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Tai Asks Why

Season 2 – When the dinosaurs died, how did other animals survive?

VOICE: This is a CBC podcast.

TAI: So I'm spending a lot of time thinking about how we're all going to go out, how it's all going to end. Earth's just going to become a rock in the middle of space, whether it be zombie apocalypse, food shortage, overpopulation, nuclear fallout. You know, just the normal thoughts of a seventh-grader. I don't really know what the end of the earth it's going to look like, but I do know that the only really viable way to predict the future is to look at the past. So I've been reading quite a bit about the huge asteroid that destroyed our planet. You know, it just got to big space rock rammed into our punishment. 66 million years ago, the one that killed off the dinosaurs. It also killed off three-quarters of the plant and animal species on the earth at the time, which is pretty big. It's probably the closest thing we have to a total extinction event. But even with all this suffering and devastation, some things did survive. Like birds, which I learned in school, though, the only really remaining twig in the dinosaur's family tree, which so is nice, you know, gives you some hope. Life will always find a way. But the important question then is how did it find a way? How would you survive an apocalypse? How did the species that survived the massive asteroid strike survived the massive asteroid strike?

[Tai Theme Song]

TAI: I'm Tai and this is my podcast, Tai Asks Why. There are just so many good questions out there that you really want to have answered. How does a song get stuck in your head? What is deja vu? What is the science of bullying? What are animals saying to each other? Why is space so dark? And when the dinosaurs died, how did other animals survive? I decided to see what my little bro Kien thinks of all this. So Kien.

KIEN: Yes.

TAI: When the dinosaurs went kapoot, why do you think other animals did not kapoosh?

KIEN: I think some of them they just were able to survive like something could lived underground and somehow survived.

TAI: But the thing is, like apparently birds survived. Do you think birds just kind of made it out by chance? I think the birds can just go really far. They can go high up and they can go far away from the blast. But and inosaur is they go like.

TAI: He's doing weird things that cannot be explained like words.

KIEN: And they can't they can't go up. They just have to stay on ground, and they don't really have anywhere to run because it's like. Just imagine you're a dinosaur close your eyes. And then you just like you see this, big fiery explosion. See you try and run away, but the explosion, dust, just this foot's too fast, and you're just just being in gulse and you tryna run but you can't you just you can't run. But the birds are just up in the sky having a party.

[Music]

TAI: Is that really it? Do the birds just fly away from their troubles? Then when the asteroid hits dinosaurs are just stuck on the ground to perish.

JULIA CLARKE: This is the question that scientists have been trying to answer. In fact, when I was first in college, that was the question that got me interested in being a paleontologist. How do we explain what survives and what doesn't after this event?

TAI: This is Julia Clarke. She's a paleontologist at the University of Texas at Austin. She studies the evolution of birds and how they're related to the dinosaur relatives that survived the asteroid strike. So can you tell me a little bit what the asteroid strike was like?

JULIA CLARKE: I guess it's exceptionally difficult for us to imagine. Some people have likened it to hundreds of nuclear warheads being detonated at one time. You're gonna have things like wildfires and tsunamis and kind of nearby the crater. And then at a distance, you'll have ejecta raining down. These are little tiny pieces of liquidified rock that are spewed up into the atmosphere at some scale and come down locally and even as far away as Europe.

TAI: Oof. It's probably the closest thing we've had to a total apocalypse event right.

JULIA CLARKE: In the last 66 million years, this is about the most devastating, near instantaneous event that has impacted the globe.

TAI: So there was the big tsunami waves, the massive wildfires and then raining fire. How could anything survive?

JULIA CLARKE: Most dinosaurs go extinct. But one group of dinosaurs survives. So what we call like flying dinosaurs or birds. But it's only one group of those birds that makes it through the boundary, and those bird dinosaurs are relatives of lineages we have today.

TAI: So my brother Kien, he thinks that the reason why birds survived was just because since they had wings, they could just soar through the air and just get the heck out of there. Is he right?

JULIA CLARKE: You know, your brother is maybe partially right, but it's only flyers that survived. But it's only certain flyers. It's confusing. Why did some of these species go completely your way and then some of them persist? Some of the hypotheses we have is that it's related to how fast living birds grow. So living birds go from being little babies to being adults really rapidly. So because natural selection acts from one generation to the next. If you can reach adult size faster, you can start reproducing and giving rise to the next generation.

[Music]

TAI: Natural selection. Otherwise known as survival of the fittest is when animals that have helpful traits are more likely to survive. So they're more likely to reproduce so they can pass these helpful traits onto their children. So by having a shorter lifespan, these species can evolve quicker because they make small changes every time. Every new version they make new versions faster. Evolving things like bigger wings or better breathing and harder conditions or a better metabolism where you have to eat less. It makes a lot of sense and it's a huge key to survive the apocalypse. But of course there are other theories too.

JULIA CLARKE: Other hypotheses have emphasized that dinosaurs that were nesting on the ground did not survive as well right, as if you could lay eggs elsewhere. We also know living birds have higher metabolic rates. That means they eat more food and they're more warm-blooded like us.

TAI: So even something as random as where they lay their eggs or how often they eat. That can totally affect the entire species survival rate. Being small apparently helps as well.

JULIA CLARKE: We think that because generally speaking, smaller animals require less food, resources than large animals that they tend to be less impacted by extinctions of all sorts.

TAI: Yeah, that's why I chose to be small. Eat less, don't get wiped out.

[Music]

TAI: So let's see if I would pass the test for surviving an asteroid strike: being small dingding dingdingding, warmblooded ding, short lifespan, hopefully not a ding. But that's just the birds. They were the only dinosaurs that survived. But there were other non-dinosaur animals that survived the asteroid strike, too. So how did they do it?

[Music]

AIDEN WILLIAMS DALE: This is one of our more prehistoric-looking animals this is Sizzle our alligator snapping turtle.

TAI: I'm meeting up with Aiden Williams Dale to get a behind the scenes tour at Reptilia, an educational facility that's home to a lot of animals whose ancestors didn't go extinct. They evolved into animals we know and love today. That looks like a dinosaur. Aiden takes me over to meet Mr. Blue, a dwarf caiman alligator.

AIDEN WILLIAMS DALE: We're gonna have our hand out like this. We want to provide as much support to the body as possible.

TAI: I'm gonna hold Mr. Blue so wish me luck and for me to keep all my fingers. It looks like a mix between a lizard and a dinosaur. It's scales feel really weird It's like soft tummy. It's not the type of thing you'd give belly rubs. We have all that later down the line.

AIDEN WILLIAMS DALE: I suppose so.

TAI: So what features helped it survive?

AIDEN WILLIAMS DALE: They're able to survive very low temperatures. There's a unique thing that reptiles and many other cold blooded animals can do. Known as Bruce Mason, it's a form of hibernation for cold blooded animals where their bodies are able to slow down.

TAI: You always hear about fight or flight, which, you know, means when faced with threats, your instinct is to either put up a fight, try to punch and kick your way out of it or to just bolt and run away as fast as you can. But there's actually a lesser-known third reaction, which is freeze. And in this case, these alligators are literally freezing to survive.

AIDEN WILLIAMS DALE: They can last a full year without eating any food whatsoever. So if those prehistoric animals had a big meal before the asteroid hit, they were able to last long periods of time without eating any food and not using a lot of energy.

TAI: Aiden also mentions how being small probably helped Mr. Blue's ancestors survive.

AIDEN WILLIAMS DALE: Although they're small and may not be as strong as larger animals. They are a lot faster. They have a higher metabolism. They're able to move around more efficiently and they're able to go into crevices where most large animals can't get to. So having a smaller size also helped with mobility and just survival as a whole.

[Music]

TAI: So the small animals survived because they're able to hunker down in burrows or underwater and wait for the figurative and literal dust to settle. But the big boy dinosaurs unfortunately couldn't hide and just needed so much food and water that they just couldn't make it anymore and they died. And once all these big guys died out, that's what gave the small animals the ability to have free reign of all this remaining resources. Fill a vacuum, you know, so they could adapt and evolve into what is now our current animal kingdom.

AIDEN WILLIAMS DALE: Because dinosaurs were wiped out, so many things had a chance to kind of grasp at that moment and adapt to become what they are today. If dinosaurs were still around now, I don't believe there would be humans.

[Music]

TAI: So because there was this near total extinction event 66 million years ago, the dinosaurs went kapoot. And then us humans filled in the vacuum. Way to go guys. But Julia tells me that humans were actually bringing another apocalypse on today.

JULIA CLARKE: There are huge extinctions happening at a scale that we have not seen under some estimates since when the asteroid hit. Striking thing is, boy, you can look outside you don't don't see a giant rock hitting the earth. But that's you know, our human impacts on this planet, cause there are so many of us.

TAI: In my expertise apocolypse research, I read that according to the United Nations, up to a million plant and animal species are near extinction and are likely to be gone completely over the next century or so. They're calling it a biological annihilation and it's happening because of human overconsumption. We're using up way too much of the world's resources. And this one isn't just affecting big animals like whales and polar bears either. Even insects are taking the hit because of things like habitat loss and chemical pollutants. There's actually a study that says that the number of insects are going down by two point five percent every year and we may not have insects whatsoever by the year 2119. Hundred years away, guys. That's like. So that's a big deal. You know, if there are no bugs. What are people going to eat during truth or dare? I talked to my friends about this mass extinction stuff, and everyone once seems pretty worried about what humanity is doing to our fellow species in the animal kingdom.

FINN: I've talked to people about this and they've told me, well, who cares about the bugs, but they don't understand how important bugs are. They help support ecosystems and without the ecosystems we don't have oxygen. We would definitely be dead if there were no insects

KADEN: Yeah, it's like a Jenga tower. If you take out the bottom, it all topples. Yeah.

ZOE: I don't think it's fair that one species just can destroy all the other species like they're so important

TAI: You know, let's be real. Humans, we're just kind of like the big asteroid just smothering the Earth and if we don't fix this, we're going the way of the dinosaurs. You know, has me thinking if we're gone or should I say when we're gone, what's going to be the next super species? I think if anything's going to survive, I'm rooting for the little guys. And I don't mean the shorties like me. I mean the little guys. So time for another field trip. Let's go to the Royal Ontario Museum Museum.

SEBASTIAN KVIST: You see all that green on the tree right there.

TAI: Yeah.

SEBASTIAN KVIST: All that's lichen. We're going to try to peel off as much as we count of that. We're going to try to fill up the jar to maybe back there with lichen.

TAI: I'm just outside the Royal Ontario Museum in Toronto with Sebastian Kvist, and he's the invertebrate expert here. Invertebrates are animals without backbones. So like leeches, spiders, crabs, those types of things. It doesn't take them long to think about which animals are the true survivors.

SEBASTIAN KVIST: If I were to hedge a bet, I would say that tardigrades would be one of the organismal groups that definitely would survive an asteroid hit. These are masters of survival the tardigrades. So if you didn't know tardigrades are these little tiny eight-legged animals, also known as water bears or moss piglets, usually coming about half a millimeter to a millimeter in size, which is around the size of your average grade assault. And that's what we're out here collecting from these trees. Turns out they're everywhere on the planet, even on the trees outside the museum in downtown Toronto. It's plentiful down here.

SEBASTIAN KVIST: Right in the tardigrades will be inside of the lichen. They live on top of the lichen.

TAI: I'm like in this interview so far.

SEBASTIAN KVIST: Now that we've collected the lichen, we're back in the lab. We're going to look at it under a microscope.

TAI: OK.

SEBASTIAN KVIST: Sound good?

TAI: Ya I'm just kinda following along.

SEBASTIAN KVIST: So if I just let go can you see the stuff moving around.

TAI: Yes. Oh it's weird.

SEBASTIAN KVIST: Let's see.

TAI: There is a little stuff right there.

SEBASTIAN KVIST: Yeah, that's right. That's right. So let me try to get that in focus.

TAI: That a tardigrade?

SEBASTIAN KVIST: That's a tardigrade right there. Yeah, it's coming out. You see that? Whoa. There's another one there quite a few, actually. So we had we had some sort of a jackpot here. There's another one.

TAI: So I know it doesn't come across great on audio and I'm seeing things, but tardigrades are really cool to look at my guys like this one is so cool it deserves its own name. I'm gonna call this one Chewbacca Scholastica? It's a long story, but he's my little bro. So screamy and chubby and awesome. So if you want to know what he looks like, there are tons of photos of tardigrades on the internet so I'm telling you to check them out. Chewbacca Scholastica and all the tardigrades are just they're my fave you know, I love them. Check out what they can put up with. This is probably one of the coolest parts about them.

SEBASTIAN KVIST: People have tested how good they are at surviving and they have frozen them. They've been boiled in acid. They've survived a perfect vacuum. They've survived gamma and ion radiation about six times the deadly dose for humans. They've survived 6000 times atmospheric pressure and they've been shot into space and survived.

[Music]

TAI: Can your favorite animal do that? Boiled in acid, burned alive, shot into space? I didn't think so. So then how how did they do it? Their magical method.

SEBASTIAN KVIST: They go into a state of sort of metabolic suspension called cryptobiosis. Cryptobiosis comes it comes along when the animal is at stress and they go into a state where they shut down their body so far or so much that the metabolic rate is impossible to detect. In effect, they're dead and they shield themselves off from the outside environment. And then when conditions become favorable again, they get reanimated and they come back to life from cryptobiosis. And tardigrades are, as far as we know, the only organism that can do this. So that's what makes them the masters of survival.

TAI: So just like the alligators, the tardigrades just freeze up in times of trouble. But, you know, they kind of one up the alligator because they pretty much just vacuum-seal themselves. But did the tardigrades survive the asteroid strike that killed the dinosaurs?

SEBASTIAN KVIST: Yes, they were around during the dinosaurs. But it's important to note that they had also survived multiple asteroid hits prior to the dinosaurs going extinct.

TAI: So, you know, they they had some time to prefect their techniques.

SEBASTIAN KVIST: They did quite a bit of time. Five hundred million years. That will hopefully do the trick, right.

TAI: So although I'm having an amazing time seeing these tardigrades, I still know why I'm here for the very serious reason to learn the survival tips to surviving an apocalypse. So I asked Sebastian for some of the key takeaways I can learn from these little guys.

SEBASTIAN KVIST: The first thing that they do really well is that they adapt to the environment that they're in. The second thing, of course, is that they if they cannot change enough with it an ever-changing environment, then they go into cryptobiosis. And then the third thing I think is tardigrades can feed on on a lot of different things. If algae come along, that's great. They feed on on masses and lichen alike. So be prepared to feed on anything that crosses your path.

[Music]

TAI: So it seems like when it boils down to it to survive the apocalypse, you just need to be able to adapt, you know, roll with the punches, the birds and the alligators and especially the tardigrades, they're able to change what they ate, how much they ate, where they lived, laid their eggs. When it got to be too much, they were just able to just pause everything and just wait out the massive superstorms until things got better. But I also feel like another key for surviving the apocalypse, however it happens, whatever it is, it's just it kind of comes down to luck. You know, you don't want to get hit in the head with an asteroid. Will these tips help with the current mass extinctions happening? I mean, with this type of thing, there's only so much you can adapt when humans were coming and stealing the resources and lighting everything on fire. So I hope the species of the world can adapt and the humans of the world can figure out how to change their ways. So my fellow humans stopping such an asteroid.

[Music]

TAI: Dear Chewbacca Scholastica, the ancient one. If you're reading this, it's too late for me. I'm writing from the bottom of the sixth. Extinction that is.I remember when I first saw you in that petri dish at the Royal Ontario Museum. I had just gathered you from some moss outside. You're so squishy and confused. I didn't know I was confused as well till I met you. I respect your life so much, swinging from microscopic leaf to microscopically. You're like your own Tarzan of your domain. You are truly tardigrade. Would a moss piglet's by any other name be as awesome. How should I compare thee two a summer day, gnarly water bear It's armageddon hard for me to live without you. I've got to let you know that I got to go. Gonna burn to dust in the extinction but you'll be fine till the end of times in your air-tight vacuum seal. Yeah. Thank you guys so much for listening. I'm Tai Poole. The show is produced by the amazing Veronica Simmonds and Amanda Buckiewicz. Our digital producer is Judy Gu. Today, my guests were Julia A Clarke, Aiden Williams Dale and Sebastian Kvist. Special thanks to Tina Verma and Sam Medina for their assistance. And my friends Zoe, Piper, Finn and Kaden for talking to me about the apocalypse. The theme music is by Johnny Spence and another big thanks to Jonny for helping me write and record the Tardigrade Song.

KIEN: Next time on Tai Asks Why: The Darkness on Space?

VOICE 1: Almost everything we know about outer space we've learned by looking at light and trying to figure out what that light is telling us.

TAI: Till next time I'm Tai, keep asking why. Hey there. Are you a teacher or friend of a teacher or just ever so slightly know a teacher because if you are you can use this podcast in your classroom. We got teaching guys available for free, including things like lesson plans, handouts, videos, homework. We got it all. They're written by teachers across Canada so you don't have to worry about them not being legit. But of course, if you want, you can change them up for different courses and curriculums. You know, all is good. So if you want to learn more about this head to our website www.cbc.ca/TaiAsksWhy to learn more.

VOICE: For more CBC podcasts, go to CBC.ca/podcasts

TRANSCRIPT: Tai Asks Why - Season 2: When the dinosaurs died, how did other animals survive?

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