PARIS, Sept 20, 2023 (BSS/AFP) - Archaeologists said on Wednesday they have 
unearthed the oldest wooden structure ever discovered, dating from nearly 
half a million years ago, which suggests that our ancestors may have been 
more advanced than previously thought.

The exceptionally well-preserved wooden structure was found at Kalambo Falls 
in the north of Zambia near the border with Tanzania.

It dates back at least 476,000 years, well before the evolution of Homo 
sapiens, according to a study describing the find in the journal Nature.

The wood bears cut-marks showing that stone tools were used to join two large 
logs to make the structure, which is believed to be a platform, walkway or 
raised dwelling to keep our relatives above the water.

A collection of wooden tools, including a wedge and a digging stick, were 
also discovered at the site.

The ancestors of humans were already known to use wood at this time, but for 
limited purposes such as starting a fire or hunting.

Larry Barham, an archaeologist at the UK's University of Liverpool and the 
study's lead author, told AFP that to his knowledge the previous record-
holder for oldest wooden structure dated back around 9,000 years.

Barham said the structure was a "chance discovery" made in 2019 while 
excavating at the site located on the banks of the Kalambo River, above a 
235-metre-high (770-foot) waterfall.

Discoveries involving such ancient wood are rare, because it tends to rot 
leaving behind little trace for the historical record.

But the high level of water at Kalambo Falls is believed to have preserved 
the structure over the centuries.

- 'Imagination and skills' -

Excavations at the Kalambo site in the 1950s and 1960s unearthed some wood, 
but it was not able to be accurately dated.

However this time around, the researchers used a new method called 
luminescence dating, which determines age by measuring the last time minerals 
were exposed to sunlight.

This revealed that the structure was much older than the researchers had 
thought, dating back at least 476,000 years.

The earliest evidence of Homo sapiens is from around 300,000 years ago.

But fossils of human relative Homo heidelbergensis, thought to have lived 
between 700,000 to 200,000 years ago, have been found in the region, Barham 
said.

The discovery of the wooden structure "changed how I thought about these 
people", Barham added.

"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," he 
said.

"They used their intelligence, imagination and skills to create something 
they'd never seen before, something that had never previously existed."

This suggests an abstract level of thinking and "probably language", he 
added.

Sophie Archambault de Beaune, an archaeologist at France's Lyon 3 University 
not involved in the study, said the structure "presupposes cognitive 
abilities such as planning and the ability to visualise the finished 
product."

But "these capacities were already assumed from the study of cut stone 
tools", she told AFP.

The authors of the study also said the discovery challenges the idea that 
human ancestors were nomadic, because the structure seems to be a permanent 
dwelling near the waterfalls, a perennial source of water.

Archambault de Beaune cautioned that this hypothesis had not yet been proven, 
because the structure could have been installed for the season, rather than 
permanently.