Have you wondered how fire science started? But I mean the real real start... not 1666 one, nor the one when we've started to build furnaces... The start when the first evolutionary ancestor of homo sapiens figured out this warm bright thing could be used to process food. The start when this bright thing was protected and used intentionally. The bright thing that was so important for our kind, that the proof for this relationship can be found literally in our anatomy...
The best way to study this origin would obviously be a time machine. I don't have that. But I have the second-best thing - a real scientist Dr Ivo Jacobs studying the relationship between animals and fire, to uncover how our ancestors could have learnt how to behave at the fire and how to use fire to their advantage. There is not much fire safety engineering in this episode, but there is something really magical to learning how impactful that thing we study was for our kind. And I hope you will really enjoy this.
And if this sparked your interest, go on and check these great resources:
Hello the welcome to Fire Science Show. Episode 58 grade heavy here. I'm middle of my summer holidays. And I don't feel that much. I like doing serious firesides. So today I both use some fun fire science. I hope you enjoy. This may be a little less engineering oriented episodes. But for me, it was a great pleasure to record it. So sometime I go, I've seen on Twitter researcher from Linden university Ivo Jacobs who did his research on how animals. Percy fire and, how they use fire, how. I felt, wow, that's such a cool subject. I need to talk with him because that is in essence, the research on the very beginnings of the fire science and. Fire engineering, maybe not fire safety engineering, but engineering with fire at least so I invited Ivo he was very keen to take my invite. I was very happy to have him interview on the subject. And I think you will enjoy the lot. It's, uh, it's very different from what we're talking about in here. I think everyone enjoys science given in a fond way. And this this discussion will make you think about things you've never thought about , when dealing and learning about fire science. So, yeah, I don't think this needs more introduction. Let's not belong this play danger and jump into the episode. And I really hope you will enjoy this fun talk. As much as I did. Hello everybody. I'm today with Ivo Jacobs researcher from Lund university. Hello, Ivo nice to have you in the show. Yeah. Uh, thanks. it's uh, really nice to be. Ivo is with Lund university, but not the part you're thinking about Ivo is in. Quite far field, he's a biologist and, is interested in psychology as well. And I've invited him because, I saw on Twitter, he's doing amazing research on how animals perceive fire and literally the studies on, on monkeys playing with fire. And that's what I do daily. I study monkeys playing with fire. It's just, they're a little more complex. so Ivo, that was like fascinating eye opening that someone researches that field. I've learned that you use also a term pyrocognition for that. So maybe let's first, like, let tell me, how did you get to studying, animals interactions with fire and then what pyrocognition is? Well, in many ways, , it kind of happened in quite a strange way, because during my PhD I was working, , on animal tool use. And I was reading, this book about animal tool use. And there were these mentions of, some crows, like lighting matches with a beak. And, uh, also some birds or prey in Australia that would pick up burning sticks and drop them elsewhere. And I thought that's, so strange wise, no one doing research on this and also these are all cases by birds and not by primates because of course everyone assumes, if you want to understand, Human evolution and how our early ancestors behave towards fire. You know, that we must study primates, which of course is an important aspect. But what has been found over over the last few decades is that in many ways, birds really rival our intelligence and then intelligence of follow primates. So that's what I've been working on. And then when I read about, uh, these interaction with fire, I really got interested. So then. You know, started doing some research and applying for grants and, that's why I'm now. I mean, I haven't done much research yet because it kind of just got started, but it's really exciting to, move forward. Mm. This is, so cool. Especially with, uh, with birds. I, I have like a, a prey of Crow, in near to my office. They always drop nuts under my car to crush them. So they're, they're I mean, I'm happy they could be throwing like matches or, pieces of burning material in my car, which I would not appreciate that much. And. and, and the term pyrocognition, how, how would you define that field of science field of knowledge? well, it's kind of difficult because, right now I define it in a very broad sense, just, the way that animals and humans. Interact with fire and use it and understand it. So that's a very, very broad definition, but it's hard to be more specific without more researcher. That's why I'm starting with a very, with this very broad definition, and hopefully I can refine it and sort of make more, a theoretical framework as we go. But it's just at this point as very little known about this understanding of fire. Yeah. Even in humans. And that's was maybe the most surprising thing in this project, because what we usually do when we work on animal intelligence is that we first look at, human psychology, you know, what do humans understand of this and that? but in this case, I couldn't even, start with that because there's been so little research on it. You know, of course there's much more applied, research, that I'm sure you and. Many lists of the podcast are more aware of, but, uh, but not this kind of principles of, you know, at what age do, , kids, know how to make fire or, you know, know how to use a tool to get something hot from Smalling calls. uh, or when do they learn about a fire triangle, these kind of things. Um, and of course these kind of basic. sort of like hands on experiences of obviously must have been very important for our ancestors as well. You know, how did they learn to cook? how did they learn, what part of like one fire is too dangerous and when you can interact with it, these kind of things. So that makes it very hard to start this residual animals as well. When that's so little known about humans, This is intriguing that you, you say, like when you think about it, I really did not hear much about studies in this field. When we, talk with our colleagues who are doing, psychology it's. Highly related usually to crowd management and, you know, these evacuation situations, I don't know much studies on perception of fire. I've heard about some really interesting studies on how people perceive fire I, I remember Daniel Nielsen. He was at at Lund university back then. He was, uh, showing research on. Virtual reality, showing people pictures of fires and, asking them, can you take this fire out with an extinguisher, you know, uh, and to, to understand how people perceive the, the threat of a fire and when the threat is overwhelming when it's not. So, so that's the thing, but I, that, that really is an interesting, like whole field of science that, requires discovery. Now if we, if we give back to like ancestry times, like what stage are like, we're talking about literally the, the first homo even earlier in, in the evolution of, of humankind So it must have been much, much earlier. And of course there is a lot of research on fire and human evolution, but then this mainly comes, you know, from like the physical evidence, uh, you know, like, burn bones used by our ancestors or, you know, small charcoal, these kind of things. And then there's also, some anatomical evidence, which, quite strongly shows. that, early humans were already really reliant on, eating cooked foods. Uh, and this is something also, I think many people don't really understand why fire is so important. Of course, this is something we, we learn early in school and everything, but by far the most important function fire is at. That it allows us to cook our foods and with, cooked food, it's much easier to chew, much easier to digest. You get much more energy from it. For example, if you would only eat raw potatoes, you get only around half of the calories from it. but if you prepare it with heat, so that's cooking, you get almost all of the calories out of it. and we can already see that in the fossil remains of our early ancestors to say around one of million years ago. that's these people started having, having smaller jaws, uh, smaller teeth, smaller, uh, ribs in the bottom, which means they had smaller guts. And these are all kind of adaptations that you get when you, start to cook your food. And, one notable, um, result of this is that our brains got much bigger because if you only eat raw food, You literally don't have enough time during the day to find, find enough raw food and you spend so much time chewing, you know, right now we spend maybe. something like half an hour per day chewing, but if he would only eat raw food, it would be about 10 times as much. And you notice, these people, nowadays that only eat raw food, you know, the raw food is, and they eat so many calories, but, that's one problem because when you look at the package, they choose the calories, you know, it's, it's been it literal, been blown up in the lab and I measured how warm the water on it gets. And of course that's not what our body. but anyway, so these people ate, a lot of calories. They, you know, shipped all over the world and process and blenders and everything, but still, they extremely healthy. They lose a lot of weight, and, many women even sub uh, mens that's, that's how much the, the body gets all in crisis mode. So that's, I think really strong evidence, how we're reli, we are on food and also every single. Human group around the world, no matter what they live on, they all cook their food. That is that's fascinating. So the evidence of fire being an important part of human, uh, life is. Literally in the autonomy of the body, even that, that is that that's absolutely amazing. Uh, for many times it was brought that the fire was like the first invention of a human or the first discovery of the human. What do you think is, was it invention or discovery? Can we settle that? I mean, it's, uh, kind of an arbitrary distinction, uh, because, at the time, humans were already. very often exposed to wildfires, you know, living in Africa, on Savannah. So, so they must have seen wildfires quite often. and. Probably before they really started relying much on fire. They were already using stone tools and they were using, so these stone tool tools to break bones and to butcher meat. Uh, so these kind of things that were already doing, before that, and here there's some interesting observations of wild primates in Africa. For example, while, chimpanzees in Senegal, where in the summers, it also gets very hot and dry and get a lot of wildfire. uh, so they're not afraid of the fire at all. They actually often travel, close to it. And if it gets too big or too fast, you know, to move a bit further away from it, but they rain very calm. And one thing that they often do is that when the fire is out. They like to travel through these recently burned areas because it's, um, it's just easier traveling without old vegetation in the way. It's easier to spot predators. and there's many predators who avoid burnt areas anyway, and also much easier to find food because everything else is, is burned up. Already cooked. that's. Yeah. Yeah, exactly. So of course, that's one way how our might have learned, about fire and cooking as well is that they often travel to these burned areas and find food. And not only that, they find it easier to find as food, but also that they thought it tasted better because of course we. Generally think that most foods taste better when they are cooked. And there's also been experiments done on great apes and they also prefer, their foods to be cooked because it's much sweeter, sweeter, and easier to chew. So, so that seems to be the sort of initial trigger for ancestors to have started relying on fire. And, I've also learned that there was like significant like societal or cultural affection to fire. At some point it was also the source of heating, but I guess this all would, be after it was used for this basic function of, prevent. yeah, that's of course really hard to say. And that. One of these reasons why I'm doing this project, because based on this evidence from the old charcoal and fossils and everything, we, we can learn many things, but many things, unfortunately we can't, and that's why it's very important to study, you know, humans and other animals, uh, living now. And, and this kind of approach has been done in so many. In so many different fields related to human evolution, is that what, you know, we study primates to understand, like how do social groups function for example, how do they use tools? so with my project, I'm kind of doing the same with fire. Uh, but of course it's very hard to, translate from animal behavior to how our ancestors must have behaved, but it just, it gives you some plausible, scenarios. So, so I do think that, Our early, early ancestors started, interacting more with fire primarily because of the food and the travel, and then probably later they started using it more, to stay warm, for example, or to one of, parasites and predators, because. Because by now there's so many functions of fire, even, even just in, uh, for societies, you know, like, uh, these, uh, groups that still just mean rely on hunting and gathering, for them. the fires mostly used for cooking as well, but that that's also, you know, the warmth and, uh, and the protection from animals and they use it to modify materials and these kind of things. So fire has so many functions and of course makes it hard to, to find. In the physical evidence of the fossils, and all the kinds of evidence, how, the main reason why they started interacting with fire. Is it, excuse me, if I'm asking silly questions, but, uh, it's, it's like, uh, so far away from my comfort zone and yet, so interesting. do we understand. When people start started to understand fire, did, did this moment where it became, someone used it intentionally, they understood that, okay. I can make this fire bigger. I can make this fire smaller. I can spread it into multiple pieces. I assume this is also like a part like you are trying to find that moment, like when it happened and how it happened. Right. the kind of examples that you are talking about while I'm really. To start with is, you know, really the basics, like imagine a primer, just living on Savanna sometimes, seeing wildfire, how do they start interacting with it? How do they understand it safe and these kind of things? it's hard to say when, early humans really. Understood the fire. but that's related to the kind of evidence that you do find, in the archeological record. because of course back then, there were also many wildfires. So there's always, uh, a lot of scientific debate about, you know, is this really evidence that humans made this fire and there wasn't wildfire. So, yeah, so that's why people, for example, are mostly looking at, caves because you know, there's not much vegetation that will burn up and, especially. Uh, especially the temperature of the fire because just a grass fire, doesn't burn so hot, but if you really make, you know, big bonfire or, you know, a fire for cooking and you keep it hot for hours, it really affects the sediment in different way. So that's generally seen as, as much stronger evidence that there was some kind of, uh, control of fire that doesn't. That doesn't necessarily mean that they made fire because making fire probably arose much later and there's still many hunter gather groups that, that can't make fire. We have to preserve it all the time. mm-hmm Uh, so yeah, because whenever I, I talk about, this topic to people, people always assume I'm talking about, you know, making fire, but that's really one of the much later things who I've, to have been discovered as it were. so at first it must have been much more, a wildfire trying Just natural fire that is preserved. Yeah. That's fascinating. I'm starting to, to come to a, a thought that fire science is one of the oldest sciences there is. That's cool. , that's a, that's, that's a cool outcome of this talk. I, I like, I like this outcome. So in the. Beginning you've said that you've observed like, animals interaction with fire that led you to this topic, Crow and, and birds of pray. Maybe you can, tell me a bit more like about these observations and what was this interesting about it? I've heard about the birds of like I've taught you in the green room. I've heard about the birds of pray because these damned birds were spreading wildfires and. If we fire scientists don't have enough problems with wildfires there's birds of parade, throwing, burning embers all over the place at vast distances. Yeah. I'm really curious about your observations on, on that. Yeah. uh, as I said, I really just started to this, not so much yet. Uh, one of, my, uh, studies looked at how. These Crow species interacted with heat lamps. So this, this particular Crow species, they're called new Cal crows. And, maybe some people have heard of them because they're quite famous for using tools in the wild. They're really reliant on using these stick tools often with hooks even, to find, food in the forest. so, many years ago when I was, working with them in, Germany. Uh, so they were there in an Avery, I noticed that they often use these stick tools and, put them against heat lamps and not just these sticks. We also had like these plastic straws for experiments. They also push 'em against heat lamps. I once, even a piece of food that they put on heat lamp, but of course it started again brown and smell really bad. So I had to, uh, so I had to take it away. So unfortunately I couldn't film anything. and at the time I didn't think so much of it just, you know, one of many strange things that these grows do. Um, but look, uh, looking back, uh, I was very happy at Lisa. I took some pictures of the burnt tools, and I have one very poor quality video of it. Uh, so at this point, it's, it's hard to say what really happened, but so first of all, these, this grows, they really just enjoy using tools. Uh, they, they're using it all the time to look in small crevices and everything. And I think in this case with the heat lamp, That they probably recognize that it's much too hot to, touch with their beak. So that's dangerous, but that they understand that with these tools, they can still interact with something while keeping their distance. so that's, I think. one of these example behaviors that must have been very important for ancestors as well, is that, you know, okay, this thing in front of me is very weird and it's moving and it's hot and dangerous, but if I take this stick, I can still interact with it from a safe distance. Uh, and so with this study, it kind of looks that these crows which are so, unlike us in many ways, you know, over 300 million years of independent evolution, that they can do it as well. And the. From a tropical island where there's not much wildfire. So it, it really shows that to have the flexibility to yeah. To change their behavior in these changing circumstances. And about this birds of pre did you figure out why they are spreading our wildfires? Just for fun, revenge. I dunno. uh, well, that's, uh, something I would really like to do research on, but, so far haven't been able, to go there yet. Um, and, this is something that happened observ for a very long time, but there's only been described in scientific literature a few years ago. Uh, so there were several independent observations, by scientists and lay people and firefighters. That they often saw these birds of pre in Australia, especially in Northern Australia, picking up burning sticks and propping them elsewhere. And of course at first it sounds very strange and there's many people who still don't believe it. But, first of all, there's many animals that actually are attracted to fire because of course, fire is dangerous for many other animals, especially prey items. So if you hunt, uh, all these escaping animals, then it's great to go to fire and just, uh, and then it's easy pickings. So that's what, uh, these birds are prey in Australia do as well. so why they. Pick up the burning sticks and drop them elsewhere. It's hard to say without proper research, but, if anything, it would likely be just to start a new fire to, to get even more animals to escape. Because if you look at these videos of all these birds of prey around the fire, it's so many, it's just crazy. How, How many birds you see, flying near the fire. So I guess I don't really get enough foods individually. So if someone figured out, if I take a burning stick and drop it elsewhere, I might be able to get more foods. So that's kinda my hypothesis, but of course, uh, we didn't know until someone looked into it. You know, in the fire science, we also have this, research on how, um, masses of air are moving with wildfires and wildfires being able to create their own, um, weather even, but the there's a thermal buoy and plumes in over large fire. So it's also probably easier for them to, High without any effort because they could be transferred by term. I wonder if they figured that out too, but so far it seems they've militarized fire, which I don't like. that's I prepared the Crow, not the bird of pray way, uh, in your project, you said, that it's, in the early, in the early stages, but, uh, I guess you already are planning like your next steps. Uh, so I was really wondering How does one approach such a research? I it's fascinating. How does one research, such a thing? How do you plan your experiments? What's are your next steps in this project? yeah, so it's quite difficult for many reasons, of course. First, first of all, you have the safety issue with the fire, but for example, what we're now that very well in fire science. Yeah. we, deal with that problem all the time. Yeah. So, so you don't wanna, you don't want to expose the, the animals to this either. so of course we have to be, very careful with that, but, uh, for example, what we do, with other experiments with the birds is that we just have, one of these small, lighter blocks, you know, uh, to, to lighter fireplace. And we, we have it, so outside the Avery, so they can't actually interact with it. Uh, so this is an experiment I'm doing now with our Ravens, uh, and it's quite similar to. To the study with the crows that I mentioned is that, if there's a fire on the outside of the Avery, just a small flame and there's food on the inside, you know, when they can walk up and pick it up, but they can also use a tool, to stay further away from, from the strange fire that they're not familiar with. so that's, uh, one approach and I mean, I don't have the results yet, but it looks quite promising. And, uh, and another study, I'm very excited about is, taking place in, uh, Japan. Uh, so there does the zoo. Where, where for over the past 60 years, uh, Zuki have been making this big bonfire in the outdoor enclosure of these Japanese mechanics. Uh, you might better know them as, uh, Japanese, snow monkeys. so, so this happens, you know, maybe a dozen time. winter. and then what the monkeys do is they all, get closer to the fire and they gather around, especially when it's very cold. So they seem to wa to, to warm themselves up. and they don't really show any fear of the fire. So often when I look at these videos, I get a bit worried, but, it seems like, you know, exactly sort of what they can and can't do. Uh, and of course, The problem with this is is that we don't really know how they behaved, in the very beginning, you know, 60 years ago. But at least we know by now this is true, you know, and they of course have many, young monkeys as well, and, which are, exposed to this fire. But it seems like they're, it seems like they learn fare well, how to interact with it. Uh, so yeah, so that's what we do now. We're just there and we are filming these interactions with the fire and then, you know, looking at the videos and you have to get these, different behaviors from, from the videos. so that's what work on now, but that's a big part of, uh, the current project. I love how you said that they seem to not, be afraid of fire. I wonder, uh, now it's a practical thing because as fire engineers, we're also like, developing, tools to save, also animals in buildings in, in, in wildfires. We also should care about that aspect of fire. And it's interesting that some animals can build, appreciation even for fire and then not. Not be afraid of, that at all. Maybe we should call them the, the Japanese fire monkeys from now on . And, and have you observed any like intentional out, outside of not being afraid and, and just using it for forming any evidence of like intentional use of fire at primates, uh, already, or it's later in your project. Hmm. Yeah. So right now, it's still just, just an observational study. So we are just there filming what they do naturally. So we haven't planned any experiments yet, but, uh, maybe we'll do that in the future. but one thing that the zookeepers do there, to Japan monkey center is that before they make big bonfire, they take these sweet potatoes and they put them underneath where they built fire. So then they light fire and after a few hours they put fire out and, Yeah. And then they just, let the monkeys take these sweet potatoes course. They're still quite hot. So yeah. So you often see the monkeys, rubbing their hands, you know, on the fur, like, Ooh, that's hot. Uh, and they're often even walking over the hot calls. So often it looks quite risky, but it seems like they're careful enough, that they know, you know, when do you get burnt and when don't you, uh, and that's probably also one reason why they like the fire, but already just when the fire's built up. So they would have to wait several hours before they get the potatoes. They're already gathering around. And, it seems to be the case that when it's especially, you know, wet and windy and cold, that they sit closer and also in bigger groups. So they often also fight over access to the fire because there's so many monkeys that they don't all fit around fire That's so cool. that's such a cool research and they seem to understand, uh, this improvement in food, from processing, like you mentioned this potato now Yeah. So it's, um, I mean, it's hard to say what they understand about it. Um, but in many ways it's, it's very easy just because. Because after the fire, the potatoes they get are just so soft and easy chew, and they are literally much sweeter because of the, heating process. so in many ways you don't have toand anything about the fire other than, you know, when's been in the fire, it gets tastier and you don't have to understand anything about how it's better for you, how you get more of the calories from it, how it's issued to digest. None of these things, you have to understand it, just, this food stays here. So, that's why I learned to really go for the cooked food. And that's likely how our well, that they didn't know, you know, of course the biological benefits of cooking, cuz that's quite, uh, that's quite complicated to understand, but just if the foods get STAs, then that's a very simple mechanism. I guess it also smells better. So that's an easy . I wonder if the fact that we like the smell of burn food is also a evolutionary outcome of, of that exposure to fire end. And I wonder if it smells better for animals to my dog seems to enjoy my food better than, than unprocessed food for one thing. But I cannot, I'm not sure if I can attribute that to his understanding of fire that's for. maybe not. Um, Ivo thank you very much for that. That was a really interesting journey into, into world of, of, uh, power recognition and, and, uh, evolution of understanding fire. And I think it's such a nice subject to study and, as a fire science community member, I, I really enjoy looking at this interdisciplinary studies around. That are so profound, like you are touching the, the very first fire engineers there. so, I hope you, get far with your research on the nature cover or somewhere, somewhere. Nice. And, uh, yeah. Good, good luck with that. Uh, if, if someone, ah, just one last question. If someone wanted to learn more about this, maybe there's some documentary series , or some books to read that someone could, , learn more. Yeah. so I would say the number one, , book on the topic is written by Richard Reham, who is a primatologist. , and, uh, his book, is called Catching Fire. , uh, how cooking made us human. And it's maybe a little bit outdated by now because it's been a lot of research on this topic, but the general points still stand. So it's, as I said, mainly about, the importa of cooking and human evolution and he, uh, has some nice examples as well about, animal behavior. Uh, even though it's, it's mostly some anecdotes, um, have for the rest. Yeah. It depends what kinda angle your incident is because there's many archeologists writing about this. And I'm not an expert in that. really, uh, I did write an, um, article for, uh, for Aon. it's a website, so essay about this whole project. So if you're interested to be sure to check it out where, where there's some references and there's some more, That's cool. I I'll link it into footnotes of, of course that's, that's, that's really cool. And, , once your research is, majored enough, you're very welcome to publish in some of the fire engineering journals on your findings. I'm pretty, I'm pretty sure it, it would be well received. Ivo Thank you very much for your time. I, I really enjoyed learn about bio recognition and yeah, man, all the best in your further journey. Yeah. thanks. It was, really fun, uh, chatting with you. And this is for this short fun summer episode of fire science show. I hope you've enjoyed this twist in the fire science while it certainly will size a fire. In, Just in a very different way that we deal normal with. I hope that opened some questions in your heads and you start perceiving the history of fire much more. For me, it was a shocker to learn that. Fire has literally changed the human adult to me. F and maybe if not fire, we would not be where we are today. Maybe I would not be able to recall this podcast. That's really, really intriguing to see how big impact fire had on our lives. And now also doing research on the firewall. It's nice to recognize we're doing research on I think so, so fundamental. Through the humanity. Um, It's I feel really out of comfort zone. Recoding this episode, there is not much more I can add to this. It was just a great conversation then. I'm looking up to read up the book that Ivo recommended. Because I certainly must say I'm intrigued by this topic. So, yeah, that is it for today. And next week, we're back to fire engineering routine and I have great lineup of guests coming. So I hoped you see you here next week. Next Wednesday. See the bye.