Australian researchers have made a groundbreaking discovery that indicates complex surgeries were performed as early as the Stone Age.
The Griffith University team has discovered ancient hunter-gatherers performed successful surgical procedures, previously thought to have only become mainstream this century, more than 30,000 years ago.
The discovery centres on the skeletal remains of a 31,000-year-old hunter in Indonesia.
The remains, uncovered on the island of Borneo in 2020, are believed to be the earliest-known evidence of a successful amputation, predating previous successful surgery by at least 24,000 years.
Griffith University archaeologist Tim Maloney explained why the discovery was so significant.
"It speaks to the extraordinary intelligence and adaptability of the human species that people living in rainforests of Borneo 31,000 years ago could undertake and survive such a complicated procedure," he said.
Buried in the centre of a cathedral-like chamber of the Liang Tebo cave, the individual had their lower leg and foot amputated as a teenager and went on to live for another six to nine years, Dr Maloney said.
Researchers dated the skeletal remains by measuring the amount of radiation tooth enamel absorbed during burial.
Prior to the discovery, the oldest known successful surgery was gleaned from the 7000-year-old skeletal remains of a French man whose left forearm was removed.
"Amputation rates were almost guaranteed to be fatal prior to the First World War," Dr Maloney said.
While the method of amputation in the Liang Tebo case was not preserved, Dr Maloney believed the operator had an advanced understanding of complications.
"There's a reasonable case to support the existence of understanding of controlling blood loss and shock and some kind of antiseptic or antimicrobial management."
Dr Maloney said a sharp stone scalpel-like instrument was the most likely tool used to perform the surgery.
"These people were not producing simple, unchanging, lithic (stone) technology. There's a host of complex retouched flaked technologies," he said.
Despite living among dangerous predators, Dr Maloney confidently ruled out animal attacks or other injuries crushing the bone, given there were no signs of infection.
"It's very neat and oblique and you can actually see the surface and the shape of the incision through the bone," he said.
The discovery calls into question the understanding that successful surgical practices came along in the last 10,000 years with the emergence of farming communities.