Discovering Homo Naledi: Journey to Find a Human Ancestor, Part 3 | Nat Geo Live

Lee: Extraordinary people doing extraordinary things. By the end of a 21-day excavation, we had discovered the richest early Hominid site ever discovered in the history of the planet. This site is one mile away from the site of Sterkfontein. It's less than half that distance from the second best known site in the entire continent of Africa, the site of Swartkrans, 800 meters away. It was right under our nose. It was an incredible environment of science. There, we had a fossil tent where we kept joking that we need a bigger safe and we had to buy more boxes and more bags than we ever envisioned. We'd set up a thing to find a skeleton and we had, first, hundreds of remains and by the end of it, thousands of remains of hominids. We would work late into the night. I, sometimes couldn't get the scientists out of the cave as they excavated for shifts of six or seven hours in these cramped, humid conditions. And no one could go get them anyway, so they could just stay there as long as they wanted. (audience laughter) Some people have said, "Well, it really isn't that dangerous." Rick is going to demonstrate to you, though, that just because we did not kill anyone that this is every bit as dangerous and extraordinary a risk as has ever been undertaken. These are the easy parts you're looking at. This was an original thing we called "Superman Crawl" which you go through. I can get through that. So, that's not a particularly tight squeeze in the scheme of what we're doing here. For those of you who are squeamish about closed spaces you may look away, because it gets worse. This is the type of journey that these remarkable scientists the runners, the people who assisted us would take on a daily basis usually three, four, five times a day, getting to these sites. Some people said to me "Why haven't you opened this cave up?" I hope you can begin to see how fragile this cave is. You do not want to do any opening of caves in that environment because if you do, you may destabilize the entire system and it could collapse. And secondly, I didn't want to do that. Who was it for me to destroy a cave that's potentially millions of years old just so it could be large enough that my ego could get in there when there is technology and extraordinary people who have the capability of doing that work today. Here, this is kind of a normal, narrow passage. You're going to see the chute and parts of it here. And you'll get an idea of the depth as you see Steve Tucker's light in the distance as we look down into the chute and you get an idea of how narrow those spaces are that they are traversing down. You'll see how dangerous some of those loose rocks are. This rock that Rick is about to touch actually fell on a National Geographic Photographer and shattered his fingers, as he was under there. Oh and... Rick can dislocate his shoulders. Watch. I just showed you that for fun. (audience laughter) Extraordinary people doing extraordinary things. By the end of a 21-day excavation, we had discovered the richest early hominid site ever discovered in the history of the planet. More fossil hominids had come out individually than had been discovered in the previous 90-year history of the search for human origins in Southern Africa. All because of these remarkable scientists. We would name a new species, "Homo naledi." Homo naledi was an incredible creature. A brain, the size of an orange, primitive characters and advanced characters teeth that are remarkable in being a little bit human-like and then primitive in so many other ways. Things we'd never seen before. We would eventually find 15 individuals. One thousand, five hundred and seventy-four fossils. From an area that big by that big. The entire floor is comprised of these fossils. We had every age group represented. From near fetal aged infants to the extreme elderly with their teeth worn right out and everything in between, males and females. We had fossils like this field has never seen before. That is the most complete foot ever discovered in the history of paleoanthropology. One of six. This is the most complete hand ever discovered in the history of paleoanthropology. One of eight. The assemblage was remarkable. Remarkable in its diversity, remarkable in its preservation remarkable in its quality. We simply had seen nothing like it. All lying on the floor of this chamber. We would name a new species, "Homo naledi." It's a crazy creature. Brain, the size of an orange, ape-like shoulders, human-like arms ending in a human-like hand with the most curved fingers we have ever seen outside the most primitive hominids. Four or five million year old equivalents. It's bizarre. It's thorax, starts ape-like, becomes more and more advanced. Its pelvis is like that of Lucy, wide and flared. So, we know what its legs and feet look like. They should be primitive too but they are at the top and become progressively more and more and more human-like until you reach the feet. And those are the most human-like feet ever discovered since humans. Look at the size of that head. That is a normal sized, modern human in the background. That is an adult female of Homo naledi. About 450 cubic centimeters. We had truly never seen anything like this. To give you an idea of how strange they would've looked. That's Lucy on the left, in the middle is a very famous skeleton called, "Turkana Boy" of Homo Erectus. And there, you can see a relatively human-like visage. There on the right, is that almost, without being derogatory pin-headed look of Homo naledi, with its very strange profile. And it is not an aberrancy because we have multiple individuals and they all look exactly alike. We now know more about this remarkable species, perhaps than almost any other species of primitive human relative that's ever been discovered. We, very quickly realized, something was-- strange going on with the way in which these fossils were in that chamber. During the course of the excavation we had found on the first day to be transparent, three bird bones. That were owl, that were lying on the surface. They were clearly much younger. Some owl had got in there. And then we found, during the course of the excavation a few, tiny, rodent incisors, mixed into the sediment. And nothing else. Nothing but hominids. Now, we had on the team world experts in many, many different things. But, all of us had the same basic training in physical anthropology, forensic anthropology, archaeology, all related to human biology. And those senior members of the team knew that there was something very strange from word go when you see an assemblage like that. We, of course, began trying to eliminate the obvious. It's gotta be a predator accumulation. But there are no predatory-- marks of damage on any of this bone. There's no marks of scavenging. We knew, very early on that the material had not been transported in. There was no sign in the sediments of water transport. We also could tell from the way they were set that they'd come in one by one by one, over time. There was time involved in this. Over on the right-hand side of this image is where that chute is. You can see that the floor slopes away from that and quite literally, from that point all the way to the end are these bones of Homo naledi. Literally, from underneath the chute. We have used, I can tell you, ground penetrating radar and other methods. We can find no other entrance. And we were left, eventually, with the unlikely conclusion that in fact, this must be some sort of deliberate body disposal site. That we had, for the first time found a species other than humans that in a ritualized, and I mean, repeated fashion had taken its dead into a chamber and secreted them there over time to prevent whatever from happening to them for whatever reason. And that is the hypothesis we put forward. That's a fairly remarkable thing. Because, until that moment, on September 10th last year when we announced the existence of Homo naledi and this situation... we had seen deliberate body disposal as sort of the last bastion of what identified us as human. When Jane Goodall wrote to Louis Leakey saying "I have seen a chimpanzee using tools." He said, prophetically, "We're going to have to redefine what it means to be human." We had precious little left until September 10th except, we deliberately disposed of our dead and whatever that means. And should this hypothesis hold true for the first time in history you are meeting another species that did just that. What these discoveries tell you is that we may have walked or set foot over most of this planet but we have not seen what we were walking on. We've not understood what we were looking at. There are extraordinary things to be found. And if it is true in a field like paleoanthropology, then it must be true in every field of science. We need to use discoveries like this to inspire this and the next generation to be explorers. To get out in the field. To look, to prepare yourself to make discoveries, to use the technology to inform you, but to physically go out and make those discoveries. We need, ladies and gentlemen, to inspire exploration. Thank you very much. (audience applause)