Independent Innovation, Not Population Expansion, Responsible For Advanced Stone Age Tools

Chuck Bednar for redOrbit.com – Your Universe Online
A cache of new artifacts discovered at a 325,000-year-old site in Armenia reveals that Stone Age tools were not strictly an African invention that spread due to population expansion, but occurred independently and intermittently at various locations throughout the Old World, an international team of experts report in Friday in the journal Science.
Lead author Daniel Adler, an associate professor of anthropology at the University of Connecticut, and his colleagues analyzed the thousands of tools recovered from the Nor Geghi 1 site – a site preserved between two lava flows that took place between 200,000 and 400,000 years ago. They found that they provide evidence for the simultaneous use of two distinct types of technology: biface and Levallois.
Biface technology is typically associated with hand axe production during the Lower Paleolithic, while Levallois technology is a type of stone tool production method usually attributed to the Middle Stone Age in Africa and the Middle Paleolithic in Eurasia, the study authors explained. Archeologists traditionally use the advent of Levallois technology and the disappearance of biface technology to mark the transition from the Lower Paleolithic to the Middle Paleolithic approximately 300,000 years ago, they added.
Experts have argued that Levallois technology was invented in Africa and only spread to Eurasia when human populations started to expand. As it began to spread, it replaced local biface technology, thus linking populations with their technologies and equating technology changes with demographic changes, the study authors said. However, finding the two types of technologies together at Nor Geghi 1 “provides the first clear evidence that local populations developed Levallois technology out of existing biface technology,” the university said in a statement.
Dr. Simon Blockley, a member of the Department of Geography at Royal Holloway, University of London and one of the authors of the new study, said that the team’s discovery “provides a major new insight into how Stone Age tools developed during a period of profound human behavioral and biological change. The people who lived there 325,000 years ago were much more innovative than previously thought, using a combination of two different technologies to make tools that were extremely important for the mobile hunter-gatherers of the time.”
The findings, he added, “challenge the theory held by many archeologists that Levallois technology was invented in Africa and spread to Eurasia as the human population expanded. Due to our ability to accurately date the site in Armenia, we now have the first clear evidence that this significant development in human innovation occurred independently within different populations.”
The newly published paper submits that while biface and Levallois technology are different in many ways, they share a common pedigree. In biface technology, the researchers explained, a stone mass is shaped by removing flakes from two surfaces in order to produce a tool such as a hand axe. Those flakes are treated as waste. On the other hand, Levallois technology involved removing flakes from a stone mass to produce a convex surface from which flakes of predetermined size and shape are detached. Those flakes, not the mass itself, are the desired products.
“Archaeologists suggest that Levallois technology is optimal in terms of raw material use and that the predetermined flakes are relatively small and easy to carry. These were important issues for the highly mobile hunter-gatherers of the time,” the University of Connecticut said. “It is the novel combination of the shaping and flaking systems that distinguishes Levallois from other technologies, and highlights its evolutionary relationship to biface technology.”
By comparing archeological data from various sites in Africa, the Middle East and Europe, the researchers were also able to demonstrate that this evolutionary process was gradual and intermittent, and that it took place independently within different human populations that shared a common technological ancestry. To put it another way, their work demonstrates that Levallois technology evolved out of existing biface technology in different places at different times. The results, the authors said, show how long ago humans developed the capacity for innovation.
Image 2 (below): This image shows Levallois and biface tools. Credit: Royal Holloway, University of London