Archaeologists have discovered what they say is the earliest evidence of wood being used in construction, dating back almost half a million years.
In a study published in the journal Nature Wednesday, a team of researchers reported the discovery of a well-preserved ancient wooden artifact found at the archaeological site of Kalambo Falls in the African nation of Zambia.
The scientists date the artifact to roughly 476,000 years ago, noting that it represents the “earliest evidence for structural use of wood” by humans in the archaeological record, although this predates the evolution of our own species, Homo sapiens.
Wooden artifacts have rarely survived from so long ago given that they require exceptional conditions for preservation. As a result, scientists have limited information about when and how early Stone Age humans used this basic raw material.
The latest findings indicate that early hominins were building structures made of wood earlier than previously thought, expanding our understanding of their technical abilities to shape tree trunks.
The evidence that the team found included two preserved interlocking logs that were joined together by an intentionally cut notch.
The study authors analyzed the wood and found that the upper log had been shaped, while they documented tool marks on both logs.
This construction has no known parallels from the Paleolithic period—which dates from more than 3 million years ago to around 12,000 years ago—in Africa or Eurasia.
“These new data not only extend the age range of woodworking in Africa but expand our understanding of the technical cognition of early hominins, forcing re-examination of the use of trees in the history of technology,” the authors wrote in the study.
It is not clear exactly what structure these pieces of wood once formed part of. But the researchers suggest that it potentially could have been used to construct some kind of raised platform, a walkway or the foundation of a dwelling.
Permanently high water levels at the Kalambo Falls site have seemingly preserved the wood over hundreds of thousands of years, according to the researchers. The site lies above a 772-foot-high waterfall on the border of Zambia and Tanzania.
The researchers attempted to determine the age of the find using luminescence dating techniques, which revealed the last time minerals in the sand surrounding the wood were exposed to sunlight.
“At this great age, putting a date on finds is very challenging and we used luminescence dating to do this. These new dating methods have far reaching implications—allowing us to date much further back in time, to piece together sites that give us a glimpse into human evolution,” Geoff Duller, one of the authors of the study from Aberystwyth University in the United Kingdom, said in a press release.
“The site at Kalambo Falls had been excavated back in the 1960s when similar pieces of wood were recovered, but they were unable to date them, so the true significance of the site was unclear until now,” he said.
The latest discovery challenges the prevailing view that Stone Age humans were solely nomadic. At Kalambo Falls, the ancient humans who built the wooden structure had a perennial source of water, while the surrounding forest may have provided them with enough food to settle and create structures.
“This find has changed how I think about our early ancestors. Forget the label ‘Stone Age,’ look at what these people were doing: they made something new, and large, from wood. They used their intelligence, imagination, and skills to create something they’d never seen before, something that had never previously existed,” Larry Barham, another author of the study from the University of Liverpool in the United Kingdom, said in the press release.
“They transformed their surroundings to make life easier, even if it was only by making a platform to sit on by the river to do their daily chores,” said Barham, who leads the Deep Roots of Humanity research project. “These folks were more like us than we thought.”
The archaeologists also uncovered a set of wooden tools dating from around 390,000-324,000 years ago, including a wedge, digging stick, cut log and notched branch.
“Kalambo Falls is an extraordinary site and a major heritage asset for Zambia. The Deep Roots team is looking forward to more exciting discoveries emerging from its waterlogged sands,” Barham said.