About the guest: Maxime Aubert, PhD is a geochemist & archeologist at Griffiths University in Australia. He specializes in the application of advanced analytical techniques to date the age of ancient rock art and hominin fossils.
Episode summary: Nick and Dr. Aubert discuss: the oldest known cave art and what it depicts; human evolution & interbreeding with different human sub-species; the origins of anatomically modern humans & advanced cognition; and more.
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Episode transcript below.
Full AI-generated transcript below. Beware of typos & mistranslations!
Maxime Aubert 1:31
Yes, so my name is Maxime Aubert, so I'm a professor at Griffith University in Australia, down the Gold Coast. I do. So I'm an archeologist, but I'm a geochemist also. So I did undergrad in archeology and anthropology, and I did a master's and a PhD in geochemistry. I do a lot of stuff about human evolution. So what I'm focusing on at the moment is dating things. So I've got a project dating cave paintings in Southeast Asia. So that's one of the things that I do at the moment, and I think that's why I'm here to talk about that.
Nick Jikomes 2:06
Yeah, yeah, among other things, probably, but yeah. So you're a you're an archeologist, you have a geochemistry background, so you know a lot about how to date the rocks and the minerals and work with that physical material.
Maxime Aubert 2:20
Yeah, yeah, exactly. So I, my first interest was, like history, and then archeology. Then I started a degree on that, and I started a master's in archeology. And then I had an opportunity in my life to came to Australia to work with someone, and then I and then I realized I needed to do more science, so I changed my master's in archeology to a master's of science, so in geochemistry, and then, and then after that, I did a PhD on that, but I had an idea that I thought we could do to date cave painting. So, so to do that, I mean, no one was doing that, really, at the time, and the reason was that the machines that was needed to do the kind of dating that I wanted to do, which is your it's called uranium series dating. You needed quite big samples. And it was a prototype of a machine that was developed in Germany. But the prototype was in Australia at the Research School of Earth Sciences at the Australian National University. So I invited myself there, and then I essentially did my PhD there. I was enrolled in Canada, but I spent 90% of my time there in the lab. Then I learned a lot how to use this machine and how to do, you know, like, what I wanted to do. And then, before I left there, before I finished my PhD, they offered me a job. So I didn't came to to here, like in Australia to stay. I just came to study. And then, and then, yeah, and they offered me a job. And then I got married and got kids, and then, then 20 years.
Nick Jikomes 3:57
So yeah, before we get to some of your research, in in detail. Can you just give us, like, a basic sense, like a basic survey of some of the most famous cave paintings in the world, in terms of where they're located, if they're concentrated in certain regions, and how old they are? The one that I've heard of, that I've always known about, that I think a lot of people probably see, is, is the Chauvet cave paintings?
Maxime Aubert 4:21
Yeah, so show their cave. So it's in France, so there's a lot of cave paintings and cave art in Western Europe. They're mainly located in southwest of France and in Spain, also like mainly northern Spain. So the cave is usually really deep inside caves, and it's usually not always, but it's usually made of black charcoal. So it's either a drawing or paintings made of black charcoal. The oldest one there, and probably one of the most famous, is Chauvet cave, so, but that was only discovered in 90s, I think. But prior to that, the there was a last. Cave, and there's Altamira in Spain. So they're really especially Chauvet cave is is very spectacular. You have like, large mammals like lions in like movements, and rhinoceros and and then. So there's a lot of animals that don't exist in Europe today. So, but when that K was first discovered, people thought it was relatively young because of the sophistication of the of the paintings, because there was an idea at the time that art starts simple, and then when it evolves with time, it gets more complicated. And now you had there, like, narrative scenes, and you had like, you know, like animals depicted in movements, etc. So radiocarbon dating was performed, and then it was shown to be about 35 or 36,000 years old. I have some issues with the dating. I think they are probably quite old, but there are some issues with radiocarbon dating of paintings like that. But like Lasco K for example, it's about 20,000 Alta murals or 20,000 so the problem that I have with the dating when they do radiocarbon dating of pigments, because they can date the pigment themselves, because it's made of of like, like fossilized wood, for example, is that it doesn't date, really, when the painting or the or the like drawing was done. It dates when the wood, when, when the tree, from the wood died. So if I, if, essentially, I walk into Chauvet cave today, and then I pick up a 40,000 year old piece of charcoal on the cave floor, and I write my name with it on the cave wall. It's going to date 40,000 years, right? Yeah. So it doesn't date when someone used it to make a painting. So that's the problem that I have with it. So it's it provides essentially a maximum age, yeah, and most of
Nick Jikomes 6:57
the paintings are probably somewhat younger than that,
Maxime Aubert 7:00
yeah, yeah, exactly so, but they don't say that. So they say, Oh, the painting is that old, which maybe, but maybe not. So there's, there's a lot of animals that are sit like that are depicted and that that don't exist in Europe now today. So it's probably an indication that it's pretty old. There's a cave also in southern France near Marseille, which is actually underwater. Now, like, the entry is underwater, because the like, sea level rose so and so we know that that, you know like, so it's probably about 20,000 years old, because 20,000 years ago, the sea level was much lower, and people could get in the cave and then made the paintings and the drawing in there. So, so we know it's, it's old. There's been some study on show they also where, like the cave entrance at collapse and all sorts of things like that, that they're trying to show that, yes, it is really, really that old, but yeah, I just wish that they would express really, the that the dating of the pigment itself is actually only maximum ages
Nick Jikomes 7:55
and so, so you said that there's a lot of cave paintings in Western Europe and places in France and Spain, for example, is that because humans were making cave paintings in that region more than they were making them elsewhere? Or is it because the geology of the region is more conducive to preserving the artwork?
Maxime Aubert 8:14
Well, so we don't know, really. So that's the thing. So the usually there the so the paintings are usually done in limestone caves, usually deep inside the cave. It's cold also, so maybe it preserves them better. But before we started doing the dating of the rock art in in solowezi and Borneo, there was so not everybody believed that, but there was some sort of an idea in the field which was very Eurocentric, that it's just when modern human reached Western Europe that they became modern, that their mind developed enough that they that they became really, really modern. So it was really a Eurocentric view of the world, because most of the research was done there, you know. And people have been said that for centuries and now, like it's part of, sort of the cultural identity of some culture, like in France, for example, they learn in school that, you know, it's part of their culture. And and they invented, you know, like rock art and things like that. And, and then when we, when we started dating rock art in in solowezi and Borneo, we show that, no, actually, there's rock art there. Also that's as old as a rock art in Western Europe. And when we're pushing the dates now it's even older. So it's either that rock art was in invented at different places, at different times, or at the same time, or that rock art really is everywhere, but it's just like it's preserved in certain places. Or also there could be so I believe probably that when modern union left Africa, probably 100,000 years ago, they had the, the capacity, really, to make rock out like anything they wanted. It's just when you when you arrive at certain places and where your society reached a certain point, that's where you actually need them. So, you know, like, for like, signaling system, for example, your population. Grows, and you need to to, like, identify to something so, so then it becomes part of your culture. But before that, if you just a small group of volunteer gatherer, maybe you don't need to do it. You know,
Nick Jikomes 10:10
even though you have the capacity, you just don't have the social need for what it's doing. Functionally, yeah,
Maxime Aubert 10:16
exactly. And, you know, like, as an example, I'm just thinking, so my, when, my, when my daughter was born, my son was not even two years old, and I remember we were at the hospital, and then he put his hand on the window, and then he and then he did this, you know, like, and then he did a handstand. So I never showed him that before. And he said, Oh, look my hand, you know? So you don't need anything special, really, like we, we know how to do this. We discover things. We just, yeah, that's who we are as humans.
Nick Jikomes 10:49
And you know? So we're going to get to some of your research, which will take us to Southeast Asia, to some interesting places that that you've been working on. But so you said, when humans came, everyone sort of knows, I think anyone who's listening to this probably that at some point humans left Africa and we spread throughout the globe. Can you just give us a basic sense of when? When do we know that humans first started leaving Africa in approximately like, when did they go west to Europe? When did they go east to Southeast Asia? Can you kind of paint a, paint a general picture there for us? Yeah, well,
Maxime Aubert 11:20
until not, not too long ago, we thought that was so modern. Human evolved in Africa. We still think that. But we the oldest evidence was Omo kibich. So that was from Ethiopia that was dated to about 200,000 years ago. So I actually did the dating of that fossil itself. So that was dated to at least 200,000 and
Nick Jikomes 11:41
so that's so 200,000 numbers, that's sort of the number. That's what we roughly consider to be the age of anatomically modern humans. Yeah,
Maxime Aubert 11:50
yes. So that's like us, like anatomically modern humans. And then recently, there was a paper that was published where there's another one, so there's actually a skull also. So that was one in Morocco at the jebelihood, and that was dated to 300,000 but there's argument that it's not fully modern human. So there's, there's, there's things in the skull, for example, that doesn't fit, really, like, like, like, what we are today. So the interpretation is that it's probably modern human, but it suggests that there may have been different subspecies of modern human living at that time. And it's not until 200,000 years ago that really we all came together, and it became really like fully modern human. And then at some stage, a group of modern humans left Africa for some reason. And we think that could have happened about 100,000 years ago, and it could have been fairly exhausted. So we think that there could have been some modern human that left. They made it to like Israel, where Israel is today, Saudi Arabia, there was a really old specimen in in China also. But that has been changed now because the dating wasn't done properly, or there was a bit of issues there. So, so they seem to be probably an Exodus Out of Africa about 100,000 years ago, and that was failed. So the modern human didn't, you know, like they they probably got extinct, or they came back to Africa. We don't know exactly what happened. But then, probably 70, 75,000 years ago, a group of modern human left Africa, and then they went everywhere. So the dating, it's really difficult to pin that, but it's based on, for example, we know that modern human arrived in Australia about 60, 65,000 years ago. There's also some dating based on the DNA. You know, when they look at the DNA, but you can't really date with DNA. So you can date that like the mutation and and this is based, if I'm correctly, on mutation, just chicken and stuff. So, you know. So it's not really a dating method, but so yeah. And then when modern human arrived in Europe, in Europe also, we used to thought it was about 40,000 years ago, but now there's a new site. It was discovered couple of years ago. Now it's ticket stated to 54,000, years ago now in Europe, at a site in France. So yeah, so we know that modern human left Africa, and they populated the world relatively quickly. And then it was thought that when they reach Western Europe, we thought at the time, about 40,000 years ago, that they start making cave art because we found a lot of it there like and also like jewelry, you know, like tools, etc. And when they arrived there, they met another human species, the Neanderthals that lived there also. And there's also a controversy about where they're making art also. So that's also one of the big, big questions in archeology. And then also. But we know that our species, modern human, we arrived, so we arrived in Asia and then Australia before we reached Europe. So because we know that modern human arrived in Australia, 60, 65,000 years ago, we know they were on mainland Asia. At the same time, 7075 there's a couple of side there's a site in Sumatra. There's another site in Laos that's pretty old, but in between, because we know they have to come from a come through a series of islands, Wallacea. So even when the sea level were lower, there was always islands there, like in Indonesia. But there's no archeological sites that whole there. The oldest thing that we have is the rock art. So we're using the rock art, actually, to date the movement of people. And now the oldest date that we have published so far, it's a paper with a vision nature. A couple of weeks ago, we had a site that's dated to at least 51,200 but it's probably older than that, and we have more stuff coming up in the near future. I can tell you more about it because it's not published, but, yeah, but we, we're going to go much older than that.
Nick Jikomes 15:50
Yeah. So, so roughly speaking, the timeline is you've got anatomically modern humans in Africa, and probably only in Africa, about 200,000 years ago, and then about 100,000 years ago, you've got some of the first attempts of those anatomically modern humans to leave Africa. And they do, but they don't stick. Something happens. Probably multiple waves of these anatomically modern people come out, but by the time you get to 75 to 50,000 years ago, people are now out of Africa. They're spreading into Asia, into Australia, eventually into Europe and and the Americas and the work, you know, there's cave paintings in Europe. There's cave paintings elsewhere in Indonesia that we're going to talk about. But basically, we know that they were making cave paintings probably about by at least 50,000 years ago. And we'll go into some detail there. And it's, I'm sort of getting the impression already that this is the type of thing where things kind of keep getting older and older as we discover more over time.
Maxime Aubert 16:47
Yeah, yeah, exactly. So things get older as we discover more, but also we're developing new techniques also. So it's not just so it's the method also that that's improving. So I can talk about that a bit later. So I'll have to go through the method, how it works, etc, how we used to do it, and how we do it now. But, yeah, so the more we're we're exploring, we're finding more sites, the more dating we do. It gets older. But also it's interesting, because the and that's why I think it's probably has a much older, you know, like it's probably much, much older, because the the oldest art that we have in Indonesia. So now I said, like dating to at least 51.2 but there's, it's, it's essentially very complex art. It's not something simple. You got that narrative scene. So you got, it's not just an stencil. You got large animal paintings. You got there depicting human next to them. They're making actually a scene. So, and all the three oldest ones in sort of lazy that we've dated, they actually scenes. So it's interesting, because us as a species, we like to define ourselves as a species that likes to tell story. Well, this is the oldest evidence of storytelling. Is on the walls there, on the caves in Southeast Asia. So it's very so it's a complicated things. It's not really something simple. So so to me, it makes me think that it so well, yeah, like probably when Marilyn left 100,000 years ago, they were fully modern, so they could do that. So it's either, it's either that we haven't found it, or they were not doing it until they reach certain places and
Nick Jikomes 18:22
so history. So before we get to some of the methods that you've used, because I know that you're using methods that are probably weren't being used even a few years ago, but like when we think about Chauvet cave, some of these more well known cave paintings that have been known for many years, you know often what you hear about is radiocarbon dating. Was that historically what was used to date some of this stuff. And how does that actually work, the radiocarbon dating? Um,
Maxime Aubert 18:45
yes, so what was was done in the past? It's still, people still do that. So you do radiocarbon dating so you can so with that method, you can only date something that was alive before, like something that is, that is organic. So in the case of the most of the paintings in in Western Europe, it's not all of them, but a lot of them, they made with charcoal. So black charcoal. So that's, that's probably from a tree you know, that burn like at some stage in the past. And then you can date that with radio carbon dating, because the So, I don't know how much detail I can get into but, but there's, there's a few isotopes of carbon. This carbon 14, carbon 13 and combo 12, carbon 14 is radioactive, so it it disappears with time. And then we know at which rate it disappears. So it's produced in the high atmosphere. We at a constant rate. Well, it's not technically true, but we know like it's produced in the in the high atmosphere. So everything that's alive today will have a known ratios of carbon 14 to carbon 13 and carbon 12, and then when that thing died. So if it's a tree or a person or like an animal, when it die, it stops actually exchanging carbon with the air. So. So the carbon 14 disappears at a known rate. So if we go and take a sample today, then we know, okay, so there's only this tiny amount of carbon 14 in it, and then we measure it compared to carbon 12 and carbon 13. And then we can calculate the age. So now, usually the limit is about 40,000 but then now, like, they're pushing it back to about 50,000 in the right circumstances. So, so after that, it's still decaying, but there's so there's so you can't see it, yeah. So you just need, like, a maybe, in the future with better machines, you'll be able to push it further back in time, but, but, yeah. So that's, that's essentially how it works. As I explained before, it doesn't date the painting event. So when someone did a painting, it dates when the tree that made the charcoal, yeah? So essentially, it provides a maximum age,
Nick Jikomes 21:00
yeah. So radiocarbon dating has, there's a couple limitations here. One, you can only date the age of formerly living things, and you can sort of triangulate the age based on how carbon is cycling through organic material over time and when it died. But there's also this other limitation of, as you mentioned, you know, if you date the material the art was made with, it's, it's, it's the age of how old the material is. It's not when it was used to actually make the art Exactly, exactly. And so how do you walk us through some of the more modern, sophisticated techniques that you've been using and how they work in comparison to something like radiocarbon dating?
Maxime Aubert 21:39
Yeah, well, maybe I'd like before to to explain why I think rock art is really important. It's fascinating. It's because so what we know about our past, like our our really long distance past, it's only based on, on, really, on a handful of sites, of like archeological sites. So people go and dig. They spend 1000, hundreds of 1000, millions of dollars to digging sites, and what you actually found is the trash of people, you know, like people eat stuff or whatever, and they leave lift the desk. So you have really a narrow window of the past, but there's a lot more rock out sites in the world. There's a lot, lot, lot more millions. The problem is that it's really hot today, so you don't know how old it is, so you can't really use it so, and that's why I was always fascinating by that. He said, Is there a way that we can date it? So then I learned about the radiocarbon dating technique, and then I saw the limitation of that. And then I thought, okay, so a lot of this rock art is made in is in limestone caves, and then in limestone caves, you have also, like stalactite and stalagmite, you know, like that forms in the caves and that sort of photos. And I remember from a book, and there was flowstone that had form on top of a bison in France in one of the caves. And I said, Surely we can date that, and we can so, so larger than like stalactite and stalagmite is so they've been dated before, with the with the uranium series dating method. So the way that it works, essentially, is that so water, like rainwater, seeps through the limestone, and then it dissolves small amount of calcium, and at the same time it picks up uranium. Also, like small amounts of a uranium, because uranium is is water soluble and uranium is radioactive. So then it will actually form. So water will drip at the surface of the cave wall. And if there's a painting there, also it's one, so it will drip on top of it, and then it will re precipitate at the surface, and it will form layers, like 1000s of layers on top of it, and they will have small amounts of, actually, uranium in it.
Nick Jikomes 23:50
And that's just natural. The uranium is just naturally present in the earth Exactly,
Maxime Aubert 23:54
exactly. So it's only small amount, but it's everywhere. It's everywhere. So there's small amounts of a uranium in the in the limestone itself, and then it's picked up by the water, and then the calcium re precipitate at surface, and then it got uranium in it. And uranium is radioactive, and it will decay to to like a few things, but one of the things that it decays to is thorium, 230 and thorium is not soluble in water, so essentially, at time zero, when those film of calcite that are forming on top of a painting, there will be uranium in it, but no thorium, and the decay rate of uranium anti thorium is precisely known. So when we go and get a sample and we bring it back into the lab, we measure the ratio of uranium and thorium in the sample, and then we can calculate back when those film precipitated over the painting. So in that case, we can have a minimum age for the painting. And sometimes there's some films that were there before. So we can have a maximum age. Sometimes we can have both. So we can bracket the paintings that it was made between, you know, 40 and. 45,000 so,
Nick Jikomes 25:01
so similar principle to radiocarbon dating. You're looking at the ratio of, you know, radiocarbon dating, it's two different isotopes of carbon, and with this, it's the ratio of uranium to to the other element. Yeah,
Maxime Aubert 25:11
exactly. The only the difference is that, so the radiocarbon works with living things. And also you're measuring essentially, the D, the the radio carbon. So the carbon 14, that is disappearing with time. With the uranium series method, you essentially measuring the thorium, 230 that's building up with time. So the holder your sample are actually, you get, like a it's actually, it's actually better. So you can get so, so the limit. It's about 600,000 that that you can go. But so the more thorium, 230 you have in your sample, the more clear it is, like, the more actually you can you you can get a better date. So it's true that we can date really, really young stuff now, but, but yeah, like at the time. So at the time when I started, well, when I wanted to do that, the limitation so this was applied to like spillutum, so large salakmar, and stalagmar, then caves and I was used to reconstruct the climate in the past. Because so those stalactite and stalagmar, they precipitate from water, and you can actually get information from the water about past climate and with the carbon also. So you can look at the vegetation that was there in the past, etcetera. So if you can date those layers, but then you can go back in time and say, okay, you know, 10,000 12,000 years ago, there was something happened. You know, the earth got warmer and colder, etcetera. You couldn't use that to date rock art, because the sample needed for the machines were too big. So, you know, you can't go on top of, like a preschooler card and say, Okay, there's this calcite on top of it. I'm just going to cut a big piece of it and take it to the lab and date it. So the so it's not until the new mass spectrometer, so the multi collector ICPMS came, came about that, that now we can, they use, like a plasma source, and then you can use much, much, much smaller samples. So that's where I came in and said, Okay, so we can, we can use this machine to actually date very small samples, like we're talking like extremely, extremely small, and so the damage to the rock art is, is really negative, so it doesn't make that big hole. And, yeah,
Nick Jikomes 27:27
yeah, I was going to ask you about that, yeah, so, so, over time, you've been able to do, you guys can do dating with very small samples compared to what you used to. So there's less concern about actually disrupting the cave art itself.
Maxime Aubert 27:41
Yeah, exactly so, so. And even now, we have another way of doing it. So, so, which is, which is even smaller. So before, what we used to do is we used to go in the in the field, and we cut so, so most of the time, what's forming on top of the rock art, essentially, in in Sulawesi, in Borneo, there was more flow stone. But in Sulawesi, there's called cave popcorn. So it's like small aggregate that starts forming, like little bits there, and then in a bit there, and then they join together, and it looks like a popcorn. And then we used to take the whole popcorn out, so usually they're about one centimeter by by one centimeter, sometimes smaller, and then in the lab, cut it in half. So then we can see the pigment layer going through it. And so you're like, 100% that everything that's above it, it's going to give you a minimum age. And then after that, you need to so I was using like a like a dentist tool with, like a rotary tool, and I was essentially doing a micro excavation. So I had to to divide the calcite layer, because it's 1000s of layers, and one of the because there's some potential issues with uranium series dating, is the main thing is you need to show that you have a closed system, that uranium hasn't leached out or came in later. So if uranium has leached out, well, then your your sample is going to get too old, because you're measuring the ratio of uranium versus thorium. So if you're in build, thorium is the same, right? But uranium has leached out. When you calculate your your age, it's going to be too old. So you need to show that you have a closed system. And the way we were doing this is we were doing at least three sub samples. So So as I said, there's 1000s of layers. But with, with the with, like a little drill, we do excavation. We start from the surface, and we divide it into three or four or five sub samples, and then we have to show that they in in like chronological order, so they're younger at the surface and they get older towards the pigment layer. Because the idea was that if uranium had leached out, you would have actually a reverse stage profiles so they will get older towards the surface. And that never happened. So we never, never really saw that. But so that's what we that's what we were doing. But there was some criticism of that. People saying you cannot be sure that you don't have any leaching in small samples like this, and it only works on a big. The Ethereum, etc. And even if you do that, you never sure that the first layer that's closest to the pigment layer doesn't have any leaching in. So, so I had an idea of doing something. Instead, we've developed this to date, actually bones. I can go into that in the in details, but, but we using laser ablation. So instead, and that's what the new paper that we published in Nature a couple of weeks ago, we had a really old site, but also we're using a new method. So, so we still get a sample in the field, but we don't need a sample as big. So we're using a little core now, like, like, like a five millimeter core. We drill that so it makes really, really small, small hole. And then after that, we we cut the core in half, and then we map it with a laser relation system. So, so we actually map how they use series isotope. So we we're measuring uranium, 238, to 34 thorium, 232, 32 etc. And we actually having a an isotope map, distribution of your of your samples, and then you can see what's going on. And then you can see that if there's any leaching of of a uranium, you'll see it. And sometimes you we can actually see it on two sample we can see it in small places. But the the beauty of it is, and while you is that after you have followed the data, so you have your map, you can calculate ages wherever you want after that on the map, so the data is there, and you can go back as many times as you want, so we can identify, Okay, so there's a little area of leaching here. We don't want to date from that. So we're going to calculate the date from here, the closest to the pink layer as possible. Then it, then it's going to give you, like, the oldest minimum age. And then you can get like, hey, ages above, you know, wherever you want, you can calculate ages and, and that's the beauty of it, and that's and that's faster, that's cheaper, and the resolution, and the resolution is better because we're using a, like a 50 micron spot size, so you can get closer to the pigment layer. So, because we're not dating the pigment, so we're dating what has formed above it. So the closer you can get, the older your age will be. So, and that's what we are doing now, and and we're not going to go back to the previous method with the solution, because, well, I call it solution, but it's a lot of work. You need to micro excavate the powder. Then there's other chemistry involved, and it takes a lot of time, and it's not as good as the laser,
Nick Jikomes 32:24
yeah. So, so, in essence, you know, using this new dating method, this newer technology, you're not dating the pigment of the cave art itself. You're you're taking samples of the geology that sort of formed layer by layer on top of the actual art. It's more sophisticated, it's more sensitive. So you can date things with more precision. You can go back further in time. And you mentioned Sulawesi, this site where you guys were excavating. Can you tell us a little bit more about this? So let's just start where is this and how did you actually start looking there? Why did you look in this place and not some other place?
Maxime Aubert 32:57
Yeah, well, we didn't excavate the sites where we dated rock art. Like my colleague, Adam Brom, is excavating some sites there, but there is a rock art there, but we don't have dates on the oldest paintings, but, but, yeah, it started there. I started to work there because so I don't know how much of the story you want, but at the time I was, I was in Australia, I was at the I was in the Australian National University, and then I finished my PhD, they offered me a postdoc, and then I applied for in Australia, you can apply for funding to the it's called the Australian Research Council. And I applied for a fellowship, which I got. And it was for three years, and I decided to move it to a different university. It was University of Wollongong. And then when I got there, then I was sharing an office with Adam Brom, who's working in Sulawesi, doing gigs there, like excavations. And in the excavations that he was doing there, he was finding a lot of Orca, like in really old layers. But he didn't know if it related to the rock art, but there's a lot of rock art there, and it's been known for a long time, but most of the people thought that the rock art was relatively recent. They thought that it was dated to the Austronesian period. So Austronesian is that this is the first farmers that arrived there. We think they arrived from probably Taiwan, maybe 4000 years ago, and they introduced rice and farming and etc. So people in general, thought that the paintings, they're dated to that time. And then one time, Adam went to a rock outside on a Sunday or something, and then he was looking up, and then there's, there's lots of hands stencils, and then he saw those small nodals on top of it. And then when he came back to the office, he showed it to me, and I said, yeah, there like cave popcorn. I'm pretty sure we can date those. And then the long story that we asked for funding from the university, they didn't want to help us, so I said we were broke, so we just paid up and myself tickets went. There I went at the bike, or like at the back of a motorbike, going around and looking at case, and then and took some samples. And. Then brought them back to the lab, and then I was like, what, like, it was, like, 40,000 years old. So, yeah, so that was a big, a big shock and a big discovery at the time. So you didn't necessarily
Nick Jikomes 35:11
expect this ahead of time. You didn't, you didn't get this old. You just, it just happened that way.
Maxime Aubert 35:16
Yeah, yeah, it just happened that way. And then we dated that more one like we had, like, at the time, we didn't, we didn't have any sample over like animal, there was only instance, and we dated, I think there was three or four instances, and we had multiple dates, you know, per because we're doing all those layers. And then then something very frustrating thing happened is that we wrote a paper, we send it to the, you know, the most prestigious scientific journal in the world was an assuredly that's going to get in, and then it was rejected. And then the reason why it was rejected was even more frustrating. It was because so the the reviewers, because when you write a scientific papers, it goes for peer review. And so, so the peer review got back and they said they didn't have any issues with the dating, but essentially it was too controversial. The result, because it essentially unceded Europe as the as the bird of art that they said that they wanted more. But I've seen a lot of papers, indoor journal with less evidence than that. So then, and remember, we were broke. So then, so then people were said, Oh, what do we do? So do, do we just submit it to like a different journal which is less impact factor and etc, but at the time, we were really young in our career, so a paper in one of the in the top scientific journal in the world will help your career a lot. So we said, Okay, we'll just buy the you know. And then we, we went back the next year. We got more samples. We got like an animal as well. So essentially, figurative art got more and stencil and then we, we changed the paper. We send it again. We we did the because when you submit a paper, you need to write a letter to the editor. We did a better letter explaining why this is important. And then it got accepted, and then it got published, and it was put on the front cover of nature. And then that was in 2014 so 10 years ago. And also, so there's nature and there's science. It's the two biggest multidisciplinary journal in the world. And science, every year they have a top 10 scientific breakthrough of the year. So they picked that up in the top 10 scientific breakthrough of the year. So then we went on from there, and then we made that list another time. So these cave paintings that
Nick Jikomes 37:27
you're talking about, how old are the older ones? And what are they actually painting? What were the humans interested in depicting?
Maxime Aubert 37:34
Yes, so the oldest one we've got so far, so that's the one we published a few weeks ago. It's so the minimum age, because we're dating the calcite on top of it is 51,200 so it's a South Korean karamuang. So it's in southwest Sulawesi, so sowezi, it's an island in the Indonesia. So it's immediately, yeah, so okay, you're sharing it on the screen. So yes. So that's that one it is. So essentially a depiction of a pig, and there's at least three human figures next to it,
Nick Jikomes 38:07
I see. So the pig is this structure here, yeah, and then smaller figures next to it are supposed to be human depictions.
Maxime Aubert 38:16
Yeah, there's three human figures. So this is a drawing of it because it's hard to see. The problem is that the the when it's the so the rock out there, the the preservation is not very good, because it's it's very old, and it's mostly preserved at the entrance of the cave, unlike in in Europe, when it's deep inside the cave, I think I'm not sure if it's because people just painted it at the entrance. I don't think so. But essentially, the the surface of the cave wall is peeling away. We're not so sure what happened. We think there's salt forming behind the surface. So anyway, it the rock art is is disappearing, you know, like with time, and the more deep you go inside the cave, you can see that the the wall, like the old surface of the cables, are gone. It's the newer surface, the fresher surface and and I remember one time I was walking in a cave really deep, you can see, okay, this is all the new, fresh surface. And then you can see a little bit of the old surface, and you can see bits of fingers there. So you mean, oh, okay. So this whole thing was painted, but what we see today, it's is 1% or less than than than 1% so, yeah, so it's difficult to see because of the of the essentially, it's flaking off. But also the ones that we can date, they're the ones that have the calcium covenant formation on top of them. So it's make them even harder to see. So this big there, like is covered with those cave popcorn details. You can see them, yeah,
Nick Jikomes 39:51
and when you discover these initially, how do you find them? Are you just looking with the naked eye, and you guys are just really good at picking the stuff up, or do you have to use. Kind of scanner, or something to sort of, to actually see that something is there. No,
Maxime Aubert 40:04
well, I didn't discover that side, but there's a there's a whole team, right? So it's not me. So there's a whole team, and the whole team of local people, also from the local office, of the preservation office, and there's an archeology office, also local there. And every year, you know, they go and survey and stuff, and they found, like, dozens of those sites every year, dozens. And then when, when they have some, some good ones and stuff. Now, you know, I've trained some people how to recognize some with samples on it for dating and stuff. And then I go back after then I say, okay, yes, that's a good one for to take a sample and then take a sample and we and we date it. So So our team, we have discovered, also news, new sites, but we also work a lot with with, with the local groups then and so
Nick Jikomes 40:54
and so. This image here from the recent Nature paper. So it's a pig with three humans. It's at least 51,000, years old. Can you tell what the scene is supposed to be showing here? Like, are these human hunters that are that are hunting the pig. What's the story being told here? Do
Maxime Aubert 41:10
we know? We don't know really. Like, the preservation is pretty bad, so we don't really know. They seem to have objects in their hands and one and one and one is making contact with the pig. So
Nick Jikomes 41:23
could be a hunting scene, and those could be spears or something. They
Maxime Aubert 41:27
could be so, but we don't know, but, but there's another one that's, it's in the same paper, but we that we re dated. So there's a site called bulusi Pong, four. So I think it's going to be above that. And that's a site which, because clearly you can see it's a saying, or like a hunting scene, that one here, and then you have multiple animals there, so there's pig and there's a NOAA, so I don't know if you can see on the left hand side, there's a human. We call a theory enteral, because they're not fully human. So I can come into that in a in an in it, but that one looks like to have a spear or rope, and it's got a and it's got a tail. So, so there's, there's a tail, and then you have a lots of pigs and an anoa. And completely on the right hand side, you have an anoa, but there's two. There's a head. There's a full aura next to it. On the left, there's a series of small figures. They all have some rope or spear and they have like animal attributes. So once they got like birds head or something like that, which is quite interesting, because we publish that site for the first time a couple of years ago, also in nature, and that was also picked up by science as the top 10 scientific discovery of the year. And we dated that scene at the moment, at the time, at at least 44,000 we re dated with, with the new laser emitter, to 48,000 at least. So it's minimum 48,000 but at the time, it was the first, really scene that that we saw in the rock arts, the first time I saw, like, anything like that. So it then, at the time, we said, well, it suggests that, yeah, like, human at the time were not just making instant skills and figurative art. They were making complex art that were
Nick Jikomes 43:29
their hands or writing, you know, simple exactly, so telling a story of some kind,
Maxime Aubert 43:34
it's a story. So that's the first evidence of of storytelling. But what's also interesting is that they're depicting not quite humans, but like what we call theory anthrope. So they're half human, half animals, yeah, and that's, and that's a concept in archeology. The oldest one that's known in archeology, prior to that was the lion men are carving from from Germany, dated to about 4000 So, and
Nick Jikomes 43:59
this is pretty common, right? These theory anthropes, these human animal hybrids in cave art, yeah,
Maxime Aubert 44:03
yeah, but, but the thing is, in Europe, it doesn't, I may be wrong, and they could be some, like small examples that are older, but usually it starts appearing at about 20,000 years ago. So in Southeast Asia, like in Sulawesi, it's much, much, much older, and it's interesting, because so before, when we dated instant wiki, okay, so they're making paintings, you know, that old, and then after that, you got large animal. Okay, so they're making figurative art, and then they're making a scene, but now they're depicting something that doesn't exist, right? Right? So, so, so then it, it gives us a, essentially a view into their mind. So at the time, they were capable of conceiving of things that don't exist. So that's the birth of a spirituality, of religion, etc. You know, it starts, yeah,
Nick Jikomes 44:50
they're able to imagine things that aren't there in front of their senses, yeah, yeah. Or perhaps come to them from their dreams, or something like that. Yeah,
Maxime Aubert 44:58
exactly. And that's. What rock art and rock art dating like enables us to do like we can't go in the brains of the people in the past, but we can look at the pictures that they produce.
Nick Jikomes 45:08
And so let's deconstruct this scene a little bit. So we've got hand stencils. People were tracing their hands. We've got these theory anthropes, which are human animal hybrids. They look human like, but they've got some animal characteristics. Most of them are holding something. Is it a rope? Is it a spear? We can't say you've got the pig here, which they may may be hunting. But again, we can't say you've got more of these human figures and then you've got a Noah's Those look like, like antelope of some kind.
Maxime Aubert 45:35
Yeah, it's a type of of draw above it. So, and that's endemic there, like too, so lazy, it's fine, nowhere else on the planet.
Nick Jikomes 45:44
And so, so people are doing this, you know, 50,000 years ago, they're telling a story, right? So they're not just hand stencils, they're not just abstract shapes. There's, there's some kind of narration happening here. And what's the significance of that, in terms of how old this narrative capability is, and what it might tell us about some of the other cognitive capabilities that people had at this time in this place?
Maxime Aubert 46:11
Yeah, well, I mean, it's, it's telling us, essentially, that that that human have been telling stories for a very long time, and and, you know, like we, as I said before, we like to define ourselves as a species that like to tell stories like, how are we different to two other species? Well, that's probably hit like we tell stories, and that's the oldest evidence of that, but it probably goes back much, much, much further than that in time, but the oldest evidence of us as a, as a, as a as a storytelling species, is, is those cave paintings in Sulawesi, so dating now to at least 51 52,000 years ago, and so,
Nick Jikomes 46:52
yep, so in these caves, do you find any other artifacts, like tools or other human artifacts that indicate you know, advanced behaviors that were happening,
Maxime Aubert 47:02
not in those case. So, because we, well, hey, we haven't done any excavations in those cave, but they also so, so those two caves, so for example, like Nian camp one, that's, that's the one at 50, 51.2 and that one there blue, 6.4 at 48,000 minimum, they're not on the floor, like on the valley floor. They're up on the cliff face. So essentially, there's caves everywhere there, but there's, there's, there's a, but this is above so you need to climb up to go up there. So that one you need, actually, they made, like local people, like a, like a really tall ladder with bamboo and stuff, and you need to climb up. You have to climb up a hole to get in that cave. And it's pretty small cave. There's no soil in there. Anyway, that's the same thing with poem. You need to climb up with like climbing gear to get to get in there. So, so there's not really caves to do excavations, but my colleague Adam Brahm is excavating another site there that it's got some stuff published from there, and they've found, so it's in the same region. There's old instances also, like at the entrance. And is is doing an activation at the entrance. And they found some, some, some like portable art, also some, probably pieces of necklace and jewelry and stuff. So so it's not just the the rock art is. People were also making other types of art, but it's very it's very hard to find because the the rock art is everywhere. But if you want to do an excavation and go that deep, then it's it's a lot of logistics, it's a lot of money, and not many people are doing that in that part of the world compared to what's being done and what's been done now in the in Western Europe. So you have lots of team that have worked there before. So they found tons of jewelry and portable art, etc. But we just need more more time and more more people, and people doing more excavation in those region. And I'm sure we just find more. Yeah, yeah,
Nick Jikomes 49:03
yeah. So it sounds like, sounds like, you know, one of the things that you've mentioned is that there's many more known sites with cave art than there are sites where we've actually done the dating. So yeah, people find this all over the place, but we only get, we only have studied in detail like this, a small percentage of it,
Maxime Aubert 49:24
yeah. So in order to date it, they need to be some sort of of, like, of a calcite formation that's formed on top of some of them. So, so, and that's quite rare, so we can actually know a few of them. But also, like the, as I said, like the local people there, they found dozens of those caves everywhere. And every time I bring people there, I just came back doing a movie there, and it's just people said, it's just everywhere. And I said, Yeah, and that's the thing that that I try to explain to people, like, imagine if in Europe, they would find another cave next to show their live show. It would be a huge. Salaries, right? But we're finding dozens of those every single year, like in sulawe, in that little part of Sulawesi, they're like hundreds of sites now, like three or 400
Nick Jikomes 50:10
known sites, yeah? So this, it seems like this was a phenomenon. It wasn't a rare phenomenon where, you know, a special artist person made one painting in this cave over here. It looks like they were kind of painting everywhere they could.
Maxime Aubert 50:23
Well, yeah, it's not in every cave but, but, yeah, it's there they have. It's quite common, but in that small part, so in the it's got, it's, it's like the southwest of solowezi, um, we've worked on so in Borneo before. So Borneo is just across, so you got the the Makassar straight between Borneo and sowezi. So sowezi was always an island sea level or always an island. So So and a lot of the like animal species are endemics and all that sort of stuff. But we also have sites in bonhoe on the eastern tip of Borneo, and that's when the sea level was lower. Was not an island, so you can walk all the way through there. So there was paintings that had been discovered by those French people working there in Indonesian, Indonesian calling now pindis Etienne, who's passed away. And then they discovered a lot of the paintings there. They were doing excavation, but just really shallow, like at the surface. So when we got the dates for the rock out in Sulawesi, before the paper was published, I contacted Pindi city, when it was a Indonesian archeologist working there, and then we organized an expedition to go there. And then I collected some samples for dating, and we got some really old days for rock out there, like dating back to at least 40,000 as well. Large Animal also, like a bovid and instancils also. But what was interesting also there is we managed to get a few of maximum ages also because, as I explained, we can date the calcium covenant that's fall on top. Sometimes they it's most of the time they paint it straight on the rock wall, but sometimes there was also calcium carbonate on top of the rock wall, and then they put the hand, or they draw something. And in Borneo there, when we look at all the rock art, they seem to be at least two different style of rock art. So one is large animal paintings and instances in red. And then you have instances also in purple, and human figure in like purple. And they most sometimes these instances, they decorated them from the inside look like tattoos and stuff. And then when they they're at the same place, they they're always super imposed on top of each other. So it's the red one first and the purple on top. So we said, Okay, so there's some sort of a pattern here going on. And when we did the tailing, we realized that, yes, there's actually two different phases. There's the red phase, it's at least 40,000 it could be much older than that. And then it stops at about 20,000 years ago, like the last glacial maximum. And then the new rock art face, like the younger one, the purple one, starts at the last glacial maximum. So which is quite interesting. So it's different a team. They're depicting humans in the rock art. They're decorating their hands, and it's happening 20,000 years ago. And 20,000 years ago, it's the last glacial maximum, and you can see changes in the rock art in Europe also 20,000 years ago. So, so there's like a global phenomenon that that's affecting the rock art worldwide, and that's the climate. And it brings me to the theory, like, Why were people doing rock art, and how did they develop this, and why they do this, you never really know, because the only way is to have a time machine and go invest in but, but so you can only speculate. But when you look at evidence, you can say, you can say, Okay, so maybe it's linked to, like, population. So, so essentially, like, at the last glacial maximum, the sea level were much lower. So, so there was probably more people moving around different groups, etc. So there's new people moving all the groups get bigger, etc. And I think that that rock out really has to do something with, with, with large groups of humans. Like, it's like, if you live in a small village today, you don't need, like, traffic lights, but if you go in the city, then you need traffic lights and you need signal. Same thing also, like, you need to identify to something. So now, like, these days, as pop artists, like Taylor Swift, for example, and you say, okay, you know, oh, yeah, I know her. And so you're part of that group, right? Because you know her. And it could have been the same for rock art. Oh, you know, there's this side there, on top of that hill there. Oh, yeah, no, that had been there. So you're part of that, you're part of that identity. You're part of that group. So it could be linked to that. But it's also interesting that the so the rock arts in Western Europe, in in Borneo, they are essentially at bottleneck, you know, like. Places. So when modern union left Africa, and then so after that, they either turn east or they turn west. When they arrive in Western Europe, there's nowhere else to go when they arrive in at the tip of Borneo, there's nowhere else to go. If you want to go to Sulawesi, you need a boat. Yeah. So maybe population increases at that time, at those places,
Nick Jikomes 55:18
because people settle there, they stop moving. They've reached
Maxime Aubert 55:22
the they stopped there for, like, a bit longer. So they need, they need the population needs to increase. So then they develop boats and, you know, etc, but in in Borneo. But also, what's, what's interesting is we did an excavation there at one of the sites, and we found the oldest burial in Island, Southeast Asia. So we found him 3030, or 31,000 excuse me, burial. So modern human that's been buried. So on purpose, he was put in like a fetal position
Nick Jikomes 55:52
in a cave, in a
Maxime Aubert 55:55
cave with rock art. They put a big bowl of orca in his mouth.
And what was really interesting is that, so the left foot was missing from from the grave, and we can see there was some modification to the bone. He said, There's something going on. And with that, look like we were not expert. We said it looks like the foot has been amputated anyway. So we brought so that there was just before the covid 19 pandemic. So we had to leave. We managed to have all of the bones and everything shipped to Australia, and then we had then analyzed by a specialist, and yeah, like the the part of the leg and the foot had been amputated, so it was a young adult, but that leg had been amputated when it was a child, so that part of the leg didn't grow, so it's still like the children's leg, and then we can see the bone remodeling on top of where they come. So the leg was
Nick Jikomes 56:53
amputated in a young child, and then the child survived and
Maxime Aubert 56:57
then lived some number of years for for probably about 10 years. Yeah, and we published that also in nature, that was a big, big discovery, because it changes also the origin of of, like, advanced medical knowledge, because it was thought that the first surgery was done in Western Europe where there was, like a like, I think the oldest one was 7000 years ago. Like agricultural society. There's more people living together. There's more knowledge being, you know, known about medicine and more disease and stuff. But now we show that hunter gatherer society, living in Borneo, in the rainforest, at the medical knowledge to amputate. So they knew they had to amputate for the for the child to survive, yeah, we calculated that he would have bled out in two seconds, so they knew they had to stop the bleeding. They must have had, have also, like, a lot of knowledge about medical plants, about, like, you know, like antiseptic, you know, the pain, because
Nick Jikomes 57:54
obviously, obviously, there was no deadly infection that ensued. So they must have done something. Well,
Maxime Aubert 57:59
exactly, they're in a rainforest, yeah. So they must have had a lot of knowledge about plant medicine, etc, and also, like a community carer, so they have to care for that person. So yeah. So that was a really huge discovery. And then that
Nick Jikomes 58:16
was, you said, How old was that? 130? 1000 31,000 Okay,
Maxime Aubert 58:20
yeah, yeah. So, so we know that at the time, there was a group there that was making sophisticated rock art. They had advanced medical knowledge. They're the first people that that that actually went over the ocean by boat, so to pass the Wallace Line, to go to to those Island and they arrived in Australia, yeah. So, there was, there was a very sophisticated culture, yeah,
Nick Jikomes 58:43
and all of these things. It's very difficult to imagine such a culture existing without language.
Maxime Aubert 58:49
Well, yeah, yeah, exactly. So they need to have language. They need to, yeah, and, and it's funny, and it's one of the things that I like about archeology, and it came about the past, is you find one thing and it changes everything. No, like you, you have, like, preconceived ideas about stuff and based on previous discoveries, and then, and then, you know, you find Fine, and you date rock art that's on the opposite side of of the world, and said, okay, so it was not invented in Europe. And then you said, Okay. And now, like you, you're showing that hunter gatherer 30,000 years ago were capable of doing an amputation, and child survived and said, Oh, wow. Like so it changes everything about what we what we thought we knew about the past.
Nick Jikomes 59:30
And so if this evidence of an amputation is 30,000 years old, and this evidence of the cave art, and so the ways that you found is at least 50,000 years old. If it's true that these capabilities are even older, I would imagine, you know, if I was just thinking about this and thinking about where to look, you know, people came out of Africa at some point, some from West, some turned east. If you work backwards from Indonesia towards Africa, you might expect that those sites would be potential. Sites were even older. Older cave art exists is, is that the way you think about it? Are you guys looking for older cave sites closer to Africa? How old do you think we this stuff could be? Yeah,
Maxime Aubert 1:00:10
there's, there's a lot of rock art in Africa. There's a there's a lot of in India, for example. The problem is not many in limestone carrots. So this, as I said, Raka is really difficult to guide. So, yeah, so, so, so that's the thing. So it may be essentially an artifact of that. So we we either it's not preserved or or it's not there at all, or it's there, but we can't date it, so we're trying to develop new methods also for dating. So we're using uranium series dating on calcium carbonate deposits, we're trying to adapt that to different types of rock surface coatings that not necessarily formed in limestone. So I think one of the most promising one would probably one called amorphous silica skin. So that's formless in different types of geology. But sandstone, for example, there's a lot of rock art in sandstone, and sometimes you see those white film transparent that form on top of it. And I think we can probably date that with uranium series dating, but they're really thin, so with the laser ablation method now, we think it's probably gonna work, but we're trying to develop it's complicated, but we're not going in too much detail. We have to develop standards that we can use to do the dating. So, so, so, yeah, so we're working towards that at the moment, but yeah, hopefully in the future, we'll be able to date rock art, not just in limestone. And so one thing
Nick Jikomes 1:01:33
I want to clarify, actually, so this narrative cave art that you found in solowezi is 51,000 years old or older. Is that the oldest narrative cave art or is that the oldest cave art period?
Maxime Aubert 1:01:46
Well, it's the oldest cave art period that's that's been dated, that we know of, that's attributed to modern humans, but that's we. And then, if I mentioned that, then we start dwelling into the the big question is, did other species lead rock art? So that's one of the big question. I actually give a guest lecture at uni on that topic, but because there was a couple of sites in Spain a few years ago that was dated with uranium series dating to 6065, 67,000 years old, and there's been a lot of controversy about that. There's lots of papers that are criticizing that. There's a paper with, like, I don't know, 2030 archeologists, and they, they said, that's wrong, because people have been studying that site and those painting for a long time. Like, you cannot deny all that knowledge, you know, but, and we wrote a paper also criticizing that. We didn't criticize the dating method as such, the uranium series dating, but we criticized that because, because we're not dating the pigment itself, so we're dating what has form on top of it. So the relationship between what you're dating and the pigment needs to be 100% clear, like you need to be 100% clear that what you're dating is actually 100% related to the pigment layer. And in Europe, in those cave to my opinion, it wasn't that clear. And the reason is because they're not as far as understanding. They're not allowed to take a sample through like the pigment layer. So they actually use a scalpel, and they do like a sort of cone shaped thing, so they scrape the the coating like this, and they stop when they think that they just about to reach the pigment layer, they see a bit of red, and they stop there. And the problem with that is that you're not 100% sure that it's the pigment layer that's underneath it, because sometimes you have natural red, you know, color that form on top of the painting. But also, is that the the so those things, so it's also cave popcorn, like, like the deposits. And therefore it's on to to explain on the like this without having like a visual. But it's essentially small clusters that start really tiny, and then they, they, they, they join together, and they form a bigger cluster, etc, etc. So you could have a little cluster that's tiny, like a few microns, that start on the cave wall, and then someone go there and do a painting, let's say, a hand stencil next to it. And then that cluster grows this other cluster, and then they drawn together, and then eventually it's it's on top of the painting. So if you take that sample, but you because they're taking essentially a cone, and let's say that what they're exposing in the middle is the pigment layer. It's possible that part of what they're taking on the side of it was there before the painting was was made. So just a tiny bit of that mix into the rest of the sample will make it too old, right? So that's why you need to to really make sure that 100% of of of all of the material that you use for dating is on top of the picnic layer. There's there cannot be any ambiguity about that. And there there was ambiguity. Really about the relationships between that so that's my issue there. But I don't have any problem with the concept that Neanderthal could make rock art, and why not, but, but I think it hasn't been,
Nick Jikomes 1:05:10
hasn't been definitively shown yet. Yeah, yeah. So with the narrative cave art that you found in Sulawesi, that's 51,000 years old or older, how do we know that that was anatomically modern humans that made that? Do Were there any other subspecies of humans in that region at the same time? Or do we think it was only anatomically modern humans that were present?
Maxime Aubert 1:05:30
Well, that's the, that's, that's million dollar question, the so we think it's probably modern human because we know that modern humans were there at the time. We know that modern humans have the capacity to do that, but we cannot be 100% sure, like we know there was other human species there also there's a Denisovan was around which is another human species you have at Neanderthal, and you have Denisovan. We know from modern DNA of people living in Papua in Australia, like Aboriginal Australian and Papuans, that there's admixture between modern human and Denisovan in that region. But also the DNA data suggests that there could be also two other species, like ghost species that we know anything about that. So, and just
Nick Jikomes 1:06:22
able to understand when we say ghost species, basically, geneticists can infer the presence of interbreeding with other species, even when we don't actually know the identity of those species yet. Yeah,
Maxime Aubert 1:06:33
exactly, exactly. So there's this genes that I said, Okay, so that's not human So, and they're not matching, and at all, they don't match to any solvent. So, so, so it suggests that it could have been two other human species that were there, like in the region at the time, and they interpret modern human as could be as recently as 30,000 years ago. So, so, yeah, it's quite interesting. We haven't found any evidence of those from the archeology itself. But yeah, it's possible that some of the Cayman is related to that. We can't be 100% sure, and we know there was other species also. So there's like Homo floresiensis, also the hobbit that you probably heard of on florists. I was involved in the dating of that also, so when they published that, I forgot the time, but it was quite a long time ago now. But they they, they said, okay, they found a new human species. You know, they call it homo, for instance. Was at the same time that the Lord of the Rings movies were, that's called the hobbit that had really short, really big feet. And then after that, they found more than one. So there's this, there's, there's, there's a lot of individual just in that cave. And what was also a very important discovery at the time is the dating is that it suggests that it was 10,000 years old, or something like the younger specimen. So, but the bones themselves had never been directly dated. So Mark Morwood was one of the Discover of that. He was at Wollongong university when I was there too. And they kept excavating there, and they realized that the stratigraphy was more complicated than what they thought so, because what they dated is they dated charcoal, you know, like in the layers in which the the like remains are found, and they dating, I think I know if it was Quas or feldspar, but you can date crystals like the last time they were exposed to sunlight with a method called luminescence dating, and then they came back at about the same age. I think it was 12,000 years old, or something like that. And then when they kept doing excavations, they get bigger and stuff, and they realize, oh, the stratigraphy is really, really complicated. And so then mark Moore would ask me, Do you want to go and do U Series dating on the bones themselves? Because I've been working on that for a long time. It's complicated. It gives you, like, a minimum age. It's open system and stuff. But then you said, Yeah, I can. I can go and have a try. So I flew to Jakarta that at the National Center for archeology. They opened the safe, and they were like the hobbit remains are in and then I cut pieces of, I think nine like difference of the like of bones of more than one. I think there's none of them. And then I bring them back to Australia. I met him in the lab. They said, Oh no, it's not 10,000 years old. It's at least 50,000 and and still got on that there's like pygmy elephant there at least 60,000 so, so it's probably about at least 60,000 so it means they probably got extinct when modern human arrived there. They not what they didn't coexist with modern human for, for 40,000 years. So, so yes, so that changed the whole view on that at the time.
Nick Jikomes 1:09:43
What? What? Where are you looking in the world right now? Are you still working in the same sites in Indonesia? Are you working with samples from other sites?
Maxime Aubert 1:09:52
Yeah, we're working still in Indonesia. So we're working in solarisi. Also, we've got some lots of samples from there. We. And run we're working in, excuse me, in Borneo, also we got new rock out, samples that we got from there, also from another, same area, but a different mountain that we never worked, that was too far, but it's already really remote there, like in in so it's easy. It's next to towns and people's farm and stuff. But in Borneo, you have to go for months, like in the jungle, and it's pretty remote, so, but so there was a we go up a river, and there's a ridge there with caves, and that's been explored. But there's another mountain from another river, further further up. It's called tondoian, and we've never been there. So we managed to go there, and we found a rock out, but we just explore a little bit of it. So we want to go back and do some more exploration, but we haven't processed the samples yet, so I don't know that. That's even if I knew, I wouldn't tell you, but, but we do have some old rock art also in solowezi, and we have rock art on the other side of solazi, not just now on, because before it was just this southwest region. So we do have rock art now on the opposite side of Sulawesi that we've dated, and it's quite old. And so we explore exploring further east also. So I'm going, in about three weeks time, I'm going to miss all island. So it's small island west of West Papua. So it's part of West Papua province of Indonesia, but it's an island. And then when the sea levels were lower, is was linked to Patwa, so in Papua in Australia were linked together. So if we can find some old rock out there, or I want to still find a good place to do an excavation next year, but then we could have some, some really old rock art, or maybe on, on what's called Saul. So, so the continent of Australia and New Guinea at lower sea level. So that's what we were missing at the moment. We have old rock art, a on mainland Asia, Wallacea, which is the islands in between. And now we're trying to get some impact Australia backbone.
Nick Jikomes 1:12:00
You know, when we take sort of a broad view of human evolution, you know, I've talked to various paleoanthropologists on on the podcast before. You know, it seems like the story of human evolution has been revised substantially, sort of over and over again. We keep discovering, you know, these new species of humans, the Denisovans, the hobbits, a Homo naledi story out of South Africa. We keep discovering that you know certain things, like cave art, like the work that you've done, are you know, older and older than we used to think. You know certain things are happening in different parts of the world that we thought were happening just in Europe, but they're happening in Indonesia even before that, etc, etc. What are some of the lessons that you've learned as an archeologist and a paleo guy in this field about the story of human evolution and and how attached we become to certain stories and how much we still have to learn?
Maxime Aubert 1:12:54
Yeah, well, I think you have to be open minded. That's the first thing. You need to acknowledge that what we know is based on a handful of of pieces of evidence. So, so you just need one more pieces, and it changes the whole lot. So, and that's why it's interesting. That's why it's interesting to do that. Because you, you, you go and look somewhere that people haven't looked before. You date stuff that people have haven't dated before, and then you and you find new stuff. And then he said, Okay, and then it changes everything. Why? Because what we know is only based on a handful of of data. So, yeah, it's interesting. Also, not just the dating, but, but, but the but the genetics. Now, you know, we can find out we talk about other species, or in braiding with us, we got full genomes of Neanderthals. We we we know that Neanderthal and modern human mixed together. And Neanderthal and Denisovan Dennis over the modern humans. You know, all you know, we all mixed together at some stage in the past. So, yeah, as the science evolve, also we, yeah, we, we're finding lots of data, so we're trying to piss piece this, this complex puzzle together, but we only have little pieces of it so and sometimes you have to look in the right place. And I remember there was a there's a scientist in Canada, Henry Schwartz. He wrote in one of his book, I think he says archeology of or the study of human human evolution. It's like a drunken a person that gets out of the pub at night and then he lost his key, but he's looking for his keys under the lampshade, because the light is better there, right? But they're not there. So it's essentially what, what, what we're doing. So we're trying to break that mold and look somewhere else. But what we always tended to look where it's easy. One thing I
Nick Jikomes 1:14:46
want to ask you about, I don't, I don't know if you know about this, or you have an opinion on this, but you know, you've done a lot of work, archeological work, you know, that we discussed today, including, you know, uncovering burial sites. The really interesting one that we talked. About just a few minutes ago, the story of Homo naledi in South Africa that's come out in recent years. I know that's that's a very provocative and interesting and controversial story there. The claim is that they found evidence of burials that are, I think, a couple million years old in that species in South Africa. Do you, do you have? Do you think that's true? And you know whether or not you think that part of it's true. What are the sort of the oldest burials that that you you are convinced of?
Maxime Aubert 1:15:29
Well, I don't think that's true. And one thing so I think that, I mean, I don't want to get in trouble here or get sued or anything. So what I say, but, but essentially the so they found a new human species there. I think there's no doubt about it, it's a new human species. They've been some dating, independent dating, being done. But then the person that's in charge of of that cave and those discoveries, then has made a lot of claims recently that were not necessarily scientifically backed by by like evidence. It wasn't peer reviewed either. So there's an interest. So they so essentially the way, the way we work is, is you, you know, you have scientific questions that you need to have some questions that that are answerable so you can, you can develop some test, you know, to test those scientific questions, and then you find some answers to that. You write a paper, you send it for peer review, and then it's evaluated, and it's accepted or rejected, or they want modification, etc. But then the groups that are working there, they they claim that they found burial and also that that nadelli was making rock art there, and they wrote a paper about it in a journal, but that journal had changed their model, where they didn't send the papers for peer review first, so they published a paper, and after that, they published the peer reviews with the comment, And then it was rejected, but at the time, it was already in the media. And the reason why they did they did that is because they had a Netflix movies that was coming out, right? So they did it like that. So I don't think it's a good way to do science like it, it's, it's, it's essentially, like, there's not enough evidence to say that it is or it is not well. I mean, I think it's not. But, you know, like in terms of the rock out there, like they found some markings on the, on the, on the wall there, but, but those caves have been visited for it's not just Natalie that has been in there, like that. Cavers have been in there for years. There was also mining in those caves. Fires also in those caves. We know that miners at the beginning of the century were growing in these caves and lighting fires, you know, that they haven't done any, any dating, like it would be easy to take a piece of the charcoal and date it. They haven't done that. They're just saying, Oh, yeah. And Nalini did that, you know, and the burial is the same, you know, and stuff. So it was just that, I don't know. So there's a lot of, yeah, and it's, and there's a lot of, there's a lot of there's things like that, but there's a market for that. It's the same thing about the, I forgot this the name of this show, like, on Netflix, like, and now they're doing another series with CUNY Reeve, like, the there's, there's a market for that out there, that that people want to know stuff that's controversial, but it's not necessarily true, you know. And there's, and there's a type, of people like that, of personality that they they that media like that, because they're prepared to be out there and say stuff that you know that makes stuff that that's you know, like it's, it's, it's controversial but, but it's not
Nick Jikomes 1:18:34
necessarily true. So in what are the oldest examples of human burials that that people agree on universally. How old are those?
Maxime Aubert 1:18:43
Don't remember, but I think there was a site in Africa where my colleague at Griffith Marco petravi had excavated. I think it's that one, but I can't remember on the top of my head, but it's pretty old, like maybe, like 100,000 or something. I can't, I can't really be sure, but at a time
Nick Jikomes 1:19:02
when we modern humans have been doing that for quite a long time
Maxime Aubert 1:19:05
for Yeah, interesting.
Nick Jikomes 1:19:10
So what are some of the I think we've already kind of touched on this, but what are some of the big questions that you and the people you're working with are asking right now? Are you simply looking for new evidence of older cave art? Are there other types of questions you're looking at that maybe are even unrelated to cave art?
Maxime Aubert 1:19:27
Yeah, well, we're looking for not just older cave art, but any cave art that we can date. We're getting dates on this younger style of cave art, also like Austronesian, so people that arrived 4000 years ago, and we can trace the movements of those people by the rock art also. So it's, so it's interesting. We can trace the movement also, of all the modern human through the cave art. So we don't have to do full excavation. So we can date the rock art. So that's, that's, that's, that's interesting, looking to excavations. Also, we're always looking for you. I. Mean, we were not looking for for, especially for for for, like, a burial in Borneo, but we found one, but, but we can find, you know, all the you know, even burials, or even, like, you know, like evidence of those ghost species that we found from, from the DNA. That would be amazing, but you need to be extremely lucky to find that, but we know they're out there somewhere, so it's a matter of getting out there and getting some funding and digging and exploring and then eventually we'll find something interesting.
Nick Jikomes 1:20:31
Yeah, and I wanted to ask you, so for this type of work, where does the funding typically come from? Is it mostly from the university system? And sort of how much funding is out there for this type of work. Because on the one hand, everyone, pretty much, is interested in the story of human evolution. To some extent, people love learning about this stuff, even if they're not archeologists or paleoanthropology people. But on the other hand, my understanding is the funding is quite limited. Yeah,
Maxime Aubert 1:20:56
the funding is quite limited. The only thing really you can apply for in Australia is the Australian Research Council, but that covers pretty much everything there's, there's another system for, for for medical research that's separate, but for everything else, you have to go to the Australian Research Council and, and, yes, you you know, you need to have a good project. You have to have a good track record. But it's also a lottery, so the funding is limited. And, you know, I always say, if I was based in the United States or or in Europe, I could get a lot more funding for the research that I do, but I'm based in Australia, and the research funding for that is less because it's a smaller pool of population. There's less money for research, but, but it's good that it's getting out there, like in the media and, and, you know, like, and when we have big papers in nature, then it brings the global attention to it. So, so it's always good, and that helps in the long term for the funding, because we're trying to find out who we are, you know, it's a it's interesting and, but, but there's also other aspect, you know, like diplomacy or so, it opens another door for the Australian government with the Indonesian the Indonesian government, you know, etc. So there's all these, these, these aspects that we're trying to sell, you know, to get, to get more money. But, yeah, I've got some grants from the National Geographic also before, but it used to be relatively small amount. I think they're bigger now, but, yeah, but it's, it's limited the amount of funding that's that's available for that target research, that's for sure. And we would like to find out more about the conservation aspect of the rock art. You know, as I was explaining, is disappearing. We would like to know what's going on, you know, that sort of stuff. But it's up to get funding for that.
Nick Jikomes 1:22:36
And so, I mean, just, can you give me a sense for So, if I look at like this recent Nature paper, the narrative cave art in Indonesia, roughly speaking, off the top of your head, how many years of work does that represent? And how much money is that order of magnitude to do a project like that?
Maxime Aubert 1:22:55
Well, it depends. You have to put that in context that we've already worked there before, you know, establishing the like relationships and, yeah, and, you know, we have demonstrated that we can date the rock art there, etc, but, but I remember, like I said, I think, like the project in Borneo that we did for the the just The dating of the rock art, not the excavation that costs. And there was only one paper that we published in Nature for that, but we spent, it's really expensive to go there. Like, we go, like 2030, people in Bremer. We did two or three field season. It costs half a million Australian dollars for that. So that paper costs like half a million Australian dollars.
Nick Jikomes 1:23:39
So, like, if, someday, if some billionaire enthusiast of human evolution decided to just grant ten million to a few different ways that would do a lot, that would do a lot. Yeah,
Maxime Aubert 1:23:52
absolutely, absolutely, yeah. But there are some people philanthropists, they're giving money. But it's mainly like in, you know, in United States or Europe and stuff in in Australia, it's really hard to get that, that kind of of money available, like, people with that kind of money that were prepared to do that, like, it's, it's hard to, yeah, but by making new, you know, making movies and making podcasts and papers and stuff, Maybe the that's going to help. But this
Nick Jikomes 1:24:21
has been fascinating. I just discovered your work pretty recently, but it was really cool to look at some of these recent papers. Is there anything that you want to reiterate that we talked about today, or any final thoughts you want to leave people with about your research or about this field of study in general?
Maxime Aubert 1:24:38
I don't know what. It's still ongoing. So is we still working there. So the project that I have at the moment, so it's funded by the Australian Research Council, where we're not just looking at the rock out, so we're looking at the northern route to Australia. So there's different so when people arrived in in Southeast Asia, when they want to reach Australia, Sahu, which is New Guinea, and Australia. We are drawn together. There's different modeling that has been done to show because there's two arcs of islands in Indonesia, you can go to the Northern Ireland chain or the southern arc. So the northern one, you go to Borneo, solaezi, and then there's a series of island and then you end up in Papua. Then from there, you can walk, you know, I'm going to Australia, or the southern route, which is Sumatra, Java, the valley Lombok, and then you probably end up in Timor. Then from Timor, then you have to go by boat to Australia, to the Kimberley. And there's been different papers over the years like modeling, like they're looking at sea level heights and what you can see the next island, and they suggest that it's probably the northern route that the earliest human abuse, but there's no evidence of human there at the time. But now with the rock art where we can piece that together. And now the oldest one that we had is 51.2 minimum, but we have some coming, hopefully next year, going to show that it's older than that. But all of the rock art that we've dated so far, like the places in rock art, it's all in the Northern Ireland, chain of Indonesia. So it's interesting, you got, like, islands like Java, for example, with this limestone cave everywhere. There's millions of people live there, and there's no rock outside at all. So so it's there seemed to be a relationship between the first wave of Bonnie Newman that reached Australia and in cave art. So I've got a project on that. So we're looking at the northern route, so not just dating the rock art, but so a part of it was to develop this laser ablation method that we just showed that it's working, but also doing excavations. So we did an excavation in Borneo. Now we're looking for a place to do an excavation in Missoula Island, as I mentioned, we're working in Sulawesi, also excavation there. So yeah. So we got this project. It's a five year project looking at that modern human through the northern route.
Nick Jikomes 1:26:54
Well, this has been fascinating. Thanks for taking the time, especially with the difference in times over here, Australia versus the US. It sounds like in the next year or two you're gonna have more work coming out. That sounds pretty interesting. Yeah,
Maxime Aubert 1:27:06
we will. We will. We got a couple of big things coming up, maybe one before the end of the year. I'm not sure. It depends on the acceptance, but about the next year to the year, there'll be some big papers coming out soon, all right. Well,
Nick Jikomes 1:27:19
I'll keep my eye out for that. Yeah, thank you. Thank you for your time. Thanks to you.
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