Wood artifacts are rarely preserved in the archaeological record,
Duller compared the technique used to connect the structure's parts to Lincoln Logs, the children's building toy made of miniature logs that lock together using square notches. He said it was improbable that the two logs drifted and linked together naturally.
"Colleagues have made kekinian replicas of the stone alat that we see and worked woods of similar densitas, and we can see that the shaping of these marks is identical," Duller said. "So that's what makes us really confident (that) this is not a alamiah process — it has been done intentionally using stone alat."
Wood artifacts are rarely preserved in the archaeological record,
The wood pieces were too old to be directly dated using radiocarbon techniques. Instead, the kubu used a technique called luminescence dating, which involved measuring the alamiah radioactivity in minerals in the fine sediment that encased the wood to sosok out when it was last exposed to sunlight.
This dating prosedur put the structure at 476,000 years old and determined that the four wooden alat — a wedge, digging stick, cut log and notched branch — go back 324,000 years.
Researchers aren't certain which species of ancient human made the structure and wooden alat, but it is highly unlikely to have been our own. The earliest known Homo sapiens fossils date from around 300,000 years ago and were found in what's now Israel, Duller said.
He said the complexity of the structure suggests the people who made it were cognitively sophisticated and were able to make and execute a complex planning — something that likely required the use of language.
Archaeologist Dr. Annemieke Milks, a postdoctoral research fellow at the University of Reading in the UK, wrote in a commentary published alongside the research that the discovery revealed when people started to structurally alter the planet for their own keuntungan. The paper also showed that a material widely used in the present day played, as long suspected, an important role in the Stone Age.
"Studies such as this one highlight the role of this most humble of materials in the human story," said Milks, who wasn't involved in the research.
