Instant Genius - How animals took to the air and conquered the skies

Episode Date: May 26, 2024

The existence of flight in the animal kingdom is something that many of us take for granted. But on closer inspection, it can perhaps be thought of as one of the miracles of nature. In this episode we catch up with the writer Lev Parikian about his book Taking Flight: How animals learned to fly and transformed life on Earth, which was shortlisted for Royal Society Trivedi Science Book Prize. He tells us about how flight has evolved independently in four separate groups of animals, how bats became the only mammals capable of powered flight, and how some birds ended up losing the ability to fly altogether. Learn more about your ad choices. Visit podcastchoices.com/adchoices

You said this place was steps from the water. We just haven't found the steps yet. How much did we save? Enough. Enough to get lost. Or you could book a stay with Hilton. Welcome to your oceanfront room. Just steps from the water.

The Hilton sale is on now. Book on Hilton.com or the Hilton app and save up to 20% to get the stay you expected. When you want savings, not surprises. It matters where you stay. Hilton, for the stay. No one goes to Hank's for his spreadsheets. They go for a darn good pizza.

Lately, though, the shop's been quiet. So Hank decides to bring back the $1 slice. He asks Copilot in Microsoft Excel to look at his sales and costs. To help him see if he can afford it. Co-pilot shows Hank where the money's going and which little extras make the dollar slice work. Now, Hanks has a line out the door. Hank makes the pizza.

Co-Pilot handles the spreadsheets. Learn more at M365Copilot.com slash work. Are your ad campaigns lighting up the dashboard? But not the pipeline. That's bullspend. And marketers are calling it out in. Dashboard, confessions. My boss asked for results.

So I opened my dashboard for the only positive-sounding metric I had. Impressions. Cut the bullspend. See revenue, not just reach. LinkedIn delivers the highest return on ad spend of major ad networks. Advertise on LinkedIn. Spend $250 on your first campaign and get a $250 credit. Go to LinkedIn.com slash campaign,

terms of conditions apply. This podcast is sponsored by name, audio and focal. Streaming has made music more accessible than ever, but true listening is about more than ease. It's about quality. British audio experts name audio, alongside French acoustic specialist focal, combine handcrafted tradition with cutting-edge innovation

and high-end materials, delivering digital precision with analog warmth, so you can experience exceptional sound at home. Music just as the artist intended. Visit name audio.com to learn more. Hello and welcome to Instant Genius, a bite-sized masterclass in podcast form. Each week you'll hear world-leading scientists and experts talking about the most fascinating ideas in science and technology today. I'm Jason Goodyear, commissioning editor at BBC Science Focus.

The existence of flight in the animal kingdom is something that many of us take for granted, but on closer inspection, it can be perhaps thought of as one of the miracles of nature. In this episode, we catch up with the writer Lev Pericium about his book, Taking Flight, how animals learned to fly and transformed life on earth, which was shortlisted for the Royal Society Trevelli Science Book Prize. He tells us about how flight has evolved independently in four separate groups of animals, how bats became the only mammals capable of powered flight, and how some birds ended up losing the ability to fly altogether.

First off, Lev, welcome to the show. My pleasure. So we're talking about your book, Taking Flight, How Animals Learned to Fly and Transformed Life on Earth. It's a fascinating subject. So what led you to it? Well, I've been a very keen birdwatcher for some years now, and I think I'm always thinking about birds a lot, but also wondering what exactly what it is that I particularly like about them. And I was searching for a subject for a new book, and it occurred to me watching a blute it just fly from the hazel bush to the feeder and then back again to go, oh, hang on though,

it flies. That's an amazing thing that we take almost entirely for granted in our daily lives. And yet it's a quasi-miracle, I think. So it led me to ask questions about the subject and thinking about how much I didn't know and how much I did know. And yeah, every question I asked had an answer. And then each answer I came up with kind of spawned a new question. which led me into areas of research that really led to the book. So you break down the book into different species. Yeah. How did you go about choosing them?

Well, there are, of course, there's millions of species to choose from. Flight has evolved four times that we know of in four groups of animals. So insects, terosaurs, which are, of course, all now extinct, birds and bats. And, of course, within those groups, and especially the insects, there's many, many choices you can make. So with the insects, for example, I broke it down according to the different modifications and adaptations that have occurred evolutionarily to the different insects to make them fly in different ways. For example, the dragonflies fly in very different ways to beetles, for example, and the Beatles adapted one pair of wings to act as protective coverings for their wings, whereas dragonflies have two pairs that they use in tandem. and in unison and in and out of sync to give them that extraordinary maneuverability and speed.

And again, with flies, there's a different mechanism at play there as well. So that was the way I approached the insects. With the pterosaurs, I chose to give an overall chapter devoted just to giving an overview of the situation, as we know it, with pterosaurs, which we have about 200 or so species, ranging in size from the smallest, which is about the size of a woodpecker, to the huge. which are the ones that I think might attract people's attention, the ones with 11-meter wingspans that would have soared over the oceans of the late Cretaceous. And then with the birds, it was a kind of personal preference. Again, trying to get contrasting style. So there's a chapter devoted to hummingbirds

and swifts, which are masters of aerial agility in one way. And then there's another chapter devoted to albatrosses with some other seabirds. And again, that's the contrast there of the frenetic activity of a hummingbird to the effortless soaring of an albatross. And I did want to devote one chapter as well to flightlessness, because it occurred to me, you know, it's a lot of hard work and time evolutionarily to develop flight. So what would lead animals to lose the ability to abandon it? And then the final chapter is the most recent animals to evolve the ability, which is our closest flying relatives, the bats, the only mammals that actually have the capability of powered flight. So in the end, it was those 14 chapters, and they're chronologically

ordered in order of evolution. So that made a quite nice pattern to it to tell the whole story or as much of it as I could. We'll get into a lot of that in a minute, but the story appears to begin with insects. So we're going back something like 400 million years here. Yeah, thereabouts for the first insects, and the flight would have developed, well, the first winged fossil we have dates from about 325 million years ago, and it's an insect called Delicala Bitterfeld-Densis, which is a long name to basically tells you where it was found in the fossil area in Germany, between a place called Delitzch and another place called Bitterfels. So there's a nice geographical naming there. And that is a beautifully preserved fossil, and you can see the curve of the wings,

and you can see the veining on the wings. And that's the first thing we have, the earliest thing that we know to have flown. And the difficulty is, as far as I gather, is that before that, for about 60 million years, there's hardly anything at all, not just no sign of how those wings developed, but hardly any insect fossils at all. It's known as the hexapoda gap, 60 million years or so, back to 385 million years, where we just don't know very much at all about the development of insects, whether they're flying or not.

But what we do know is that once they'd got it, into the air and we have those very well-developed wings in Delicalla, it proved enormously useful. So we've got millions of insect species today and the vast majority of them fly. So this powered flight, once it had taken off, it really enabled insects to radiate and diversify and to conquer the world, really. If we're talking about the evolution of wings, how exactly did that happen? You mentioned things like half wings and something known as the Gill hypothesis. Yeah, so there's a few hypotheses about how it might have happened because you go, well, a fully formed wing isn't going to just develop by itself without any other reason.

So there may well be different ways that it might have done. So the Gill hypothesis, if you look at the lava of a dragonfly or a mayfly or something, you'll see that it has Gill, that life before they take flight, They spend a long time developing underwater, in the case of dragonflies, for example, and noplies. And so they develop those gills. And that hypothesis is that those gills will have developed into wings from there. The contrasting hypothesis, or one of them, is that the lobe hypothesis, you might call it, which is that they have these little nubs on their bodies that would have given them some sort of advantage with,

they might have acted as solar panels, for example, to help the insect warm up, to get going quicker in the day, which gives an advantage. And so evolution would have favoured those little nubs to grow gradually, and over a long period of time, they would have developed into something that actually had an aerodynamic use. So you imagine insect running away from a predator, and it gets to the end of the tip of the stalk of a plant, for example, and it finds itself in a corner and it jumps. and actually those things that have developed as solar panels will have helped it just get away a little bit further to glide a bit.

So that is, you know, that those ones survive and that is favoured by evolution and so on and so on over a long period of time. There's a question, of course, then how the powered bit developed, and there's all sorts of difficulties with the development of the wing joints. And also the muscles that you use to power the flight, you might want to develop those, but there. they in turn add weight. So the conundrum for any flyer is to tread that very tricky balance between lightness and strength. You need to be strong enough to get into the air, but the apparatus with which you do get into the air weighs more. Muscles weigh a lot. So you have to, it's always this very fine balance, which may well be one of the reasons that it hasn't been universally adopted. But once they've found that balance, then it's incredibly useful.

So, yes, the jury, as with so often I found that researching this book, that with a lot of these subjects, that there are contrasting and conflicting hypotheses about how things exactly happened. Because, of course, the fossil record is, you know, it's irregular and it's sparse. So we're working with not always all the information that we might want to work out exactly how things happen. So you mentioned mayflies there. I mean, these are really interesting because of their life cycle,

and especially the fact that the flying part of the life cycle is only right at the end. It is, and this is something, of course, the mayfly is famous, and it's in the name, Ephemeroptera, which is the scientific name for the genesis. They're ephemeral. Famously, one of the things you learn about in early biology is that the mayfly only lives for a day. And, of course, there's thousands of species of mayfly, So those actual ending adult life cycles will be varying in length. But some of them are just genuinely of just a few hours and some are a few days maybe long enough,

really just to breed and then start the next generation. But leading to that is up to a couple of years of development of the larva, which goes through several stages. But the unique thing about mayflies is that they're the only insects, of many, many insects and many flying insects that have two adult flying stages. So they have the lava, which goes on this long journey out of our site on the riverbed,

developing and growing over a longer period of time. And then when the time comes, it'll float up and it'll turn into the intermediate stage. It's known to anglers as the done stage. And all it does, The purpose of that stage is simply to get from the water's surface to land, to the edge, to the riverbank, or maybe to perch on a plant somewhere. And once it's done that, it develops into the fully adult stage. And so the mayflies are unique.

They're the only ones who do that. But they're also fascinating, I think, because of the anatomy that they have, which they share with dragonflies, where they have this very intuitive muscle arrangement, whereby their muscles act directly on the wings, which is how you might do it. If you were thinking, you know, I want to fly, you might just get something that will tug down on the wing to pull it up, and then you have another one, a counterbalancing one,

to pull in the other direction to make it going down. So you have that up and down motion. And this is an extraordinarily primitive arrangement that's been around for hundreds of millions of years, and yet it still serves the mayflies extremely well for their purpose, which is simply to get into the air and breed, they breed mid-air, and then once that's done, the female will float down and lay the eggs on the water, and so the cycle begins again.

With dragonflies, they have the same mechanism, and even more extraordinarily, because they're hunters, they have to be extremely fast and agile, and maneuverable. And if you've ever seen a dragonfly or a damsel fly flying, They've just this fantastic combination of speed and skill and adeptness in the air. And they're doing this with this system that evolved over 200 million years ago and yet is still incredibly effective. To the extent that dragonflies are pretty much the most efficient hunters in the animal kingdom, they have a success rate of something like 95%.

So if you're something that is prone to be eaten by dragonflies And the vicinity of a dragonfly, you've got your worries, I think Ambition comes in all shapes and sizes At First Citizens Bank, we roll with your goals Because we're built for what you're building Fit for your ambition for Citizens Bank It's peak pollination season And my business is scaling fast

To keep the nectar flowing, I need a phone plan with top priority data speeds That's why I chose GoogleFi Wireless. My connections stay strong even when the hive is buzzing. Plus, unlimited plans started $35 a month. Now that's a deal that doesn't stay. Explore Google Fi Wireless plans today. Plus taxes and government fees. Google Fi Wireless is not subject to data traffic deprioritization

during times of high network usage. This podcast is sponsored by Name, Audio and Focal. With over 100 years of combined expertise, name and focal have been bringing music to listeners just as the artist intended. Since day one, this mantra has shaped every innovation in hi-fi design, technology and acoustic engineering, balancing craftsmanship and tradition with pioneering thinking. Name audio pushes cutting-edge technology to ensure digital precision whilst sustaining Pratt, pace, rhythm and timing, the elusive quality that makes music feel alive and gives it a

emotional texture. Today, in partnership with French acoustic specialist focal, name audio creates systems that deliver exceptional sound and unforgettable listening experiences at home. Try it for yourself at a focal powered by name boutique. Visit focal powered by name.com for more information. So moving on from fantastic flyers, let's look at the ones that aren't quite so good. So you have a chapter in the book about Beatles. And when I was younger, I was lucky. I was lucky. enough to live in the countryside in Japan, and there they have very large rhinoceros beetles. Sometimes I'd see them flying outside my door, but the thing that struck me most was how clumsy they were in the air. Well, I think this is one of those things throughout the range of flight

capabilities. I mean, we like to think of the glamour flyers, you know, the peregrine falcons and the hummingbirds and swift, which have just arrived here back in England, and so on. But it's a spectrum, and some things. And mayflies are a good example. They do it just as well as they need to. And in England, it would be the stag beetle, I think, would be the one that springs to mind. That does it just as well as it needs to. So they don't need to use it to outwit their prey. They just need to get to whatever other food source they have or just to get as far as they need to get to that plant over there or that bit of rotting wood or whatever it is. So a stag beetle, I mean, just to take that example, which if you've seen one or probably heard one on a warm summer evening. It's that sort of pluttering sound,

isn't it? And it's like an old biplane. And you'll look up and you'll see it kind of meandering in the manner of something that's just had a couple of gin and tonics in a sort of very meandering, very aimless kind of way and slow as well. So it feels like it's about to drop out of the sky. But what they're doing is that's the male stag beetle, and it's trying to latch on to the pheromones of the female that are going to be floating around amongst all the other things that are floating around in the air, this extraordinary mix of aromas.

And so they're able to latch onto that, and they're doing it in a kind of meandering kind of way because it's elusive. They might catch a bit of scent and then lose it, so they have to turn right and then left and back and forwards. So, yes, as I say, this spectrum of flight abilities manifest itself in so many different ways, which is one of the things I found fascinating about it. It's just to see this extraordinary array of different ways

of using it and things that have served animals so well for millions of years. So let's go back in time again then to the teresore. So they're not actually dinosaurs, are they? I think that's a common mistake. Yes, there are many misconceptions if people are aware of them at all. So the first thing is that I think, as you say, they're not dinosaurs. Another one is that people will call them pterodactyls, which is, it's half true and it half isn't. So it's because the first terosaur fossil to be found in the late 18th century was called Terradactylos, wing finger. And so that name has stuck, even though relatively shortly after that, the genus Terasoria was named by Richard Owen. So even, even,

even though we had that alternative name to cover all of the range of different terasauras, the word terradactyl seems to have stuck. And you do see, I mean, if you watch the Jurassic Park films, for example, the focus is mostly on dinosaurs, and you'll see a terrosaur floating around in the airs and somewhere. And I think they've been slightly hard done by, but they're a fascinating group. They evolved flight. They were the first vertebrates to evolve flight before the birds, before the flying dinosaurs. And that was about, the first one we have is from about 232 million years ago, I think.

And it's a small sort of woodpecker-sized thing that would have been quite good at flying, I imagine. I think, again, we don't have these intermediate fossils that will tell you exactly how the wings developed and how they went from being on the ground to in the air. but they were around from there for about 150 million years and in general the size of the pterosaurs got bigger so from that small one it's not university true because there were smaller ones around later on but in general they breached the limits and stretched the limits of size to their upper limits and by the time of the extinction event 66 million years ago or so there were the largest things ever to have flown were in the air and they were terracled. So they're a fascinating group and there's again there's wide range of them. We have 200 or so species I think have been

identified sometimes from the scantest of fossil evidence and so the people who work on these things are really extremely good at deducing from what they find. But one of the problems is, with teresol research especially, is that with other things we'll have something living that we can compare it with. But we don't have any terosaurs that we can compare with. So a lot of it has been conjecture and I think there's increasing certainty about their nature nowadays, but there have been lots of

outlandish ideas about their nature over the last 50 years. So they represent a fascinating slice of fossil history and especially because they were living alongside dinosaurs, but although not whatever, there's a common ancestor there somewhere, so they're their cousins. But they were sharing the air with birds for quite a long time as well. So you have this great idea that the air would have been full of all different kinds of things through those periods.

So let's shift gears now and have a look at flightless birds. The most iconic of which is probably the penguin. Yes, I think so. Although I have to say that chapter, the penguin chapter, started out as the ostrich chapter because I think the ostrich is also an extremely recognisable bird. And as I say, I wanted to explore this idea of flightlessness, and what would it cause things to abandon flight. And it occurred to me also because there's nearly 11,000 bird species in the world, and very few of them are flightless, but they are very recognizable. You know, we have loads of birds that the general public wouldn't recognize that are flying around.

And yet, you know, we know what ostriches look like. People know what emus and Kiwis and Kassaueris and penguins look like. But yes, having written the first draft of the chapter about flightlessness in birds and called it the ostrich, I got a lovely little note from my editors saying, yes, this is all lovely stuff. It does seem to be for a chapter called the ostrich mostly about penguins. Can we change that? And I thought, well, we could do. We could just change the chapter title to the penguin. So penguins are extremely endearing to us, I think, because they walk in a very similar way to us. You know, we think of them as waiters or footmen or whatever. We anthropomorphise them quite easily as well, don't we?

So we like to give them characters. And of course, they would have evolved from birds that could fly. And they found themselves in the southern hemisphere and in the Antarctica. And as the land masses and the shape of the landmasses, manoeuvred and changed over long periods of time, they found themselves mostly isolated in this cold part of the world and away from things that might chase them and eat them and hunt them down. So they found that they didn't need to take to the air so much.

And at the same time, they were in a habitat that was icy and solid, but also had water. So they were swimming to get their food. and gradually the wings that had propelled them into the air, they lost the need for that, so they lost the ability, and because they were spending a lot of time in the water, those wings turned into something that would propel them extremely efficiently and quickly through the water

so that they could become more effective hunters. And so that's where we are now, and that we have those emperor penguins, all sorts of different kinds that we're so beloved from nature documentaries. So I just found that fascinating. And also the way they survive in those cold temperatures. So feathers have evolved as a unique feature of living birds. And again, this thing of lightness and strength, feathers are magnificent for that.

They're so wonderfully evolved to cope with not just being aerodynamic, but also protecting the body of the bird. And in the case of the penguins, they have all these different range of different kinds of feathers. and nearest the skin, as well as they have their fat under the skin, which keeps them warm, but they have these wonderful feathers called plumeules, which are extremely efficient insulators. So the outer layer is one thing, but underneath that they have this fantastic downy fluff, which helps insulate them and keep them warm. So, yeah, again, an example of evolving perfectly for their habitat and their environment. So let's move from feathers to fur and finish up looking at one of the

my favorite animals, bats. Yes. So they're the only flying mammal, right? So bats are of the flying animals. They're the most recent to evolve. So if you'd think about the extinction event, the asteroid, the hit in 66 million years or so ago, that extinction event, up until then we had the dinosaurs,

famously the dinosaurs rule the world. They went extinct except for the ones we now call birds. And not only did the birds in the aftermath take the advice, take the advantage to evolve and diversify in enormous ways between 66 and 50 million years ago. But the mammals then began to hold sway. And among those were the bats who took to the air, the only ones to do so with powered flight. Of course, there are other things that are in the air, which most of which will have names that include the word flying. So you think about, you know, when I was talking about, oh, I'm right.

writing this book about flight. People say, oh, yeah, yeah, flying squirrels and flying frogs and flying snakes and all that sort of. Well, the one thing a lot of those things have in common is that if they have the word flying in their name, the one thing they're probably not doing is, in fact, flying in the sense of powered flight. They're gliding, which is incredibly impressive. So, you know, seeing a flying squirrel jump from top of a tree and up to, you know, 90 meters or whatever it is that they can do from the top of one tree to another. That's a wonderful thing. and they may well be evolving powered flight as we speak. But with bats, they actually manage to tread that incredibly thin line.

The first one we have is about 50 million years ago. One of the problems is with bat fossils is that their bones don't preserve at all well. So a lot of the fossils that we have are little fragments, tiny fragments sometimes, but it have been pieced together. So entire bat skeletons are quite rare. So again, we don't know how that transition happened from non-flying to flying. But one of their big challenges is that they are cursed with the mammalian respiratory system, which is much less efficient than the reptilian one.

So birds and pterosaurs had this fantastically efficient way of breathing, the system of air sacks. And it was like a one-way system. So the air would go through the body in a circular system with a lot of, you know, diversions, but it would go in one way and come out the other. But what that means is that the oxygen gets into the blood system much more efficiently than with our system where it's all in and out of the same way. So what bats had to do was like the birds before them, they had to develop the power, but also the lightness. So their skeletons had to become lighter. Their bone walls are very thin. Their wings, which are adapted forelims,

are incredibly versatile and maneuverable, enabling them to produce the lift with those extraordinarily thin wing membranes as well, some of which are quite furry, as you referred to, but also some of which are quite smooth. And again, these are adapted to the different conditions in which they live. But that's the extraordinary thing is that of the mammals, they're the only ones that fly. And I think because they're nocturnal, and that's the niche that they've evolved to do, dominate, we have a tendency to have a bit of disgust or revulsion about nocturnal things or fear maybe. So I think in the public image, you have this image of the bat as being something a little bit scary, the creature of the night. And among many others, they're keen to change that image

because they're extraordinary creatures. And again, this extraordinary agility they have to swoop and turn and the ride in mid-air to catch insects is quite something to see. Thank you for listening to this episode of Instant Genius, brought to you from the team behind BBC Science Focus. That was the writer Lev Pericion. To discover more about the topics we've just discussed, check out his book, Taking Flight, How Animals Learned to Fly and Transformed Life on Earth.

The current issue of BBC Science Focus magazine is out now. Pick up a copy wherever you buy your favourite magazines or downloaders on your preferred app store. You can also find us online, 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. Name Audio believes you can have digital precision with analogue warmth. Alongside French acoustic specialist focal, name creates high-end audio systems, combining innovation with craftsmanship so you can listen to music, just as the artist intended.

Discover more at name audio.com. Relax and let Ralph's delivery handle your grocery shopping this week. We start with only the freshest items, then review your list and carefully choose each one. Then we pack it all up and deliver it in as little as 30 minutes, so you can feel confident it's what you ordered. Fresh groceries, your way. with Ralph's delivery and pickup. And right now, you can save $20 on your first delivery or pickup order.

Ralph's, fresh for everyone. In a place like Los Angeles, people don't stop being who they are. Writers, thinkers, creators, people with stories still unfolding. That spirit lives on at Kingsley Manor, a community shaped by individuality, creativity, and lives well-lived. So when the conversation turns to what's next, it isn't about. stepping away. It's about continuing the story. Explore your options at kingsley manor.org, a nonprofit month-to-month senior community within the Front Porch family.