Our missing ancestor may have believed in gods and the afterlife – and walked the earth beside us
FOUR years ago a couple of experienced cavers, Rick Hunter and Steven Tucker, ventured into a cave system known as Rising Star, less than three dozen miles from Johannesburg. Part of their mission in exploring the caves was to see if they could come across any fossils of our early ancestors.
Such things had been found in this part of South Africa before, so much so that it has become known as the Cradle of Humankind.
The cave system has been described as the richest fossil hominin site in the entire continent – hominin being the name for modern humans, our ancestors and extinct related species.
Hunter and Tucker succeeded in reaching a stalactite-heavy cavity. Hunter wanted to shoot some video and in trying to squeeze out of the frame Tucker accidentally came across an extremely narrow chute.
Both men entered it – and in doing so came across what National Geographic has termed “arguably the most astonishing fossil discovery in half a century, and undoubtedly the most perplexing”. What the men eventually found was a collection of bones in a chamber, including a piece of lower jaw with intact teeth. The discovery enthralled Professor Lee Berger, a noted American-born South African paleoanthropologist, who quickly organised an expedition to excavate more than 1,500 hominin fossils.
In September 2015, Berger and his team proudly announced the discovery of a new species of humankind, Homo naledi, named after the Dinaledi cave in which it had been found. It caused a huge international stir, even though for a variety of reasons the specimens could not be dated at the time.
Many in the field assumed that naledi was between one and two million years old, if not even older. But now new dating evidence has revealed that the skeletons are, in fact, a mere 200,000 to 300,000 years old, which means primitive, small-brained hominins may have lived at the same time as the first modern humans in Africa. It is an astonishing assertion.
In a video posted online, Berger, of the University of the Witwatersrand, says: “This means that Homo naledi – this primitive hominid that appears to come from the root of the genus, homo – actually lived not only through the last several millions of years, but was contemporary with when we thought only homo sapiens lived on the continent of Africa.
“This is undoubtedly going to have a profound effect on our understanding of archaeology. In fact, it’s a little bit confusing because now we have at least two potential makers of these very complex stone industries which are scattered about southern Africa and perhaps the rest of Africa.” It is, he added, going to give rise to more questions than answers.
The discovery of a second naledi cavern, dubbed the Lasedi chamber, adds weight to the idea, Berger believes, that naledi deliberately disposed of their dead in a ritualised fashion in these deep, remote, underground chambers of the Rising Star system. A ritualised death would imply a belief in the afterlife, and in the capacity for abstract thought.
“Inside of this chamber are several individuals – some children, a couple of adults, one of which is now among the most complete skeletons ever discovered,” he said. This adult has been given the name of Neo. Berger says there are “thousands” more remains in the Dinaledi chamber and probably many others in the Lasedi one. “So we have a great future ahead of us for discovery in these caves,” he adds.
Berger has also said that we can no longer assume that we know which species made which tools, “or even assume that it was modern humans that were the innovators of some of these critical technological and behavioural breakthroughs in the archaeological record of Africa. If there is one other species out there that shared the world with ‘modern humans’ in Africa it is very likely that there are others. We just need to find them”.
Naledi fossils have just gone on display at Maropeng, the official visitor centre at the Cradle of Humankind World Heritage Site. A Washington Post article says some scientists not involved in the naledi research have “urged caution about some of Berger’s bolder claims”, including the burial of their dead and devising the sophisticated stone tools that make up southern Africa’s Stone Age.
The article added that ritual disposal of the dead is an advanced behaviour and that only humans and Neanderthals have been conclusively found to do it. Several scientists say the possibility cannot be ruled out that the bones were deposited in the cave naturally. But if naledi placed the bones in the caves for ritual reasons it would mean the species “was capable of something profound”, the article added.
There’s no masking the scale of the reaction, however, to the news that naledi is younger than had been hitherto suspected. Late last month, Dr Adam Rutherford, presenter of BBC Radio 4’s Inside Science, interviewed paleoanthropologist John Hawks, one of the naledi team. A few minutes before it began Hawks told him of the new age of naledi.
“My response was unbroadcastable, so I apologise for that,” Rutherford told Hawks on air. The actual age, he added, “is just breathtaking. We’re talking about a new species of human, very different from homo sapiens but present at the same time”.
The Dinaladi fossils, says Hawks, “are the age of Neanderthals in Europe, they’re the age of Denisovans in Asia, they’re the age of early modern humans in Africa. They’re part of this diversity in the world that is there as our species is originating”.