How the Naledi Team Solved a 1,550-Piece Puzzle

The announcement of Homo naledi last week was just the latest phase of a scientific adventure that’s been going on for two years in and around a tiny cave in South Africa.

It started in November, 2013, with the three-week long expedition to recover what National Geographic Explorer-in-Residence Lee Berger and team at first thought were bones from a single ancient hominin. We lived in tents, swapped theories around a fire, and I wrote about it all daily for this expedition blog. (Relive the discovery by reading the original posts in order.)

The scientists were chosen for their excavation skills and ability to fit through tight spaces. I’d like to think I was chosen for my writing skills, but being roughly Tom Cruise sized, I have a sneaking suspicion they may have had more practical “emergency uses” for me in mind.

Back in the Lab

The above video gives a glimpse of phase two of the project: a six-week workshop six months later, when established experts and early career scientists gathered in Johannesburg to make sense of the 1,550 fossil pieces the team had recovered. This time we were in hotel rooms, not tents, and the closest most of us came to getting into a cave was entering the newly renovated fossil vault at the University of the Witwatersrand.

Glass-fronted cabinets full of fossils and replicas lined the walls. The central area contained Tetris-like configurations of folding tables at which sat groups or pairs of researchers, each focused on a particular section of anatomy or area of analysis.

Several of the “Underground Astronauts” were there the week I visited: Elen Feuerriegel studying the arm and shoulder; Alia Gurtov tucked away in the “tooth booth”; Marina Elliott hosting a geologist down into the fossil chamber to investigate the context of the bones.

It was a diverse group facing the “busiest, messiest 3-D puzzle ever” as Elen called it.

In a matter of a few weeks, the team members contributed thousands of hours of work, comparing the fossils with casts of other hominins, creating and analyzing 3D images of the bones, and running statistical analyses. The heavy vault door stayed cracked open as people scurried in and out for a meal or to pick up the latest model from the ever-whirring 3-D printer.

Berger’s Big Idea

Two years from dirt to desktops is a pretty unusual turnaround for such a major find. The nearly complete skeleton of “Little Foot,” discovered more than 15 years ago just a few miles away from the H. naledi site, has yet to be fully described in the scientific literature.

That kind of delay is what Lee was hoping to avoid. Such a large amount of new material is inherently relevant to practically any study of early hominins, and with so many bones recovered, and so many more still in the cave, he didn’t want the paleoanthropology community (or the public) to have to wait.

He also wanted cross-pollination of ideas for the researchers. “You interact with experts on all parts of the body,” said Damiano Marchi from the Università di Pisa, working on the lower limb, “and it gives an overall understanding of the morphology and function.”

Lee and his collaborators would like to see the famously slow and siloed field of paleoanthropology handled this way in general: Find something, get a large team involved, get the results out quickly, open up access to the fossils—and then go find more bones.

Not So Fast?

Not everyone in the field agrees. Some critics point to possible errors from inexperienced team members, who may lack the perspective of seasoned paleoanthropologists. Others say it simply takes more time to analyze material thoroughly. Since hominin fossil finds have generally been rare, researchers also tend to keep them closely guarded, accessible only by the discoverer and trusted colleagues. Berger thinks the greater risk is not to try new approaches.

He knows the workshop might have the appearance of people working too fast, but that’s in appearance only, he says. “This is a marathon, not a sprint—even though it looks like a sprint.”

And as to what it’s like to work this way, “the reward is more than stress,” Damiano Marchi told me. “It’s a very, very stimulating environment. This experiment worked.”

Watch the Two-Hour Special: The NOVA/National Geographic documentary, “Dawn of Humanity,” premieres in the U.S. Sept. 16, 2015, at 9 p.m. ET/8 p.m. CT on PBS.