Review of Netflix’s Unknown: Cave of Bones

Let’s get a few things out of the way. Cave of Bones is well worth watching. The entire team at the Rising Star cave system has been doing incredible and incredibly valuable work in a very difficult context. They are heroes of science, no doubt about it. The discovery and the recovery of naledi remains is changing our understanding of who we are and how we got to be us. None of that is in question.

The footage is amazing. It gives the audience a rare glimpse into an amazing fieldwork process. It lets us listen to the thoughts and reflections of fieldworkers and other researchers. We see the reconstruction of a naledi skeleton. The whole thing is at once exciting and sobering.

And I have questions. And a few thoughts. First, it’s important for the audience to keep in mind throughout that the central claims around which the program is built, that naledi buried their dead and that they made engravings on cave walls, are not well supported by the evidence presented, either in the documentary or in the published academic papers. 

That fact doesn’t take away from the value of watching the show, but it must be borne in mind to get the most out of it. It is entirely possible that the claims will be well supported in the future, but they are not right now. You can see the original paper in which Berger et al. present their case for burial here, and you can see the peer reviews here.

Briefly (tl;dr, as the kids would say), there is currently little evidence that the claimed pit burial is actually a pit, and there is little evidence that it is more than a jumble of bones. Of course it could be, but I am not convinced by the published data, and neither are many of my colleagues.

Are these claimed burials just naledi who didn’t survive the incredibly dangerous trip through the caves and were never recovered by their people? Berger even comments on that at one point, and in the current state of the published data, that explanation is at least as convincing as the one presented in the program.

There is perhaps even less evidence that the claimed engravings are not natural. Maybe that will be forthcoming, but it isn’t there now.

But this stuff is not what Cave of Bones is really about. It presents the claims as established fact and uses them to discuss something bigger: What it means to be us, and how we go about finding out through paleoanthropological investigations. That’s a worthwhile set of reflections in itself, and it is merely unfortunate that the makers of the program felt the need to justify them with fairly weak hypotheticals. The reflections can and should stand on their own. The claims are just papier mâché props.

On the other hand, it isn’t surprising that the focus appears on the surface to be so strongly on the claims. This is archaeological mysticism at its purest. Everything is about the experience, and the experience is sufficient evidence of truth.

Once he has made the dangerous descent into the cave in which he never thought he would stand, Berger examines the claimed burial in person for the first time: “There is no doubt when you look at it from here”, and “I wish everyone could see this in real life.”

He’s been there, and we haven’t. He’s made it out alive and he’s told us his experience. That should be enough for us Thomases. “I came out of there a very different person”, he says. Experience is proof.

And when he looks at the claimed engravings: “I do not think that’s natural.” No need to physically compare the lines he identifies as engravings with the multitude of others, plainly visible elsewhere on the cave walls, or with other similar ones in other caves where there is no suspected naledi presence. Which is what I am waiting for to have an opinion on the whole potential engraving thing.

Of course, we don’t know how much of this archaeological mysticism belongs to Berger, and how much to the producers, or the editors, or anyone else. It is simply the impression left by Cave of Bones.

I sympathize with this mystical approach to archaeology to a certain extent, and am not immune to it myself. There are things I know in my heart about some of the sites on which I have worked, and that I will never be able to prove to someone else. I try to be careful to mark those things as speculation when I bring them up in any context, whether in class, in papers, or at a wine and cheese reception.

The impression left by what we see on screen is that Berger, Fuentes, and perhaps a bit less visibly Hawks, really want these claims to be true. They want the burials and engravings to be real. 

So do I. And I constantly have to remind myself that I am capable of holding simultaneously a strong desire for interesting possibilities to be true, and a powerful need for claims to be scientifically evaluated with evidence. It’s a difficult balance to maintain, and Cave of Bones is excellent training for it.

But as a viewer, I wish some of the considerable screen time given over to Berger’s personal expedition had been spent with the people who actually do the work in the cave. I wanted to see how they actually get down there, how they carry their gear, how they record their data. I wanted to hear from them. The team. Yes, even about their experience.