Quirks and Quarks - 'Gifted' dogs learn from eavesdropping, and more...

Episode Date: January 23, 2026

Some dogs are more adept at learning language than others. Researchers studying these special dogs discovered that, much like toddlers, these smart furry canine companions can pick up words just by eavesdropping on their owners' conversations.PLUSTracking space debris using seismometersUsing nitrogen to boost treesHow Mars shapes our climateExtracting ice age mammoth RNA and using lichens to find dino bones

I am an actor, fresh out of theater school with big dreams and an even bigger drug habit. But things are pretty good. That is until my best friend is set up on a date with David Lee Roth. Yeah, from Van Halen. If you know, you know. From CBC's personally, this is Discount Dave and the Fix. The true-ish story about how a fake rock star led me to a real trial that held up a mirror to me. And okay, let's just say that not everyone in this story is who you think they are.

Personally, discount Dave and the Fix. Available now on CBC Listen or 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, Mars's unexpected influence on Earth. So I came to this study thinking that, well, Mars is not going to have too much of effect. But instead, what I found was the opposite.

And how nitrogen can help superintend. supercharged carbon sequestration. If we're looking for ways to take carbon dioxide out of the atmosphere, we think that this is a way that we can accelerate that. Plus, the dying moments of a 40,000-year-old woolly mammoth, tracking incoming space debris and gifted word-learning dogs that eaves drop. All this today on quirks and quarks. Space is getting really crowded these days.

We've got satellites, research payloads, and spent rockets floating around our planet. And as these things start breaking apart, they create even more of a mess in orbit. According to the European Space Agency, there are more than 1.2 million pieces of space junk over a centimeter in size orbiting our planet, though many are much larger than that.

And more and more often, we're hearing of large chunks of this junk falling from space and hurtling towards our planet. What the hell? At about 1.40 a.m. on Tuesday morning, Angelinos, who were out late partying, I guess, looked up in the sky and saw this trail of flaming debris. But it's often a huge challenge to figure out where this junk goes once it gets into our atmosphere. Yeah, a bit of sci-fi hitting home for a Michigan couple when a satellite crash landed in their backyard. As a farmer in rural Saskatchewan, Barry Sautchuk is used to remove.

moving rocks and weeds from his fields, but he recently discovered this two-meter-wide, 40-kilogram heap of twisted, burnt metal. Whether it is his insulation, I have no idea. Well, a team of researchers have come up with a way to keep tabs on this space junk after it re-enters using earthquake monitors to listen in on the sonic booms they produce. Dr. Benjamin Fernando is a planetary scientist and seismologist

at Johns Hopkins University in Maryland. Hello and welcome to our program. Hi, Bob. Thanks for having me. So how often do we have space debris reentering our atmosphere? So we're now at a point where we often have multiple satellites per day reentering the atmosphere. Per day? Yeah, exactly, per day. In the early part of last year, we had multiple Starlink satellites entering the atmosphere per day.

And each of those poses some risk to life, both on the air if you're in a plane and on the ground and they're beginning to change the composition of our atmosphere as well. Wow. Well, what kind of materials are these satellites made of that makes them so dangerous? That's a great question. And part of the problem is we don't know exactly what they're made of. There's no mandatory reporting in international standards for this. So the stuff that makes up battery packs, fuel tanks, solar panels, some of that stuff we think has a pretty substantial climate warming potential and also the potential to deplete the ozone layer. But the trouble is, without exact data,

trying to understand exactly what those impacts are is challenging. Well, that's the upper atmosphere, but how much of that stuff actually reaches the ground? Again, we don't really know. Many of these companies say that their satellites demise entirely, that is, they burn up entirely within the atmosphere. Yet we've seen a few cases of pieces of space debris hitting the ground, and we don't always know where they've come from.

Some of those fragments, they might be toxic, they might be flammable. There's even been a few instances of things that are radioactive being spread on the ground from reentering space debris. Well, is there any current way to keep track of debris that's falling through our atmosphere? So people do this using radar, which is great, except that in many parts of the world, we don't have great radar coverage. And other nations keep their radar coverage classified, whether it's civilian or military. So very often, we don't have access to the sort of open source data that we're, we'd like to track and characterize these re-entries as they're happening. Well, take me through your work. How are you planning to track this stuff more accurately?

So what we've done is demonstrate that seismometers, that is, the sensors that are normally designed to record earthquakes, can also be used to track the sonic booms from reentering debris. So if you imagine debris comes into the atmosphere, it's going many, many time to speed of sound. It generates a sonic boom. And we showed that seismometers can record those sonic boom. booms, and from that we can reconstruct things like the direction, the speed, the descent angle of the reentering debris, and also something about how it fragmented in the atmosphere. That's astounding, because we always think of seismometers as measuring the earth, what's going inside the earth. I didn't realize they were so sensitive that they could detect vibrations

in the air. Yeah, so what happens is those vibrations in the air actually shake the ground, and that's what we detect on our seismometers. These instruments are incredibly sensitive, in addition to detecting earthquakes, they often pick up things like ocean waves, things like vehicles, planes. Occasionally, they pick up whales as well. They really are incredible pieces of technology. So how much of a satellite's track can you follow using seismometers? How would it work? So in theory, we can follow the satellites track from the point where it starts producing a sonic boom, which is somewhere around 100 kilometers in altitude, down to the point where it's going subsonic. so it slows to fasten the speed of sound or it hits the ground.

And it can be a little more challenging than that, because often if these things are breaking up, the pieces that are left to hit the ground are quite small. They're quite quiet and difficult to detect. But what we're trying to do is characterize that sort of terminal phase of reentry where all the stuff that's relevant to people on the ground is happening. So the breakup, the stuff separating, and then beginning to ablate that is burn up as it enters denser and denser portions of the atmosphere.

Have you tested this? So we tested it on a case study from a piece of Chinese space junk called Shenzu 15. Now Shenzu 15 was a particularly sort of risky target in some sense because it entered over metropolitan Los Angeles in April 24. But the good thing for us, at least, about this happening in Southern California, was that there were lots of seismometers that we had to test our theory on. And we were able to show that we could basically reconstruct the trajectory of that object using the seismic. network in California. Oh, I see. You have a network, a bunch of seismometers on the ground, and each one of them tracks it as it passes overhead. Exactly. And so different ones on that network will see the sonic boom at slightly different times. And from putting all that information

together, we can work out something about where the object was, how fast it was going, and so on. How big was that object? So it started off in the atmosphere being a couple of meters across. By the time it crossed the coast of California, it looked like it. it had broken up into fragments that were more like a meter across. And then we see evidence of what we call sequential fragmentation. So that is, bits broke up, and then those bits broke up into smaller bits and so on and so forth. So we kind of had this cascade of a big piece of space junk breaking into many smaller pieces, which have the potential to fall over a much wider area. Boy. So can this method of using seismometers to track falling space debris be used anywhere

on Earth? So California is a particularly good test location because it has a very dense network of seismometers. But we've also been able to make measurements like this in other locations where there are far sparser networks. For example, we've got some really interesting data from the Caribbean last year where we saw a series of SpaceX's Starship rockets explode and rain down debris on beaches in the islands there. We've also been testing it by taking the data from California and then imagining that we throw away or discard 50, 60% of the measurements we made to see how many stations we need in order to reconstruct that trajectory if we were working somewhere that has fewer seismometers on the network. So how few do you need to make an accurate track? There's some

detections in the Caribbean where we have only one or two, and that still tells us something about the direction the objects traveling in. But the more sensors that we have, the more reliable the results become. So how big or small are the items that you've been? So how big or small are the items that you could see with this method. I'm thinking of the Starlink satellites where there's thousands of them, and SpaceX says, well, they're small enough that they'll all burn up high in the atmosphere. You don't have to worry about them. So we've definitely seen some sonic booms from re-entering Starlink satellites. That is very clear. The question, again, is, of course, whether any of those fragments survive to reach the ground. But we've seen things down to around 50 centimeters or so

in radius very clearly on our seismometers from dozens of kilometers away. So where do you see a system like this being used? Unfortunately, space debris is a global problem. It doesn't particularly care what country you're in. It doesn't care whether your country or your company was the one who launched the satellite or not. And so what I'm hoping is that over time we can develop this sort of network approach of seismic monitoring for space debris to try and understand and characterize re-entries wherever they occur on the planet in near real time. That is, as soon as we detect a series of sonic booms, we try and put together a best-fit trajectory for that object,

so that when it comes to trying to understand where it might have landed and what the environmental consequences, both in the atmosphere and on the ground are of that re-entry, we're well placed to help locate it. Dr. Fernando, thank you so much for your time. Thank you for having me. Dr. Benjamin Fernando is a planetary scientist and seismologist at Johns Hopkins University in Maryland. The climate is changing and it's changing fast. And now the clock is ticking for us to deal with our fossil fuel emissions before global warming causes even more irreversible damage than we've already seen. One of the most powerful tools at our disposal to get rid of the carbon dioxide already in our atmosphere is our forests.

There's just one problem. Trees grow so slowly. But what if we could hit the fast forward button? to speed up tree growth, to pull more carbon out of the atmosphere more quickly. Well, in one of the world's largest and longest experiments, Dr. Sarah Batterman and her team have now shown they could do just that in tropical forests in Panama. Dr. Batterman is an associate scientist at Cary Institute of Ecosystem Studies in Millbrook, New York, and an associate professor at the University of Leeds in the U.K.

Hello and welcome to the show. Thanks. I'm delighted to chat with you. So first of all, what was the original intention of this study? Tropical forests are globally important for taking carbon dioxide out of the atmosphere, but their future is three times more uncertain than any other parts of the world, in part because trees need nutrients like nitrogen or phosphorus in addition to carbon to be able to grow. So how did you test the role of these nutrients in the forest without waiting hundreds of years? Yeah, exactly. That was a big challenge because that's what you would really ideally do. But of course, we're not going to be here for hundreds of years. So we used an experiment where we use space for time substitution. So this is called a chronosequence approach. And we had forests that ranged in age from recent pastures that we abandoned and allowed the forest to naturally grow back. We had 10-year-old forests.

30-year-old forests, and then mature forests. Across those forest ages, we tested how important the nutrients, nitrogen, or phosphorus are for the forest growth. So how did you do that? How'd you conduct the experiment? Yeah, we established 76 plots in the forest that were about the size of a hockey rink. And in each of those plots, we identified all the trees to their species, and we measured how big they are and how much carbon they store, and then we added fertilizer to some of the plots. We added nitrogen in some plots, phosphorus and other plots, both nutrients in a third set of plots. And then we compared, we measured the growth of the trees and how they changed over time over four years in this experiment. And we compared the growth in the fertilized plots to plots that did not have any

nutrients added. So that's the way that we could identify the effects of nutrients on the forest carbon recovery. So what kind of differences did you see in the plots where you added fertilizer? Yeah, we saw amazing effects of nitrogen in the young forest. So in the first 10 years, the forest grew back twice as fast if they had enough nitrogen in the soil compared to when they did not. That's just amazing effect. We were kind of, we were blown away by that. But then we, as we looked across the forest ages, by 30 years, we found no evidence of nitrogen, a nitrogen effect on the forest recovery. And then we thought that they would switch to limitation by phosphorus, which is widely considered the most important nutrient that is scarce in tropical forests.

But actually, we also found no effect of phosphorus on the growth of the trees in the older forest, 30 years or mature forest. So that was also surprising. Well, why do you think that the younger forests were absorbing nitrogen and growing faster than the older ones? So after a disturbance like deforestation and use of the land for agriculture, there is a lot of loss of nitrogen from the soil, from the trees that used to be standing there. And those nitrogen losses then cause a shortage for the trees that are growing back. Oh, I see. So then you added, Nate, they were very happy about that. Exactly, yeah. But over time in these forests, the forests have natural ways of fertilizing themselves

with nitrogen. And that's through the presence of trees that have ability to fix nitrogen. These are trees in the legume family, so they're related to beans, peas. But they're trees. in tropical forests, and they form a symbiotic relationship with a bacteria that can fix nitrogen from the atmosphere. And through that nitrogen fixation, they can actually build up nitrogen in the forest over time. And that's why by 30 years, we didn't see any evidence of nitrogen limitation anymore. Oh, I see. They got the nitrogen they needed over time. So how much carbon could a young tropical forests removed from the atmosphere if it gets some extra nitrogen and grows more quickly? Yeah. So in that, the first 10 years, when they have that boost where they can sequester twice

as much carbon as a forest that does not have enough nitrogen, we estimate that globally, if our findings hold for other tropical regions, which we do, we have reason to think that nitrogen limitation may be relatively widespread, we estimate that new reforestation efforts, if they considered the fertility of the soil and made sure that reforestation was done in areas with sufficient nitrogen, they could sequester an additional 0.69 gigatons of carbon dioxide each year. that's about as much as the emissions of the country Indonesia. So it's not huge. It's probably globally only one or two percent of our carbon emissions, but it's also not nothing.

And if we're looking for ways to take carbon dioxide out of the atmosphere, we think that this is a way that we can accelerate that, especially over the next 10 years when we really need to offset our emissions so that we can have time to transition. to other energy sources and reduce our carbon emissions. Okay, so this is not a total solution to our carbon emissions, but every little bit helps. Exactly, yep. Now, in Canada here, we have very large boreal forests. Could it also work there by adding nitrogen? Boreal forests don't have a lot of nitrogen fixing trees. In some areas they do, and I guess it could be possible to plant, for example, Alder is the

dominant species of nitrogen fixing tree in Canada. But you could definitely think about, like, where is there a lot of nitrogen pollution and do reforestation there. Now, you mentioned 10 years. Are you saying this approach could have a meaningful impact on our atmospheric carbon in the near future? It is. Yeah, exactly. This is something that, you know, we could start today and just take land that is used for agriculture and abandon it and let the forest grow back. or plant trees on it, and this carbon boost could start immediately. It's interesting because we hear about rewilding areas just to have forests so that, you know, we can go in and explore them and discover nature again, but you're saying there's also

an atmospheric, a climate benefit and a pollution benefit as well. Yeah, exactly. Dr. Batterman, thank you so much for your time. Thank you very much. Dr. Sarah Batterman is an associate scientist at Carey Institute of Ecosystems, studies in New York and an associate professor at the University of Leeds in the UK. Sky, who's a good girl? If you have a dog that knows basic commands like sit or stay, you likely think it's pretty smart.

Or if you've trained it to recognize its favorite toy, you probably think your dog is really smart. But if your dog knows each of its toys by name, even if you've only mentioned it in passing, well then your dog just might be a gifted word-learning dog. Next one is Armadillo. Scientists studying these special dogs discovered that, like kids, the smart, furry canine companions can pick up words just by eavesdropping on their owner's conversations. Yes, good girl, yes.

Dr. Cheney Dror led this research. She's a post-doctoral researcher at ELTE University in Budapest and the Veterinary University of Vienna. Hello and welcome to our program. Hi, thank you for having me. First of all, what classifies a dog as a gifted word learner? So as he said, we know that the majority of dogs have no problem learning action labels like Sitterdana State.

In our previous studies, we found that there's only very few dogs that are able to pick up names of objects. And basically, once we see that a dog can learn the names of objects, we classify this dog as a lifted word learner. So how many words can these dogs learn? Seems to be endless, only bound by their owners' patients and how much space they have in their house for toys. We've seen in previous studies a dog that learned the name of over a thousand toys.

And in our studies, we have many dogs that have somewhere between 2 to 300 or even more toys. Wow. So when you say identify their toys, you say you just say the name of the toy, like dog bone, and they go get it. Exactly. So what we find is dogs in general are very good in picking up any visual cues that humans are giving them. And often if we're sitting with a dog in the same room, you know, before we think we're going to go for a walk, our dog is already jumping and getting through the door because they're so attuned to us.

Does breed have anything to do with it? We see this in many different breeds, but it is true that among the gifted dogs, there are many border collies. This is still a very rare trait even among border collies. So it's not like if you have a border collie, this dog would be able to learn the names of toys. And we've also seen dogs that we would not expect. So we've seen breeds that were not bred to work with humans. For example, Pikini's Shih Tzu, we've seen a few Yorkshire terriers that are able to do this.

So it's not a breed-specific trait. Well, take me through how you tested this in the dogs, to see if they could identify toys just by words. So the basic setup that we do is that we have the toys placed in one room and we have several toys on the floor to make sure that the dog is not just by chance picking up the right toy and the owner is sitting in a different room. That's how we test it. But we also want to check are the dogs able to learn from overhearing?

So in this condition what we had is the two owners speak to each other. One owner would talk about the toy and explain about the toy and both owners were not allowed to interact with the dog. The dog would be sitting close to them and would only be allowed to follow the interaction but not to take an active role in it. And after a few exposures to this, then we tested the dogs again to see if they learned the names of the toys.

Oh, I see. So instead of showing the dog, the toy and say, hi, here's your doll or whatever the toy is, the two adults were talking about it just among themselves and the dogs are listening. Exactly. The interesting thing here is that we know that infants, when they're already 18 months old, they can already pick up words by overhearing other people speak.

And I'm sure that a lot of parents know this embarrassing situation when you realize that your kid has picked up on words they're not supposed to. And what we found in our study is that not only the dogs were able to pick up the words, the names of the toys this way. So just by overhearing the owners speaking, but also their performance. was equal to their performance in the control condition. This means that they were equally good in learning from overheard speech and from direct interactions.

Wow. How does this ability to learn language, basically, compared to what humans do? So that's a very good distinction. This is not language, right? They're only picking up here these labels of the toys. But the labels of the toys, they are very specific to the toys that they see. We cannot generalize from this very specific ability to learning language,

because language is a very complex mechanism. It's not only the ability to understand that certain things have names. It's also the way that these things interact with each other, so how we combine words together and how we generalize certain words to other things. So the fact that the dogs are performing the same way as a children does not mean that they're thinking the same thoughts as the children. What went through your mind when you realize that the dogs were just as good at identifying their toys by eavesdropping? To be honest, I wasn't surprised by the fact that they learned, but I was surprised by how good they were learning.

Because many of them were what we call at ceiling level, so they had 100% correct choices. And they were really confident in what they were doing. They really knew which toy they're supposed to bring, and they just went into the room and immediately bought it. Now, if someone has a dog, how could they tell if their dog is one of these gifted learners? So if you think your dog knows the names of toys, all you need to do is put the toys somewhere that you do not see them. So either in a different room or behind your back and put a bunch of toys on the floor and then just ask your dog a few times to get the toys one by one. And if you notice that your dog does know the names of the toys, then please contact me. I would love to hear from you.

we're always searching for more dogs that know names of toys. Dr. Dr. Dr. Dr. Dr. Dr. Dr. Dr. Dr. is a postdoctoral researcher at ELTE University in Budapest and the Veterinary University of Vienna. Now, if you think your dog may be a gifted word learner and want to connect with this study, we have the information on our website at cbc.ca.ca slash quirks. I'm Bob McDonald and you're listening to Quirks and Quarks on CBC Radio 1 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, uncovering a genetic snapshot of a woolly mammoth's dying moments. We checked, okay, did we find something? Yes. Was it mammoth? Yes. Was it good enough? Yes, in some cases. 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. In Gustav Holt's musical work The Planets, His piece about Mars, named after the Roman god of war, makes for an ominous character in his musical solar system. But if the planetary version of the god of war was a boxer, it wouldn't compete in the heavyweight division. Mars is only half the size of our other next-door neighbor, Venus,

and compared to Jupiter, the gas giant of the solar system, it's puny. The gravitational pull of these planets is so powerful, they subject the Earth to what's known as Malankovic cycles. These are regular periods that help shape the Earth's movements and climate over many thousands to millions of years. And for the longest time, scientists didn't think the red planet had much to do with these cycles. But now, according to a new study, scientists say Mars is punching above its weight and that life on Earth likely would have been different had it not been there.

Dr. Stephen Cain is a professor of planetary astrophysics at University of California, Riverside, and the lead author of the study. Hello, and welcome to our program. Hello, Bob. Thank you for having me. Well, first off, let's make sure we understand the Melancovitz cycles. Generally speaking, how do the other planets affect the Earth? Yes, the Malakovic cycles of the Earth are fairly complicated because our system of planets has eight major planets in it. and all of the planets are slowly affecting each other's orbits and causing them to go through this somewhat of a dance

where they're interacting with each other, their orbits are slowly changing through time, including Earths. Give me some examples of a couple of these cycles. Yes, so there's various things about Earth and its orbit, which are changing through time. The two main ones that we often talk about is the shape of the Earth's orbit and the tilt of Earth's rotational axis.

the orbits of planets are actually slightly different from a circle, and they're what we call an eccentric orbit, which means they have a slightly elliptical shape. Now, the extent to which these orbits are elliptical, as opposed to circular, depends on a lot of things, and it depends on the interactions of the planets with each other. But also the other thing, as I mentioned,

the tilt of the Earth's axis, its rotational axis, this is primarily what gives us the seasons on Earth, which means that during the summertime, the northern hemisphere is pointed towards the sun during the winter time, it's pointed away. But the amount to which Earth is tilted can change as well. And these are the two main pieces of what we generally call Malankovych cycles. And how will they affect the Earth's climate? Well, so the major source of the seasons, as I mentioned, is the tilt of the Earth's axis.

and that is dominating the amount of energy that Earth receives from the sun. When the Northern Hemisphere is pointed towards the sun, it receives a lot more energy. And so this produces warmer weather. Now, when the Earth is in an eccentric orbit, this oval-shaped orbit, that means that sometimes it spends part of its orbit closer to the sun and sometimes further away. So these two effects are competing with each other, and they're also changing with time, but generally it's causing a change in the amount of energy that Earth is receiving from the sun. Well, how did you go about finding out what kind of role Mars plays in these cycles? Yeah, this was quite an interesting study because it started from a point of skepticism.

I spend a lot of time thinking about the way in which planets in our solar system and in other planetary systems interact with each other. and often we're thinking about the effect of the primary sources of these changes in orbits, and that is usually giant planets like Jupiter and Saturn. And so when it comes to small planets, particularly planets which are smaller than Earth, it's often assumed that their effects can be more or less neglected. However, because Mars is further away from the sun, it actually has a very large, what we call a hill radius,

which is the extent of its gravitational influence. And so I came to this study thinking that, well, Mars is not going to have too much an effect, but instead what I found was the opposite. And I learned that by performing some simulations which remove Mars from our solar system, and then I was able to quantify that. Now, when you say that Mars has a greater effect because it's further away from the sun than, say, Venus and Mercury, why is that?

Because the amount of gravitational influence that a planet has depends on how much its gravity is overwhelmed by the Sun's gravity. So, for example, if we go to something like Venus and especially Mercury, then their gravitational influence is very small. However, once you go out to a distance like Mars and further, then the Sun's gravity is felt a lot less, and it means that those planets can exert far more influence around them. So it does mean that Mars, in this case, is actually punching above its weight. So what happened when you took Mars out of your simulation? Well, when we took Mars out, there were a few cycles of these Melankovic cycles that actually disappeared. And I was surprised by that.

There's a few very well-known cycles in the Earth's orbit and the tilt of its axis, which people have been studying for a long time, and they look for evidence of this in the geological record, for example, the extent to which we have ice ages. And these sorts of things happen on very long periods of time. For example, there's a 405,000-year cycle, there's a 100,000-year cycle, and there's even a 2.5 million-year cycle, and there's even a two and a half million year cycle. Well, what we found when we took Mars out was that the 405,000 year cycle,

that remained because that is primarily caused by Jupiter and Venus. However, the 100,000 year cycle and the 2.5 million year cycle, both of those disappeared entirely. And particularly the 100,000 year cycle is thought to be a major source of Earth's Ice Ages. So without these two cycles,

if Mars didn't exist, what kind of effect would that have had on the Earth? There are two main aspects of the Melanchorage cycles. One is the shape of the orbit, the other is the tilt of the axis, and Mars is affecting both. So the cycles that I've been mentioning so far, the 100,000-year cycle and the two and a half million year cycle, those are changes in the Earth's orbit. There's also changes in the tilt to Earth's rotational axis. You will still get changes in the tilt of the tilt. of the Earth's axis, but it'll actually be on a much faster time scale as you decrease the mass

of Mars. The effect of this on Earth is a dramatic change in these cycles of ice ages and could have had a profound effect on the way in which life evolved. How so? Well, because when we look at the fossil record and colleagues of mine who are paleontologists, in my department and elsewhere, they spend a lot of time thinking about different trajectories of evolution, and evolution is primarily determined by things like reproduction, but also adaption to the environment. And adaption to the environment is really the great filter when it comes to which species are going to move forward or going to be forced to change in their evolutionary pathway in order to prolificate and survive. And so when there are periods of

extended of ice over covering the surface of the earth, then that means that you're going to have species which are more able to survive those kinds of circumstances that are able to move forward. Wow. Do these Melanchovic cycles play any role in our current climate crisis? they don't play a role in the current climate crisis and unfortunately they're the sorts of things which can actually cause some source of confusion about what is going on with the Earth's climate because the kinds of climate changes that I'm talking about happen on very, very long time scales and that's because the Earth thermostat system which is able to remove carbon dioxide from the atmosphere and release it back into the atmosphere. These generally happen over hundreds of thousands a year timescales because it's a geologic process, whereas what we're seeing right now is undoubtedly the cause of human industrialization, and we can see that very clearly in the amount of rise in CO2. So it'll be interesting going forward to see how the Earth is able to recover from what we are currently doing to the climate of birth.

Dr. Cain, thank you so much for your time. Oh, thank you, Bob. Dr. Stephen Cain is a professor of planetary astrophysics at University of California, Riverside. The vast Arctic holds a treasure trove of ancient remains from animals that once roamed the landscape in times gone by. And as global warming continues to melt the glaciers and thaw the permafrost, it's also slowly exposing a wealth of bones and tissues

that can tell us a lot about those prehistoric animals. But unlike fossils we find in warmer and drier conditions, the bones coming out of the Arctic are often frozen in time. One remarkable example of this is an incredibly well-preserved 40,000-year-old woolly mammoth from Siberia. It's in such good shape that now, for the first time, scientists have found a way to extract RNA from it, genetic material that's a lot more fragile than DNA.

Where ancient DNA can tell us about the woolly mammoth itself, how well they were adapted to the Arctic, and may even be able to one day help us resurrect the ancient beast, DNA doesn't tell us anything about what the animals were doing, but RNA can. Dr. Emilio Marmel Sanchez led this project at Stockholm University in Sweden. He's now a postdoctoral researcher and geneticist. at the University of Copenhagen in Denmark.

Hello and welcome to our program. Hi, thank you, thank you very much for just housing me. Tell me about the woolly mammoth samples that you studied. Where did they come from? So we got access to 10 different samples, and there were muscle and skin tissues, a mix of them, from 10 mammoths. They are all coming from these northeast coast of Siberia,

and one of them was called Yucca, and it was the one that we were, able to get access to these very, very old ancient RNA molecules with more detail. And when it was discovered, you could still see the fur and the skin and all the organs preserved in these mammoths. It was one of the most well-preserved carcasses of woolly mammoths ever unearthed. Wow. You mean they've still got the fur on them and everything? They still look like a mammoth. Not all of them, but some of them. Now, you're looking for RNA. Tell me a bit about that. How is that different from the DNA in terms of what it can tell us about these animals?

You know, DNA is like a static view of what you are, like each cell of your body has the same DNA. And they all contain the whole information of what you are as a living being. They contain all the recipes, which are the genes, in a sense, that make up who you are and where you are coming from. But on the contrary, if we look at the full content of molecules of RNA, that is present in a cell in a given time point. It's very dynamic. You know, it changes over time. It's like even from the day to night, from when you are away,

from when you are asleep or you are stressed or you are relaxed. All these changes affect the set of genes or how much they are activated or not. Therefore, what you see when you kind of go and analyze this layer of information is which genes were more active or less active or more activated right in the moment or at some hours or minutes right before the mammoth died because this is the moment we capture when we sequenced those molecules. Wow. So the DNA tells you what the animal was, the RNA tells you what it was doing. Yes, right.

How were you finally able to isolate RNA from these woolly mammoths that lived so long ago? Well, we essentially apply the techniques that are designed for nowadays fresh tissues, but we were very careful into preserving this very small RNA molecules. because we were expecting them to be very highly fragmented and damaged. Therefore, we ended up more or less tweaking these kind of methods to really, really capture very low, low yields of concentration of these molecules and also when they are very highly fragmented. So in the end, we managed to modify a bit of the chemistry of the lab methods,

and then we said, okay, did we find something? Yes. Was it mammoth? Yes. Was it good enough? Yes, in some cases. It sounds like the RNA is more fragile than DNA, less stable. Definitely is, yes.

So once you got your RNA from this woolly mammoth, what did you find out about its life? Well, first they managed to validate that they were coming from mammoth. And then we found some kind of biology of the muscle. In this case, we found many, many of the genes that a muscle is constantly generating to function. And also we found a huge complement of regulatory molecules, very small molecules, that they do not code for any protein or whatsoever. So you are not going to see them in the proteins or in the DNA. You just see them being expressed in the RNA layer. And by looking at those, we were able to see that these muscle cells were kind of showing signs of stress, which is more or less expected because, you know, it was close to death.

That would be one reason. The other reason might be that we do know that this mammoth, moments before it died, was attacked by some kind of predator. I mean, because we have the marks of claws in the skin of this mammoth, and by the size and shape of those claws, we do think that predator was probably a kale lion. But it's just a hypothesis. We kind of prove that, you know.

But we do see this kind of stress metabolism going on in the muscle cell. So we do say in the paper that both being nearly to death or also maybe kind of attacked by some predator could be the reason that we do find these sisters. Wow. How old was Yuka when it died? Do you know that? Based on the size of the carcass, it was about five to six years old. So it was like not a baby, but more or less like an infant calf. Oh, well, that makes sense that it would be attacked by a predator because they always go after the young, right?

Yeah, yeah, right. If you were able to extract the RNA from the muscles of the mammoth itself, does that mean that you could also perhaps extract RNA from viruses or bacteria that might have been infecting the animal at the time? Indeed, I mean, when you extract these molecules, you just don't extract the mammoth or the whatever animal or host you are working with. you end up extracting both the host or the endogenous molecules, but also all sorts of the contamination and viral bacterial infections

that were present when the animal was alive, and also that contaminated the carcass or the tissue when the animal died. The good thing is that there are some nasty viruses that tend to have genus-based on RNA, and those viruses are particularly nasty and interesting because they tend to create pandemics. Like, you know, the coronavirus, the flu, the HIV, all those are viruses that have genomes based on RNA. So you cannot see them if you just sequence DNA. Boy.

But if you do sequence RNA, you do see them. Boy, our picture of the past life on the planet is just getting clearer and clearer as we explore the RNA. Yeah, that would be right. Now, a big part of the reason you were able to sequence the RNA of this woolly mammoth is because it was so well preserved. So how much of a race against time are you facing to do more work on specimens like this as the North warms up and more of these animals are coming out of the ice? The fact that we are able to get access and study this very well-preserved mammoth is because also the permafrost is being defrosted at some point. and those carcasses and those animals that were buried and frozen for thousand years are being exposed because the thermophrost is melting.

If you keep an animal frozen for thousand years and then you expose it to room temperature or less frozen temperatures for a while, then your DNA and RNA is going to suffer and it's going to be degraded more than it was when it was frozen. So it's a double-edged sword. We need some sort of meld. something to happen to be able to find them because it's very hard to find them just by scanning the soils. But at the same time, we are racing against time so that they don't get exposed too much time so that they just completely degrade and everything's lost. Still so much to learn.

Dr. Marmal Sanchez, thank you so much for your time. Thank you. Thank you very much. Dr. Emilio Marmal Sanchez led this project at Stockholm University in Sweden. He's now a postdoctoral researcher and geneticist at the University of Copenhagen in Denmark. So now we are in a race against time to collect as many of the ancient animal remains that are being exposed as the Arctic thaws. But how are we going to do that? Well, scientists digging for dinosaur bones have a new tool in the works that might one day be able to help us locate ancient bones before the scientifically valuable material inside of them degrades. This tool is not a fancy robot or an expensive, complicated piece of equipment. It's lichen.

Yep, lichen. The plant-like organisms that are part algae, part fungus, and usually found on tree trunks or in mossy areas in the forest. Well, it turns out that there's a particular type of lichen that has taken a lichening to dinosaur bones. And now researchers have discovered they can use drones to search for this bone-hungry lichen in the Canadian. Badlands. Dr. Caleb Brown is a curator of dinosaur systematics and evolution at the Royal Tiro Museum in Drumheller, Alberta. Hello and welcome back to Quarks and Quarks. Thanks for having me back. Well, tell me about this lichen. What's it like?

Yeah, so the lichen is a symbiotic relationship between algae and fungus. It tends to grow on kind of all sorts of different surfaces. You mentioned tree trunks, but it also grows on things like rocks. It's kind of a bright orange color, it's very striking because most of the rocks in the badlands here kind of this drab buff color or like a bit of a greeny gray and then you have this bright orange thing that stands out like a sore thumb and that that's part of the whole importance here. And when you get these bones covered in lichen,

the whole thing can light up like this giant orange signpost. Wow. Now is the lichen found in other places besides the badlands? Yeah. So the species of lichen that grow on these bones, They kind of have a circumpolar distribution. They grow all over the northern hemisphere kind of in the temperate areas. Well, as someone who digs for dinosaur bones for a living, what's been your experience with this lichen? Well, we've known that in some areas, this lichen grows preferentially on bone for a long time. Some of my colleagues here at the museum have noted that occurrent since the 1980s.

I'm guessing the historical collectors also noted that this bright orange thing that's hard to not to see grows on these exposed dinosaurs. bones. So that association is not new. The first part of what we did in this paper was try to quantify that. And really, it was an attempt to see if we can actually show that, yes, this lichen does preferentially choose to grow on bones as opposed to rock. I shouldn't say choose. It's not a conscious decision. It's just the bone is a more suitable substrate for it to grow on than the surrounding other substrates. Oh, I see. So it's growing directly on the fossil bone. So that means that that fossil bone has to be exposed in some way before the lichen gets to it? Yes, we're not talking about bones that are still on the ground.

We're talking about bones that have been eroded out naturally. These are bones that Mother Nature has eroded out. They've been sitting on the surface for probably decades in some cases. And that surface then is a potential host substrate for lichen to grow on. And what we found is that this lichen does indeed tend to grow on that fossil bone and not the surrounding sediment. What does the lichen get out of the bone? Why does it grow on it?

We're not sure exactly. There's a couple of reasons why it probably grows there. First off, fossil bone, just like modern bone, is porous. So it's a good anchorage site for these lichens to grow on. Also because it's porous, it could potentially retain water, which is nice. It could also be the chemical component of the bone. The bone is slightly alkali, which may be good for some of these lichen to grow on. Likens can be very sensitive to pH, and that might provide a stable pH for it to grow on. there's also phosphate from the original bone chemistry that's still there so they can actually be digesting the chemicals and minerals and using those to grow. And finally, it's also just how long they sit on the surface. These bones are often more resistant to erosion than some of the aerobinic surrounding rocks.

So just a matter of time, they've been there for longer than the rest of the sediments. So there's more opportunities to colonize. So a whole bunch of different reasons why lichen can grow on the bone. Well, if the lichens are taken minerals out of the bone, are they eating away at the bones? Yeah, that's basically what lichens do. Lichens are a great example of what we call a primary colonizer. So when you have areas that have been stripped clean of life, like after a glaciation, you just have barren rock surfaces.

Likens are kind of the first colonizers there. They latch onto the rock and they actually digest the bone and they start the process of soil formation over over decades and decades. And they're doing the same thing on the fossil dinosaur bone. They're basically digesting. They're extracting nutrients and minerals from that bone. So in a way you have this modern animal that's kind of eating this 74 million-year-old dinosaur ball. It's this weird kind of almost a trophic interaction across 74 million years, which is mind-blowing to me.

Well, take me through your idea of using drones to spot the lichen. Yeah, well, since the lichen are so bright, one of the questions we had was because our eyes can pick up on that quite easily, can we actually pick up on that through kind of a remote sensing approach? So looking at kind of different spectral signatures and trying to identify, can we pick out these lichens and use them as a proxy for bone? And there's kind of a precedent for this because lichens are used for proxies for other habitats elsewhere. Likens are used for a proxy for a caribou habitat in the Arctic. We thought maybe we could do the same thing with these fossil bones. If we find a way to easily find this lichen areaally, whether it be drones or satellites, maybe that will kind of target our search area towards.

where there's bones or high accumulations of fossil bone. Well, what have you found so far and how well it works? We found that it does work in this test case. We were able to use a kind of what we call an R-pass, a remotely piloted aircraft system. And we flew this thing 30 meters above the ground, so not super high. And then we were able to train the algorithm

to look for the spectral signature of lichen, and we were able to find areas where there's high concentrations of lichen. And then we can ground through with it, going back and indeed those areas where there's lichen is where there's these high concentrations of bones. So we did three different bone beds in dinosaur province of park and we found that in one case about 20% of the bone had lichen on it. The other two sides about 50% of the bone had lichen on it and all the other substrates was about 1%. So a really strong difference there. These are areas called bone beds. So we have lots of bones in one kind of horizon within the rock. It doesn't necessarily

represent a skeleton but it represents an area where a whole bunch of bone was deposited. And often that's a good site for us because we can look at either a herd of animals that die together or a whole ecosystem that's all preserved together. So what impact could this have if you were to apply the drone to a wider search for dinosaur bones? Yeah, the first question will be how well does this scale, both scale areaally to kind of higher elevation surveys, but also scale to other areas. This association of this lichen with the bone, we know that it's common in Dinoswarka Park here in southern Alberta, we know that it does

occur in other areas of Alberta, but we're not sure how well that scales globally. But if it does hold, and if we can expand this spatially, then this might have some implications for finding fossil accumulations in areas that are more remote or harder to survey

or more expensive to survey. One of those particularly is the Canadian Arctic. If this can work, then maybe we can target where some of these similar bone deposits exist in the Arctic. And then you can kind of target where you're going to look in your ground surveys. You still have to go there and look and get boots on the ground. We're not saying that won't be the case, but we're trying to target those surveys a bit more effectively. But it's nice to have a new tool in the toolbox.

It is. Paleontology, we're weird science in that we like to use the fanciest new tools you possibly can, yet that's also combined with like the most old school possible techniques. Most of field paleontology is just putting on your boots, hiking around, looking for new sites, and that hasn't changed in hundreds of years. We might. add a new wrinkle to that, a new tool. But we're never going to be stuck by our computers. We're always going to be going out and doing fieldwork. And most paleontologists that I know,

that's their favorite part of the job anyway. So we don't want to eliminate that. Never put down the shovel. Exactly. Dr. Brown, thank you so much for your time. No worries. Thank you very much for having me. Dr. Caleb Brown is a curator of dinosaur systematics

and evolution at the Royal Tyrell Museum in Drumheller, Alberta. And that's it for Quarks and Quarks. week? If you'd like to get in touch with us, our email is Quirx at cbc.ca.ca. You can find our web page at cbc.ca.ca. slash Quirks, where you can read my latest blog or listen to our audio archives. You can also follow our podcast, get us on SiriusXM, or download the CBCL listen app. It's free from the App Store or Google Play. Quirx and Quarks and Quartzyx is produced by Rosie Fernandez, Amanda Buchowitz, and Livia Diring. Our intern is Dionne's

Sudial. Our acting senior producer is Sonia Biting. I'm Bob McDonald. Thanks for listening. For more CBC podcasts, go to cBC.ca.ca slash podcasts.