AUDIE CORNISH, HOST:
Scientists working in Kenya have made a discovery that challenges conventional wisdom about human history. They found stone tools that were made before the first humans arrived on the scene. NPR's Christopher Joyce has more.
CHRISTOPHER JOYCE, BYLINE: The first humans had a handy talent. They whacked rocks together in just the right way to fashion sharp tools. In fact, scientists named the earliest humans Homo habilis, meaning handyman. Until now, the evidence suggested this talent emerged about two-and-a-half-million years ago, but now anthropologists have found stone tools way older than that. The tools are now in a museum in Nairobi where team leader Sonia Harmand of Stony Brook University explained that at first they didn't quite know what they had.
SONIA HARMAND: We were very, very excited.
JOYCE: But unaware that these tools were 3.3 million years old, which is hundreds of thousands of years before humans evolved from their ape-like ancestors. Another member of the Stony Brook team, Jason Lewis, says once they did confirm that this assemblage of stones was indeed that old, they knew they had to prove they were actually tools crafted by hand and not just banged-up rocks.
JASON LEWIS: We very quickly had to put our nose to the grind stone to put everything together to convince the rest of the world.
JOYCE: As they report in the journal Nature, what convinced the team was the fact that there was a whole stone-tool-making kit right there in one place. It was just like the ones the first humans used - big core stones and flat anvil stones and sharp flakes. To make a tool, you hold the core stone on the anvil stone and strike it with another rock. What breaks off are sharp flakes. And it was clear from marks on these stones that that's what was done. And the team found lots of those sharp flakes. These could've been used to cut meat off of bone or cut up vegetable matter.
In all, they found over 140 tool-making artifacts in one site. So who made these tools? Certainly chimpanzees can use stones as tools to break up nuts, for example, but they don't manufacture them. The Stony Brook team suspects it was an ape-like creature called Australopithecus. The famed creature Lucy was one such. About four feet tall, they lived both in trees and on land. But even if humans can no longer lay claim to inventing stone tools, it's worth looking at whether tool-making would have been a regular part of the Australopithecus skill set.
ERIN MARIE WILLIAMS-HATALA: The question, I think, is not could they have, but would they have done so repeatedly?
JOYCE: Erin Marie Williams-Hatala is a paleoanthropologist at Chatham University in Pittsburgh. She says the hands and wrists of an Australopithecus were adapted to grasping tree branches - long fingers and a slender thumb - not great for making tools. Williams-Hatala says sure, maybe they could do it, but it would've been a chore.
WILLIAMS-HATALA: And maybe that's because it took them so long to do it that it just didn't make sense for their subsistence strategy - for the way that they lived their lives.
JOYCE: So being able to make tools doesn't mean they became a regular part of the Australopithecus lifestyle. That probably didn't happen until the first human hands evolved with a big, strong thumb and more motor control.
WILLIAMS-HATALA: When our hands and wrists changed to a sufficient degree, it began to make sense for our ancestors to engage in these behaviors in a new way and probably more frequently...
JOYCE: ...To the point where making good tools gave humans an edge in the fight for survival. Christopher Joyce, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.