Quirks and Quarks - A terrifying T. rex of the sea, and more…

Episode Date: May 29, 2026

The newly described Tylosaurus rex was a violent bus-sized Komodo dragon-like creature with serrated teeth. Dubbed the ‘T. rex of the sea,’ it would have occupied the top of the food chain in the marine ecosystem over 80 million years ago.PLUS:Pigeons use their livers to find their way homeFrom the archives: How Jocelyn Bell Burnell discovered pulsars Scientists discover an underground network of lakes hidden under Arctic ice New book explores the million year history of how we sleep — and why we’re doing it wrong today

If you sold somebody a loaded gun who you knew was in a vulnerable state and they shot themselves. I think it is murder. Just because you're using the internet doesn't mean you get away with murder. I'm Damon Fairless, host of Hunting Warhead. This season, I take you inside the business of suicide, and the places desperate people go when they can't find what they need in the real world. Hunting the Suicide Salesman. Available now wherever you get your podcasts.

This is a CBC podcast. Hi, I'm Bob McDonald. Welcome to Quarks and Quarks. On this week's show, the unexpected way pigeons find their way home. This is completely new and fundamentally changes our understanding of both the immune system and animal navigation. And a bus-sized commodo dragon-like lizard that once ruled a sea of monsters. Even as fossils, they're kind of intimidating to be around because they're so big and so heavy. And the teeth are still pretty.

sharp even after 80-inch million years. Plus, I'll look back at the discovery of pulsars, big changes with Arctic glaciers in a warming climate, and how the way we sleep has changed over time. All this today on Quarks and Quarks. Pigeons these days are considered an urban menace, pooping all over statues and nesting in buildings. Some even call them flying rats. But it wasn't that long ago that we used to revere pigeons. We kept them as preaches. We kept them as pets, ate their meat, and collected their poop to fertilize crops. We also used them to send messages because of their impressive navigational skills, flying hundreds of kilometers and still finding their way home. In the First and Second World Wars, soldiers used homing pigeons to deliver

dispatches from the front lines. This sense of navigation has always fascinated scientists who couldn't quite figure out exactly how pigeons found their way home. They seemed to use the Earth's magnetic fields to navigate, but how they tapped into that magnetism remained a mystery. Well, thanks to new research, we now have an answer. And surprisingly, it's in their liver. Dr. Clevia Lozovsky led the study. She's an immunologist at the University of Bonn and the University Hospital of Bonn in Germany. Hello and welcome to our program. Hi, Bob. First of all, why has the pigeon's sense of navigation being such a mystery all this time? Well, Humans, they have these senses like smell and seeing and hearing, and pigeon have this additional sense.

It's hard for us as humans to grab, and they orientate themselves according to the magnetic field, and they can sense it somehow, and they need it to find their direction. And this is actually the interesting thing, because you need to think of finding direction means you need to understand where you are on the spot, but then also where to go and to go in a straight path. This is actually, it has been a mystery for 50 or 80 years already, and so it's interesting to study this, and it's a very fascinating topic. Before your study, what were some of the guesses as to how the pigeons were doing it? So people thought there might be some visual input,

so there has been a theory that special light-sensitive molecules in the eye might transfer this magnetic information, and other people thought maybe there are small magnetic particles in the beak of pigeons, but none of these theories really could answer the story completely, and they remain rather theories than actual experimental evidence. Now, are the pigeons just using the magnetic field of the earth, or do they also use the sun and other cues? Well, actually, they mainly rely on the sun.

So if the sun is there, they can orient. And also if they have a very good olfactory sensing system, so this tells them where they are, and then the sun tells them in which direction they have to go. But just imagine the pigeons have to fly during the night or if they are a completely overcast condition, and the sun is not there. They need to have another mechanism as a backup to find their direction.

And for this, the magnetic sense is essential. So what made you think that the liver might be involved in the magnetic sense? Well, we had an idea from actually studies in mice that we usually use for immune studies. And I have to credit my professor, Christian Quartz, he actually figured out that in mice, spleenic macrophages have the capacity to degrade red blood cells. And due to this degradation function, they accumulate iron. And this renders them super paramagnetic. And when he and Martin, Martin Bicholsky, the professor for animal behavior from the Max Planck Institute here in Germany, when they met and they discussed what kind of science they are doing, they had this eureka moment where one person tells about the mystery of animal navigation and the other person tells something about superparamagnetic macrophages. And then when they met, they looked at each other and they were like, hey, why not? Why is it not the macrophages that are actually conveying this magnetic sense? And so a couple of the of years later, I joined Christian's lab, and since I'm interested in how self-sensei

environment and how they communicate, he told me about this crazy idea that they had. And, yeah, I was captivated by this idea, and then we started to screen for several organs, and we actually suspected it to be the spleen, but we figured out that it's actually the liver that contains these super-parmagnetic macrophages. Now, these macrophages, what are they? What do they do? So macrophages are usually immune cells that sit all over the body and their function is to engulf several pathogens or old cells and debris. So they are kind of recycling hubs. We know that these macrophages, they degrade red blood cells. And in the red blood cells and the hemoglobin, the color that actually makes the blood cells red, they contain iron.

And when the dead and old red blood cells are degraded and recycled by these blood cells, they contain iron. And when the dead and old red blood cells are degraded and recycled by these macrophages, this iron cannot be lost because it's very valuable for the body. And so these macrophages, they collect and they store all this iron, and then they release it whenever it is needed for development of new red blood cells. And so they are kind of the recycling hubs of the cell. Oh, I see. So the macrophages hold on to iron, and iron is sensitive to a magnetic field.

Exactly. Okay, so they're sensitive to the magnetic field because of their iron content, but do you know how it actually helps the pigeon find home? So they know where they are due to olfactory cues that they have, and if the sun is missing, then they orient themselves. So when they are flying through the magnetic field, then these cells react. And then how exactly this magnetic compass, I mean, it's a kind of feeling that the pigeons have. And it's like a gut feeling and how exactly this information is transmitted.

We don't know yet. So how did you show that these macrophages in the liver of the pigeon are helping them navigate? How did you prove that? Well, we had an exciting experiment, and we used the combined expertise of us immunologists and the behavioral biologists. And what we used was clodronate, which is a certain drug that helps us to temporarily deplete macrophages. And when we injected

these drugs into the pigeons, then for 24 hours we left them and then they were allowed to fly. And interestingly, we could see that the control group where macrophages were still able to

transmit information, the pigeons could orient themselves under completely overcast conditions where no solar cues or any other information were available. But The pigeon group where we depleted these macrophages, they were completely lost. They were confused. They couldn't find their way.

They didn't find home. So they flew in all kinds of directions. And it was really, Martin said it was amazing to see how lost they actually were. Wow. That's amazing. So on cloudy days, they couldn't find their way home. Exactly. So putting this all together, what does this tell us about how the birds are able to tap into the Earth's magnetic field?

Well, it's the first evidence that really there's a ferromagnetic mechanism behind this magnetic sense. And the beauty of it is actually that it's a general mechanism that we found. So this is not only important in birds, but this is important for all migrating animals. And it can be present in all migrating animals. And if you think of all these millions of birds flying twice a year north to south and back, then this is a very good explanation, but it also applies to other animals like sharks and animals in general living in dark environments or migrating throughout the night. Then for all these animals, this is a general mechanism how they could sense the magnetic earth. And with our experiments, we provide the first experimental evidence for this.

Were you surprised that immune cells would help in navigation? Absolutely, absolutely. I mean, the immune system is really fascinating because for a long time, people just thought it's there to defend us against pathogens and just to degrade bacteria or viruses. But the immune system has so many components and actually here in Bonn, we have a big hub of immunologists and we are all investigating how the immune system is actually a sensory organ. But now that it can also sense the magnetic field and has a magnetic sense, this is completely new. and it's really, really exciting about this whole story. Dr. Lysovsky, thank you so much for your time. Thanks for the interest in our study, and thanks for having me.

Dr. Clevia Lysovsky is a postdoctoral researcher with the Institute of Molecular Medicine and Experimental Immunology at the University of Bonn and the University Hospital of Bonn in Germany. Sometimes great discoveries are hidden in plain sight, such as the fossils of a massive prehistoric marine lizard, known as the T-Rex of the Sea. The Tylosaurus rex measures up to 43 feet, roughly 13 meters, more than twice the size of the largest great white shark. It was a beast in a sea of monsters at the top of the food chain cruising the waters 80 million years ago. Dr. Amelia Zietlo traveled to 22

museums in North America and Europe over five years to study more than 300 fossils of a type of ancient marine reptile known as a mosesaur. When she was at the American Museum of Natural History in New York, she noticed one fossil was a lot larger than the others. It had a bigger head, a stronger jaw, and saw-like teeth. Well, it turned out to be a new species, and just one of dozens like it at other museums that were also mislabeled. Dr. Zietlo is a museum specialist at the History Museum at the Castle in Appleton, Wisconsin. Hello and welcome to our program. Hi, thanks for having me. What was it about these fossils that first made you suspect it was different from the others?

It's kind of funny that it was hard to put into words. Like, just something was wrong with the one that I found at the American Museum. Something that did stand out was that it was from Texas, which is unusual for this kind of mosa. That alone doesn't mean it's a new species necessarily. They're large marine animals, which tend to have large ranges. So it's totally possible that it was the species that it was identified. as previously Tylosaurus per rigor. But something just didn't sit right with me.

One of the characters that stood out in particular was the serrated teeth. So the blades of the tooth have like a cutting edge like a steak knife. And that's kind of uncommon in mosasaurus generally. So I thought that was strange. But the little features are so thin, I thought maybe, okay, and other specimens maybe they're eroded or just lost a time in that kind of a way. Wow. Well, tell me about these mosasars. I mean, what were they?

And how does this new species fit into that? picture. Sure. So mosasors are a group of extinct marine lizards that lived at the very end of the age of dinosaurs. So the first mosasaur show up about 100 million years ago, give or take, and they persist all the way to the end of the potassium, and they go extinct with the same asteroid that kills the dinosaurs. But mosasors themselves are not dinosaurs. And they're actually also not super closely related to other marine reptiles that people might be familiar with. They're not very close to ichthosaurs, which are kind of their own group of reptiles altogether. And they're also not close to pleasosaurus, things like the Lochmas monster. They are literally lizards. So their closest

living relatives are things like Komodo dragons and snakes. So what did they look like in the water? In the water, they would have looked very much like a Komodo dragon, but if you took it and scaled it up to the size of a bus, gave it flippers and a shark-like tail. And they also have an extra row of teeth on the roof of their mouth that they would use to help kind of bite down and hang on to slippery prey like fish and squid and things. Okay. So that's the Mosasar. Now what about this new tylosaur T-Rex? Tylosaurus in general is distinguished from other mosasors by having kind of a longer, poignier face.

Specifically, they have an extension of bone at the front of their snout that doesn't have any teeth on it. It's called a rostrum. This was probably mostly a sensory adaptation. It's covered in little holes for nerves and blood vessels and things. But it's also not impossible that they were using it as some kind of battering ram kind of weapon. because the first, like, third of their face is solid bone. So they're really, really strong, thick, heavy-built animals in general.

Wow. And were they bigger than the other Mosaurs? Yes, Tylosaurus is the first group of Mosaurs to achieve large body size. So nine plus meters in length. It's being referred to as the T-Rex of the sea. Is there any connection between it and the T-Rex on land? Not other than being big, mean apex predators. And the kind of funny thing is like that, that term or that phrase is used a lot in media when new animals are discovered and they're predatory.

It's the new T-Rex of blank, fill in the blank. But in this case, it's actually accurate to call it T-Rex because we named it Tylosaurus Rex. Well, the way you're describing it, it sounds similar, you know, with the big head and the serrated teeth. It sounds like a pretty formidable animal. Oh, absolutely, yeah. Even as fossils, they're kind of intimidating to be around because they're so big and so. heavy. And the teeth are still pretty sharp even after 80-ish million years. So what do you think their behavior was like? I think they were unpleasant. I think like most lizards today, in general,

like lizards don't tend to be friendly. And like I love lizards. They're really fun. But like, they're not super friendly social kinds of animals. They're typically kind of ornery. But if you take that, like the typical lizard kind of anger and scale it up many, many times. So Tylosaurus and other large mosasaurs were three to four times the length of, you know, the biggest lizards we have alive today. Boy, another good reason to be thankful that we were not around during that time. Yeah. Now, you say that this fossil was originally found in Texas.

What does that say to you about its original habitat? So it lived in what was called the Western Interior Seaway. So during much of the late Cretaceous, the entirety or the entire like middle of North America was covered by water. It was underwater. So there was a warm, shallow sea that connected. the Gulf of Mexico to the Arctic Ocean. And it was home to all kinds of sea monsters, basically. It was a very different ecosystem in the water than we have nowadays. Like, there's no whales. There's

not really coral reefs in the same way that exists today. It was an ecosystem dominated by marine reptiles of all kinds. So mosasors, pleasiosaurus, sea turtles, some sea turtles as big as a car. Parts of the seafloor were covered in like these giant flat clams that were like one to two meters across, all kinds of different fish that all have crazy teeth and faces and things like that. It was really a very different world, underwater and on land. Well, if that inland sea went all the way up to the Arctic, how far north do you think these tylosures went? The northernmost specimens that we have of this species in particular is in Kansas.

Tylosaurs broadly, though, do range up into Canada. There is one, there's one that's not formally described. it was described as part of a master's thesis a couple of years ago that I believe is actually from the Arctic. But something to keep in mind is that Earth at that time was much warmer overall than it is now. Like there were no ice caps at all. It was so warm. So they did fully range through the whole thing. There were different species at different points.

The problem is like we don't have a complete record from start to finish of all time in all places. So we're kind of piecing together a puzzle of where these things were. But they seem to have spanned the whole thing. And then beyond that, they have relatives that were in Europe as well as Africa and Antarctica and Japan and like literally everywhere. Well, we have lots of dinosaur fossils here in Canada, so maybe we should take another look at our collections to see if they're in there. Oh, absolutely. I know at least the Royal Tirol Museum in Alberta has a lot of really cool mosasors. Not too many tilosaurs. It's more of the later, a different group of mosasors altogether kind of is more common in their collections. But they do have one or two.

Why do you think the species sort of got by everyone? It wasn't identified before. Historically, like, first of all, there's not many people that specialize on mosasors in this level of detail. And the ones that do exist are either in Canada or on the east coast of the United States. And so it's just farther to travel to go. You'd have to really go out of your way and be looking for them almost to make your way to Texas. And really the only reason I did is because I found that one at the A of NH. and I wound up working with someone on my committee who was based in Texas. It makes you wonder how many other undiscovered species are sitting in those bone collections. Oh, yeah, a lot, probably.

Well, now that you've identified a new apex predator in the waters, 80 or 100 million years ago, how does that change what we know about that time period? I think there was a lot more of these animals than we thought, like going through and seeing like literally hundreds of Mosasars now, I have a better sense that I feel like they're much more diverse than we currently understand them to be. So I think it's painting a better, more complete picture of those ecosystems. And a more violent picture. Yeah. Dr. Zietlo, thank you so much for your time.

Of course. Thank you. Dr. Amelia Zietlo is a museum specialist at the History Museum at the Castle in Appleton, Wisconsin. We're celebrating our 50th anniversary this year, and with a Quarks and Quarks Archive that stretches back that long, you'd better believe we have some real gems. Like this one, from October 13, 1979, when then host Jay Ingram spoke with radio astronomer Dr. Jocelyn Bell-Bournell. In 1967, she made a major astronomical discovery as a PhD student at Cambridge University. She spent her first two years there building the radio telescope that she operated and recorded radio signals onto rolls of graph paper, nearly 30 meters of paper, a day. She was looking for evidence of quasars, the cores of active galaxies with supermassive black holes.

One day she found the signals she couldn't quite explain, a series of pulses, 1.3 seconds apart. Bell Bernal discovered a rapidly rotating neutron star that spins like a lighthouse emitting beams of radiation, a phenomenon we now know as a pulsar. It was so exotic, she had a hard time believing what she found. It turned out to be one of the most important discoveries in 20th century astronomy that won the Nobel Prize in physics in 1974, but Bell Bernal was left out. Though she did win, the special breakthrough prize in fundamental physics were $3 million US dollars in 2018.

Here's Dr. Jocelyn Bell-Burnell in 1979, explaining to host Jay Ingram what she had to do to discover that first pulsar. What happened was that soon after we started operating it, in scanning all those paper charts, I occasionally noticed a signal that I couldn't quite pigeonhole. It wasn't one of those quasars that we were meant to be looking for. The other likely thing was man-made interference because radio telescopes are very, very sensitive

and very easily pick up a badly suppressed car driving down a local road or something like that. But it wasn't exactly that either. I called it the scruff, and in our efforts to explain the scruff, well, it was quite a long story, we tried to get a better chart recording of them an enlarged chart recording by running the chart faster underneath the pen so the whole thing got spread out.

And I had six or eight weeks of trying to get that chart recording before I actually got it because this bit of scruff, whatever it was, went away, just disappeared. We now know that they're very variable sources, and sometimes they come through fairly strongly, but sometimes they drop below the level of sensitivity of the telescope, and that's what had happened, and we didn't know what was going on. And I was getting accused of all sorts of things. supervisor. But we finally got it and it came out as a series of pulses, a series of flashes. This

thing was sort of blinking at us or bleeping at us. Same strength all the time? No, the pulses were different heights, different strengths, but they had the same repetition rate. That was very accurately kept. It was about one and a third seconds. The period worried us, partly because it was so accurate, that suggests that whatever's sending out those pulses has a very big energy bank to draw on. It's not visibly slowing down or running out of steam, so to speak. But in contrast to this, the fact that they were so rapid meant it had to be very small. It had to be something small and nippy and fast, and that didn't sound like a star. I don't quite know what would have done next, except that just before Christmas, 1967, I stumbled upon a second one of these. And this was a tremendous

relief and honestly was far more exciting for me than finding the first one, because it then begins to much clearer that you are looking at a star. It really looks much more like something cosmic out there. And shortly after Christmas, we stumbled upon the third and the fourth as well. And that really, you know, you did begin to feel you were dealing with a new class of star. Where did you go from there? Well, again, it was quite a long time before it was clear just what it was. When we actually announced the discovery of the first one,

we weren't clear whether it was a white dwarf or not. Now, this isn't a pun on little green men. White dwarfs are a known kind of star. They're very small, hence the name dwarf. They're pretty compact, and they were sort of the most exotic type of star known. So we thought it might just be these at a pinch, though it was a little bit fast for them. The other possibility was that they would be neutron stars, which is what they've turned out to be. The neutron stars were first suggested in the 1930s.

A physicist by the name of Landau had speculated what would happen if the at a time. got much closer crushed together in material than they are in the material we know around us. And he reckoned that there'd be another stable state of matter at ultra-high density. And this idea was applied by several other astronomers who suggested that perhaps when a star explodes in a supernova, as it's called, perhaps the kick of the explosion compresses the core of the star and makes it into a very compact, very dense star, ultra-high densities. And this is probably what happens.

is the core of a star that has exploded that we are seeing, and the phenomenal kick of the explosion has forced the atom in on itself, and the negative electrons around the outside of the atom have merged with the protons in the core to make neutrons, and of course there already were neutrons in the core. So you get a material that's very largely made of neutrons, hence the word neutron star. The only place where this comparable density is the nucleus of an atom, be the sort of mass of the sun compressed into a sphere about 10 miles across.

So the kind of density you come out with is that a pinhead would weigh as much as a battleship or a big line or something like that. It's incredible, isn't it? It's hard to believe. It's very hard to believe, yes. Somehow I feel honour-bound to believe in them, but it is a bit difficult.

That would explain the small size. Yes. But that doesn't say much about the pulses. No. Well, we think that the accurate flash pulsing is to do with the rotation of this star. The whole thing is spinning, just like the earth spins, only a good deal faster. The pulsars typically flash once a second, twice a second. So what we're dealing with are stars that spin once a second, twice a second. The neutron stars are really very peculiar thing.

It's not a burning sphere of gas. It's got probably a solid surface made of crystalline iron. And it's got very strong gravity, so strong that if there was a really real, in this crust, just half an inch high. The work that you'd have to do climbing over that half inch wrinkle is comparable with the work you'd do climbing Mount Everest here on Earth. That was radio astronomer, Dr. Jocelyn Bell Burnell, on our episode from October 13th, 1979. I'm Bob McDonald, and you're listening to Quarks and Quarks on CBC Radio One, and streaming live on the CBC News app. Just go to the local tab and press play wherever you are. Coming up later in the

program how the way we sleep today is helping and hurting us. When I think of the modern sleep epidemic, I actually don't think of it in terms of total sleep time. I think of it in terms of how poorly we are aligned with our environments. If you sold somebody a loaded gun who you knew was in a vulnerable state and they shot themselves, I think it is murder. Just because you're using the internet doesn't mean you get away with murder. I'm Damon Fairless.

Host of Hunting Warhead. This season, I take you inside the business of suicide, and the places desperate people go when they can't find what they need in the real world. Hunting the Suicide Salesman. Available now wherever you get your podcasts. Glaciers are constantly on the move, with gravity tugging the heavy ice down slope.

But recently scientists noticed some glaciers moving in a more unusual way. Dr. Wesley Van Weichen from the University of Waterloo was going over some of his mapping data from the Arctic when he noticed that some glaciers were moving a lot. He tracked them over a few months as they were rising and falling in height, sometimes by more than 100 meters. That's how Dr. Van Weichen and an international team of researchers discovered a complex hidden underground network of lakes,

filling and draining under these massive glaciers. This discovery is shedding new light on how glaciers are moving in a warming climate. Dr. Van Weichen is a glaciologist at the University of Waterloo and was a senior author on this research. Hello and welcome to our show. Great. Thanks for having me. What was going through your mind when you first noticed these drastic changes in glacier height? At first I was kind of confused about the amount of surface elevation that we were changing because usually I'm looking for much subtler changes in the glacier surface, but we were seeing

changes in the order of 10 meters or more. So I was really kind of interested about what these might be caused by. Well, I'm just trying to get a picture of what that is. You're talking about the surface of the glacier going up and down, sort of like my chest heaving when I'm breathing deeply? Yeah, that's kind of exactly how you might think of these. So the glaciers usually the surfaces are very stable. But in certain situations, they do tend to buys and fall. usually related to changes in ice flow. But we also, in this study, found that they were changing as relation to storage of water underneath of the glaciers. So the water kind of lifts the glacier up as it accumulates. During the summer melt season, we get water melting on the surface, and that can percolate down through the glacier.

And that will pool in depressions on the underside of the glacier. And as we get more and more water percolating through the glacier and getting stored in these depressions, what happens is it pushes the surface upward, and we can detect those surface changes. Well, how common are the sub-glacial lakes in the Arctic region? They're actually quite uncommon when you look at the kind of total area of the Arctic. And the key thing is we can only detect the ones that are causing changes in surface elevation over time. It's possible that there are others that they're not actively filling or draining.

So it's a possibility that they're more widespread than they actually are. Well, where are the lakes that you did find? What part of the Arctic? So we are talking about the ice mass, fully located in Nunavut, but it's impressive in that we find these lakes all the way from Baffin Island, all the way up to the far northern regions of Ellesmere Island. So it's across this very wide swath of the Arctic underneath our glaciers and ice caps. How big are these lakes? Most are about 10 square kilometers in size, although we have some that are quite large, kind of closer to the 50 square kilometer size, and those ones are very rare, but they are quite large. How are you able to map out the lakes if they're underneath the ice of the glaciers?

What we use and what we relied on for this study is satellite imagery and data collected from space, and we use what are called digital elevation models. So digital elevation models, you can imagine that they are pictures of the Earth's surface, and every pixel in that picture is a measurement of the Earth's surface height. And so when we have a whole bunch of these digital elevation models and we stack them together, we can look at how does a particular area on the Earth's surface, how does it vary in its elevation over time?

So what did you learn about the lakes once you map them? What we've learned is first how widespread they are and where they're located. So previous to this, we've only had one or two actual locations for subglacial lakes in the Canadian Arctic. Now we know that they occur across the Canadian Arctic underneath these ice masses. And we've also able to learn a little bit about their drainage patterns as well. So how do they drain? Well, they drain in a variety of different ways. So we have some lakes that kind of very steadily fill over time and then drain very abruptly. We have some lakes that kind of very abruptly drain and fill multiple times over the 10 years study period that we looked at.

We have some situations where they're just steadily draining over the 10 years. and we have other situations where we have two lakes that drain at the exact same time, meaning that they are connected to each other in some way. Oh, so if the lakes are connected, does that mean there are also rivers underneath the ice? Yeah, you can essentially think of it as a river sometimes connecting these two lakes with one another or connecting out to the ocean, which is where this water eventually drains to after it exits one of these sublacial lakes. So how long does this filling and draining process take? Sometimes the filling can take five to ten years to fill fully and then it can drain rather abruptly in a matter of three to four months seemingly.

In other situations, we might have filling and draining events happening kind of episodically every three to four years. You say some of the water is coming through the cracks. Where is all of it coming from? The majority of it is coming from the, surface melt on the glacier. As that kind of collects on the glacier surface, it will eventually make its way down through the glacier, through crevasses, through cracks, through pipes in the glacier system that get that water to the bed. So if these lakes are forming underneath the glaciers and they're causing the glacier to rise up and down by a fairly large amount,

what effect is that water having on the glacier itself? Any time that we have water underneath of our glacier system, there's the potential for that water to kind of help the glacier slide more quickly over its bed. And so we see this happen on glaciers seasonally. They speed up during the summertime as the water gets to the bed and acts like a lubricant, allowing it to flow faster. And so I think future work that we're doing is going to look at that. Do we see that process happening with the storage of these water within these sub-glacial lakes as well? So how does this fit into the effect of climate change on the glaciers? Well, we did find kind of a connection between how much mass loss there was in the Canadian Arctic

and the drainage and filling of these lakes. And so what I'm really interested in terms of looking at going forward is tracking the draining and filling of these lakes to see if we see this connection. Dr. Van Wynchon, thank you so much for your time. Thank you. And thank you for your interest in the work. Dr. Wesley Van Weichen is an associate professor in the Faculty of Environment at the University of Waterloo. I've got my sleep mask, my sound machine, my humidifier, my duvet, my king-size bed, all to myself. I'm finally ready for a nap.

Well, these days our social media feeds are filled with tips and tools to help us settle in and get a good night's sleep, but it didn't used to be that way. Our ancestors didn't have sleep apps or pillow-top mattresses. They slept on animal hides and tucked in when the sun went down. Sleep anthropologist Dr. David Sampson has spent a decade studying how we and our closest relative slumber. He embedded himself with the hunter-gatherer Hazda people in Tanzania and climbed trees to siesta in a chimp nest in the forest of Africa to learn about how the way we sleep has changed over time.

Now in a new book, he explores what we know about our million-year evolutionary quest for rest and how the way we sleep today is both helping and hurting us. Dr. Sampson is an evolutionary anthropologist at the University of Toronto, Mississauga, and the author of The Sleepless Ape, The Story of Sleep in Human Evolution. Hello and welcome back to Quarks and Quarks. Thank you, Bob. It is a pleasure to be back. What is it about sleep that fascinates you? You know, if somebody had asked me whether or not I'd be interested in sleep or become a sleep specialist about 10 years ago, I would have thought they were crazy.

But once I realized that what we knew in terms of the scientific community and especially the evolutionary anthropology community, what we knew about sleep from the vantage point of evolutionary theory in human evolution was effectively almost. almost nothing. We had these beautiful ethnographic reports, but we hadn't done any really broad, phylogenically deep analyses in it. And that's what made me really fall in love with the topic. Well, considering how much time sleep takes up in our lives, why is it still so poorly understood? Yeah, I mean, here's the question. And I love to open my horse with this particular question. What is sleep? And the reason why it is a stumper for a lot of my students is that it's actually three different kinds of things. It's a behavior. So you have eyes closed, you're lying down, you have low motor activity, you have a high arousal threshold, meaning it takes a lot of

stimulus in your environment to wake you up, which brings us to the second kind of thing, sleep is it's a brain state. There is distinctive sleep architecture that's been quantified scientifically since the 1950s. And we know that it goes through four to six different cycles, usually about 90 minutes each, and we spend about 75% of our sleep state in what's called non-REM. And this is deep, slow-wave sleep. We do a lot of it in the early part of the night. And then the other quarter of it, which is REM, it is the place where we are most associated with dreaming, and we have a lot of it later in the evening.

And then finally, it's a neurophysiological process. So things like the glimphatic system, where you have this basically, fluid, cleaning out the interstitial tissues of your brain and clearing out all that beta amyloid gum that's associated with things like neurodegenerative disorders later in life. Boy, and when you say REM, that means rapid eye movement. That's correct. And so it's actually doing things to our body. I mean, what's it doing to our health as we sleep?

Yeah, so remember I highlighted the non-REM part? That is what's most associated with this immune function and deep repair. particularly it is a place where memory cells, they match on to see what the invader is such that when you're awake, you can produce the correct response to it. If you get under five hours of sleep, for example, the likelihood of getting the rhinovirus, the common cold, if you're exposed to it, goes up 80%. So there are some fundamental basic processes that especially occur in that deep sleep. slow-wave sleep early on in the night that are crucial for our health and our well-being, both short, mid- and long-term. Now, we typically associate REM sleep with dreaming, so how does that factor into our health?

Yeah, so REM is most deeply connected, in terms of the scientific literature, it's most deeply linked to our capacity to emotionally regulate. And Matthew Walker, the sleep scientist, calls REM our nighttime therapist. So think of REM as that part of the sleep process that allows you to replay a traumatic memory or some really important event in the day. And to consolidate that information stored in the hippocampus for later retrieval, but then when you retrieve it, not experience the emotional valence. of the memory. Effectively, if you don't get enough sleep, you're not going to be able to jettison the emotional content of the memory. This is why some of the leading cutting edge research with PTSD is looking at how to solve her sleep first and then the PTSD heals itself because of this

process. So it's really kind of a way to emotionally regulate. Now, in your book, you talk about what you call the human sleep paradox. Tell me about that. Yeah. Okay. So I'm going to ask you a question. Recall the last time you had really significant sleep deprivation. How did you feel? If I have a bad night's sleep, I'm groggy. I can barely keep my eyes open. I find it hard to focus.

Keep a sentence together. I feel like I'm almost on drugs if I haven't had a good night's sleep. Well, that's perfect. And that mirrors a lot of people's experience under sleep deprivation. In fact, you really highlighted the cognitive, angle of this. So when we look at things like imagine tool use or tool function, so if you're driving a car and you're under four hours of sleep, then you're driving effectively at the legal limit of alcohol, if you had the up to the legal limit of alcohol. This is to say we really

need sleep for all the things that makes us human. But the paradox is when we measured sleep in every single primate on the planet, humans sleep the least. of any primate. You would think with our big brains and our big bodies, we would sleep the most. But no, owl monkeys do that. They sleep 17 hours out of the day. We are by far the least sleeping primate, and that's the sleep paradox. So why do you think we would have evolved like this? Yes, and that is the central question that I explore in the book. We often think of a good night's sleep is one that is fundamentally anti-social. And it's going to be this very minimally stimulus environment. And that's how we, in the global North, imagine a perfect sleep environment. But that's

not how we evolved. In fact, the irony here is that we changed our sleep through time. About 1.8 million years ago, we began the process of whittling down our total sleep time as primates and securing REM. So we reduced the non-Refs. So we reduced the non-Rexam. We kept the REM. And the reason we could afford to do that wasn't in spite of the fact that we were social. It was because of the fact that we were a U-Ssocial species living in camps and bands of about 25 to 30 adults in the shared project of reproduction and survival. And so the acronym I've been working on is that of a shell. So if we start with the letter S, we have shelter.

And what this does is it reduces the amount of temperature variability in our environment. So we have a more predictive environment. And then you have the hearth. This is H. And the hearth helps regulate temperature. And then you have E, which is environmental preparation. So you have mobile sleep sites that we had been, we've been shaping and selecting the best sites that have the greatest access to water or defensive crawls.

And then L is Lux, continual exposure to light, but good kinds of light. So the sunlight. And then after the sun goes down to firelight. and firelight only, unlike the blue light that we get bombarded with day to day. And then the final L is lookouts. When we looked at the sleep patterns of the hods of, for example, it was incredibly rare for all individuals to be asleep at the same time, meaning you functionally have adults looking out for everybody at any given moment, which means that throughout the 24-hour period,

you have this shell that allows you to go into deep, high-quality restorative sleep in the shortest amount of time possible. This whole thing put together is the reason why I think humans are incredibly bizarre and unique sleepers amongst the primates. Wow. So it's our sociability that led to the shorter sleep. Now, you visited the Hosda in Tanzania. You talk about that in your book. It's a great adventure story. Did you try sleeping in one of their huts? So I had my own tent. It was effectively the same square footage as a hut, but I have been in the huts. They build Acacia huts, takes them about four hours, these 20 centimeter thick huts that are then insulated with, say, a animal hide. It's very simple, but quite effective. And then they sleep on two to three centimeter thick

animal hives or textiles. And there aren't any pillows in this environment. In fact, when I asked them about, well, what's, what do you guys use as pillows? It looked at me kind of weird. Like, there wasn't actually a, a word for pillow in a hudzani language, click, click based language. And they said, just keeping your neck straight. Oh, we do that with our arms or we shove a little dirt under our textiles. Now, going a little further back in our evolutionary history, you also talked in the book about how you climb trees to see how our primate relatives sleep. Tell me about that. Yeah, so I had the opportunity to work with Kevin Hunt, who was my doctoral supervisor, and he had ran a chimp site out in East Africa and Uganda. And I was really interested in this topic of

chimpanzee beds or sleeping platforms because great apes are really unique in the primates. And I'm including humans in this because a human is a great ape. We all build sleeping platforms. This is a proper bed and they build one of these every night. And so all the great apes do this and what I wanted to do was climb up into these nests. And sometimes my highest climb I think was about 22, 23 meters in a kola gigantea tree and quantified these chimpanzee sleeping platforms in situ to understand what they serve in terms of how a chimpanzee or any other great eight solves for the problems of sleep. Wow. So did you sleep in one or at least lie in one?

What was the like? Bob, I took a nap, a good siesta. I didn't have the courage to do it overnight. But it was quite comfortable, especially the ones that were built by the males, they were typically a little bit lower in the canopy. The females would go really high up in the canopy. And at my body mess, it was just a little bit less comfortable. Wow. Well, what did this sleeping in trees do to our evolution over time? So apes figured a really ingenious way to get deep sleep. And there's this hypothesis that starting about 18 million years ago, once they built these beds,

they could have deeper sleep, meaning they had more potentially more REM. But they preferentially selected Sinometra Alexandria trees, so like 80% of the time, even though it was not readily available in the environment, meaning we could really get into the minds of a chimpanzee to see what kind of things they love in their bed. And this miracle tree was not only super resilient, and it had these beautiful, very thick, protruding branches. They were resilient under pressure. And the chemicals that you smell when you break it were repellent to things like insects,

particularly anophilies insects that carry plasmodium, the parasite that transfers malaria. So it had all these properties, including it increasing warmth for the individual, that all these apes had this beautiful sleeping platform that solved for all these challenges that other primates didn't have the benefit of. So we had to solve for these things. When we came down out of the trees into East Africa and we started evolving in East Africa, we needed to figure out how to do what our chimp ancestors were doing, in the trees.

Okay, so we got primates that sleep in trees with their comfortable nests. We've got the Hazda people who socialize and there's always someone awake so that lets them sleep with the higher quality sleep. How does all of this compare to what we're doing today in our modern civilization? Yeah, so there's this idea today that we live in a kind of sleep epidemic of sort. that our sleep has never been worse and that we are the worst sleeping cohort of homo sapiens that have ever existed. And so we wanted to test this idea. And we went across 54 different societies, including the small scale societies that myself, my team and my colleagues have been working with.

And we wanted to see, is sleep actually better or worse in small scale societies compared to large scale agricultural societies, post-industrial societies? And we found something rather interesting. It was that in large-scale societies, we're actually sleeping significantly longer and have higher quality sleep than in these small-scale societies. So, for example, in large-scale societies,

on average, we're sleeping about 7.1 hours, and in small-scale, it's about 6.4. And the sleep efficiency itself is 14% better, meaning the time that we spend in bed, we're actually sleeping longer. When we looked at circadian function of the small-scale societies versus large, the small-scale societies have much stronger circadian function, meaning the timing of their biological clocks is much more consistent. And so when I think of the modern sleep epidemic, I actually don't

think of it in terms of total sleep time. I think of it in terms of how poorly we are aligned with our environments. So why is that? What's causing us to get out of sync with the environment and mess up our circadian rhythm? Yeah, there's a number of factors, but there are two, maybe three, major culprits. I would say the first is light. We have what I like to call fast food light overload. We take in light that is, we'll say, very poor nutritional quality. And it has almost no infrared light. And infrared light is absolutely crucial. Infrared light is what powers our mitochondria. And that is what creates ATP. It is basically the energy of our entire life is fueled by this process. So if you're not getting high quality infrared light, you're doing your

biological timing a very big disservice. And then of course, we have to note that as soon as the sun goes down, a lot of people love looking at their cell phones and watching LCD screens. And it emits this really crappy blue wave light, which is fine during, say, like noon, but it's really bad for us after the sun goes down. And it's going to inhibit melatonin, which is the principal hormone that regulates sleep wake activity. So we're sleeping a little longer, but the quality of our sleep is not as good. I think the overall quality of our circadian timing is being disrupted. And that's crucial. Yeah. So what's your recipe for getting a good night sleep in modern society? I think sleep is the effect, not the cause. And I think the real cause here is circadian rhythms. And that's because

we evolved circadian rhythms. All life on this planet evolved the circadian rhythm about a billion and a half years ago long before the first organism ever slept. Really, sleep is kind of a recent evolutionary phenomena if you're looking at it from that deep time perspective. So I think sleep is downstream. And the best way to sink our sleep in a modern world is to get the data that we're denying it from the outside world. So tether your morning wake up with the rising of the sun. Make sure by noon to get that full wave spectrum light, you want that infrared light. And there's really great news if you have a garden, for example, sit in that garden while you're eating lunch or get some exposure to some green leaf and material around you because it absorbs infrared light.

And then it actually jettisons it out into your mitochondria. So you can get basically this forest bathing benefit from just being in green. And then of course, make sure your body is connected to the temperature, both outside and inside. And then we have to be very mindful of when we have the last calorie for the day, because if we eat before bed, it doesn't allow your physiological system to metabolically cool down and give us the most restorative sleep possible. Well, Dr. Sampson, thank you so much for your time and get a good night's sleep tonight. Oh, thank you, Bob. And sweet dreams. Dr. David Samson is an associate professor of evolutionary anthropology at the University of Toronto,

Mississauga, and the author of The Sleepless Ape, the Story of Sleep in Human Evolution. And that's it for Quirks and Quarks this week. If you'd like to get in touch with us, our email is Quirx at cbc.ca. Our web page is cbc.ca.ca slash quirks, where you can check out our past episodes and find more information on the research we covered in the show. You can also follow our podcast. Get us on SiriusXM or download the CBC Listen app. It's free from the App Store or Google Play. Quarks & Quarks is produced by Sonia Biting, Rosie Fernandez, and Amanda Buckowitz.

Our senior producer is Hannah Hoag. Special thanks to CBC Radio Archives, Patrick Mooney, Ross Tawley, and Zoe Beraclough. I'm Bob McDonald. Thanks for listening. For more CBC podcasts, go to cbc.ca.ca. podcasts.