How Finding This Human Ancestor Is Making Us Rethink Our Origins | Nat Geo Live

MARINA ELLIOT: Homo Naledi's story is changing our story, the story of human origins. And, in fact, this discovery is changing how paleoanthropologists and scientists think about and craft the story of our past. (audience applause) All of you have actually seen this image before, I'm hoping, and it tells a story; it tells a really good story; and it's a story about two cavers and some bones, but it's also about how that discovery led a paleoanthropologist to place a very unusual call for excavators of a particular type. (audience chuckling) And how this call brought six women, myself one of them, together with a huge team of scientists, volunteers, and cavers, to undertake an extraordinary three-week expedition in South Africa. Now, the pictures and perhaps the video give you a little idea of what it's like. But as one of those people that had to traverse that route every day, I'll give you a slightly more personal idea of what that was like. So that is some of the damage. I am not the hairy ankle, thank you very much. (audience laughing) But the top three pictures are of me at various stages during the expedition. But it really was all worth it. You saw the fantastic results of our expedition. Just an incredible treasure trove of material that we couldn't possibly have imagined, with images that really still send shivers down my back when I see them. I was the first scientist into the chamber once the remains had been discovered. And it really was one of those watershed moments. There's a little narrow hallway that then opens up into the Dinaledi chamber itself. And as I squeezed through that hallway and looked into the Dinaledi chamber, for me, what flashed through my head that very instant was Howard Carter and what it must have felt like for him to step into Tutankhamun's tomb for the first time. Both of us only had a lamp to illuminate what was in that space. And I think, for me, I really felt like all I could see was what my headlamp showed me, and that was flashes of bone everywhere I looked. And I really thought: "Wow, this is what Carter must have felt like when he saw flashes of treasure everywhere he looked." It's an exhilarating feeling. And by now you know that these remains actually represent one of the most unusual and incredible assemblages of material in history, and an entirely new species: Homo Naledi. When Homo Naledi was announced last September, it trended number two on the Twitterverse, briefly usurping the Kardashians, which I understand is quite a feat. But one of the reasons it made such a splash was the volume of the material. I mean these 1500, and now 1700, specimens that we'd recovered was unprecedented. And what people maybe also don't realize is that all that material, those 1500 fragments that we recovered during that initial expedition, came out of an area 80 centimeters by 80 centimeters by 20 centimeters deep. That's the size of a child's sandbox. And for a discipline as used to making a fuss about one tooth or finding a jaw, that really was quite traumatizing to the paleoanthropological community. You see, for decades we'd believed the story that the human fossils were as rare as hens' teeth, that it took basically an act of God or a lottery ticket or being hit by lightning in order to find this material. But here was a situation where not only was the material ridiculously abundant but it'd been found by someone who'd been electrocuted once before. (audience laughing) So, what was going on here? But what a lot of people forget about getting hit by lightning twice is that you can increase your odds tremendously by getting out there every day with a lightning rod. And what Lee proved in finding Sediba and then Naledi is that experience, persistence, and knowledge really can pay off big time. But if you don't look, you certainly won't find. Then we actually started looking at the bones. And within those 1500 fragments that we were looking at, we had the skulls and the bodies of at least 15 individuals; and we had almost every bone in the body represented more than once. And what we found was totally unexpected; a combination of features that we couldn't possibly have imagined and couldn't have predicted in advance. What this meant, though, was that our understanding of skeletal shape and species identification kind of had to be rethought; because if we took just a scrap of Naledi's jaw, we would say it was one thing, but if we took a scrap of its foot, we would say it's something totally different. And then there were parts of Naledi that were unique to it. So it was really one of those situations where we had to start thinking about those stories again and trying to figure out what these features actually were telling us. It presented a problem for paleoanthropology, though, because it meant that scraps really aren't a good indication of the whole anymore. And it raises questions about all those other little scraps that we've been making stories about so definitively for so long. So it really is challenging us to go back and look at the material we have with new eyes and maybe think about how we need to reconfigure those stories. In addition, Naledi's mosaic of features raises questions about how we view our origins in the first place. Now, we don't have a clear date for Naledi yet. But if Naledi is old or if it's young, either way, it suggests that we don't really understand that human family tree very well at all, and that it reinforces the fact that we just need to maybe think about that story again in a different way. Not only is the tree much bushier, maybe, than we originally thought about it, but our family tree may not actually be a bush at all. What we may be looking at is more like a river delta; a whole bunch of rivulets coming down from a common source; some that trickle down and dry out and we never see them again; other rivulets come back and join another rivulet to make a bigger rivulet that continues on down; and all of them ending up in a big pool at the bottom; and that big pool is the now over seven billion humans that we see on the planet today. And this analogy may stand the test of time, or not, we'll have to see. And as it turned out, the next chapter, doing the analysis and description of the material, also needed a bit of a rewrite. Lee and the team decided to open up the primary analysis of the fossils to young scientists, early-career scientists, and not just a few; almost 40 researchers met in South Africa to do the analysis of the material. And, even in estimating for a modest 40-hour workweek, which we certainly exceeded, this amounted to almost 10,000 hours of research; something that would take a single researcher almost five years to match. But it did rattle a few cages because it presented a new model for research; one that was more inclusive; one that allowed engagement and discussion among each other. And it was really exciting, and something, in fact, that I think our discipline has been very sadly neglectful of in the past. And that actually brings us to the last way in which Naledi may be changing our human story; and that is in how we tell it; how anthropologists and scientists share that information with each other and with the public. The scientific papers that describe Naledi were released in a open-access journal called eLife. Shortly thereafter, we released all the shape files for the fossils on a website called MorphoSource, hosted by Duke University. This meant that the primary information on Naledi and basically casts of all the fossils were available to anyone who wanted them, free of charge. Our team really felt strongly that because this material is not ours to hoard, it's South African heritage, it's actually world heritage. This material relates to the origins of all of us; and it was really important for us to share that with all of us. It's a human question. For me, the open-access model is actually one of the best parts of this story. In the last year, well, since September, I have done over 400 interviews and almost 60 talks on Naledi; and everywhere I've gone, the response has been the same: excitement, interest, and a real desire to learn about human origins and scientific exploration. But I think one of the things that I have seen in that is that people maybe kind of feel isolated by scientific research; not because they are stupid or the science is too hard, but because perhaps we as scientists have done a poor job of telling the stories. People cannot be expected to know what they haven't learned; and if they feel isolated from that learning, it develops into mistrust; and mistrust breeds fear; and fear blocks curiosity. It's really up to us as scientists and educators to make our research comprehensible and accessible to people and help them engage with what we do in a really meaningful way. Science really is all about adjusting one's views in light of new evidence. And, in many ways, by pushing the dark spaces of South Africa, Homo Naledi's discovery is pulling paleoanthropology into the light of new ways of doing and thinking about our science. And as much as I love the underworld that I work in, I think this research is really putting a necessary and very positive spotlight on human origins and giving paleoanthropologists an opportunity to tell some very cool new stories. I hope that you will help me share those with the rest of the world. Thank you. (audience applause)