Instant Genius - The golden age of dinosaur discovery, with Prof Steve Brusatte

Episode Date: June 17, 2021

Prof Steve Brusatte tells us how the latest findings in palaeontology have turned our picture of dinosaurs on its head. Once you’ve mastered the basics with Instant Genius, dive deeper with Instant Genius Extra, where you’ll find longer, richer discussions about the most exciting ideas in the world of science and technology. Only available on Apple Podcasts. Produced by the team behind BBC Science Focus Magazine. Visit our website: https://www.sciencefocus.com/ Hosted on Acast. See acast.com/privacy for more information. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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I'm Jason Goodyear, commissioning editor at BBC Science Focus magazine. In this episode, I speak to Steve Brissate, a professor of paleontology based at the University of Edinburgh. When we talk about dinosaurs, let's start like at the beginning, what exactly are we talking about? What makes a dinosaur or a dinosaur? That's a good question. it's a bit of a challenging question to answer, I must say, because the answer to the question

might be a little bit unsatisfactory in the sense that dinosaurs like mammals or snakes or insects or whatever group we're talking about, there is a formal definition, and that definition depends on the characteristics that those animals have. So dinosaurs are defined as those animals that have things like an extra vertebra connecting their pelvis to their backbone, a big open window in their pelvis where the thigh bone connects, a long and extra big muscle attachment for some of the muscles on the forelim on the upper arm bone. And it's those kind of things that technically make a dinosaur a dinosaur. And it's because of that that things like T-Rex and Brontosaurus and T-Rex and T-Rex and

triceratops are technically dinosaurs, things like pleasiosaurus and pterodactyls and woolly mammoths and other giants from prehistory are not dinosaurs. But I think in the popular parlance, really, we kind of know what a dinosaur is. It's a big, ancient, prehistoric reptilian-ish creature. That's what people think. We think we know it, but actually it gets to be a bit more nuanced than that. And I'm sure we can explore that a little bit more in this chat. Yeah, that's great. So, sort of coming at that then from a slightly different angle, when did they live? Sort of what time periods are we talking about?

Well, they do live today, and there's some right outside. This is, you know, beautiful day here up in Scotland, shockingly. And I've been out, you know, working on the grill a little bit to do a little barbecue today. And I've seen some dinosaurs out there. I've seen a couple of magpies, and I've seen a few pictures. So modern day birds are dinosaurs. They descended from dinosaurs. That makes them dinosaurs. That means there are still 10,000 or more species of dinosaurs that share the modern world with us. But, of course, when people normally think of dinosaurs, we're thinking of things like T-Rax, Brontosaurus, Triceratops, Stegosaurus, Phloceraptoros. So those classic dinosaurs, in other words, all of the dinosaurs other than the birds, which just happened to be the only ones that have survived today. All of those other dinosaurs lived from about 230 million years ago until 66 million years ago. And this was during what's called the Triassic,

Jurassic, and Cretaceous periods of Earth history. And now not every dinosaur species live together. We have to remember this. And in fact, one of the great trivia questions or factoids about dinosaurs is that T-Rex is actually closer in time to us than it was to Brontosaurus. If you can believe that, and it's true, because T-Rex lived right at the end of the time of dinosaurs 66 million years ago. Brontasaurus lived in the Jurassic period about 150 million years ago. So the point really is there. There were lots of dinosaurs.

They lived for a long time. There were probably millions of species of them. And they still do persist today in the guise of. of this very unique descendant group, the birds. So that's really, really fascinating, the sort of longevity there. This sort of, when I first read this, I don't know, it was a good while ago now.

It's like my head exploded. It's, they're millions, like 150 million years of this period where the dinosaurs, what we commonly know. And if you compare that to Homo sapiens, the difference is huge, right? So we're talking a few hundreds of thousands of years for Homo sapiens? It's mind-bending when you think about it.

And you're right. Homo sapiens, you know, people are always finding slightly older fossils in Africa where Homo sapiens originated. But by and large, we're talking about a few hundred thousand years, 200,000 years, 300,000 years, maybe a little bit more, which is a lot of time if you just think about, you know, my goodness, how much our world has changed in the last year and a half. But when you compare any of it,

of this stuff to the reign of the dinosaurs, that's when you start to get this mind warp of deep time. And it's, I think it's really impossible for us as humans to feel what it means when we talk about 150 million years. But dinosaurs were around for a huge span of time. They were incredibly successful. Any group of animals that survives for that long and is that diverse and lives through the climate changes, the temperature changes, the sea level rises and falls, the volcanoes, and so on, that dinosaurs had to live through that group is incredibly successful. And so we need to think of dinosaurs as some of the great success stories of evolution and of Earth history, and not as failures simply because after a very long time, most of them went extinct.

So you sort of touched it there. Obviously, there's massive variation in, the body shapes and the behaviors of dinosaurs. So just sort of, you know, by way of comparison, can you sort of tell me what the most extreme differences are? So what are the smallest compared to the largest and that type of thing? So we can get an idea of how vastly different they were. Maybe the most incredulous thing about dinosaurs is their range of sizes.

And I think when you hear the word dinosaur, and that's true for me too. somebody who studies dinosaurs, your mind automatically goes to T-Rex or to Brontosaurus or to Diplodocus, to some of the absolutely enormous dinosaurs. And some of them were gargantuan, in a way that nothing else has ever been. Certainly anything else that's lived on land. Yes, some whales have gotten bigger, but living in the water is a whole different thing. You can just kind of float around passively in the buoyancy of water, but living on land, you have to hoist yourself up against gravity and you have to move and you have to worry about drying out and you have to

worry about temperature extremes. And when you think about all of those challenges, it seems almost fictional that you had real dinosaurs like Argentinosaurus or Patagatitan that were actually larger than Boeing 737 aircrafts. And these are real animals. We have their fossils. We have their bones. We can measure their bones. We can estimate how big they were. These were animals. these were long-necked dinosaurs, by the way, close cousins of Brontosaurus and Deplodocus, and they lived south of the equator back in the Cretaceous period. These were animals that would have hatched from an egg that was no bigger than like a coffee cup, and they would have grown up into something, the size of an airplane, bigger than an airplane,

within about 50 years at most, and they had to move themselves around, and they had to get food, and they had to raise their young. That's the size extreme on one end. But you can also think of the size extreme on the other end. And the very smallest dinosaur is one that's actually still alive today. It's a tiny little bird, the bee hummingbird. It lives in Cuba. And it's about the size of a bumblebee. And think about that size range. Bumblebee size to airplane size in one single group of animals. That is crazy. And by the way, yes, that bumblebee hummingbird is a bird. It lives today and maybe you might be thinking, well, did those tiny dinosaurs live during the time of Argentinosaurus and Patagotitan? We don't know of anything quite that small, but there were

definitely other dinosaurs, not birds, other types of dinosaurs that were just about the size of pigeons that were living at the same time as those dinosaurs the size of airplanes. That's amazing. So you mentioned there that takes like the Argentinosaurus, you say, you said 50 years there for it to mature entire. adulthood. What do we know about how long the dinosaur's lifespan was? This fascinates me. And it's not an area that I really actively study myself, but I have a lot of colleagues and a lot of good friends in the field that have pioneered a lot of this work of studying dinosaur growth and dinosaur longevity. And the way you can do it is by taking really thin slices of dinosaur bones. I'm talking, you know,

salami thin, actually thinner than slices of salami, putting them on glass slides, looking at them under the microscope. What do you see? You can see growth rings, just like in a tree trunk. And you can count those rings, and that will tell you how old that particular individual animal was when it died. And if you have enough fossils for a certain species, let's say T-Rex, you can cut up a bunch of them. You can see how many growth rings there are. You can see the size of that fossil. You can make a very simple graph, and that graph shows you not just how long those dinosaurs lived, but how big they got and what rate they were growing at over time. The thing that is incredible is that when this work was really first done in earnest in the early 2000s,

and it was done on T-Rex as one of the pioneering dinosaurs, because we actually do have a lot of fossils of T-Rex from youngsters all the way up to adults, there were a couple of pretty shocking revelations. The first one being that there were no T-Rex fossils that had more than 30 growth rings. So T-Rex never lived to be more than 30 years old as far as we know, which is not. So, you know, I don't consider myself that old. I hope I'm not that old. I'm in my late 30s.

I don't feel that old. But I know we've all aged tremendously over the last year and a half. But if I was a T-Rex, you know, I might have been dead a decade ago. And that's living a good life as a T-Rex. That was a shocker. Before that evidence came out, a lot of people thought, like T-Rex got really big because they grew bit by bit, little by little, every year, kind of like an iguana does or a crocodile does. And if they live for 100 years, 200 years,

they could eventually become huge. That's not the case. The other crazy revelation is that really to get to be the size of a double-decker bus, which is what T-Rex was, it weighed about seven or eight tons as an adult. To get that big, growing from, from a hatchling that would have come out of a small egg that could have, you know, you could have held a T-Rex egg in the palm of your hands, to go from that size to bus size in less than three decades. You had to grow so fast, and these Tyrannosaurs grew so fast during their teenage years that they put on three, four, five pounds of weight every single day on average. That is a growth spurt, and that explains how they got so big. And that's just a different picture of dinosaurs.

then the idea that was presented, even in a lot of the books and TV shows that were around when I was in school in the late 80s and in the 90s, this idea of dinosaurs as these slow-growing, slow-moving, dim-witted, oversized lizards. We now know that's not the case. A lot of them were active, energetic, dynamic, they grew fast. And I tell you what, if you're going to put on five pounds of weight every day for a decade on average, you're probably going to be warm-blooded, or you're going to have a metabolism that is much more like a mammal than like a lizard or a snake. So yeah, you mentioned there that, you know, recent, over recent, you know, the last decade or so, a lot of what we think about dinosaurs has been turned on its head. So one of the sort of biggest, most interesting revelations of these for me is that they

didn't have scaly lizard-like skin at all, but in fact they had feathers. This is the big one. This is the biggest change in our perception of dinosaurs that's happened in my lifetime. And probably in the lifetimes of many of you who are listening, although some of the younger listeners out there, this would have happened a little bit before your time, but not that long ago. This was in the 90s. In 1994, there was a particular, very famous, very iconic movie about dinosaurs that hit the cinemas. And I remember seeing it very well. Jurassic Park, maybe some of you have heard of it.

And I'm really privileged now. I'm the science advisor for the Jurassic World series. So there's a full circle thing there, which is so much fun. But I remember seeing the film in the cinema when I was nine years old in 1993. And those dinosaurs, they were active. and energetic and dynamic, and they moved fast, and they were smart. That new image of dinosaurs was hitting the big screen. Jurassic Park did that. But the one thing that's a little bit weird about those dinosaurs that maybe looks a bit outdated is that they did look like overgrown reptiles,

especially the raptors. So those velociraptors, they had green, scally skin. That was the picture of dinosaurs at the time. But three years after the film came out, some farmers in China, in northeastern China, in a place called Liaoning, a province of China that straddles the border with North Korea, is way tucked up there. Farmers in Liaoning started to find skeletons of dinosaurs covered in feathers, including a lot of different raptor dinosaurs. And so unfortunately, Mr. Spielberg didn't know about that evidence. That's why the Jurassic Park Raptors looked the way they look. But this was all starting in the mid-90s. You know, this was really 25 years ago. Not that long. ago. And since then, farmers have continued to find there are now thousands of different fossils

of feather-covered dinosaurs from China and a few from other places in the world. It's very hard to preserve feathers or skin or muscles or other soft bits on a fossil. That's why these are so rare. And that's why they're really concentrated in this one part of China, because you had really entire ecosystems that were buried, almost Pompeii style by volcanoes. And just like at Pompeii, you know, humans, they were covered up. When Vesuvius erupted, and you had people that were kind of locked in place by the ash as they were walking their dogs and cooking breakfast and so on, living their lives. The same, or something at least quite similar was true of these dinosaurs. So that locked in their feathers. That's why so many were found in China. That's why so many

continue to be found there. And what's really interesting is that it's not just a few species of dinosaurs that have these feathers, it is lots of them. Meat eaters and plant eaters. Small dinosaurs and big dinosaurs. There is a Tyrannosaur from China that was about eight or nine meters long, so getting to be about 30 feet long. It would have weighed over a ton. It's called U-Tyrannis, by the way, and it was found covered in feathers. And so you have a lot of of dinosaurs across the dinosaur family tree, different diets, different body sizes, they had feathers. Feathers were a normal thing for dinosaurs. Feathers for dinosaurs probably was a lot like hair for mammals. It was a dinosaur thing. Now, that's not to say that these dinosaurs all had wings, and they certainly

were not flying because they had simpler feathers. They had feathers that looked a lot like hair. simple little strands, little filaments. No way they were flying with those things any more than we can fly with our hair. So that's telling us that these dinosaurs, they did not evolve feathers to fly. They probably evolved these simple feathers initially to keep themselves warm, to retain body heat, part of their physiology, their metabolism, maybe even as display structures to attract mates and intimidate rivals. And most dinosaurs kept it that way. Most dinosaurs retained these very simple feathers.

But one group of dinosaurs, these very advanced raptor dinosaurs, they got smaller and smaller over time, whereas many other dinosaurs were getting bigger and bigger over time. But these raptors got smaller, and as they got smaller, they elaborated their feathers, and those simple little strands turned into quill pens, and those quill pens lined the arms and turned into wings. And then you got this one group of dinosaurs

started to experiment with dothes, different ways of moving in the air, gliding and flapping their wings and so on. And that is where modern birds came from. So another thing that came from this, which is really mind-blowing, is that from studying the fossils of these feathered dinosaurs, we can to a certain extent determine what color they were.

Another mind-boggling, amazing thing. And this is one of my favorite discoveries. And in the rise and fall of the dinosaurs in my book, and then in the new kids version, the age of dinosaurs. I tell the story. I think it is one of the most fascinating and also inspiring stories of recent research because some people figured out how to do what was thought to be impossible. And I remember this.

And the books that I had in school, it was said explicitly in some of these books that we will never know what color dinosaurs were. All we have are their bones and their teeth. So maybe they were green, maybe they were pink, maybe they were purple, maybe they were polkaed out of it, we just will never know. And that is a very dangerous thing to say in science because around 2010, somebody figured it out and that somebody was a student. He was a brilliant young student, Jakub Vinters is his name. He's now a distinguished paleontologist, and he works at the University of Bristol. But he figured this out when he was a PhD student. And he actually wasn't

even studying dinosaurs. He didn't really have much interest in dinosaurs, but he was studying ancient squids and other invertebrates. And he noticed that these things had these strange structures preserved that looked a lot like what are called melanosomes. And these are the little vessels that hold pigment. There are little cells, basically, that hold pigment. And they're basically little bubbles. and we know in the modern world, you know, we have them, my hair, your hair have these, our skin have these, bird feathers have these. You know, this is where a lot of the colors come from. And we know from studying modern day animals that the rounder, more meatball-shaped ones give a certain color, and the longer, more hot-dog-shaped ones give another color. And so Yaakov figured this out, and he figured out that

these melanosomes were actually preserved in some of these feathered dinosaurs. They were buried so quickly by those volcanoes that even locked in their pigment cells. And by looking at the size and the shape and the distribution of those things, you could make a prediction, a really confident prediction of what color that dinosaur was. And so this has been done now for maybe about five or six different dinosaurs. Yacob and I have a student, Angus Krautus, who did an undergrad project at the University of Edinburgh with me. So we have great undergrad students doing this work now, and Angus has just finished looking at another dinosaur. But what we see in that handful of dinosaurs that have been studied is they had quite the diversity of colors. There were ones that had

white feathers, black feathers, brown feathers, ginger feathers. There were ones that had camouflage patterns, ring patterns on their tails like raccoons. Some even had shiny, iridescent feathers like crows do today. So I think when we look at birds today and we see the absolutely amazing diversity of colors and pigments, dinosaurs back in the Jurassic Cretaceous, they would have been the same. Yeah, that's amazing to think of that. Another sort of recent discovery that actually from reading your previous book, and I think you wrote, actually you wrote an article for us about this, it's the new scanning work on the brains of dinosaurs. You know, like you said earlier people used to think of them as this sort of slow-witted lumbering oaths,

but actually the more we study them, if that's not the case at all. Could you tell me about how we do that? Yeah, and I did. I wrote an article for you guys. I think it was in 2018. And by the way, just I want to say publicly for the record, Jason, for you and for everybody at Science Focus, you know, you've always been very kind to me and giving me some great opportunities to write some really fun articles. So I do appreciate it. And that all really factored in a lot to the books I've written. You know, that sort of writing, working with you guys, it really helps set the stage for the books.

And that one article in particular was particularly fun to write because we basically looked at this stereotype of dinosaurs as these dim-witted, you know, let's just face it, kind of morons of prehistory. You know, that's what you see in a lot of the old books and you hear these things like, oh, Stegosaurus, was the size of a truck, but it had the brain the size of a walnut, you know, these things, which actually turns out to be wrong.

Its brain was the size of two walnuts, but I digress. But we've learned that a lot of those stereotypes are wrong. And actually dinosaurs probably had a range of intelligence. Some probably were pretty dull. And others, like the raptor dinosaurs, like Velociraptor, were incredibly smart, probably on the same level as many modern birds, which are very smart. Don't let that bird brain insult fool you. Birds are very smart. Birds and mammals have the largest brains relative to their body size of any living animals. So how do we know this stuff?

How can we possibly know what the brain of a velociraptor looked like or how smart it was? Well, the answer is in cat scanning. We can put the skulls of these dinosaurs into a cat scanner, and a lot of us now do this regularly. We have a scanner in the basement of our building in Edinburgh. It was built by Ian Butler, who's a colleague of mine. I was actually a geochemist by training, but he built this machine, and now we've got him hooked on scanning fossils. And you can use the x-rays of the scanner to build digital three-dimensional models of the head, and that allows you to see inside the head as well.

And you can digitally fill in the space where the brain once was, or where the ear once was, or where the sinuses, were, and you can build a model, and you can look at the size of that. You can measure the size, measure the shape. You can compare it to modern day organisms. And what that has shown is that actually quite a lot of dinosaurs were pretty intelligent. They had brains that for their body sizes, because remember, when we're talking about brain size, it's always going to be relative to body size. You know, plenty of things have bigger brains than us in absolute, you know, mass terms, but it's brain relative to body size. And when it comes to dinosaurs,

like Velociraptor, their brain relative to body size was just off the charts for reptiles. And it was really getting close and in some cases maybe even overlapping with not only birds, but mammals today. So sort of you touched on it there a bit. So through these scanning procedures, can we also learn more about how dinosaurs use their different senses? Yes. So we're learning a lot more about not just intelligence, but about senses across the board. And some of that can come from the brain itself, from scanning the brain, building those models. There are regions of the brain, like say the olfactory bulbs at the front of the brain, that control the sense of smell. And we know for modern day organisms, you know, things that have bigger olfactory bulbs relative to not only their

body size, but their brain size generally can smell better. And they use smell more as a sensory tool. And so we can tell, for instance, from measuring those olfactory bulbs and dinosaurs, that two types of dinosaurs in particular had really off the chart senses of smell because of their really big olfactory bulbs. And those were the raptors like velociraptor and the Tyrannosaurus. So T-Rex itself was a smeller, a champion smeller. And that's why that famous movie scene, whereas, you know, if you stand still, the T-Rex won't know you're there. Nope, no. It would sniff you out really quickly. And so that's one example,

but we can also learn things about dinosaur hearing and dinosaur, their senses of balance and equilibrium from doing scans of their inner ear because those senses are basically controlled by not only the cochlea in the ear for hearing, but there's a system of three canals that are basically kind of like a gyroscope accelerometer type thing in the ear. We have these,

and they help control or regulate different aspects of balance and coordination and so on. And so we can see that some dinosaurs there were quite agile because they have these long looping canals that would have given them really great precision over their movements. We see some dinosaurs, again, like Tyrannosaurs, had really long cochleas. We know from modern day animals that the longer the cochlea, the greater range of sounds you can hear. So as you can see, we can really use this evidence from cat scanning to start to flesh out what these dinosaurs were like, not just as these fossilized objects in our museum collections, but as living, breathing, moving, growing, thinking, sensing animals. So that's really what follows on nicely to what I was going to ask next. So from all of this, all of this information, all of this data that we're gathering, on their brain sizes, their senses, other aspects of their anatomy.

Can we piece together what their hunting behavior was? And, you know, what's like a day in their life or a velociraptor? Can we figure that out? We can figure out snippets for sure. I think we're a bit maybe like a police detective putting together a timeline of a suspect. You know, we're not going to know everything from fossils. Even the best fossils in the world, these are things that are tens or even hundreds of millions of years. old. Usually you only have bones and teeth. Sometimes you get lucky and you have feathers. Sometimes

you get lucky and the skull is so well preserved. You can cat scan the brain and so on. But we're not able to see these things actually alive. So of course there's going to be aspects of their lifestyle, of their behavior, of their biology that we can't easily get from fossils. But that should not stop us from focusing on what we can obtain from fossils. And that is actually a lot of information. And so we can tell, for instance, that some dinosaurs were social. How do we know that? Well, we find bone beds.

We find mass graveyards where there are hundreds or sometimes even thousands of individual dinosaurs preserved together, usually because they were engulfed by a flood when they were crossing a river or something like that. We see this today with, say, you know, herds of wildebeest or so on. So those kind of fossils really do give snapshots into the behavior of organisms. Fossilized footprints and handprints, the trackways dinosaurs left behind. Those can directly tell us how fast those dinosaurs were moving. It's a simple calculation based on the spacing between the footprints. Just think about it.

If you're walking on a beach, there's very little space between your footprints. If you're running on that sand in the beach, you know, there's much greater space between your footprints. because your strides getting longer. It's a simple calculation. You can calculate the walking or running speed of dinosaurs. So that's another way we can get a snapshot into the lives of these dinosaurs. And there are many other examples, too. So we can learn a lot from fossils, not everything.

There will always be unknowns. We always have to be honest about the caveats. But what's incredible to me is that with that detective analogy in mind, we can actually be pretty good detectives. And we can get a pretty good sense of what happened at that crime scene, you know, beyond a reasonable doubt, let's say, even if we don't know all the details. So kind of, I could speak to you for about 10 hours about this, I think, but we've got to wind up. So it's just sort of last topic.

Obviously, 66 million years ago, there was a big change on the earth. And the dinosaurs, as you said, they live on as birds, but the big ones, as we know, died out. So how much do we actually, how confident are we and what do we know about that event? 66 million years ago, there was one day. What's today? Today's a Tuesday. I don't know which day this will be broadcast, but let's say it's a Tuesday. We'll say it's a Tuesday afternoon, because that's when we're talking. Somewhere around the world at that time, it would have been a Tuesday afternoon. Things were fine. The animals and plants and ecosystems had no idea this would be the last day of the Cretaceous period. Because that day, literally a rock fell from the sky.

There was an asteroid. It was about 10 kilometers wide, so about six miles wide. Imagine a rock, the size of Mount Everest, or about the width of the city of Edinburgh, where I'm, you know, joining you from, hurtling through space on a random trajectory, moving faster than a speeding bullet, literally, it was. And it just so happened to have the terrible luck of slamming into the earth. It hit what is now the Yucatan Peninsula of Mexico, and it hit with the force of over one billion nuclear bombs put together, and it punched a hole in the crust that was over 100 miles wide. He even went all the way down to the mantle, that hole, and instantaneously, the earth changed. Tsunamis, earthquakes, wildfires, hurricane force winds, volcanoes going into overdrive. It was

an apocalyptic scene. And of course, the closer you were to ground zero, the worst. Within the first few minutes, hours, days of that eruption, a lot of the world was scarred and a lot of animals would have died. But then over the next several years, there would have been a nuclear winter, a global nuclear winter from all of the dust and dirt and grime and ash and soot and rock that was lofted, vaulted into the atmosphere, it would have circulated around the earth, it would have blanketed the earth in darkness for at least several years. Plants couldn't photosynthesize, forests collapse, ecosystems collapse like a house of cards. And then, over the next few thousand years, there was global warming following that nuclear cooling scenario. So all of those things put together

spelled doom to about 75% of all species, including all of the dinosaurs except for a few types of birds. And actually, most birds died out. There were a lot of birds that were around back then. There were birds with teeth and claws and long tails that were fluttering over the heads of dinosaurs, and they were annihilated by that extinction. It was only the birds that had beaks and no teeth and that had short tails, basically no tails, and that could fly really well that survived. And there were other survivors too, of course, including our own ancestors.

And this was really the turning point when mammals seized the crown from dinosaurs. But in fact, most mammals died too. And only a few survivors made it through. And like the birds, it seems like the mammals that made it through were the ones that were smaller, the ones that were more generalist, more omnivorous. They could eat lots of things. They could hide easier. they were better at weathering that tragedy.

And it was from those survivors that on one side, today's birds came. So the only animals in today's world that carry on that genetic legacy of the dinosaurs. And then from some of those other survivors, our own ancestors came. And it all goes back to what happened that one day. And this was really a case where the entire history of the earth changed, hinged on that one instantaneous moment of impact between asteroid and Earth. Thank you for listening to this episode of Instant Genius. That was Professor Steve Brissette.

If you want to know more about dinosaurs, check out his books, The Rise of Fall of Dinosaurs and the Age of Dinosaurs. Or, to hear him tell me more about dinosaurs and his fascinating life in science, head over to the Instant Genius Extra podcast. The gene issue of BBC Science Focus magazine is out now. Pick up a copy in store or visit sciencefocus.com. This podcast is sponsored by Name, Audio and Focal. The texture and emotional depth of music can be lost through digital sources or poor signal.

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