Archaeologists have discovered the oldest evidence of a wooden structure created by the hands of a human ancestor. At the bottom of the Kalambo River in Zambia are two tree trunks carved like Lincoln logs. If the logs’ estimated age of 476,000 years is correct, this would mean that woodworking may have appeared before our own species, Homo sapiens, highlighting the intelligence of our hominid ancestors.

Archaeologists have unearthed logs at Kalambo Falls on Lake Tanganyika in northern Zambia, which has been studied by scientists since the 1950s. Previous excavations around a small lake above the falls have uncovered stone tools, preserved pollen and wooden artifacts that have helped researchers better understand human evolution and culture over hundreds of thousands of years.

But new analysis of five modified pieces of wood found at Kalambo pushes back the earliest occupation of the region and provides researchers with new insights into the minds of our Middle Pleistocene (781,000-126,000 years ago) ancestors.

In a new study published in the journal Nature, researchers led by Larry Barham, a professor in the Department of Archaeology, Classics and Egyptology at the University of Liverpool in Great Britain, detail the wooden objects they unearthed. Two of these were found with stone tools below the river, while three were covered with clay deposits above the river level. These wooden artifacts have been preserved for hundreds of thousands of years thanks to the constant rise of groundwater levels.

Using luminescent dating of sand samples from the site, which involves measuring how long ago grains of sand were exposed to light, Barham and colleagues found three clusters: a sawn log and a tapered piece of wood dated to 324,000 years ago; A fossil stick from 390,000 years ago; and a wooden wedge and two overlapping logs dated to 476,000 years ago.

“The small, modified pieces of wood at Kalambo closely resemble 400,000-year-old foraging and hunting tools found in Europe and China, but the jointed logs have “no known parallels in the African or Eurasian Paleolithic,” the researchers write.

The upper log, extracted from a layer that also contained stone tools, was 141.3 centimeters long and was found at a 75-degree angle on a large tree trunk.

Both the lower part of the upper hull and the upper part of the lower hull had marks of chopping and stapling to create a notch that allowed them to fit tightly together.

“Wood from tree trunks allowed people to build large structures,” Barham and colleagues wrote in their study, suggesting that “life in the intermittently wet floodplain could be improved by building a raised platform, walkway, or residential foundation.”

The new objects could push back the date of the earliest examples of woodworking and help scientists better understand the technology our hominin ancestors had.

Archaeological evidence for hominin behavior usually comes from artifacts that are nearly indestructible, such as stone tools, so the discovery of well-preserved, perishable wooden objects at Kalambo Falls is significant.

“Given its widespread nature, it is implausible that hominins would not have used wood,” Shedrek Chirikure, a professor of archeology at the University of Oxford who was not involved in the study, told LiveScience in an email. Chirikure added that the new study shows that “humans and hominins used the resources available to them.” Chirikure suggested that the very early date of the excavated logs “requires a rethinking” of how human cultural and biological evolution is understood.

Scientists had previously thought that the hominins who lived at Kalambo during the Middle Pleistocene were nomadic foragers with little technological skill, but the new findings suggest they were much more intelligent than first thought, the researchers suggested.

“This evidence allows us to look at different materials used by hominins, including those that left traces and those that disappeared quickly,” Chirikure said. said. Source