HUMANITY’S BIGGEST SECRET
Six slender ‘underground astronauts’ take the gap
AT THE time Lindsay Hunter was told she’d been selected to be one of six “underground astronauts” to climb down a 90m chamber to retrieve a new species of human relative, she thought it was just one skeleton she’d be involved in excavating.
One skeleton alone was enough to be career making and field changing. But it wasn’t – parts of at least 15 individuals of Homo naledi consisting of more than 1 550 fossil elements were found.
“Usually that is something very difficult for a scientist to admit, being wrong. But we were so pleased to have been wrong,” she said.
Hunter, 36, had answered Professor Lee Berger’s call for experienced scientists who could fit through the 17.5cm-wide cave opening.
She’d been living in Austin, Texas, at the time, but came to the country almost immediately after finding out she had been selected.
“I wasn’t even seeing all of the fossils (on her first day inside the chamber) because the other scientists had gone before us and begun excavating. I was overwhelmed by the quantity. At first it was just about figuring out where to put your feet.
“Our first job was to surface clear the area at the entrance so we’d have a clearer ground that proved more difficult than originally expected.”
The sediments were quite soft, the excavators would pack them down as they travelled over them but they seemed to have a churning effect that caused more fossils to come to the surface.
“We knew we were walking on fossils, sitting on fossils; the entire excavation was taking place on a bed of fossils,” she said.
The danger of damaging what they were trying to recover was very real.
Generally, the astronauts would rotate shifts of three people going into the chamber in a day.
“We were always pushing how long we’d stay down there because once you’re down, it’s like you’re a dog with a bone, you don’t want to leave,” Hunter said.
“That’s the really cool thing about being in caves… time is immaterial. What’s happening on the surface is so distant and far removed from your experience underground, that we might as well have been back in time with the naledi fossils.”
After the 21 days were up, Hunter said none of them wanted to leave, but leaving was a necessity – they still had decades of analysis work ahead of them on the retrieved fossils alone.
“What really speaks to me,” she said, “is here we have a kind of human relative, that’s not human, but it appears to have behaved in ways we previously thought of as exclusive to humans…
“So our understanding of what it means to be human is broadening and we’re understanding that someone who may look very different to you may be very much like you.”