand manipulation that is not observable among other animals. With the new study, however, it's found that these flakes aren't as special as scientists think as they can be made without foresight, and could even be created inadvertently.
"The fact that we have discovered monkeys can produce the same result does throw a bit of a spanner in the works in our thinking on evolutionary behavior and how we attribute such artefacts," said Dr. Michael Haslam, the lead of the Primate Archaeology project at the University of Oxford. The discovery of sharp-edged stone tools has been an imperative indication of intelligence that helps scientists map out when this evolutionary occurred in the past.
Scientists Are Unsure Why The Capuchins Are Exhibiting This Behavior
After the monkeys left the area, researchers took out 111 samples of the fragmented stones. They identified complete and broken hammer-stones and complete and chipped flakes. Some of the samples collected had rounded, smooth surface and shaped like a scallop.
Scientists aren't sure why the capuchins are engaging in such behavior but they hypothesized that the primates are doing so to remove lichen for medicinal purposes. Or they could be trying to extract powdered silicon, an essential trace nutrient, as they were observed to be licking quartz dust created when smashing the stones.
The findings also gave researchers a reason to not quickly attribute future findings of fragmented stones near a stone core to ancient humans, said CS Monitor. Dietrich Stout, a professor of Paleolithic archaeology, said that the resulting flakes from the capuchin behavior could be thrown into an early hominin assemblage of tools and "nobody would be the wiser."
