Extinct humans buried their dead and marked graves with inscriptions up to 330,000 years ago, archaeologists have found – the earliest evidence of funeral practices ever discovered.
Until now, archaeologists believed only large-brained, modern humans and Neanderthals had the emotional intelligence to commemorate death and create memorials to their loved ones.
But experts excavating the Rising Star cave system in South Africa found geometric markings of lines, squares, crosses and triangles carved into the walls close to where the bones had been interred.
The fossilised remains, first identified in 2013, belong to an extinct group of small-brain hominids called Homo naledi, who lived between 241,000 and 335,000 years ago.
The graves are up to 200,000 years earlier than the first burials performed by modern humans and suggest emotion developed before intelligence.
Research shows the walls were smoothed down before the markings were made and perhaps polished afterwards.
Social and emotional development
Professor Penny Spikins, from the University of York’s Department of Archaeology, said: “The evidence in these caves points to significant effort being made to care and attend to the dead, and given the size of the brains of Homo naledi, suggests that emotions developed ahead of intellect in our evolutionary history.
“It has always been assumed that complex, emotional responses between individuals was exclusively a feature of our large-brained ancestors.
“We were surprised to find that this is not the case. Homo naledi developed social and emotional parts of their brains hundreds of thousands of years before homo sapiens.
“We assumed big brains and technological advancement went hand-in-hand, but way before this, emotional connections were formed, and therefore could be a more significant building block in our timeline than we ever thought possible.”
Homo naledi stood five feet tall and weighed 100 pounds, with hips similar to our earliest ancestor, the hominid Lucy, but their shoulders were well designed for climbing, and they had long arms and curved fingers as well as human-like legs and feet.
The shape of their skulls were like those of early humans, but their brains were tiny, about the size of an orange, similar to that of a chimpanzee.
The team said Homo naledi “could not be more different to humans”, yet seemed to have made emotional connections and collaborated with one another in a “very human-like way”.
When archaeologists first discovered the burial cave located about 30 miles from Johannesburg, they assumed a mass death or catastrophe had befallen a group of Homo naledi.
The fossils were found about 300 feet inside the cave entrance and experts initially thought they had simply been dragged there, perhaps to avoid the diseases associated with rotting bodies.
Careful positioning and markers
But later digs showed the individuals, ranging from infants to the elderly, had been carefully deposited over a long period of time, and the remains had been purposefully covered up with sediment near intricate wall engravings.
Experts now believe the dead were carried deep into the cave chambers and placed in a specific location with grave markers in a funeral practice similar to how humans remember the dead.
No other hominid or human remains or archaeology have ever been found in the caves, so experts are confident the cave wall carvings were made by Homo naledi.
Significant cognitive leap
Researchers said the creation of intentional markings that communicate meaning are considered to be a significant cognitive leap in human evolution.
Professor Agustin Fuentes from Princeton University said: “This is simultaneously the oldest example of burials and one of the earliest examples of engravings on cave walls – evidence of complex culture and meaning-making by a hominin who is not us.
“This changes how we have to think about human evolution.”
The research was published in the journal eLife.