Hello everybody, I'm back to discuss the Homo naledi controversy that has been going on over the last two months. I just want to warn everybody in advance that there might be, we will be showing hominin remains. So, if you have an issue with that, please tune out now! So, millions have seen the Netflix series that came out a few weeks ago unknown Cave of Bones and some of you might be aware that the series and the research behind it has caused a bit of a controversy in a sense as to if we look at the topic here, we're looking at these hominins, Homo naledi that lives several hundred thousand years ago in these caves in South Africa. And several of the skeletal remains have been published back in 2015 by Lee Berger and his team presenting this new species of early
hominin or early human. And just recently, two months ago published were these pre-prints in eLife about Homo naledi making engravings or art. Burying their dead and then about what that means for the cognition of these species. And the reviews that came out just recently, a few weeks ago said that this is a landmark finding, but the claims are inadequate. And that has created a huge controversy. And so, I am here today with Professor Jamie Hodgkins from the University of Colorado at Denver, who was actually one of these reviewers reviewer number one on the burial paper to discuss this. And with Professor George Leader, at the College of New Jersey who, has directed projects and studied Paleolithic remains in South Africa, fairly near to where these fines were, to get a bit of context. So, hi Jamie! I just wanted to ask you first off. You chose to not be an anonymous reviewer with the reviews coming out. And I'm just wondering if you're if you're enjoying the publicity? I'm not sure that I have gotten much publicity but the reason I decided to you, know, to say who I was that, you know, I think the criticisms from all of the reviewers are really valid. And I'm more than willing to confront any issues with those reviews head on. Because I think there's a duty in science really to portray the work in a very understandable and very scientific light. So you know I'm happy to talk, to talk about the reviews, my review in particular. - Good, I hope we get into it! And George, so I'm just curious as well. You actually did your undergrad and your Master's at Wits? I forget, I should have looked this up. I did my graduate work at the. your Masters and your PhD. So you're familiar very much with the academic stuff down there and the context. Yeah, I spent a lot of time in the Cradle of humankind, working in various cave systems there and throughout southern Africa on Paleolithic archeology. So I'm pretty familiar with what's going on down there. And you know, I also think that we do have a responsibility to be as accurate as we can on the front end of all scientific discoveries and claims, rather than walking things back. And I think that's why it's important to have these conversations. Good! So thank you for having us! Yeah of course! It's good to have other people on as well. So I'm not just a talking head. But so, what I want to do is, I think the key goal here is to express how archeology approaches its claims, right. So in many ways archeology is an empirical science, so we go and we excavate, and we discover something new, and we describe it, and we try to make some claims, conclusions based off of what we find. And so that's what I think is very much at the center of this controversy. Is how do we make conclusions from these kinds of empirical claims. And so, I thought we could briefly walk through a few but we'll focus on the burials, since Jamie was a reviewer there and can bring some insight in particular. But I do hope we'll walk through some of these various claims and each of you can bring up whatever comes to mind in a sense. And let me go back to sharing my screen really quickly. So I really want to focus on especially since what we do as an empirical science. What that means is we find something. We want to try to understand how it got there. But the problem is there could be multiple explanations for that. And archaeologists call this equifinality. Where there's potentially multiple effects that can have the same kind of results, right? There are multiple things. And so, when you think about it like a group of bones in a single place, that archaeologists have found in the sediment, there could be multiple explanations for why they are there. They could be buried, they could be washed in, they could be abandoned etc. etc. And so, I sort of thought we could walk through these hopefully in increasing difficulty and detail each of these different claims. And so, I thought first off we could start with the idea of fire. In the Netflix documentary and in an earlier talk, Lee Berger and his colleagues have argued that there was fire inside the cave that they've excavated. On the other hand, they haven't published it. So, the details are difficult for us to get at. And so, I was curious from what both of you have seen in these talks, or Netflix, what you thought about the evidence for fire? And what the different explanations might be for it? George, I know you emailed me about this, so do you want to go first? Sure yeah, I'll take it. Well the thing, you know, and we'll get into some of the other claims that the team made. But the thing with the fire, particularly for me is that these lines of evidence all come together to create this narrative that they've put together for the naledi, both in the burials, and the engravings, and being in the cave. And one of the things that they have been very vocal about is access to the cave, as far as, who was in the cave after naledi, might have been in there. And possibly, as they claim in the, at least the film,
producing fire in there to move about it. There it's problematic in the sense that they have not done the very first thing that all archaeologists would do, which would be to radiocarbon date that, and then publish those results immediately. That would be step one. If those dates in any way come out as young, meaning post naledi or pre-miners in the 1800s or, the early 1900s in those cave systems, then the engravings can possibly fall apart. And some of the other kinds of ideas about, you know, movement throughout the cave and those systems. So if they, you know, in the in the lecture that that Lee gave in I think December of last year, he showed pictures of about four or five, maybe six small what looked like hearth features. Some were surface level, and some had some sediments on top or, at maybe a slightly deeper level. But you would have taken immediately multiple samples from each of those and run all of those samples very quickly to determine their age. If however, none of those radiocarbon dates work, then that might indicate that they are in fact too old and demonstrate that naledi was perhaps bringing fire down there. As it stands, they have not done that. And let me just be clear about it. I don't have an issue with a small-brained hominid doing any of these behaviors. I really don't. Even burial, as controversial as that might be, engravings as controversial as that might be, fire, whatever it is, I don't. But what I do think is, we need to step back and demonstrate it. And the fire is step one for disproving individuals in the cave in possibly historic or, early sapiens in the cave at any one time. So yeah, so just to just to clarify. In a sense, radiocarbon dating only goes back so far. How far does that go back? Depends how good the sample is. Some radiocarbon dates have gone back as far as 75 or, 100 000 years. Really good samples. - But naledi was there 200 000 years ago. So if you got a radiocarbon date back on this carbonized material, then that would suggest that it's not Homo naledi that created the fire. And so in a sense, one of the alternative explanations to naledi using this fire is that, it's humans, modern Homo sapiens that are using fire, right? In this cave Right! Yeah so I think that that's important!Do you have anything you'd like to add Jamie? No, I mean I agree with everything
that was just said. I think, one of the things we've seen discussed a lot with the release of the documentary and the pre-prints, is the idea that this team feels that they have, that it's their duty to present these thoughts to the public before, you know, they have the scientific results back. And so, they've been quite happy to go, you know, at forward with this idea that Homo naledi was using fire without first getting radiocarbon dates. Because somehow, that is supposed to be open science. But I think what people need to understand is that that's just an assumption. It's the same as me saying, you know, I think that this thing lying
on the ground is 100 years old. And just, I mean, do I have a duty to like just say that to you? No, it's just a thought in my head, right? It hasn't been tested in any way. And this is the exact same thing. - Yeah, I mean, to me it really goes back to that equifinality. I mean when I'm doing my own research, for example, into animal remains. I downloaded at some point an image of manganese staining, because there have been other cave sites in the Paleolithic where people have claimed fire that is manganese staining. I don't really think that that's the case with these, but it's something, since they do mention manganese staining on bones in the Dinaledi chamber, it's something that I would like them to at least, exclude somewhere. But I doubt they've made that mistake. The idea is to think about all the different potential hypotheses and then exclude them till you can get down to the one that Homo naledi might have been making this or not, right? So yeah! And let's move on to number two. Again, one that none of us are necessarily experts in. But the engravings, and I think what are the different possible explanations for these engravings besides Homo naledi making them. Which of you wants to go first on this? - Jamie you want to go first? - Well you know, I have worked in South Africa too for five seasons But you worked in the Cradle humankind, so I'll let you. - Sure! So
again, for me it comes down to a few different lines of evidence here. One we need to talk about access to the cave and who was down there for various reasons over the many years? Could Homo sapiens have been down there? The fire dating would answer that. Miners we know were down there. And we do know that there have been cavers down there many times in all of these systems, for many years historically. So, you know, I am not an expert on the engravings themselves. So I cannot really speak to as if these are anthropomorphic. I will say that many many people have been discussing the fact that dolomitic limestone throughout the cave systems in these karst cave systems in the Cradle of Humankind, have these what appear to be, kind of you know, symmetrical weathering patterns as they continue to weather in the caves. And people have actually been sharing those all over social media that look very similar to this. Now I understand that these are unique in kind of
their depth, and the way they're presented, but for me it comes down to one, the access to the cave, and demonstrating undeniably that there are no other patterned walls like this in this cave system. And they haven't shown various other walls of this particular cave system as a comparative tool. That would be something that I would like to see and I know that many of the other people who are discussing this would like to see as well. Again, building the fair, the many papers together in and supporting one another in that evidence it kind of falls apart. Now again, that doesn't mean it's not possible that these are engravings. it's just linking them to naledi without any dates on them and dating these types of things is very difficult if you don't have a stalactite or any mineralization or crystal growth of any kind over them, it's nearly impossible. But again, it to link that to naledi without the additional supportive dating evidence and access evidence, is it's really kind of an irresponsible way of approaching this scientific claim. - Yeah! And I would just add, you know, we use the comparative method a lot in Anthropology and Archeology and so what George was just saying, not only would I want to see the, you know, comparison to the rest of
the cave walls, which by the way, you can see pretty well in the documentary. And you can see that their hashings throughout the cave system. But also, to the outside geology, right?
- To the right here, this is some natural hashing in these caves that comes from one of the Berger's talks last year. Sorry! - Yeah, I mean, so you know, there is this very well known geological structure throughout
the Cradle of humankind I'm probably gonna say it wrong, but it's a 2.6 billion year old elephant skin Malmani dolomite. And that is how it weathers, right? And so, even if you're just walking around the Cradle and you're looking at rocks on the surface, you get that kind of, you know, that kind of patterning. So, I also don't have a problem with this assertion that an earlier hominin could have modified cave walls. But it absolutely has to be demonstrated, and it has to be demonstrated convincingly, using a comparison to what is around the rest of the cave, and outside the cave. Has to be demonstrated through detailed geological analysis. And it has to be demonstrated also through experimental archeology, which is a whole, you know, way of trying to test things that happen in the past, you try and replicate those things in the future to see what would it take, what kind of tool would you need, what would it look like? I mean there are many archaeologists that embed that within their published studies. - Yeah! Okay, I mean, I think that from both of you this makes a lot of sense. Let's go back to the image really quickly. In the sense that yes, Homo naledi creating these is one possible explanation, but another is, of course, that they are natural and there needs to be a clear comparison that documents these are made in a non-natural way. And hopefully some way of coming up with dates because we know that humans were in this cave over the last hundred years and certainly, humans make marks in caves. - I would just add that in all of the caves that I've been in in the Cradle of Humankind, there's modern graffiti, scratches in the walls. People carving their names in the walls from the early 1900s, you know, 'Bob was here', that kind of thing. And there's also just scratch marks, you know, people you know, scratching in there. So, and again, I I'm not saying that that is necessarily what this is, but you need to kind of rule out those additional kind of very variables. Yeah! Okay,
let's move on to our number three then! A tool-shaped rock. So, this was presented in the burial paper. It was in a CT scan of one of these possible burials. And it was also presented in the TV show. This rock that was found near the articulated hand of a Homo naledi. Though in the documentary they say in the hand, but in the paper, it's nearby. So I guess we should start with George again! Sorry Jamie, we're gonna get to you! Since you reviewed this, this is going to be really interesting. But I'm just curious, since George is a stone tool expert. I might be named after stone tools but I'm not a stone tool expert. So George, does this look like stone tools from within the area to you? Is this actually a tool-shaped rock? - Yeah, unfortunately this is pretty
ambiguous evidence. One, let's go back and remember that this is from still in a block of sediments. This, what we're looking at here, is the CT scanned imagery of that tool that's still in there. The arrows that you're pointing at, you know, they say striations, visible in both places. Well it's interesting to me. striations how they particularly formed on that interior curvature of that stone tool, I don't understand. I'm also not seeing the classic signs of a flake that it was removed from a core, a bulb of percussion, a striking platform, that type of thing that we always look for. It is, in this context, for me to say that that is a stone tool, it is not the case, Again, here's where it's tough. Could it have been? Sure! It could. There is a small chance that that could have been a natural stone that was brought and used. But what you haven't done is ruled that ruled that possibility out, that it's just a natural stone, that has, you know, ended up in this deposit in the cave or, even a piece of the cave ceiling or, wall that has fallen off and ended up there. Striations like that are very interesting, you know, they're not notches. It's not a scraper. I've never really seen scraper edges on that kind of an interior curvature like that. And it doesn't have the classic properties of a stone tool. Would it have been a good carving tool? It might have been. But, you know, we don't really, we don't know what the raw material is. So it might have been, you know, too grainy or too soft a material. If it was a piece of the dolomitic limestone from the cave system itself. It wouldn't have been great to use the same raw material on the cave wall, as your you know, your tool is. So there's a lot of again, questionable things here that don't really build to making that claim. The issues I have with it. - That makes sense! Jamie, what did you think about this when you first read about it, reviewing the paper? - Yeah, I mean, I am not a stone tool specialist. I'm also a taphonomist and a faunal analyst, but I thought the same thing. This has not been excavated. It's still inside of the sediment. So really all that they know is that this thing is a different density than what's around it, and then they got that image. But that really doesn't tell us anything. It doesn't again, tell us what it's made from. You would ideally need something that's like tougher than the rock surface to actually sort of engrave in it. It's also a total assumption that would have been used to make engravings by the way. There's actually no one-to-one correlation there. And it doesn't have any other classic signs of a stone tool, as George was saying. So, usually you're napping a stone tool, right? You have a nodule and you're hitting it, and you get those bulbs of percussions. You get evidence of flaking off of something else, and none of that is there. - Yeah! No, that makes sense as well. And then I mean, certainly, in some of the earlier papers that the team has published, they mentioned stones this size as clasts in the chamber and in the cave. And so, it's certainly within the realm of plausibility that it's just a piece of the cave wall that's eroded off. It's
an alternative explanation. And it ended up fortuitously near some of these bones, right? Which happens after all in archaeological sites Now, Jamie you get to switch up to going first. So let's look into this first burial. So I did an in-depth review, so I'm going to step aside. I want to hear what Jamie's thoughts are in this first burial and the different explanations there might be for why there's an accumulation of bone here or, there are methods to prove it as a burial. - You know, there was just... So first of all, I think we have to go get a hypothesis testing. So generally, and this has picked up a lot of a lot of chatter, right, generally, when scientists test hypothesis, you start with the null hypothesis, right? Which in this case would be that these bodies were covered naturally inside of the cave. And then, that allows you the ability to either support or reject that hypothesis. So, if you were to find evidence of other ways in which sediment is infilling within this cave, which we know that it is, right? Because there's sediment inside of the cave and somehow it got there. And in fact, there's a really good paper written by this same team Robbins at al. 2021, Lee Berger is the last author. It's very detailed and there have been other publications by Dirks and other people where they do show how sediment has infilled within this cave. And they have shown sediment like sediment drains, so the sediment comes in and then it drains down cracks and fissures that are occurring within the cave. And that all causes movement, right, of the sediment So, instead of setting this paper up with a null hypothesis, the team just sets out to say these are burials and, you know, these are burials. They're burials because... But there's no way... They don't actually test it and they don't seek to support or reject it. And so, in essence that's
just not science. That's just stating an opinion, and then showing things that are convenient that
might help you convince people that you're right, right? That burial in particular, some of the things that are really problematic about it is it's very tiny. In fact, it's about the size of a domesticated cat bed like if you go to PetSmart and you bought a domesticated cat's bed, that is the same size in centimeters as that burial. And where in the skeleton, inside the burial, the ones that they can see. because it's not fully excavated, it's only the bones of the surface they can see, are described as adults. And Homo naledi, an adult, would have been somewhere around four foot seven, four foot eight, maybe five foot two. That's a big body to try and fit into a little domestic cat-sized burial pit. So that was really problematic for me. It was also problematic for me that they do this kind of mineralogical testing, but they can see that the that there's differences in the sediment surrounding the bones, which sort of makes sense because as bones deteriorate they change the signature. But it was different from the sediments surrounding it. And there's no indication of backfill, right? Like when you dig a burial pit, you have to backfill it with something. There was no explanation of what could have backfilled that pit. A lot of the bones are actually not at all in anatomical position and there's actually bones from several individuals in there. So it's really kind of a jumble of bones which, is really not typical of what you would find in an intentional burial. I have in fact published a really high impact paper on a burial, by the way, so it's something that I have done before, and I am aware of how you do it. What else? So, it's a jumble of bones. There are some bones that are in articulation, and that is something really interesting about this whole cave structure, is that there's a big jumb- there's a lot of bones that are just jumbled. But you have some bones still in articulation. Aands and feet in particular. That's interesting. And as a taphonomist of someone who studies how things come to be in archaeological sites. I mean I agree that that means that they were buried before they had before the bones had become disarticulated, right? Probably fleshed. But that doesn't have to happen quickly inside of cave sites like this. One of the main agents that starts to cause bodies to decay and bones to disarticulate are maggots, right? Which get to a dead body pretty quickly out in an open environment. That we don't have evidence for maggots being able to get inside this cave. It does seem to be pretty secluded. So no other you know large animals are getting in there moving things around. And you know I spent five years working in South Africa. I've spent about 20 years working in Europe. And in European caves in particular we find fully articulated cave bear bones that were not intentionally buried, right. But they're just deep inside a cave and so that's where they died. They were buried naturally as sediment accumulated in the cave. And the bones are still in articulation. And they just sort of decomposed that way. So, I think you've got a system in the back of this cave that allows for clearly sediments moving things are getting jumbled. Clearly these excavators themselves have been in and out moving over those sediments over and over again. But at the time Homo naledi got in there some of the bones were buried before they had fully decayed. Before the body had fully decayed. Yeah and I think that that's the key is
how do you exclude these possibilities which is difficult. George what do you think about the first burial? Jamie really is the ultimate authority on this. So I will I agree with everything she said. I will add that yeah I do think it is it is a bit kind of erroneous to suggest that an articulation can be a strong indicator of an intentional burial because we do have so many hominid remains that are recovered that look like they were buried you know prior to the soft tissue decay. I have a slide for you. I have a slide for you. Okay One second on a something you've helped publish some of the context on. Oh okay. Yeah so here you know here you have Little Foot. And that's you know that's a great example of an Australopithecus that's you know possibly in the ballpark of you know three and a half million years. And this is you know a couple kilometers down the road in Sterkfontein Caves. And this is the most complete Australopithecus ever discovered and it is largely articulated. The entirety of the body is kind of the kind of lower portion and the upper portion are separated by about you know 25 centimeters. With a kind of a maybe solution a shift in some of that cave sediments. But the arm, the hands as you can see in the pictures that you've shown are really beautifully articulated. And so it's not I mean it's a rarity but it's not unusual to find these things - these remains articulated like that. So eliminating you know using that null hypothesis as Jamie says and eliminating all the extra possibilities. So that's what we need to get to in a scientific study like this. So yeah and then the mineralization I'll just add too you know I think that was one of their stronger pieces of evidence that they really presented or they believed it was. Some of that the micro morphology of the sediments immediately around the articulated bones is really is what needs to be done there in a more you know kind of very stronger way. You know they should get Paul Goldberg or somebody in there to take a look at some of those micromorphs and do comparative samples. Yeah I think the unan - the reviewers were fairly unanimous on that. I think I stated that in my earlier video. It seems like a well-known technique that could be used. Wait I wanted to go back to this because the other thing that as someone who studies bones myself I had some issues with the fact that this burial was also half only half excavated or who knows how much of it was actually excavated. And none of the bones that were excavated were washed and so to be able to actually put together how many individuals you have... Whether material all belongs to the same individual or not. When it's very fragmentary. In their appendix they have measurements and stuff like that. That's very difficult to do. I've worked with burials and in much later periods where we know that they're in a cemetery, right? And the materials in much better condition than this. And it's fully washed. And I work and I put together a horse burial, for example. And then all of a sudden I find - oh wait there's two horses here, right? And so that's when I have the full thing excavated and washed and conserved as well as we can. And in this case to be so confident that it's even just one individual with an extra intrusive one struck me as very preliminary when the material has not been washed nor even fully excavated. It makes for a very difficult assignment and assessment. And I've done a lot of this on burials myself. With animals of course: with dogs and horses. I don't study humans or hominins. But you know that so yeah that's my two cents. Do we want to move on to the CT burial really quickly though? Just to present some context for people they took out blocks of sediment. They found these bones coming up near the slope at the entrance to the chamber. And they took out blocks of sediment and this plaster and CT scanned it. Producing kind of results like this, which they then identified as a potential other burial or they actually they identified it as a burial. But it's a potential other burial and so Jamie do you want to share what your thoughts were when you first read about this this context? It's hard because there's really not a lot of detail presented in the paper because because it's not excavated. So they you know they built this plaster cast around it. They've CT scanned it. They're inferring what is in it. And you know the logic behind doing it that way is that they that you know the methods are improving all the time. And maybe better methods will be available in five years or ten years to try and excavate this. The problem with that logic is that if you don't feel like you have the methodology to investigate it now. Then don't publish on it until you have engaged in that methodology that would tell you what is actually happening there. I mean this particular spot is really close to the chute. Right so there's this they'd show you in the documentary, they've written
about it many times. But you have to you have to climb up this Dragon's Back, and then there's a steep vertical shaft that goes downwards. And that's where sediment is going to be coming, filling in this chamber, right? So you're going to get an accumulation of sediment right there. And so I think a lot more work needs to be done to truly understand you know how you know if - how would decomposition happen in that location? How would sediment in filling occur? And then as you see in this picture what what's really not mentioned very much in the main part of the pre-prints is these drains, right? You can see that drain in the floor. Well that's a natural area of erosion where the sediment is coming down from the chute and then moving towards those sediment drains over time. Which means all of the sediment is moving. Including fossils. Right? Fossil elements that are in that sediment. So, we talked about micromorphology before. So for
people who don't know that's where a geologist comes and creates little plaster cast of the sediments. They turn it into plastic. Right they impregnate it with plastic. They can look at it under a microscope. And you can actually see how fine grains have been moving throughout the cave. So if there's been movement in a direction you can see as the grains, as they're sort of turning & moving. You can see the components of the sediments. All of that is really critical to understanding how the material got into the cave and how it was buried and deposited. And none of that was done. And especially they already have the plaster cast of the sediment. So you think it would be a no-brainer to go do that. Yeah George did you have anything you wanted to add about the CT scan context. Actually, you know I sort of have to say that I applaud the team in their novel approach to not excavating it. Part of me when I first read that thought, 'okay, well rather than plastering it and taking it out, why didn't you maybe leave it in the ground until you had different methodologies that would be a little bit better to excavate.' But I understand what they're trying to do with utilizing new technologies and new techniques in
in taking that plastic cast to the to the CT scanner. And going about it
that way. Again the articulation of a singular - maybe - a singular individual doesn't indicate necessarily a burial. If it had been a really cool fossil of like a Parapapio or something like that that you were taking out in a single bunch of sediment, you wouldn't say that this was a burial, right? You wouldn't say that this extinct baboon had been burying just because you found the entirety of the skeletal remains. You know one of the other things that Jamie brought up is the chute. And the accumulation of fossils at the base of that chute. And you know we didn't really touch on it too much, but we did talk about access to the cave. Some of these cave systems take years and years and years to understand the full geomorphic processes of the openings and closings of different you know time periods to these cave systems. So basically you can have old entrances to these caves that are no longer there. For people who might not be familiar with that. They'd close up over time. And new ones that opened back up. And you know I think it was maybe Marina maybe Marina Elliott's paper a few years ago that said that they didn't find any other openings. But you know just to use an example from other cave systems like Swartkrans and Sterkfontein down the road it has taken after 50 or 80 years of you know geologists working in these caves. They still find new areas where there were new openings and new chambers. And things of that nature. Whereas you know kind of, it's been suggested, you know
I don't think suggested. But that we understand how this cave completely was formed with only 10 years of working on it. And you know even they had published this you know when they first found the naledi material. You know years 10 years ago. So I think that that needs more work
as well. The thought that everything got down through the chute. And maybe that's maybe that's correct again. But I'm not entirely sure. Jamie might, do you have anything to add on that? Well really quickly I wanted to show this paper for everybody. This Jesse Robbins et al. paper that Jamie brought up earlier where they actually too suggest. And Lee Berger is an author here as is Paul Dirks. Where they suggest that the access has changed. So entry from the Dragon's Back chamber into the Dinaledi subsystem at the time of Homo naledi, uh Homo naledi, may have also been different. So Dirks et al. described the Dragon's Back - that part you climb up to get down to the chute. That we saw on the show, describes the Dragon's Back as a loose block that dislodged from the roof along a discontinuity at the base of a chert horizon. The block fell by about 60 centimeters and rotated about 10 degrees before it lodged against the pinnacle at the base of the Dragon's Back. And so put more simply: before the Dragon's Back block
fell, access into the Dinaledi chamber may have been more direct, i.e., by walking below the Dragon's Back block, and entering the fracture system behind it. The important question therefore is when the Dragon's Back block fell relative to the age of the Homo naledi fossils in the Dinaledi chamber. And so what this paper is suggesting is that heck you might have just been able to walk right through here. Because it depends on when this huge block fell. And they even discussed how the falling of that huge block might have led to that accumulation of soil and sediment at the entrance to the Dinaledi chamber where the CT scan block was taken. And so yeah I think that that's a very important question is kind of access. How has it changed? I think in the documentary they mentioned that the original entrance that they thought Homo naledi used had since been blocked, right? And so yeah. They're still working on that. And I think there's a lot that needs to be done. Sorry, Jamie didn't want to steal any thunder. No I think that's so great that you brought that up. And if you go back to that last slide. You know it's really significant because in the Robbins et al. paper, they actually think that this Post Box chamber, which opens to the surface was probably the route by which both sediment and Homo naledi would have gotten into the cave. It's a much more direct route. You don't have to go through the Superman's crawl, which is this teeny tiny little narrow space. Again the Dragon's Back was still attached to the ceiling. And so you did have to go over a barrier in the sediment that's pictured here but it's a much shorter barrier. And then you basically could have just walked from there. So it's a really different scenario. And it's not a scenario I see being discussed much when this is being presented to the public. Mostly you just you get this very complex route where you go through the main entrance you're in now. You just go through this Superman crawl where you have to be super tiny and skinny to get in it. And I think this is all really important because: #1 caves are dynamic systems. They're changing all the time. And we're talking here about 300 - 250 - 300 plus thousand years of time for this cave system to have had many changes in terms of sediment getting in, water, and all of that. And you know it's been sort of presented as -- It's not often presented that Homo naledi would have had a different set of conditions. But of course they would have. I mean the cave has really changed a lot. And you have to keep that in mind if you're going to test the null hypothesis, which is a natural burial occurred. Because you have to understand all the cynamics of how sediment is getting in and moving through the cave system. And how bones that are laying in that sediment would have also been affected by all the things that were happening. Yeah, I think that makes a lot of sense. The last little bit of evidence to discuss was - or hypotheses to discuss - is and this relates to everything we've just been talking about, which is funerary caching. Let me share my - am I sharing my screen? No Sorry. Where this was the original idea that was published back in 2015. And what I've noticed is while everybody's hyper focused on: is this a cut and a fill-in burial. One of the things that seems to be missing out is this topic of funerary caching. Were they bringing their dead even into the cave? Or is this a result of accidental deaths or individuals going back there and dying? And so part of their explanation for this being funeral cushing - caching - is it's just so difficult to get back there. Why would Homo naledi go back there? But what this ignores is a cave nearby. After I did my first video, I was emailed by Jason Heaton who shared some information that he and others: Charnel Nel and Travis Pickering have published on Misgrot cave. And they've done an analysis that shows that the accumulation of bones there - what's in Misgrot is a collection of baboons. It's also a difficult cave to enter, and there's mummified baboon remains inside the cave that are still oftentimes in articulation. Though not always. There's accumulation of jumbled remains as well. And they also are in the process of being covered over by sediment. And so these are a parallel of a sleeping chamber for a different primate - in right nearby in the Cradle of Humankind - where there's these baboons. Some of them are articulated, some of them are not. It actually is fairly similar as a potential parallel for this find. And therefore I think needs to be excluded as a possibility if we're going to talk about ritual or funerary behavior by Homo naledi. Did either of you two have anything to add on baboons? I think there's even a baboon tooth in there, in Dinaledi. I think that's you know that is what we talk about when we talk about comparative archaeology is looking for other sites that are similar. So that's great. And I think you know you said that this was a baboon sleeping den. So, they're using this cave regularly you know. And that's what we find all over the world is that when you have animals that are regularly using cave sites, they also regularly die in cave sites. And depending on how accessible that cave site is to other animals, they may be fully preserved. You know there's amazing sites in Israel where you have fully preserved hyena. The cave hyenas skeletons. Because they were using the cave sites. You've got caves in multiple areas of the world, we have fully preserved wolf skeletons, right? We - I talked about cave bears because, I mean my team found an entire family of Cave Bears that died during hibernation. All curled up together. Really kind of sad. Yeah, sad find. But completely articulated. So yeah. So maybe what's more interesting, maybe the more interesting thing to say is that Homo naledi might have been regularly using a cave site. You know. So you're getting it a little bit maybe of behavior But these are the types of analogies, these are types of comparisons that need to be made. Alright, should we rush on to the presentation of everything to the public to sort of end. Because I think that that's a key thing, is that there's all these other possibilities for the evidence that's been presented. That seems somewhat valid and need to be tested more thoroughly. But the controversy of course is largely over how this has been presented to the public. And the E-Life publishing model. So I don't know, sort of as a reviewer, Jamie what did you think about the reviewing experience? And how that related to the publicization of the finds? I was really taken back by it, because I was asked to review. And then shortly after being asked to review, I was sent an email saying: "just so you know, there will be a press release for this on June 5th." And that was before you know, our reviews were due like by like May, the end of May. So this was before -right- the authors would have been able to really see any of the reviews. And I would, and I almost refused to review. Because it, because my thought process was that means their own narrative. The narrative that's just in their heads, right? Untested, unchecked is what's going to be portrayed to the public. As if really it has been checked. As if it's fact. And I think that's exactly what happened. So I would say I'm not... I don't like the, I absolutely do not like the idea that a
press release is coming out with pre-prints I'm not sure how I feel about preprints. Preprints is this idea that you get your papers out there immediately before the review process. And I can see where that might be beneficial in some ways. But in other ways, it's really just. I don't... I'm not sure students or the public really understand the difference. And then to create a press release from that is really, I think, very problematic. Because once a public narrative is out there, it's really hard to check it, right? It's really hard to
combat it. I mean. And I really feel like this is what politicians have been doing for a long time. You say what you want to say and you know that when the fact checkers come out, people just won't pay attention. So you know I don't. I do think it's good that the reviews are public. I think that's fine I think that's a good way for people to see how science is done. So I don't have a problem with necessarily a paper being posted. But I think the reviews need to be posted at the exact same time. And I think you know a press release, probably - absolutely - should never come out before reviews are out. Because it's really just giving your opinion. Like here's my opinion to the world, right? And the public certainly doesn't take it that way. The documentary is a whole other thing. Wait a second, we'll get to that. Yeah, but no I agree it's sort of is like thumbing your nose at the collaboration that we think of as scientific publication. Right it's saying the reviewers don't matter it's just what I think. Yeah, George did you want to add to any of this? No I mean we can move on. I agree with everything Jamie said there. You know she was she actually reviewed the paper. The difficult part is that you know then a number of scientists take it upon ourselves to discuss it in a more, you know informal, you know in in a situation like this. And you know the argument is, 'oh you know these the mainstream archaeologists' - call us whatever you want - 'don't agree.' And it's not that. There's no, there's no bitterness. I don't dislike anybody on the team as human beings. I just.. This is not the way that the scientific process is most effective. And it is problematic. So now we can talk about the show if you want. Haha. So, yeah one of the things that struck me while watching the show, was how it looked - and correct me if I'm wrong.
But it looks like Lee was the one that discovered the engravings when he went down there. Am I wrong on that? Did you guys read it that way when you saw the show? Yeah I sort of got that when he finally made it down there, he discovered the claimed soot on the, you know the staining on the ceiling. And the engravings as well. Because it sort of shocked me, because it was filmed in 2022. But one of the things that I noticed while looking on Twitter for a public record of the timeline of this stuff, was that he submitted the engravings paper in September 21st. Which to me strikes me as if this is all gone very quickly, right? How often do you discover something in one field season and get it into peer review within sort of three months? Is that is that something that you guys have ever done that fast? I'm actually trying to do that with a paper right now. But no typically not. That would be that would be quite fast for a big claim like this for sure. Yeah okay, because it just struck me as if so much of this timeline is about trying to get some data out in time for the Netflix show that we're about to get to. To get something out there because one of the things that struck me was just how that even the reviews. I don't know how the reviews were released, but it's interesting that they were released a week before the Netflix show itself. Right? And so it's almost to get this in the media again right before the show is released. Because any publicity is good publicity, right? I don't know. Maybe I'm being too harsh here and seeing things that I shouldn't see. But it's shocked me as a little strange. But okay so let's move on to the show itself, now that we've gone through the publication timeline. Unless either of you wants to elaborate on that. Well I think that you know I feel like the papers themselves were rushed. I mean we now know because of the author's response and also the Twitter thread that they had had these papers sitting at another journal, right? For a long time. And they were rejected. So Lee. Yes Lee said that it was submitted to Science magazine for about six months. And that was on January 25th 2023. And then he got that note that it's the referees that are slowing it down. And he says he's stunned by this indifference, because he knows how things work in Science magazine. And this is not working. And so then he went and turned around, and I guess pulled them. And went to eLife, is what I gathered. Yeah and they. It doesn't appear that any revisions were made. That's my main gripe right? With the, with the burial paper in particular, it's very poorly written. And it felt rushed to me. And I actually wrote that in my review. It felt rushed. Like it was just throw this thing down. It's so poorly cited, which is something you pointed out Flint. But these papers that we've been referencing in this discussion were hardly referenced in this paper at all. And the entire amount of literature that's been written on burials and what qualifies as a burial and how you find intentional burials. Absolutely left out. And what I found I find really troubling about that is that John Hawks has written, he has a blog. For years he wrote on the intricacies of Neandertals and modern humans and burial practices. So I know that he knows the literature. And it just wasn't there. And so I feel like... I do feel like it was rushed. I think revisions can't have been made before it was submitted to E-Life. I don't think our reviews being published was rushed. We were told there was going to be a press release and then they gave the authors more time than they typically would to respond. So it was over a month before our reviews were actually published. But they had it on lock right that the press release was going to come out, and then the documentary were coming out. So I think there was a timeline from the authors for sure. Yeah I mean one of the things that I go back to is how poorly cited it is, with only 32 citations. That's fewer citations than authors. And half of those citations are to the team itself. So it doesn't engage at all with literature. It's a very sloppy paper. If it was like a Master's level paper I would not give it a very good grade as a professor. So yeah I don't know. Thoughts on the documentary? George you're unmuted. Do you want to go first? Sure, I mean just real quickly first of all. I give media like that and films like that a little bit more leeway than I would with the scientific paper, you know? I can excuse a few more things that you know that make it exciting and kind of fun for viewers. And I appreciate that in the sense that it gets a wider audience, you know, excited about archeology and human evolution and all that. But that said, there's a lot of issues with some of the some of the animations that almost present the naledi as this kind of alien-like being. Yeah, there you go. There you go. You know, a reconstruction of a hominid is a very difficult thing. Reconstruction of a, you know a facial reconstruction of anatomically modern humans has proven time and time again be to be not entirely accurate. But you know how they're presented there is a little bit dramatic for me. Jamie, do you have anything...? Yeah I was really disturbed by that, actually. It was just unnecessary to describe them as being alien-like. Because I think you know when we're talking about the media now. You know, we know that there's this whole faction of Ancient Aliens. And I really felt like the music, the reconstructions was calling to that. Was sort of giving space for that. And you know, to me these were living, breathing individuals. They're not Homo sapiens. But you know they're on they're on the human lineage. and they just... More respect is deserved. And I really felt like that was not well played. Yeah I mean especially when you're trying to link them so much to such what you know we kind of consider advanced cognitive, you know cognitively advanced behavior. And at the same time kind of alienating them with some of the way they're presented is interesting. Yeah it was a strange choice of words, and I mean you know at the same time I do know that documentary filmmakers will sometimes just take that quote that you wish you never made, and go and run with it. And so to a certain degree I'm willing to give the benefit of the doubt on that because it is a weird choice quote. And I could imagine that that after all their goal in many ways, their scientific goal is to show how similar they are to modern humans in some ways. With engravings and fire and burial and whatnot. So it seems like a weird slip of a phrase. Yeah. Any other thoughts on the documentary, Jamie? Well I actually run a documentary discussion group at my university, and for the Denver Museum. You know what strikes me about this documentary is that it's just... It's really just four people being interviewed. And there's no one else. You know, if you watch a Nova documentary, you watch you know most other documentaries, you have experts from the profession coming in and giving their opinions. And there's just nothing. It's just one narrative. Again the point of all of this, the preprints was just the team's narrative. The documentary is just the team's narrative. The press releases really have been just the team's narrative. So it's consistent with that. But you're not getting any, you're not getting any outside ideas. Yeah and I mean in in that sense I wanted to bring up this image really quickly. They do a similar one in the documentary, but this is from the press release. And this shows an artist's sketch of the possible grave. And you mentioned earlier the size. It really should be the size of one-third the size of this individual. The hole in the ground. And so it seems as if this art itself, that the
team itself has commissioned - I would imagine - is not to scale. Which gives you the wrong impression for the public of kind of what the evidence is. Because this is probably at least half, if not more, the length of this individual. Instead of, it should be about a third. Should be tiny. Absolutely tiny. You'd think you'd need the feet up by the head to get somebody to fit inside the hole that small. A 50 centimeter long hole for a 1.4 meter individual. So yeah I think that the way everything is presented in a one-sided way, I think it creates this kind of false impression. And a kind of, I don't know, the confidence with which everything is presented is also I think not representative of how most scientists are. We're usually somewhat cautious in how we present our conclusions to the public. And it's the journalists and the TV documentarians that that take our words and cut out those cautious bits and make us sound overconfident. And so something about that struck me as someone who pays a lot of attention to how archeology is represented in the media and on TV. I'm very interested in this. It struck me as strange that it's the archaeologists and the scholars themselves that are more confident than the journalists like Carl Zimmer in the New York Times or Kristina Kilgrove on Live Science and how they write about the burials and the art and things like that. So I guess I had one last image that we could look into which is from the documentary. They lit all these fires in the cave. Do you was this actually in the cave itself? That's what I've heard from social media chatter. I wanted to believe this was in just some nearby cave that had no archaeological significance. Either of you two have any thoughts on lighting fires on an archaeological site? I mean it's completely irresponsible. I don't I don't know where those fires were lit, but I had also hoped that it was not within you know the actual subsystem. I don't know if they were in the actual system or in a different cave system. I don't know. But I just assumed they were in a different one. And then when I brought that up as an explanation on Twitter - I forget who - some scholars said no they were in the site itself. And I don't remember who said it. I don't remember. There's been a lot of scholars that have been talking about this. But yah I don't know. I sure hope they did not light fires inside the cave itself though. Because that would be contaminating, in a sense, your samples for future excavations. And that's a that's certainly a problem as well. Any sort of final thoughts from the two of you on how we can improve the presentation of science in the media in the future? Or archeology specifically? How do we get people interested? Like I got all these comments after my first video saying, "why are archaeologists dumping
on this on this idea? We are all interested in this, and now you're coming and critiquing it. And it's like you don't want us to be interested in your field. How do we respond to that? That's so unfair because it is such a cool site. Naledi itself is so cool. The fact that they're in a cave and we can't figure out how or why, you know, is very cool. But you know that can that in itself can be a really interesting documentary. Cave of Bones. Or whatever you want to call it. But the idea that that you've pushed this narrative of engravings and fire and all these things... That some of them might be actually you know have happened. Some of them might be you know the naledi's own hands doing the burial. Whatever it might have been. But it's such a flimsy house-of-cards built narrative on these kind of circumstantial evidences you know that are not really completely thought through. That you pull any one of those cards out - and the entire thing falls down. Now rather than going that in in that manner why not why not pull it back and say what you do actually have and can clearly demonstrate with the evidence. And it's just as cool. And what we don't know is just as exciting. So there's the media. There's the show, the film, or whatever you want to do. Rather than pushing the envelope farther than the evidence supports. Yeah I think it's a really and it's a really interesting comment because it essentially means that in order to make this interesting broadly to the public you almost have to fictionalize it, right? So you have to say, "they were lighting fires" without radiocarbon dates. You have to say, "they were burying their dead" without the actual geological microscopic detail to confirm that. Or a proper size of a burial pit. You have to say, "they were making etchings with a tool" without ever seeing the tool, right? It's a it's a way to fictionalize a very real story. And that's why it's important I think to all of us, is that again: These are really important fossils. The fossils are real and they have this really interesting mix of traits that we don't see anywhere else in the in the human evolutionary tree. And in an understanding them as a group is really important. And I want to know how they got down into this cave. I want to know how they were deposited. I want to know what they were capable of. But the evidence hasn't been presented for that, right? So that's the frustrating part of it. And yeah like George said, I don't think you have to fictionalize it to make it broadly interesting. I think NOVA documentaries do a great job of showing the science behind it, right? And in essence it's almost it's almost more juvenile than even juvenile shows about science. Because I have a five-year-old and she's watching all these shows like Molly of Denali or Alma's Way. And they've got these little kids with you know microscopes and magnifying glasses. And they're trying to actually deduce the answer. They're actually trying to use the scientific method to come up with the answer. And that's being presented to children and this is like a documentary to be presented mostly to adults. And it's not deducing anything. It's just saying we think that this is fire by naledi, but we haven't done the background research to actually say that as a fact, right? I mean it's really it's just frustrating. Yeah I completely agree. I think it really misrepresents the care and nuance that we all try to take in in doing our jobs and how we communicate with the public. And so that's I think hopefully why hopefully people can understand that's why some of us at least are speaking up. I also think that it's not everybody. There's probably only 30 to 40 scholars in the world that have spoken up about this. So when people say there's such an outcry. It's people that are interested in how archeology is represented in the media or people that are in this specific subfield. They want to make sure that that it's being represented in a fair, nuanced fashion. So thanks to both of you. I really appreciate chatting with you. And great. Thanks. Thank you
