'Earliest' evidence of human violence
A healed fracture discovered on an ancient skull from China may be the oldest documented evidence of violence between humans, a study has shown.
The individual, who lived 150,000-200,000 years ago, suffered blunt force trauma to the right temple - possibly from being hit with a projectile.
But the ancient hunter-gatherer - whose sex is unclear - survived to tell the tale: the injury was completely healed by the time of the person's death.
Details are published in PNAS journal.
"There are older cases of bumps and bruises - and cases of trauma," said co-author Erik Trinkaus from Washington University in St Louis, US.
"But this is the first one I'm aware of where the most likely interpretation is getting whooped by someone else - to put it bluntly."
The skull was unearthed at a cave near Maba, southern China, in 1958. Before it was buried, a large rodent - probably a porcupine - gnawed on the bone, removing a significant portion of the face.
Prof Trinkaus, who was part of an international team that re-examined the specimen, said the depressed fracture in the right temple region was the result of an impact that was "very directed, very localised".
Being struck hard with a stone cobble might produce this type of injury, the researcher told BBC News.
But he added: "One of the problems was that these people led rough lives. They were hunting medium-to-large animals at close quarters. And when you stick a spear in an animal, they usually do not appreciate it.
"They tend to kick and fight - and many of these animals had horns and antlers.
"Can we completely rule out a hunting accident? No. But it's less likely to be that than getting hit on the side of the head with a missile."
In addition to the severe headaches it undoubtedly caused Maba man - or woman, experience of present-day injuries like this one suggests the person probably suffered some temporary amnesia.
The English philosopher Thomas Hobbes wrote that life in the natural condition of mankind was "nasty, brutish and short"; and the Chinese discovery is unlikely to change any modern preconceptions about the lifestyles of our ancient forbears.
But the Maba individual survived for weeks or months "at least" after sustaining the injury, based on the completely healed state of the fracture. And according to Professor Trinkaus, this presents an important flip side to the latest finding.
He told BBC News: "It's another individual in a growing number of human fossils going back in excess of a million years who show long-term survival with serious injuries and congenital problems - a variety of things along these lines.
"We have many instances of trauma - some serious, some minor. We also have a surprisingly high incidence of conditions that occur in the modern world but are extremely rare. So the probability of finding them in our meagre fossil record is extremely low."
Whatever the reason behind this latter observation, he said, "they are surviving them remarkably well".
Researchers believe such evidence points to the existence of care and support networks within ancient human groups.
"They hit each other, they squabbled, they had weaponry - so it became serious. But at the same time, they were helping each other out," Prof Trinkaus explained.
The Maba individual was not a modern human like us; it instead belonged to a poorly defined population of so-called "archaic" people who were living in East Asia at the same time the Neanderthals dominated Europe.
It is possible that the Chinese specimen is linked to a mysterious population known as the Denisovans, who have been identified as a distinct group of ancient humans on the basis of DNA alone.
However, Prof Trinkaus thinks there was a population continuum across the Eurasian landmass.
The Neanderthals were the western representatives of this continuum, with Maba and other specimens representing an eastern physical form. "It's just that the Neanderthals have a name," he said.