The Evolution of Stone Tools Reveals Human Innovation was Worldwide

Stone tools may be more of a common invention than researchers once thought. Scientists have found that this human technological innovation occurred intermittently throughout the Old World, rather than spreading from a single point, as previously thought.

The findings come after researchers examined thousands of stone artificats that were discovered in Nor Geghi 1, a site preserved between two lava flows dated to 200,000 to 400,000 years ago. Layers of floodplain sediments and an ancient soil found between these two flows contain a wealth of archaeological materials, including the stone tools.

The newly discovered tools actually provide early evidence for the simultaneous use of two distinct technologies: biface technology, which is commonly associated with hand axe creation during the Lower Paleolithic, and Levallois technology, which is a stone tool production method attributed to the Middle Stone Age in Africa and the Middle Paleolithic in Eurasia. Usually, archaeologists use the presence of Lavallois technology and the disappearance of biface technology to mark the transition between the Lower to the Middle Paleolithic about 300,000 years ago. The presence of both these technologies at the same site, though, puts a kink in the theory that the technology spread from elsewhere.

"The combination of these different technologies in one place suggests to us that, about 325,000 years ago, people at the site were innovative," said Daniel Adler, lead author of the new study, in a news release.

By comparing archaeological data from sites in Africa, the Middle East and Europe, the researchers found that the evolution of stone tool technology was gradual and intermittent. More specifically, it occurred independently within different human populations who shared a common technological ancestry. In other words, Levallois technology evolved from biface technology in different places at different times.

The findings reveal a bit more about tool use and how our ancestors developed this technology. It turns out that it wasn't a single event; instead, it occurred in several places over time.

The findings are published in the journal Science.