In November 2013, Marina Elliott squeezed through an 18-centimetre-wide vertical passage into an underground chamber in South Africa and began to excavate the bones of what turned out to be a new species of hominid — an early human ancestor.
Since then, about 1,700 Homo naledi fossils have been excavated from the pitch-black Dinaledi Chamber in the Rising Star Caves, belonging to at least 15 individuals.
The discovery made headlines around the world, not least because it appears to show that an ancient human relative did something only humans were thought to do. It seems possible that Homo naledi deliberately disposed of its dead.
This Saturday, Elliott will answer questions about the discovery via Skype at the Beringia Centre in Whitehorse, as part of activities planned for International Archaeology Day.
“I think probably the fundamental thing that it tells us is that we really don’t know what we thought we knew about our history,” she told the News in an interview. “It reinforces the fact that the human family tree is a lot more complicated than I think people have liked to believe in the past.”
The discovery of the underground cavern and the hominid fossils sounds like the plot of a Hollywood movie.
In September 2013, cavers Steven Tucker and Rick Hunter were exploring the Rising Star cave system when they came upon a fissure in the rock — just 18 centimetres wide in some places — that led 12 metres down into a previously unknown chamber. The floor of the chamber was littered with bone fragments.
South African paleoanthropologist Lee Berger was alerted to the find, and quickly put out a rather unconventional request for help on Facebook.
“We need… individuals with excellent archaeological/paleontological and excavation skills,” it read in part. “The catch is this — the person must be skinny and preferably small. They must not be claustrophobic…. They must be willing to work in cramped quarters….”
And that’s how Elliott got involved. She spent her youth in Calgary climbing and caving in the Rocky Mountains, and has a PhD in biological anthropology from Simon Fraser University in British Columbia.
“I have an adventurous spirit to begin with,” she said. “So the prospect of picking up and taking off to South Africa for a month of digging God only knows what, at that time was really compelling.”
But even she had second thoughts when it came to climbing down into the Dinaledi Chamber. Part of the route, she described in a recent TEDx talk, involved squeezing through a crevice so narrow she could only push herself through with her toes.
“At that point, I thought, ‘Oh dear, I may have bitten off more than I can chew at this point.’ But then, of course, the excitement of the actual excavation and everything kind of took over,” she told the News.
Berger himself wasn’t allowed to go past a certain point in the cave system after getting himself stuck one time for 45 minutes, she said.
The fossils Elliott and her team excavated were officially described in September 2015 as a new species, Homo naledi.
Elliott described the human ancestors as having a blend of modern and primitive features. “We’re looking at a very lightly built species, so not super tall, about 1.4-1.5 metres and somewhere in the range of 40 to 50 kilos,” she said.
Homo naledi had ape-like shoulders with human-looking hands, except for their curved fingers. Their hips are those of a species that walked on two legs, and their feet are “almost indistinguishable from a modern human except that they’re quite small,” Elliott said.
The species hasn’t been dated yet, so it’s still difficult to know exactly how it fits into our evolutionary history. But Elliott said it shows our history didn’t follow the clean, linear path that we like to imagine.
Perhaps the most interesting feature of the discovery, though, is that the bones of at least 15 individuals were found in an underground cavern with no other animals. Typically, if animals fall into a cave and die, multiple species will be found in the same spot.
That suggests to Berger and Elliott that Homo naledi was intentionally disposing of its dead in the Dinaledi Chamber, a type of ritual behaviour that is usually only associated with modern humans and Neanderthals. That theory has been the subject of some debate in the scientific community, but Elliott said it’s still the best explanation out there.
“Even after a year and a bit of it being out in the academic and public sphere, no one has been able to come up with a viable alternative, given the evidence that we’ve got,” she said.
Elliott and her team have made a point of making the new discovery as publicly accessible as possible. They published their findings in an open-access journal, and have made shape files of all the fossils available for free. That desire for openness is part of the reason she agreed to speak to Yukoners on Saturday.
“One of the reasons… that a lot of people have kind of a reluctance or fear around human origins research is that they simply don’t understand what we do,” she said. “And I think that’s a shame.”
Elliott’s enthusiasm for her field is partly why the creators of Long Ago Yukon reached out to her to kick off their third season of talks by paleontologists and archaeologists.
“This is that continuing desire to know more about ourselves and our roots and also to share in that sense of exploration and discovery, which is always fascinating,” said Michael Dougherty, a co-convenor of Long Ago Yukon.
The Beringia Centre will screen Elliott’s TEDx talk at 11 a.m. on Saturday, and she will then answer questions via Skype.
Visitors are invited to bring bagged lunches to the event. Over the noon hour, the centre will serve cake and refreshments, and will host activities for kids and families.
At 1:30 p.m., the centre will screen Werner Herzog’s 2011 documentary, Cave of Forgotten Dreams, about the Chauvet Cave in France, whose walls are covered with the world’s oldest-known paintings.
Long Ago Yukon plans to hold at least four more Skype lectures this season.
“In the larger frame, archaeology… as well as paleontology and anthropology provide us with a lens on the past which helps inform our present and future,” Dougherty said. “Studying the past definitely allows us a lens or a framework with which to assist us as we plot our course forward.”
Contact Maura Forrest at firstname.lastname@example.org