From obscure caveman to global rock star
Cave explorers had to fit through a tunnel as wide as this picture on their journey of discovery
OUR new relative, Homo naledi, was laid bare for the world to see this week. Knitted into the fragile bones on display is a host of mysteries that only time and dogged research can unlock.
With the face of this new species splashed across global media, it is easy to overlook the sheer wonder that these fossils were ever unearthed at all, lying in an almost inaccessible tiny chamber 30m underground and 92m from the cave entrance.
The single biggest hominin find in Africa began exactly two years ago today with two amateur cavers who may have missed the fossils altogether had they not been “pushing themselves to the limit”.
Steve Tucker, the first to see the bones, recalled: “I had been caving for five years. To find unexplored places, you have to push yourself to the furthest places and deepest cracks.”
He and fellow caver Rick Hunter had explored the Rising Star caves in the Cradle of Humankind at least 20 times.
This time, they went much further into the cave — which included a harrowing journey down a chute just 18cm wide — and ended up in a remote and inky-black chamber.
There, illuminated by a pool of light from a headlamp, was a floor covered in bits of bone protruding from the ground. A few lay loose on the surface.
“They are the same colour as the floor, so it was not easy to see them right away. But then it became clear: we were seeing a collection of bones.”
At first, the two men couldn’t tell what type of animal the fossils had come from.
“But then we found a lower jawbone and it had teeth in it. It looked so similar to a human jawbone. And that was when we realised this is something interesting.”
The camera’s battery had died, and so, like two messengers from a forgotten world, they reported their findings by word of mouth to geologist Pedro Boshoff at the University of the Witwatersrand.
Boshoff retrieved the cast of another jawbone and asked the men if it looked the same. Indeed it did, they said. A week later they went back, and took as many photographs as possible.
Meanwhile, palaeoanthropologist Professor Lee Berger of the University of the Witwatersrand, a die-hard warrior for the Cradle of Humankind as a site of human evolution, had used Google Earth to map tree clusters that indicated the existence of caves in the area.
In 2008, at Malapa in the Cradle, he discovered the remains of six creatures of the species now known as Australopithecus sediba — a new species that raised many questions about human evolution.
His endless search for fossils in the area has been met with some scepticism, and Au. sediba’s spot in the family tree has been contentious.
Several researchers who have published papers on early Homo have not included Berger’s Au. sediba findings.
But when the two cavers arrived at his house at 9.30pm, Berger’s chapter of vindication began: “The moment Lee saw the photographs, he was literally speechless,” said Tucker. “He was so excited he could not actually utter a single word.”
The wheels of the expedition were set in motion that night.
“We celebrated, and I sent them home,” recalled Berger. “At 2am I called Terry Garcia [chief science and exploration officer for the National Geographic Society]. I explained everything until he finally said: ‘Do what you need to do.’ ”
Wanting more images but being “physiologically inappropriate” — too broad to fit through the chute — Berger trained his lithe 16-year-old son, Matthew, to do it for him.
With the new images driving him on, Berger put an advert on Facebook: PhD graduates, nar- row enough to fit down the chute, and with an aptitude for caving.
“They had to be willing to drop everything and come to South Africa for a month of unpaid work,” he said. Later, he would also need “the finest team of 60 senior scientists from around the world” to make sense of the collection of fossils.
The scale of their intricate research has revealed that our newly discovered relatives deliberately deposited the bodies of their dead, a behaviour up to now solely associated with modern human beings.
But it would first take the careful footing and nerves of steel of the “underground astronauts” to recover the bones before these cataclysmic research findings could be made.
One of the six people who had both the scientific know-how and the right physique was Canadian palaeoanthropologist Marina Elliott, one of the “underground astronauts”.
She said it was clear from the beginning: the route itself “is thrilling because it is so physically challenging”, while being in the chamber for the first time was “beyond remarkable”.
“These were some of the most dangerous conditions ever encountered in the search for human origins,” she said.
Meanwhile, an elaborate system had been set up to ensure the safety of the team, to document every moment inside the cave system and to bring the priceless treasures to the surface without causing damage.
Tucker and Hunter were brought on board, and the ancient cave quickly became a monument to modern technology: “Cameras, cables, live feeds, a command centre just outside,” said Tucker.
Back at Wits, a 3-D printer worked overtime to print exact replicas of the specimens so that the scientists could recreate H. naledi.
But, for all this fastidious documenting of this historic fossil expedition, the actual findings were kept under an iron veil of secrecy until the team of 60 scientists had gone through all the new data in a way that only scientists could.
With a collection of 1 550 specimens, their task was to hypothesise and analyse and deduce, rather than shouting halftruths to a media-hungry world.
University of Wisconsin-Madison’s John Hawks, a senior author on the academic paper describing H. naledi, said he marvelled at how science closed the gap.
“The time and place where these bones come from is a place I will never be. And the fact that we now know as much as we do comes purely from science. I keep reflecting on that.”
This week, H. naledi was introduced to the world to much fanfare at a massive press conference at Maropeng, under the watchful eye of local and international media.
But the bones of the 15 individuals who have so far been reconstructed are just the beginning.
There are many more specimens to be recovered from the cave, and whether these will provide any further clues is not yet known.
With the minutiae of the bones fresh in her mind, Elliott shed light on the bigger picture: “It should make us realise it is a lot more complicated than we had thought. Our family tree is not made from clean leaves and simple lines. It is a tree where the branches curl back in on themselves and split off again. All we know is that there is so much we don’t yet know.”
Berger tried to put the new find into perspective. “This is like opening up Tutankhamun’s tomb. It is that extreme and perhaps that influential in this stage of our history.”
This is like opening up Tutankhamun’s tomb. It is that extreme and perhaps that influential in this stage of our history