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Stone tools may have been used before our genus came on the scene

The tools may look like boring rocks, but they show evidence of being much more. (MPK-WTAP)

Researchers have reported evidence of stone tools over 3.3 million years old, putting the origin of tool use some 700,000 years earlier than previously assumed. That would mean that tools were used before our genus (Homo) came on the scene. If the findings are correct, that's turning a common assumption -- that the ability to create tools is what distinguished us from other hominin lineages and allowed us to survive and adapt into modern humanity -- right on its head. The findings were reported Wednesday in Nature.

The tools, found at a site called Lomekwi 3 in northern Kenya, look pretty much like rocks to the untrained eye. But Sonia Harmand, co-lead of the study and Research Associate Professor in the Turkana Basin Institute (TBI) at Stony Brook University, says they show signs of something called "knapping." That's the act of striking one rock with another to produce smaller, sharper pieces of stone. And that makes these rocks very special, because it means they were probably intentionally-crafted tools.

"There is no doubt these were intentionally knapped," Harmand told The Post. Plus, they stuck out from the rocks and sediments around there, as if they'd been dropped instead of being part of the natural scenery.

It's not a particularly artisan process -- in fact, the work seems similar to what chimpanzees do when they strike nuts to open them -- but it's more than researchers have ever found in terms of tools this old.

[Humanity’s first conversations were probably about butchering (and rocks)]

These new tools aren't actually the first sign that pre-homo species could use tools, however: In 2010, researchers reported on bone markings that they felt indicated tool use around 3.34 million years back. Because the tools themselves weren't found, this finding has remained controversial. But coupled with the new evidence -- and another recent study that suggested hominins living over 3 million years ago had hands better adapted to tool use than to tree climbing -- it seems that tools may truly have had a presence at the time.

So it seems increasingly likely that the Homo species dubbed "handy man" was far from the first to figure out tools. But that doesn't mean tool development wasn't an integral part of our becoming human: Because these Lomekwi tools are more primitive than the ones we know Homo used, they provide a sort of missing link between the dawn of tool use and its evolution into something more sophisticated.

“This reaffirms the argument that the repeated and competent manufacture of useful sharp edges, on which we came to depend, may have been a driving factor in the evolution of our genus, both anatomically and cognitively," Alison Brooks, a professor at George Washington University and Research Associate at the Smithsonian Institution's Human Origins Program who wasn't involved in the study said in a statement. The findings also affirm previous claims that the tools we've found are too well-made to be the first ever created, she explained.

Shannon McPherron of the Max Planck Institute for Evolutionary Anthropology, who lead the study on suggestive bone markings but wasn't part of the Lomekwi find, agreed that the findings don't make tool use less important to the development of humanity -- they just give new context.

"Hominins went through a long period -- now even longer -- where stone tools and meat consumption were sporadic but became increasingly important," McPherron told The Post. "Then sometime after 2 million years ago or so, we see these behaviors become an essential part of the early hominin adaptation."

We can't be sure what species created the tools. "If they were made by an even earlier and as-yet unknown member of the genus Homo, that's a different but equally interesting story, in which our genus evolved half a million years before, and in response to completely different natural selective pressures, than we currently think," co-lead author Jason Lewis said.

[The human family may have evolved half a million years earlier than we thought]

But there's another, more likely culprit: Fossils found nearby in the 90s were named as a new genus and species called Kenyanthropus platyops, which could end up being an ancestor of our own lineage once we learn more about it -- or just one of the many hominin lineages that died off instead of meandering on toward modern humanity. There's increasing evidence that Neanderthals, for example, were more intelligent than we used to give them credit for, possibly producing things like art and jewelry without more modern humans' help. Neanderthals stemmed from the same genus as we do, but it could be that pre-Homo groups have secrets of their own to reveal.

[Neanderthals may have invented jewelry]

"Our tools shed light on an unexpected and previously unknown period of hominin behavior. They tell us a lot about cognitive development in our ancestors that we can't understand from fossils alone. They show that the knappers already had an understanding of how stones can be intentionally broken, 3.3 million years ago, beyond what the first hominin who accidentally hit two stones together and produced a sharp flake would have had," Harmand said.

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