Quirks and Quarks - The sensitive secrets of elephant whiskers, and more…

Episode Date: February 13, 2026

An elephant’s trunk is incredibly strong and rugged, and yet it is one of the most sensitive touch organs in the animal kingdom. New research reveals that this sensitivity is partly powered by over 1000 whiskers.PLUS:A new 'inside out' solar system is making astronomers question planet formationPaleo-Inuit people in the high Arctic were masterful seafarers, new study showsTwo-month-old babies can categorize objects in their brainHow insects deal with smog or microplastics can impact them and the environment

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 Corks and Corks. On this week's show, crickets eating microplastics poop them out as nanoplastics. If these crickets are creating these nanoplastics from these microplastics, they're potentially making our problems worse within our environments.

And the length some scientists will go to understand elephant whiskers. He sprinted into my office and he's like, oh my gosh, Andrew, these whiskers have this functional gradient. And then I was like, Gunter, aren't you going to be late for an anniversary dinner? Plus, ancient Inuit master seafarers, an inside-out solar system, and insects in the Anthropocene. All is today on Quarks and Quarks. The discovery of a new solar system 117 light years away is making astronomers question what they thought they knew about how such planetary systems are formed in the first place. The thinking was that planets and other solar systems formed like ours, with rocky planets like Earth closer to the sun, and gas giants like Jupiter farther out, and ice giants like Neptune, the farthest out. Now, when astronomers first spotted this new solar system, they only saw three planets

that, by all appearances, look perfectly normal. But when they went in for a closer look with a different telescope, lo and behold, they saw a fourth planet that made them realize the solar system was inside out. Dr. Thomas Wilson led this research. He's an assistant professor in the astronomy and astrophysics group in the Department of Physics at the University of Warwick in the UK. Hello and welcome to our program. Thank you very much for Amory, Bob.

It's fantastic to talk to you about this. First of all, tell me about this planetary system as you first saw it with three planets. How normal did it appear? Oh, Bob, it appeared fantastically normal. Where we started looking at this with NASA and MIT's test space telescope, we found these inner three planets, as you said,

and it seemed to follow all planet formation theory and conventions, right? We had a inner rocky planet that's a little bit bigger than the Earth, but so far so normal. And then we found these outer, larger planets, and everything looked as we expected from theory. Well, how do you get a solar system like ours in the first place, with the rocky planets in close and the gas planets further away? The way we currently think planet formation works is that you have this protoplanetary disc that's full of gas and dust, and then over time, the dust, the dust. particles start to collect together, they agglomerates together into larger pebble-like features,

then collide themselves into what we call planetesimals, so we just think smaller planets, then themselves also collide and come together to form rocky planets. Now, what we believe is happening across all planetary systems is that for rocky planets, this is kind of where the story ends, right? We have a rocky planet full of whatever the dust was made out of. But if you further away into the outer parts of these solar systems, then you start to get a lot of gas and ices in the cooler outer parts of these planetary systems. And this is where, after you have this kind of rocky core of a planet, you could start gathering more and more gas and dust. You start collecting more and more of an atmosphere. And this is how we would then form Jupiter's

and Saturn's and the ice giants as well in the outer regions of these solar systems. Oh, I see. So if the planets are too close to the sun, any kind of big atmosphere like that kind of gets burned off. So you're left with the rocky core. Oh, exactly that, exactly that. Okay. Now, tell me about this fourth planet that you discovered, what stood out to you about it. Now, what we pointed the European Space Agency's K-OPS mission at it, fortuitously, in one of the transit light curves that we took with our space telescope, we saw this additional dip in the data. we're getting. And this loss of light that we are getting from this host star means that another planet came between the host star and us, causing the amount of light that we received to drop a little bit. And so when we saw this data that we were getting from chaos, we were quite astonished, really, we said, okay, there must be a fourth planet of the system.

And then when we went back and reanalyzed the data or we looked back at previous data sets, we could piece parts of the puzzle together and find and discover this new fourth planet in the system, which is in a much longer orbital period than the other three, but also smaller than the middle two planets in the system. And this is where we got really excited, right, because we expected it to be much larger following the conventional trends. But no, we found this to be a much smaller planet. And is it small because it's rocky or just,

the small gas planet. We went down to the Canary Islands where there's an observatory. We used the Harps North instrument on the TNG telescope to start weighing the masses of these planets. What we found is that what we combined the sizes, the radii of these plants with the masses of them, we found that this outer planet really is rocky. It has a density very similar to our own Earth, whereas the middle planets in the system likely have a very large gas. atmosphere. And that was where we started to finish our observations and start thinking about what this actually means for planet formation. Well, yeah, what went through your mind when you saw a rocky planet on the outside of a solar system where normally you would get the gas giants?

Hands in the air, of course, originally we were quite confused, right? We double and triple-checked our data sets. We didn't want to make sure this was any kind of error, of course. And after of validating that, we started coming up with a few hypotheses of what could cause this. We thought, okay, could this be due to the star stripping away the atmospheres of these planets? This is so-called photo evaporation effect where the planets closer to the host star receive a lot of light, a lot of heat from their sun, and they have their atmospheres lost. But of course, in this system, it didn't really work because we have this outer rocky planet. The strength of this atmospheric loss on the heating from the host star goes down the further you are away from the star.

So we didn't think that this particularly cold planet could have had its atmosphere lost through this mechanism. Well, is it possible that this planet started out close to the star and somehow wandered to the outside? So we thought about that as well and we ran these dynamical simulations. Basically, if we take the current orbits and rewind the clock, could they have migrated or shifted around in their orbits compared to what we see them today? And running these dynamical simulations, what we found is that any kind of shifting between the planets would result in a highly unstable system that would throw the planets either out of the system into each other or into the host star.

Oh, okay. So throw out that idea. What other ideas do you have about how this rocky planet appeared way out there in the edge of the solar system? Talk to any astronomers in the past, you'll know that the default ideas that we can have is, well, what if two things collide with each other? And what we found was that to have the high amount of energy to remove an atmosphere from a planet, especially for this outer planet, would effectively destroy the planet itself. And obviously, as we see the planet still there, we could quickly reject this idea. Okay, so it didn't wander out from the inside.

It didn't collide with another object. Any other ideas of how it got there? The idea we had was what if you formed these planets, not all at the same time, but rather at different times. And if you start to form these planets, this planetary system, maybe inside going outward. So you form the inner planet first, and that takes a few million years, for example, and then you form the next planet, and then the next planet and then the last planets in the system. By the time you've gotten to forming this outer planet, there's simply less dust and gas available, right? Because the other planets have kind of scooped up all the gas and dust that we think could have been there. And so this outer planet would have formed later than its inner

neighbors in a reduced or depleted environment. That's why it's smaller because there wasn't that much material around. And that's why it doesn't have a huge atmosphere because all of the gas has been depleted by the other planets. Oh, I see. Okay, so it formed naked out there in an empty part of space. Exactly. There was just enough material to build it, but beyond that, there was not that much out there. So how does this discovery change the way we think about how solar systems form? We talked a bit earlier about this ideal formation theory, right? Do you have rocky and then gaseous or ice worlds? But the discovery of this outer planet and the system kind of throws this up in the air, right?

and it could be due to this formation timing effect, and you could have planets that form at different times in different environments. So we basically have to go and look back at all of the 6,000 planets that we found with a new lens. Dr. Wilson, thank you so much for your time. You're both welcome. Thanks for having me on. Dr. Thomas Wilson is an assistant professor in the Astronomy and Astrophysics Group at the University of Warwick in the UK. A voyage to the remote Kitsasut Islands north of Greenland is a hazardous one even today.

That's partly because these small islands are situated in an unusual area in the high Arctic that never freezes. The only way there is to cross a 53-kilometer stretch of unruly open water, regardless of the time of year. Yet we know ancient humans were there thanks to archaeological evidence they left behind. But how far back does evidence of humans on these islands go? Well, scientists from Greenland and Canada, with the help of local community members and hunters, went to investigate. And they discovered hundreds of archaeological features dating back to about 4,500 years ago, as well as lasting impacts to the environment. Altogether, their findings shed new light on the paleo-inuit people's remarkable nautical capabilities

and the role they played as ecological engineers on the islands. Canadian Dr. Matthew Walsh was part of the team that went to Kitsisut. He's an associate professor of archaeology at the University of Calgary and led the study. Hello and welcome to Quarks and Quarks. Hello, Bob. Nice to join you. So take us to the Kitsy Soot Islands. What's it like there? Paint me a picture. Well, it's an incredible experience.

When we went, I had spent many months looking at them through satellite imagery and things like that. And so I had sort of expected them to be kind of empty and barren. But actually, they're very busy places during the summer. So there's a nesting colony of thick-billed mirror. It's a species of seabird that nest in the cliffs around the islands by the thousands. So it's actually quite a lively place. Well, why doesn't the water freeze around these islands? It's what's called a Pallinian in the Arctic.

It's partly the geography. You get this ice bridge that forms across what's called Smith Sound between Greenland and Canada. And then you have a combination of wind and currents and a few other factors, but this creates an expanse of water that doesn't freeze throughout the winters. So you have a kind of refugia for sea mammals there as well as very rich phytoplankton blooms that feed a very unique ecosystem. Now, if it's 53 kilometers from shore, Can you actually see the islands from shore?

Like, it makes you wonder why people would go there in the first place. Yeah, so on a very clear day, you can see across to Greenland, and you can also see across the Canada on the other side. But that's a very rare circumstance where you have clear weather. And that's partly because of the mixing of the currents. You often have fog banks and all kinds of weather in the area that makes them very rarely visible. But one thing that you can clue into is the movement of birds, which go out to the islands. And so I think there's always some indicator that there is something there.

Well, once you got to the island, what kind of archaeological features did you find there? Well, this was very striking for an archaeological crew because there's hundreds of features all over the beach ridges there. And these are quite small islands, so a couple hundred meters across. But everywhere you look, there's pieces of basically ancient campsites. So old tent rings, hearth features with charcoal still in them, and scatters of bone and artifacts, things like that. So lots of clues that people have been there and returned many times over. So what would they have been doing on such small islands with so many birds? Well, there's a few clues around that.

So the campsites themselves are located directly under the bird cliffs. So the birds are a very important reason why they're traveling out there. You can collect eggs and you can also hunt the birds as well. And indeed, we found scatters of bird bones associated with the features, including some of the bones that we used radiocarbon dating to get a better understanding of the time frame there. You mentioned some of the artifacts you found were tent rings? What are those? Yeah, so from this period there's very distinct tent rings. They're very small, if you can imagine, between three and five meters. And they have these, we call them axial features, which are basically stone features that run down the center of them.

And then on both sides of the tent, you have sometimes different representations of different. activities, so different types of stone tools or bone tools, things like that. So the rings define the outside of the tent, the size of the tent? Yeah, essentially, it's a skin tent that you're pinning down to kind of keep it stable when there's wind and things like that. What about the journey to the Kitsasud Islands? I mean, 53 kilometers, what would that journey have been like for them? Yeah, so there's a few ways of estimating that, but we think, you know, at minimum, it would have been a trip of about 15,

to 18 hours of very difficult paddling. You'd have to know an awful lot about the weather in order to be able to do that. Because if conditions change when you're halfway across, you could be in significant trouble being blown off course into Baffin Bay. And we know a little bit about the watercraft from the period because there are a couple sites in the Arctic where you just get small fragments. So these tend to be pieces of wooden frames that would have had a skin covering that you can seal with fat.

So something very similar to kayaks and ummiacs that, later innoque communities use. So it probably would have been something fairly similar that they're using to travel out there. But if you say that there's fog and there's currents, that also means some navigational skills. Yes, absolutely. So they'd have had to have a lot of knowledge about seafaring, essentially, which isn't quite how we really understood them prior to this discovery. The implication here is that they could certainly intercept sea mammals or seabirds and have reach across, all these different components of the Pallinia system.

Can you tell me how the presence of paleo-inuit people back then altered their environment? Yes, I think it probably a number of different ways. So just by virtue of hunting the birds and collecting eggs, they are related to their population dynamics. But another important feature that we often observe through things like satellite imagery is that they seem to have played a very important role in transferring nutrients from the sea to the landscape as well. And at this very early period, one of things we can see is that you get these little tiny clusters of vegetation in what otherwise is a polar desert. And those are often associated with either seabirds or archaeological sites. And so there's some sort of maybe collaborative engineering in terms of the growth and development of the terrestrial system.

That is the vegetation and soils. They added vegetation or improved it? Well, I think by taking animals out of the sea and butchering them or. doing all those kinds of activities around the campsite, there's a transfer of nutrients. And you can see these clustering of vegetation, even thousands of years later, where they've become anchor points for the development of vegetation and then soils as a result of that as well. They fertilize the soil. Exactly. So what's your takeaway from this study in terms of our understanding of the Paleo-Inuit people

in Greenland? Well, I think it opens up many great new questions about the long-term influence of those communities through time and maybe helps us rethink some of the big questions in the presence around the co-management of some of these areas between Greenland and Canada. So there is, I think, a very good argument

within this for the kind of sustained and well-supported sovereignty of communities in terms of making environmental choices in this area. Dr. Walls, thank you so much for your time. Thank you very much, Bob. Pleasure to join you. Dr. Matthew Walls is a professor of archaeology at the University of Calgary.

An elephant's trunk is unique in the animal kingdom. It's incredibly dexterous, like our hands, and they use them for similar things to grip or touch things in their environment. But their trunks are so strong they can tear down trees. They're also extremely sensitive and covered in whiskers that protect their trunk and help them sense their surroundings

to compensate for their notoriously terrible eyesight and thick skin. Well, scientists working on touch sensors and robotics decided to get to the bottom of how elephant whiskers work and how they factor into how nimble elephants can be with their trunks. Dr. Andrew Schultz led this study. He's a postdoctoral researcher in mechanical engineering at the Max Planck Institute for Intelligence Systems in Stuttgart, Germany.

Hello and welcome to our program. I'm grateful to be here. Thank you so much, Bob. First of all, tell me about how nimble elephants can be with their trunks that got you interested in studying their whiskers. They have these trunks that are made up of tens of thousands of muscles. And as engineers, we think of these as infinite degree of freedom systems. So they can move in infinitely different ways with all of those muscles. And they're so dexterous.

And I think something that is so impressive is they can lift 200 to 300 kilograms with their trunk. And then they can be so delicate to pick up. a tortilla chip without breaking it. So they have all of these different capabilities. And as an engineer, it's really difficult for humankind to build materials that combines all of all of the intricacies of biological systems. So I get really excited about something like the elephant trunk to provide inspiration for things like engineering innovations. Well, we all see their trunks doing incredible things from picking up people to tortilla chips. But what about the whiskers? Where are they? So the whiskers are covering the entirety of the trunk.

And so I think a lot of people see elephants and they think one of the first things they think of is wrinkles. And so if you think of the elephant's trunk, it has these wrinkles and these folds going along the trunk. And inside each of these wrinkles, they kind of have these whiskers that are protruding out. And if you look at your arm, you can kind of think of these whiskers are covering a little bit like your forearm hair. And these whiskers really help the elephant sense their surroundings, and they're born with about a thousand whiskers covering their trunk at birth. So how did you go about studying these whiskers? What we did is we took these whiskers and we looked at them.

And what we found is that the elephant's whiskers base is filled with all of these hollow, porous channels. And elephant whiskers don't actually grow back. So when they lose a whisker, part of their trunk becomes you can think of almost invisible. So what these porous holes do is they actually help the elephant absorb energy when they're contacting different objects during their 16 to 17 hours of eating food every single day. So I think that is one of the first big outcomes that we found. Now that's the base of the whisker.

Is it the same all the way to the tip? No, it actually changes along the tip. So the base of the whisker is hollow and then as it gets to the tip of the whisker, all of those holes start to fill in. So at the very, very tip, it's very, very dense. The cool part is we found there was some of this porosity, but then simultaneously we also looked at the stiffness of the whiskers. Okay. And how does that change? So this, this to me was one of the coolest, uh, scientific, let's say, eureka moments and one of the few things that I've, I've had in my career like this. So, so what we found, I still remember I was, I was in, uh,

one of the collaborators and co-authors on this paper, Gunter Richter, who's a material scientist that was the expert on all material science on this paper, he found that the whisker base is really, really stiff and the whisker tip is really, really soft. And I still remember he sprinted into my office and he's like, oh my gosh, Andrew, these whiskers have this functional gradient. And then I was like, Gunter, aren't you going to be late for an anniversary dinner? And then he looked at his watch and then sprinted back out of the room. So what does this mean? So a functional gradient stiffness. So what this means is the base of elephant whiskers is really, really stiff. So stiff is something like plastic. And then as you go along the whiskers length, it gets softer and softer until at the very, very tip, it's as soft as something like rubber. And we didn't really know how we could like understand how this functional gradient

could be impacting sensing. But an idea from my boss, Catherine, was, why don't we make a physical mimic? And let's try to think and interact with objects like the elephant whisker. So we 3D printed a structure that has a stiff base and a soft tip. And Catherine walked around the halls and was tapping different objects. And she came up with this hypothesis that was, well, maybe what this stiffness gradient actually does is it helps an elephant know exactly where along the length contact is happening. So what we did is we looked at some simulations and we found that hypothesis was confirmed where when you have this gradient, each signal, each tap along an elephant's whisker is uniquely encoded in that material stiffness, allowing the mechanoreceptors at the base to kind of like fire differently for different places

along the whisker. So they're able to use this actually in sensing. Okay. So is the idea here that if the elephant touches something and only the tip moves, that it'll say, well, that thing's pretty far away. Whereas if the whole whisker moves, that must be something larger or something closer. Is that how it works? Exactly. So how are you going to apply what you've learned from the elephant's trunk to robotics? So how we can apply this is we can take this material intelligence inspired by elephant whiskers. And we can look at combining stiff bases and soft tips on sensors to try to understand how we can

build things that have the ability to have a soft and light touch while still able to communicate just how far something might be. And these have advantages over traditional sensors maybe like cameras because these have the ability to work in almost any environment. And they consume a lot less power than something like the camera would. So we're going to give robots whiskers? I would love to do that. We're just really at the tip of the whisker,

trying to understand how many of these gradients exist in biology and how as engineers we can take inspiration from them to design more intelligent robots. Dr. Schultz, thank you so much for your time. Thank you so much for the invite and happy to talk about whiskers. Dr. Andrew Schultz is a postdoctoral researcher in mechanical engineering at the Max Planck Institute

for intelligence systems in Germany. 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, infants are doing more in their baby brains than we realized. The two of us looked at it, and we just looked at each other, kind of in disbelief, like, wow, we did it.

We're seeing the category structure in the two-month-olds, and we were super surprised. 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. If you've ever wandered around a big box store,

you'll have noticed that they're divided into sections. So suitcases and handbags are in luggage, and pants and shirts are in clothing. Well, our brains categorize things like that all the time, without even thinking about it. We see dogs, cats, and horses. And our brains automatically know that, yep, they're in one category.

And cars, trains, and bicycles are in. a different category. Now, you might think it would require a certain sense of understanding about the world to do this, but it turns out that infants, even as young as two months old, can pull off this categorizing feat. And that's a lot younger than scientists thought humans could do this, which is really highlighting the richness of baby's thoughts, even in those first few months of life. Dr. Kleena O'Dardy is the lead author of the study, She was at Trinity College Dublin when the research was carried out. Now she's a postdoctoral researcher at Stanford University in California.

Hello and welcome to Quarks and Quarks. Hi, thank you so much for having me. Your study involved babies as young as two months of age. I mean, how developed are their brains at that age? Yeah, well, that was a big open question of the study. It's quite difficult to collect brain data from infants this young. So it was quite ambitious to really look at what was going on in their brains at this time point. And you might think that because they can't walk or talk yet,

that maybe there's just a more simple version of the type of processing that we have as adults. But really what we found is that there was a lot more going on there than we might have expected. Well, at two months old, as you say, they can't talk to us to tell us what they're thinking. So how did you go about figuring out what's going on in their brains? Yeah, so we used MRI machines, just like the types of MRI that URI might have if we need to go get one, with a few differences. So, of course, we wanted to make it as comfortable as possible for the infants, but critically, we also wanted to show them images while they were awake. And by doing that, we can really activate lots of brain activity using those images. And also, it makes it nice and engaging for the infants too.

So it makes them comfortable and enjoy the experience. And then we can collect lots of rich data to start to understand how their brain is processing the things that they're seeing. Wow. What kind of images were the baby seeing? So we showed them 12 different categories. And each category had three images each. These were things like cats, crabs, even rubber ducks, a tree, the shopping cart that you might see in a supermarket. And they were chosen across all different things that an infant might maybe see in their first year.

And also that they spread across animate and inanimate categories as well. Okay, so after you have your babies in the MRI machine, they're lying there, they're looking at all these different images, you're watching their brain with the MRI at the same time. What did you find? Yeah, so after we looked at the data and we started to really process it and use all of these fancy MRI processing analyses to look at their brain patterns. What we could see is when you look at a picture of a cat, the part of your brain in your visual cortex,

that processes that fires in a specific way. So say, here is your cat activation pattern. And then when you compare that to the activation pattern for, say, something inanimate, like a tree, you can see how similar or different those two patterns of activation are. And by doing that for lots of different categories, like the ones we showed the infants in the scanner, we can start to see the organization of the brain activation patterns. And what we expected was maybe that between two and nine months, we would start to see this structure emerge.

But we were really surprised to see that already at two months of age, the brain is processing the things that we see into distinct categories, organizing by animacy and inanacy, and really already starting to parse out the visual world into those meaningful categories. How surprised were you to find that even these young babies were sorting objects into categories? Yeah, so I had been working on this type of analysis, in adults, getting used to doing it, and really trying to get it to work with the data. and I didn't know what it was going to look like in the infants.

And then the day I finally went, okay, I think that this is all ready to go. We're going to run the analysis and I'll get the results up. I saw the initial picture that really showed me that I think they're organizing this into different categories. But immediately I thought, no, I think this must be wrong. I must have done something incorrect in my analysis or I've looked at the wrong age or something, but I checked and I checked and I really just sat there and I looked at my screen for a few minutes before I told anyone in the lab. And then I called in our principal investigator and the two of us looked at it and we just looked at each other kind of in disbelief like, wow, we did it. We're seeing the category structure in the two month olds and we were super surprised.

So what do you think is going on in the baby's mind that only two months? Yeah. So what I think is maybe that we already have the structure to tell apart these different categories, but I would definitely be cautious about interpreting this, that they really know what each of these things are. I'd say that we can already start to distinguish these categories like cats and trees and animate and inanimate things, but maybe to really know what these are, what they mean, might require a bit more learning in the world. So that would kind of be my interpretation, is that we have this system built in to allow us to tell apart these things, which you can imagine would be very beneficial to be able to do from a

young age, but perhaps to understand the broader meaning takes a bit more time. So you're saying this sort of baked in evolutionarily? It's an innate part of our brains. Yeah, I mean, that would be my guess. I suppose to play devil's advocate, they do have the two months and one might say maybe they could have learned it all extremely rapidly in two months. My interpretation is that there's something a bit more structured in the way our brains are wired up to allow us to do this rather than something that's more rapidly learned. Why do you think it's important to understand the inner worlds of baby's brains? I think it's still a huge mystery, what's going on at this time of life.

And I think we can't remember what it's like because of, our own tendency, our own experience of infantile amnesia. So we actually can't remember what this time it's like. And then a lot of mysteries remain about this time of life, meaning it can be quite difficult to maybe treat problems that might arise earlier and then lead to later difficulties in cognition, say, with infants or toddlers. So having more tools to be able to really understand typical development within the first year of life,

may be beneficial and have later clinical outcomes, the more and more research we do into this. Dr. O'Darity, thank you so much for your time. Thank you. This was great. Dr. Kina O'Dardy is a postdoctoral researcher at Stanford University in California. We talk about Earth like it's our planet, but when you consider the numbers,

you could argue it's more of an insect planet. Insects were here long before human. They make up about 90% of all animal species, and if you put them all on a scale, they'd weigh about 70 times more than the entire human population. Yet despite these large numbers, insect populations around the world are collapsing. A 2019 report suggests we lost more than half of the world's insects since the 1970s, and this matters, because in many ways, our survival and the health of our environment depends on their success. Insects, the tiny engines of Earth's ecosystems are mysteriously falling silent,

and that sounds is being heard as a stark warning for humanity's future. Dubbed the insect apocalypse, a staggering number of insects are disappearing worldwide. They help with decomposition by eating leaves and help with various aspects of plant reproduction. Caterpillars are taking biomass from the canopy,

putting it into the soil and enriching the soil. And that is the biodiversity that we're losing. Scientists blame it on death by a thousand cuts, with issues such as habitat loss, pesticides, invasive species, light pollution, and climate change. Those are the big ones. But now new research is increasingly pointing to lesser-known ways our human footprint may be impacting insects,

which in turn may be affecting the environment. Take ants, for example. They're largely considered one of the more successful types of insects on the planet. Scientists estimate there are about 20 quadrillion ants on Earth. That's a 20 followed by 15 zeros, which translates into approximately 2.5 million ants for every human on Earth. They can live in almost any environment and play a crucial ecological role, spreading seeds, errating soil, and recycling nutrients.

Their success is in part because of how their social structures allow them to work together in colonies. Well, a new study found that air pollution may be messing with their social nature. When ants are exposed to air pollution from cars, power plants, and industrial activities, they stop playing nice, and the colony descends into chaos. Dr. Marcus Canadden led the study. He's from the Max Planck Institute for Chemical Ecology in Jena, Germany, where he leads the older guided behavior research group.

Hello and welcome to Quarks and Quarks. Hello, nice to talk to you. Now, before your study, what did we know about the effects of air pollution on insects? So we knew already from studies of other teams and also of our teams that sexual communication in insects can become corrupted by ozone. So we found a while ago that flies, where usually males emit very attractive compounds to the females, the males lose their compounds when they're exposed to ozone. So the compounds become degraded by ozone, the males become less attractive to the females,

and that somehow corrupts their sexual behavior. Now, you're mentioning ozone. So where's the ozone coming from? I mean, the ozone has been on earth everywhere, and there's also actually a healthy layer of ozone, far of the ground that protects us from UV light. But close to the ground where we produce, for example, nitric oxides, we produce also ozone. And together with UV light, then oxygen that is healthy for us,

becomes turned into ozone, which is not that healthy. So why did you want to look at the effects of ozone in ants? When we did the study on the flies, we realized that whatever compound carries a specific chemical feature, and that is a carbon-carbon-double bond. Ozone connects to this double-bonds and breaks this off, and that destroyed the pheromones, the sexual compounds in the fly study. And I knew that ants discriminate nestmates from foreigners by chemical cues,

and some of those chemical cues that they use for this have also those carbon-carbon-doublem bonds. So therefore I was wondering whether the same reaction might lead to a corrupted recognition in these ends, then also. So are you saying that ants use scent to communicate with each other, that that's what these chemicals are? I wouldn't necessarily call it scent because it doesn't work over distance. These are compounds that are on the surface of the ants and they actually have to touch each other. So they use their antenna, which is basically the nose of an insect, and smell and taste the other end via that. So they can smell the ants of a very short distance only, few millimeters, or better if they get direct contact, then they can taste it.

And then they can taste the difference between their nestmates and non-nestmates. So what did you do to test how the air pollution may be affecting the ants' ability to detect these chemicals on each other? The good thing is in Germany, ants have become very famous pets. So we went to a store that is specialized on selling different kinds of ant species. We brought them back into the lab. We established the colony of 50 or 100 workers. What we then did was we took individual ants and exposed them either to normal ambient air

or we exposed them to slightly increased levels of ozone. And we used 100 parts per billion. That is a level that you can find many days in a year in a town like we are living in here. So on hot summer days, in the evenings, we'll reach those levels, maybe 10. times a year. We exposed them for 20 minutes and then we put them back into their colony and we observed what would happen. And what happened when you put the ant back in the colony? So when they were exposed to normal air, they were fully adopted again by the colony after 20 minutes. No problem. They had internal contacts. They test it, they taste each other and everything is fine.

When we, however, put them back after being exposed to ozone, then their nestmates turned aggressive against them. So they opened their mandibbles. They threatened these ants. They took them and tried to pull them out of the nest again. Wow. So what exactly is the ozone doing to change the chemistry of the ant? The ant is just running around. And on its surface, it carries this colony-specific blend of compounds. So by that, it smells and tastes like its colony. And so therefore, their compounds are exposed to the air. And if there are higher levels of ozone, then ozone attacks those compounds that carry those carbon-carbon double bonds and breaks those double bonds. By that, a long compound breaks into two smaller pieces, and that is then not detected by the ants anymore,

or at least they don't smell like before. They suddenly smell different. Now, you say you had several different species of ants. Did they all behave the same way? Most of them. So in five species, we could mess up the colony behavior by exposing individual ends to ozone and bringing them back. The sixth species didn't show any difference, but this species is quite special in its behavior anyhow. They don't have queens. They all can lay eggs and they form also in the wild these super colonies that are all connected and they are never aggressive against neighboring colonies there also. So therefore, obviously, they just don't have this aggressive behavior and therefore we couldn't provoke it. by ozone. So what we did then, instead of exposing individual ants, we exposed full colonies to

ozone and checked what would happen to the colony then. And these colonies lost their larvae, because obviously the communication between larvae and the adults who take care for the larvae and feed the larvae, this communication was broken down by ozone then. So therefore, they disregarded their larvae, they neglected them and then the larvae died. Wow. Now, most people don't think of ants is particularly consequential to our lives. So why is it important for our environment to understand how human activities are affecting ants? So there's a huge biomass of ants on earth, and they fulfill a lot of roles in the ecological system they are living. And for example, they are spreading out seeds from plants. They fight pest insects. So ants feed a lot on the

offspring of pest moth. They feed on caterpillars. And they feed on caterpillars. so on. So I think they fulfill extremely important roles in the ecological environment that might not all be clear to us. Well, how common do you think this effect of air pollution is on other insects? If we take a look at the flies again, we corrupted the sexual communication in these flies. And that was because their pheromones, that's the compound that they advertise themselves to the sexual partner, become degraded by ozone. We have taken a look at all so far identified sexual compounds in insects. More than 1,500 pheromones have been described,

and over 90% of them carry those carbon-carbon-carbon double bonds. So we think this sexual communication might be really harmed in many more species than we showed for the flies. If we look for other social insects like bees and wasps, it's also known that they discriminate nestmates and non-nestmates by those chemical cues, and they also use those compounds that have these carbon, carbon double ones.

So actually, I'm pretty sure that what we observed in ants transfers also to bees and wasps. I mean, the honeybee is a good friend of humans, and humans really would understand if we harm the honeybee, then we have a problem. Not only do we get honey, but they're pollinators for us as well. Exactly. And there are also studies that show that pollination itself again faces the same problems, because flowers emit compounds to attract the pollinators. So a lot of pollinators go for the nice shape and color of the flowers,

but many, especially those at night, follow the flower odors. And again, if there is increased levels of oxidant pollutants, that changes the flower odor, and again, the pollinators become less efficient. So ozone hits insects in many different ways. So what's the takeaway message here you would like people to get from this research? The main take-home message is that we always should be aware what we are doing. Ozone is really directly connected to burning for soil fuel. So if we produce oxygen pollutants like nitric oxide and ozone,

we harm insects in a way that we were not so aware of before. So it comes with cost and we just should be aware of it and should maybe consider burning less. Dr. Kahnaden, thank you so much for your time. Thank you for your interest. It was very nice talking to you. Dr. Marcus Kahnadden leads the odor-guided behavior group at the Max Planck Institute for Chemical Ecology. Now, another lesser-known way that insects may be indirectly impacting the environment is through microplastics. A group of researchers at Carlton University, who were studying crickets, wanted to

understand why they end up with so much microplastic in their bellies. And they found that crickets will happily eat a plastic meal if it's around, and as a result, may be making the plastic problem worse. Marshall Ritchie is a Ph.D. candidate in the Department of Biology at Carlton University. He led the study. Hello and welcome to our program. Thanks, Bob. I'm happy to be here. Now, before your study, what was known about how microplastics affect insects? There's been a growing research in the last five years in terms of our understanding on how they affect insects. But up until this point, it had mostly been done through understanding when they eat them, if there's an increased amount of death occurring.

This was one of the stepping stones and understanding how different sizes of round beads of microplastics affect them. So why did you choose crickets in your research? In our lab, we had previously published several other papers on crickets and found them as a really helpful model in terms of understanding the effects of microplastics, especially since these crickets during my masters in the same lab with Dr. Heath-McMillan, I discovered that they can break down plastics into nanoplastics. Oh, you mean break down small pieces into even smaller pieces? Yes, that's correct. Almost a thousand-fold difference and change of size. Wow. Do we have any reports of insects eating plastic in the wild? Yeah. One of our goals in our lab was to expand our research, taking from the lab, into the real world setting. So we went to a experimental field that was known to have higher increase of plastics due to a treatment that was applied to it.

And we collected wild crickets that were in the area and then looked in their digestive tracks to see if they had plastics. and unfortunately they did have a lot of plastics in them as well. Wow. Well, take me through your work. What were you looking for? In our current paper, we wanted to understand what was the limitations that the plastics of these crickets able to ingest in terms of the size that they're able to ingest, as well as if we are giving them in the lab, are they willingly eating these plastics or are they just going about their day and they just have them eat these plastics? Oh, so how do you feed plastics to a cricket?

it's actually quite simple. We just mix them into their normal dry feed and it just easily blends in because they're such tiny particles. How tiny were they? In our study for this one, we fed them the range of 500 microns all the way down to 38 microns. So 500 microns is about half a millimeter. So what did the crickets do when you introduce them to the plastic pieces mix them with their food? Yeah, they very unexpectedly to us don't seem to actually mind at all if there's plastics mixed within their food. They just go munching along like it's not even there, which is really unexpected. They can do this for their entire growth. So these crickets live for about six to seven weeks.

And they don't seem to mind it all doing it for this entire period. Wow. Which is quite surprising. Well, okay, so they don't care. But what about the effect on their health? Yeah, so we looked at the amount of mortality that it can concur from them ingesting these plastics. We've also done this in other studies going up to 10% plastics in our diets, which is an insanely high amount of plastics for them to ingesting. And it turns out that they're totally fine in

terms of what we can visually observe them. So how are they able to do that? I mean, does it just pass right through without having any effect or are they actually eating it? Yeah, no, they're absolutely eating it. We confirmed it multiple times by doing dissections as well it's in their poop or in the insect world is called frass. So in their frass, it's like glowing bundles of plastic when it comes out the other end. What about their bodies? Was there any physical changes in response to eating the plastics?

Not that we observed, which was quite surprising. They grew to the same size as the control crickets. So the plastic that was coming out, how different was it from the plastic that was going in? The majority of it was quite different in terms of it was getting quite a bit smaller than that original plastics we were feeding them. And this insect species, these crickets in particular are very unique in that regard in terms of this causing that large amount of breakdown happening as it passes through their digestive tract. So how much smaller did the plastic get? We found all the way down to one micron size. And so when we fed them those large 500s, we did fine pieces.

just above one micron in size. However, they could potentially be going smaller, but our limited detection in terms of the methodology we employed was limited at one micron. Boy, one micron. Can you even see that with the naked eye? Oh, no, not at all. Well, isn't this a great thing then

that the insects are helping break down microplastics for us? Yeah, this is actually one of the favorite questions I get when I described this to people. It's actually not super great, because if these crickets are creating these nanoplastics from these microplastics, they're potentially making our problems worse within our environments as nanoplastics are thought to potentially be more harmful because they can cross through cellular barriers.

So it's spreading even more through the environment and our bodies? Yes, potentially from these crickets having this ability to break it down to increasingly smaller sizes. Wow. Now, you were working with crickets. What does this mean about the role of insects in general in terms of moving plastics through the environment? Yeah, so we chose crickets as it's also a very common insect across the entire world and a food source for many different animals. So it's very likely that the crickets, as I mentioned earlier, in terms of collecting from the field,

if those crickets got ingested by a larger prey like a bird, for instance, that bird would then be ingesting those plastics as well. So they're not actually helping the issue, but could potentially be spreading it further. But do you think other insects also deal with plastic this way? Very likely. However, there hasn't been a lot of research done to date in terms of expanding it out, as we're still in the infancy of studying a few key model organisms. Were you surprised at how the crickets were processing plastic in this way? Yeah, it was an accidental finding during my master's, actually.

When we chose crickets originally, it was due to that we had already established them at Carleton University, as well as that we could, as I mentioned earlier in their diet, it was very simple for us to feed it to them. So when I started looking at the frass on the other side, I started noticing these plastics were so much smaller than what I had originally fed them, and I couldn't believe it. Oh, we love surprise science. It's amazing how it always happens. Mr. Richie, thank you so much for your time. Not a problem. Thank you very much, Bob. Marshall Richie is a PhD candidate in the McMillan Lab in the Department of Biology at Carlton University.

And that's it for Quirx and Quarks this week. If you'd like to get in touch with us, our email is Quirx at cbc.ca. You can find our web page at cbc.ca.ca. 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 CBC Listen app. It's free from the App Store or Google Play.

Quarks and Quarks is produced by Rosie Fernandez, Amanda Bukowitz, Olivia Diring, and Dan Falk. And with this show, we say goodbye to our intern, Dionne Sudial. Thanks and good luck in the future, Deon. Our acting senior producer is Sonia Biting. I'm Bob McDonald. Thanks for listening. For more CBC podcasts, go to CBC. cdbc.ca slash podcasts.