Nearly 500,000 years ago, humans in Africa assembled wood into large structures, according to a report. study A paper was published Wednesday that describes cutouts and tapered logs buried under sand in Zambia.
This discovery marked a significant setback in the historical record of structural woodworking. Previously, the oldest known example of this ship was her 9,000-year-old platform on the edge of a lake in England.
Annemieke Milks, an archaeologist at the University of Reading who was not involved in the new study published in Nature, said ancient wood products are extremely rare because organic materials typically degrade over thousands of years. Stated. “It hardly ever saves,” she said.
It’s not clear what early humans were building in Africa. Dr Milks said the new findings suggest they used wood not just for spears and drilling rods, but also for far more ambitious creations such as scaffolding and walkways.
“I think most early human groups used wood in some way,” she says. “We just don’t see it.”
The log was discovered in 2019 by an international team of scientists near a giant waterfall in Zambia known as Kalambo Falls. There, the Kalambo River drops 770 feet into Lake Tanganyika.
For archaeologists, the site has a checkered history. In the 1950s, British archaeologist Desmond Clarke discovered ancient stone tools and pieces of wood believed to have been used to make sticks and spears near the falls. Other parts looked burnt. It would have been some of the earliest evidence of people starting fires.
But by the early 2000s, much of the luster of Dr. Clark’s discovery had worn off. First, he could not reach a clear conclusion about the age of the wood. At the time, the only reliable method available for determining age was radiocarbon dating, which he said could only be used for objects less than 50,000 years old. It turns out that the piece of wood at Kalambo Falls is older than that, but how old?
Other researchers questioned whether humans actually made wooden objects. Dr Clark acknowledged that they may have been branches that fell into the Kalambo River and were re-formed by sand grains carried by the water flowing towards the falls.
In 2006, archaeologist Lawrence Burnham from the University of Liverpool and his colleagues revisited Kalambo Falls. By then, researchers had developed a new method for determining the age of archaeological sites, using the way quartz particles function like a geological clock. When naturally occurring uranium atoms break down in the ground, the energy trapped within the quartz is released. Over time, the grain stores more and more energy, which scientists can later measure in the lab. The more energy there is, the older the specimen becomes.
During a visit to Kalambo Falls in 2006, scientists discovered more stone tools. Geoff Darragh, a geophysicist at Aberystwyth University in Wales, spent several years collecting sand from riverbanks and measuring the energy trapped in it. He determined that the oldest layers of deposits containing stone tools were between 300,000 and 500,000 years old.
This means that this tool was created long before modern humans evolved. Scientists suspect that they were created by an earlier species in Zambia, known as . homo heidelbergensis.
Researchers visited the falls again in 2019, and Dr. Dollar planned to use a more powerful dating technique based on feldspar grains rather than quartz.
However, when they arrive at Dr. Clark’s old site, they find it is gone. It has been 13 years since his last trip, and the river has moved away. All that remained was a wetland covered with reeds.
Fortunately, Dr. Barham had a plan B in place. Before the expedition, he used his Google Earth to find promising beaches along the Kalambo River. When they arrive there, Dr. Barham immediately notices a stick sticking out of the sand. He found a sharp point in the water that fit perfectly on one end of the stick. If he had come a year later, the debris might have been washed away. “It was a moment of luck,” Dr. Barham said.
Researchers found stone tools in the same area, along with wood shaped into wedges and V-shapes, clear signs of handiwork.
Dr. Dollar used feldspar particles to determine the age of the artifacts. He discovered that these objects were from three different eras of his time: 487,000 years ago, 390,000 years ago, and 324,000 years ago. People may have lived near the river throughout the period, or may have returned to the river over thousands of generations.
At the end of the 2019 field season, researchers made the most amazing discovery. Among the oldest sand layers was discovered a 4.5-foot log of a small African tree known as a. Zeihar’s Yabuyanagi. Researchers noticed a large notch near the tapered end of the log. As they dug further, they discovered that the notched part of the log was on top of an even larger tree trunk.
The researchers took high-resolution photos while exposing the wood. Photos show cuts on the log and trunk, suggesting that people used axes or planers to work on it. “This is by design,” Dr. Barham says. “This is intentional.”
Dr Milks said it was important to take photos soon after discovery to understand how ancient wooden products were made. Thanks to the flooded sand, the wood has been able to survive almost unchanged for hundreds of thousands of years. But when ancient wood is exposed to the air again, important clues can be lost within minutes. “It can shrink, it can distort, all sorts of things can happen,” Dr. Milks says.
Dr. Barham and his colleagues worked with John Mukopa, a traditional Zambian woodworker, to interpret their findings. They suspect that people used stone axes to cut down live trees. Next, they processed the wood so that he could combine the two pieces to make larger structures.
Dr. Barham surmised that the logs and trunks were part of a structure built over wetlands along the Kalambo River. “The key is to keep your feet dry, keep your food dry, keep your firewood dry,” he said.
“Place yourself in the mind of someone who lived there with a big brain about 480,000 years ago,” he said. “Don’t be afraid of complex proposals.”