We tend to take widespread communication for granted – but even just a couple of centuries ago it would likely take weeks to get a letter across the country, and that's if it even got there at all.
However, a brand new discovery from researchers spanning the globe has proven that communication and technology transfer is about as old as humanity itself. How do they know? It all comes down to a particular stone tool, known as a “backed artifact” – or, less formally, the “stone Swiss army knife.”
It’s a little thing – no more than five centimeters or so in length – but it’s incredibly versatile. Our forebears used it for just about everything, including working bone and hide, and drilling and shaping wooden objects. Examples of the tools have turned up all over the world, from China to Europe to Australia, in many different shapes.
Around 65,000 years ago, something interesting happened. All across southern Africa, the backed artifacts all started to follow the same design.
“During the Howiesons Poort [technological period of prehistory] backed artifacts are produced in enormous numbers across southern Africa, and it is this abundance which speaks to their success in this region at this time,” explains the study, published today in the journal Scientific Reports.
“Our morphometric analysis demonstrates that the Howiesons Poort backed artifacts are made to a similar template across great distances and multiple biomes.”
That’s important: the only way these tools can have been so similar across such vast distances is if these early humans were talking to each other.
“While the making of the stone tool was not particularly difficult, the hafting of the stone to the handle through the use of glue and adhesives was hard, which highlights that they were sharing and communicating complex information with each other,” explained Paloma de la Peña, co-author of the study and Senior Research Assistant at the McDonald Institute for Archaeological Research, Cambridge University, in a statement.
“What was also striking was that the abundance of tools made in the same shape coincided with great changes in the climatic conditions. We believe that this is a social response to the changing environment across southern Africa,” she added.
The discovery does more than just show the networking capabilities of our ancient ancestors, though – it provides a deep insight into just why humanity is such a globally successful species.
“People have walked out of Africa for hundreds of thousands of years, and we have evidence for early Homo sapiens in Greece and the Levant from around 200 thousand years ago,” said Australian Museum and University of Sydney archaeologist Amy Way, lead author of the paper.
“But these earlier exits were overprinted by the big exit around 60-70 thousand years ago, which involved the ancestors of all modern people who live outside of Africa today,” she explained.
In other words, exactly when these backed artifacts were spreading across the continent. The success of both the exodus from Africa and the stone Swiss army knife depended on one thing: the strength of social networks and communication.
“This analysis shows for the first time that these social connections were in place in southern Africa just before the big exodus,” said Way.
So, in the face of dramatic climate change and incredible migration, the thing that kept humanity together has turned out to be our ability to co-operate. That’s important not just for understanding the past, but perhaps the future as well.
“Examining why early human populations were successful is critical to understanding our evolutionary path,” said Kristofer Helgen, Chief Scientist at the Australian Museum. “This research provides new insights into our understanding of those social networks and how they contributed to the expansion of modern humans across Eurasia.”