Science Friday - Yeast Superbug, Dino Dinner, Toxic Algae. July 20, 2018, Part 1

Episode Date: July 20, 2018

If you hear the word “superbug,” you’re likely to think about drug-resistant bacteria or even viruses. But in a case that’s been unfolding since 2009, a drug-resistant yeast is increasingly worrying epidemiologists. The yeast, Candida auris, has popped up in 27 countries so far, with 340 cases in the United States. It has a mortality rate of 60 percent. Unlike other kinds of fungal infection, C. auris seems able to hop from person to person and persists on sterile surfaces. Inconveniently, the yeast’s spores are unusually resilient against standard hospital cleaning solutions. On top of that, it’s already resistant to most of the anti-fungal drugs in existence—there weren’t many of those to being with. Science writer Maryn McKenna and CDC Chief of Mycotic Diseases Tom Chiller joins Ira to discuss the underestimated risks of fungi and how health systems can combat them. One-hundred fifty million years ago, long-necked sauropods roamed the planet munching on plants and trees. Some of the largest herbivorous dinosaurs could grow up to 115 feet and weigh 80 tons. A team of scientists wanted to see how much nutrition this vegetarian diet provided for the dinosaurs. The group grew horsetails, ginkgos, and other plants similar to Mesozoic vegetation under high levels of carbon dioxide to mimic the atmosphere of the era. Paleontologist Fiona Gill, who is an author on that study, talks about what we know about dinosaur digestion and how this could be used to model other ancient ecosystems. Mary Radabaugh peers over her mask at the toxic algae spread across Haney Creek off of the St. Lucie River in Florida. “You can see the flies that are on the top of it. They’re eating the rot so that’s like the sewage that is out there. You can see the big brown spots that look like sewage.” Here boats bob sadly in the blue-green algae that if ingested can cause nausea, diarrhea and vomiting and even can affect the liver and nervous system. But for Radabaugh that hardly is the worst of it, which is why she wears the paper mask over her mouth and nose. “The smell is comparable to a Port-O-Let that’s been sitting in the hot sun for about three months. It’s really probably the worst smell you’ve ever smelled.”  The toxic algae bloom is the worst in modern history here where the Indian River Lagoon, St. Lucie River and Atlantic Ocean converge. Some 160 billion gallons of polluted water have been flushed from a rain-swollen Lake Okeechobee to the area since January, triggering the widespread bloom that has prompted emergency declarations in three counties. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. First, it was Diamond Rain on Uranus and Neptune. And now scientists believe that our very own planet may be full of the very same gemstone. It's just a hunch, but they suspect that as much as 2% of the Earth is made up of diamonds. So what makes them suspect our planets chock full of the sparkly stuff? Well, here to tell us that story, as well as other short subjects in science, is Ryan Mandelbaum, science writer for Gizmoto. Always good to see, Ryan.

Yeah, always great to see you. Ira, how's everything going? Hey, so you know the song, the Earth moves under my feet? Well, there are diamonds under my feet? Maybe. So what happened was there's these cores of continents called cratons, you know, the oldest part of our continents, and sound waves moved too quickly through them.

And some scientists did some calculating, some lab experiments, and figured out that if the Earth was both 50% of one kind of rock and then 2% diamonds, it would explain, the sound waves moving too fast. So it's a hypothesis, is what I'm going to say. But it would be crazy, of course. Do we know where they might be so we can start looking for them? It would be like 100 miles underground.

And so, I mean, the issue is that, well, when the diamond ore comes to the surface of the earth, it doesn't contain 2% diamonds. So the question is, okay, well, if they're there, where are the diamonds? So, you know, like I said, a hypothesis, but people are looking and maybe. Is there any way to follow up this with an exception? experiment of some something. Well, unless you, like, recreate the movie, the core, it's going to be pretty hard. But the, I mean, there's just more modeling and more observations to be done.

I mean, with more science, hopefully they'll be able to find something out. Would these be the same kinds of diamonds I'm getting at the jewelry store? They wouldn't be quite as pretty. They wouldn't be cut diamonds. No, but I guess diamonds are carbon, right? Right, right. So, still carbon. And it would be crazy for the earth to have that much carbon underneath the, in the mantle like that.

I mean, it would be important. Listen to this segue I'm going to do. Dark, black, well, you know, carbon, there's a story you have about the black sarcophagus in Egypt? You really love this one, I know. I've been, if you are on Twitter today,

you should look at the jokes that people are making. What happened was on July 1st, in Egypt, there was a sarcophagus found a 2,000-year-old sarcophagus in Alexandria, Egypt, and everybody thought this black granite thing might, you know, maybe it's curse, like, should we open the sarcophagus and lest we unleash some crazy, you know, but they opened it up yesterday, and it was not nearly as exciting.

It was three skeletons in a pool of red sewage. Highly disappointing, I imagine. Disappointing, but still scientifically interesting. I mean, these skeletons are, again, they're 2,000 years old inside this sarcophagus. It's just that, you know, the mummies weren't as well preserved as you might have hoped. But now people are joking online that the water must be cursed or something. So, you know, let us drink the red juice. The biggest non-event since

Saraldo Rivera's Al Capone Volta opening back in the 80s. At least there was something in the sarcophagus. There's something in there. All right, let's go on to, speaking of strange, strange physics story. I know you're really good at finding these, so tell us about these two particles spinning.

Very, very fast. Yeah, so these are scientists constructed these nanoparticles made of silica. So they're about 100 nanometers, like the size of viruses, and they spin a billion times per second, which is the fastest mechanical motion on record. So that is cool on its own, and the way they make it spin is by shining it with light

that has been circularly polarized, so the electric field is spinning. And why do they do this? Well, they did it for several reasons. One of them was looking to create a torsion balance with a different experiment, which is sort of like a little force detector. Another was just doing it

because they wanted to test the fundamental limits of physics, But really, like, if there is, you know, you may have read in quantum mechanics, this idea of sort of the quantum vacuum, that particles are appearing and disappearing out of nowhere in the vacuum of space. And if that was true, then perhaps these virtual particles would create friction against this spinning nanoparticle. And we might be able to detect this friction of space time itself. Whoa. Head exploding motion. Oh, so let me see if I understand this. So if, you know, if let's say it takes a certain amount of energy and you can rev up the spinning particles theoretically to a certain speed.

Yep. But if when you apply that energy and it doesn't get to that speed, there's something holding the particles back from spinning. That's the idea that perhaps they've measured some friction from the vacuum fluctuations of space time. Like trying to run in water, underwater. Yeah, it's like the way that you could tell that there's air resistance because when you do this, you make, you know, you flap your hands back and forth and make wind. Wow. And so we know from quantum mechanics that particles can pop in and out, and this is an idea to try to prove that they're there, even though we can't see them. Yep, basically. Well, yeah, actually.

Wow, that's kind of cool. This is a don't try this at home sort of thing. Unless you can spin it up. If you've got the lab equipment, it's not going to hurt anyone. Let's talk about something really amazing that astronomers saw for the first time using one of our space telescopes, a planet getting eaten by a star. Right. So there is about 450 light years from Earth, so sort of an hour, you know, stellar neighborhood is this star called RWRA.

And they were observant dimming every few decades, and the dimming would last a month. But then in 2011, the dimming behavior changed. And modeling appears to show that this could be from not just a planet being eaten by the star, but pieces of planets colliding and then being sucked up by this young star. It's cool. But, yeah, I mean, the idea is that these are, this is a young star, probably only a few million years old. And we think that around these young stars are these disks of rock and debris. And in that case, then there is a lot of chaos that's going on around this early star as planets begin forming out of this debris. And it's possible that, you know, some collision would have ended up in the star eaten up some pieces of planets.

So sort of seeing what might have happened in our own early days of the solar. Exactly. Looking into at these early young stars could potentially shed some light on our own solar system. Wow. You always bring such good stuff. I love this stuff. This is great. It is good stuff.

You know, you like it in your mind blowing, your hair hurt. It's just thinking big thoughts about physics and everything. It's kind of cool. I just like reading the stuff I see on the Internet. All right. Keep it coming and keep coming back to us, Ryan. Thanks, Ira. Ryan and Mandelbaum, a science writer for Gizmodo.

And now it's time to check in on the state of science. This is KERNO, St. Louis Public Radio News. Iowa Public Radio News. Local science stories of national significance. Summer, as you know, with the warmer weather is the season when algal blooms start to pop up. That's when colonies of algae grow out of control in lakes and rivers and beaches. This summer, there have been some duzies. Some reports of blooms in Massachusetts, North Carolina, and other states.

But Florida has been hard hit this summer with a bloom taking hold in the state's largest, Lake Lake Okeechobee. Some reports have the bloom spreading to over 100 miles of water. Amy Green is here to fill us in on that story. She's an environmental reporter with WMFE in Orlando. Welcome to Science Friday. Amy. It's nice to talk with you. There was an algal bloom on Lake Okeechobee in Florida two years ago, so what's different about this one? It's just another step in this trend that we're seeing where every summer this time of year we're seeing these algae blooms, some of them toxic, and it's just becoming kind of a bigger problem and a more frequent problem in the state of Florida. Well, is this one toxic? Yes. Certainly in some places the algae is testing positive for toxicity. And, you know, that's kind of one. thing that makes this algae, you know, kind of especially dangerous or something people should be especially cautious of, you know, this allergy, it's a living organism. And so it lives and it dies.

And so, you know, a waterway that may test negative for toxicity one day, the next day it could be positive. And so residents who live along these waterways really should, you know, take care and really should stay away from this water because it's really hard to know. know how this algae is going to test from one day to the next. To get an algae bloom that big, it's got to eat something to grow, doesn't it? What is it feeding on? Yeah, well, you know, what we're kind of seeing here in the state of Florida is the consequence of two problems, and the main problem is nutrients.

That's the main thing that this algae thrives on. Nutrient pollution is something that comes from fertilizers, that people use to make their lawns green. Farmers use it on crop lands. And in the same way, nutrients, you know, help your lawns to look green. It also feeds this algae. And so in the state of Florida, where we've had such dramatic population growth in the past few decades, as the population grows, as the nutrient pollution grows and becomes a bigger problem in waterways, that's one of the things that's really feeding this algae. Yeah, and we get lots of intense weather and hurricanes,

or hurricanes have anything to do with, you know, moving the algae around? Well, the other problem that we're seeing with these algae blooms in the state of Florida is the fact that Florida's waterways have been just dramatically altered to make way for the state's booming population. You know, a century ago, most of the state was underwater. We had the Florida Everglades. Well, today, the state, South Florida, has been dramatically drained for population growth. And so when the waterways are very full, are very water swollen, as the cases with Lake Okeechobee,

they have to release that water, and that water has to go somewhere. And so it flows into the coastal estuaries. Toxic algae needs fresh water to thrive. and as those estuaries become more full of freshwater, that again helps this algae to thrive. And so that's why we're seeing this algae in Lake Okeechobe and the coastal estuaries to the east and west of the state's largest lake. That's fascinating.

I know you're about to go on a boat with a fisherman for a story. How are the residents dealing with this? Well, here in Cluiston, which is where I am, and this is a town that's just on the southern shore, of Lake Okeechobee, this is a town that, you know, where the economy, like so many others along Florida waterways, is very much based on fishing and boating and all of these things. And so here in Cluiston, one of the things this fisherman, the message he's trying to get out is, you know, look, you know, there still is fishing in Lake Okeechobee. There are still things to do on Florida's

waterways, you know, one of the reasons this is such a big problem in Florida is because our economy is so based on our environment. People come here to go to the beach and to go boating, and so. So the algae blooms are really wrecking that whole economic possibility. That's a real worry. Amy Green, thank you very much for taking time to be with us today. She's an environmental reporter with WMFE in Orlando, and you can read her stories about the Florida algal blooms on our website, Science Friday.com.

com slash Florida. When we take a break, we're going to come back, and you've heard the word superbug. I bet you're thinking of bacteria. But what happens when a yeast, that's a fungus, goes rogue? We'll give you some answers after the break. Stay with us. This is Science Friday. I'm Iraflato. If you're working at a hospital, the last thing you want to deal with are superbugs, usually drug-resistant bacteria. Think Mercer. That take advantage of sick and weak patients. But have you ever heard of a super-bug? yeast. Perhaps you've had a mild yeast infection, many of us have, but yeast can be fatal in humans. Candida albacans is a major culprit of blood infections that can lead to septic shock and

other fungi around the world can cause lung infections and gastrointestinal problems, but now there's a new infectious yeast in town. That seems capable of spreading as fast as bacteria, persisting outside the human body for long periods of time, and with high mortality in the patients that acquire it. Oh, and by the way, we don't have a lot of drugs for combating this virus. Here to tell the tale is Marin McKenna. She's senior fellow and the Schuster Institute for Investigative Journalism at Brandeis University and science writer and columnist for Wired, and she recently wrote about the rise of Canada orris and troubles that could pose for public health. Welcome to Science Friday.

Thanks for having me. Dr. Tom Chiller, Chief of Micotic Diseases at the Centers for Disease Control. He joins us by Skype. Welcome, Tom. Great to be with you, Ira. Marin, what the heck is this yeast? Tell us about it. So this yeast only came on the radar of scientists in 2009,

initially just via ear infection in an elderly woman in Japan. And that was not that unusual. And then as people started to look at it, they realized that it really was very unusual because this yeast behaves like a bacterium. In fact, everything that we think about that's bad about superbugs, which are bacteria, is worse in this yeast. There are fewer drugs. It has higher mortality. It spreads in a mysterious manner. It seems to have arisen all over the world at the same time. It's like superbugs on steroids in a species where superbugs shouldn't occur at all. Does it, is it infectious differently?

Does it spread differently than other yeast were familiar? So the interesting thing about this is that when you talked in your intro about people being familiar with yeast infections. And most of the time when you have a yeast infection, it's because you've actually inoculated yourself or infected yourself with a yeast that you were already carrying. What's different and troubling about this new superbug yeast, Candida Oris, is that it passes from person to person. person. So it may have originated in one person, but it causes outbreaks through person to person transmission and through transmission by surviving on cold, inorganic surfaces. That's totally new. Do we have any sense about how many people may have died from this new yeast? So there have been 340 cases, I believe, in the United States, but I'm sure that Dr. Chiller is more up on the numbers

than I am. All right, Dr. Chiller, can you fill us in on that? Sure, I'd be happy to. And just back to Marin's point about these organisms generally being with us. So we think of the organisms that are in our intestines as part of our what we call normal flora. We have trillions of bacteria there, and we also have trillions of candida. So Canada has been with us evolving for millions of years. And it's interesting to note that this particular Canada, as Marin described, isn't in that space. They're not thought to be part of our normal flora, as we like to call it, but instead they're on our skin.

And they seem to be very happy on skin and other surfaces and therefore transmit much more readily between people or from people to surfaces and then from those surfaces to people. As far as the numbers of infections and people with this infection that we're seeing, there's a wide variety. of ways in which we're finding this. So the most severe and significant, obviously, is when this organism gets into the bloodstream. And so far, in the United States, those patients are very medically experienced. So they're quite sick, quite ill,

are very much exposed to hospital environments, and those are the patients that we've seen in the hundreds that have it in their blood. There are many people that have it on their skin that are also in these health care environments, but at least if it's on the skin, it can be contained or one can try to contain it. In other countries, the situation is a bit worse. And there are some countries where now 40% of the bloodstream infections caused by Canada

are actually caused by this Candida oris. And that's really our concern in public health, is we've seen where it can spread and become very dominant. And that's one of the things we're concerned about here. Our number 8447-4-8255. You can also tweet us at SciFri. You know, we don't hear a lot about killer fungi as much. Is this because they're just not as good as infecting us?

They've been around. You say they're a natural part, normally fungi of our microbiome. And so this is sort of an outlier then. Yeah, I mean, I think what there's a couple things going on. Number one is fungi generally are opportunists. So they live with us, and then if there are some breakdown in our skin barriers, breakdown in our intestines, you have surgery, you have an intravenous line, and they can get in and invade and cause problems in our blood.

But there are also lots of fungal infections out there that are just misdiagnosed or underdiagnosed. We unfortunately, for all the different types of infections that we see, have a real hard time diagnosing fungal infections. And we really need to develop more diagnostic tests to diagnose these diseases. So, Marin, now that we know a little bit more and news about this and just fungal infections is getting out, how are the hospitals responding to this? What can they do? So this is really a problem. I think when people think about superbugs, they realize.

that outbreaks within hospitals among the sickest patients. That's sort of how superbugs surface. That's where we notice them first. That's where they pose the most challenges. And every superbug over the past 20 years or so has taught us something new about the kind of threat they are. So MRSA, which you mentioned came along. It lives on skin.

And so hospitals had to learn that everyone had to wash their hands really well. Then the CREs, the highly resistant gut bugs, came along and people realized, oh no, things live on surfaces as well, so we have to learn how to clean the hospital environment. Now, Candida Oras pushes us further than that because the things that we're using

to clean the hospital environment, which is mostly cleansers based on quaternary ammonium, don't appear to kill this bug. So we have to go back to much more harsh cleansers that generally aren't used because they're kind of destructive to things that exist

in hospitals, and also to the kind of old-fashioned, but, I mean, reliable, but not as thought of. Infection control practices like putting patients together in one part of the hospital, putting patients in isolation, making sure everybody thoroughly gowns and gloves and masks up before seeing them. It requires a lot more attention to really find details of infection prevention. With Canada, Orris, you just can't slide. But just going back to the future, is what you're saying. Health care-wise and cleanliness, washing hands, possibly using more toxic. And it sounds like that ought to be simple, right? But from the, you know, from 25 years of hospitals

working on things as simple as washing hands, there have been studies after studies that show that healthcare personnel actually aren't all that good at washing their hands, even when they know someone's watching them to see if they do it. So these things that sound very simple, they're actually hard to do. Tom, you agree? Yeah, and I think just, you know, to add to what Marin is saying, you know, these physicians and health care providers, when they think of Canada, Canada, as you mentioned at the beginning, Canada, AlbuCans, a very common Canada in our intestinal tract, which can cause bloodstream infections and does, and in fact very common cause of bloodstream infections in hospitals, is not something the health care providing community worries about transmitting. So as Marin mentioned, it's almost as though you infect yourself with the organism that's in your GI tract because the barriers have broken down because you're in a health care facility and you're getting treatment. Whereas this, so this organism, Canada ORIS, is not acting that way.

And so part of this is just the awareness. We don't generally react to a Canada species with intense infection control and disinfection. And so part of this is just getting the health care community. more aware that for this particular organism, which is a candida that normally you don't react to, here you have to react. And on top of that, as you probably mentioned at the beginning, to me, the definition of a superbug is something that's highly resistant to the available treatments. You know, unfortunately, unlike the bacterial world, in the fungal world, we have really three main antifungals that we can use for invasive infections. This organism has been found to be

resistant to all three in some, thankfully, rare situations. So that leaves us with no options. And that's really the other big concern is that if this is able to get a foothold and set up shop, so to speak, and become more globally spread, then we're going to worry about our ability to be able to treat the serious infections. You know, we hear all the time, Marin, that drug companies don't want to get involved in something if there is not money to be made because there are not enough people being infected to sell their drugs too.

Will that change now if people start hearing about and panicking about... I wonder. I mean, we've been panicking about bacterial superbugs and the loss of antibiotics for quite a while now. And yet, most of the companies that once made antibiotics have moved out of that manufacturing space because they say with actually fairly good data to back them up, that it's not in their economic best interest to make antibiotics. They just don't make their R&D money back. So at this point, though Canada Oras is highly fatal to people, has really high mortality rates, there aren't all that many cases. Does that therefore mean that companies are going to rush into the space to make these drugs? When they haven't rushed into the space to make drugs

for bacterial superbugs, that seems unlikely to me. Tweet coming in from David Eckerd who says, how much of it is airborne, this new canopy spread? I think you mentioned is by the skin. Dr. Chiller, how much is canopy spread through the air? Yeah, that's a good question. And honestly, Candida, in general, we don't think of as an airborne fungus. There are plenty of other fungi. In fact, most fungal infections that do invade do come in through the lung.

But in this case, Candida generally does not. Again, it's been, it's in our intestines and it's on our skin, and so it's transmitted by touch. But there's still a lot unknown about Candida orus. And so I think we still need to understand whether there is the potential for this to be aerosolized. But it's certainly not the primary way that it's spread. Is this, and we're getting a bunch of tweets saying the same thing, is this something I should be worried about at home, or were we only talking about hospitals as the places where this is being spread?

Yeah, I think that's a really important question. because no, I think the shorter answer is this is not something that I want the general public to go home and be concerned about. This is right now one of these organisms that is very health care associated, that is really set in health care settings. But both the hospitals and the longer-term care facilities are having issues with this, and it generally, again, affects people that are sick and have been exposed or, as we like to say, medically experienced. But I do think it's important for the general public to know about it and to know that their loved ones that maybe in hospitals could be getting this or could be exposed to this. And so it's important to know what you're getting into in a health care environment. I'm Ira Plato. This is Science Friday from WNYC Studios talking with Tom Chiller and Marin McKenna about this new superbug fungus among us. You know, because I can see from my Twitter board lighting up and whatever, people are saying,

uh-oh, I'm going home with a bottle of bleach and I'm going to start spraying everything. This is not something they should be doing. So, true. People should not be spraying their households with bleach. Bleach is bad for your clothes and bad for your lungs and just that's not a good thing. Someone here says oven cleaner. Oh, even worse. No, let's not do that.

Let's not go sterilize our entire environments. However, I think what Tom said is really important. You know, what's become clear in the past couple of years in sort of studies of superbugs and infection control is that no hospital is an island. They exist in very complex networks of nursing homes and long-term assisted care facilities, and people move in and out and back in kind of unpredictable ways.

So to say that it's only a risk in high, hospitals, which sounds like, oh, it's never going to affect any of us, actually means that it's a risk in hospitals and in all the other institutions that touch hospitals. And we shouldn't discount it as a public health threat just because it's not going to show up in our kitchens the way drug-resistant salmonella does. And Dr. Chiller, picking up on your point before about saying, you know, we need to take fungal infections more seriously now like we do some of the bacterial infections. Yeah, I think that we are trying very hard, certainly in the fungal infection world, to advocate and make people aware that these infections are occurring and they occur actually quite frequently.

They're often misdiagnosed, and one of the problems with misdiagnosis of fungal infections is they get treated like bacterial infections. And so we know patients will get courses and courses of antibacterials, which, of course, are then killing off the good bacteria that you have in your GI tract or in your intestines. And then they can actually cause fungal infections to become worse because you've now out-competed everything that is competing with the fungi. So there's a lot to be said about thinking fungus, and we try to have awareness campaigns around think-functive,

fungus, and this is both for the public and for the health care communities as well. Is climate change going to affect the spread and toxicity of these fungus? Well, certainly, fungi are environmental organisms. So they live in the environment. Now, as we've talked about, some candida are part of our conventional organisms, part of our microbiome, as you mentioned. But most fungi live in the environment. And so changes in the environment change the fungi that are there. They can either proliferate or they can die off.

They can be selected for resistance depending on what types of pesticides and other things are used in the environment. So certainly environmental changes dramatically affect the fungi. And we know this when we're looking at a disease that we call Valley Fever that is caused by a fungus down in the southwest. We know that drought and rainfall can dramatically affect. infection rates on the years depending on whether there's been lots of rain followed by drought, etc. These are environmental organisms and the environment changes affect them for sure.

So one of the intriguing mysteries of Candidores, remember, this is a really new species. It was only identified 10 years ago. It appeared in four different places around the world at the same time. Didn't spread from one to the other three. What happened to make it appear in all those places at once. That's one of the questions that has to be answered, and it seems as though the environment ought to have played a role. All right. That's a good way to end the program with a question, which you always like to answer later. Maren McKenna, science reporter and columnist for Wired, Tom Chiller, Chief of the Mechotic Disease Branch at the Centers for Disease Control and Prevention in Atlanta. Thank you both for taking time to be with us today. Thanks. Thanks for having us.

We're going to take a break, and when we come back, we're going to talk about the paleo diet of dinosaurs, How nutritious was the dino dinner, and how do we know how much they actually ate to survive, these big dinosaurs, you know, the herbivorous ones? We'll talk about someone who measures that in her lab. Stay with us. We'll be right back after this break. This is Science Friday. I'm Ira Plato.

One of the iconic scenes of Jurassic Park, I'm talking about the original movie, is when the two dinosaur experts encounter their first dinosaur in the park. Remember, they run out of their Jeep next to a giant sauropod munching on some tree. trees. The dino even has a bit of tree leaf stuck in her teeth. This thing doesn't live in a swamp. This thing's got what a 25, 27 foot neck? Brack your saura 30. Yeah, you've probably seen this image of the tree leaf stuck in the teeth, you know, in other places too. Plant eaters grazing on tops of trees, places like that. The biggest of these sauropods could grow up to 115 feet, way up to 80 tons. But how nutritious was this vegetarian dynod?

it. And how many leaves would it take? You know, what does a dinosaur really need to eat? Well, a group of scientists investigated this question by growing trees under mesozoic conditions and creating a sort of dino digester. The results were published in the journal Paleontology, and my next guest is an author on that study, and she's here to tell us about it. Fiona Gill is a lecturer in paleontology and geochemistry at the University of Leeds in England. She joins us by Skype. Welcome to Science Friday. Thanks for staying up late for us. Hi, thank you. Thanks for inviting me to speak today. You're quite welcome. So you are a paleontologist, but not the dinosaur kind.

Why were you interested in questions of sauropod diets? Well, my previous research has been all to do with fossilized feces, and I ended up looking at a lot of modern feces as well. But one day at a conference, I got chatting to an experimental paleobotanist. And we realized that maybe our interest could work together. And one of the questions that we thought we might be able to tackle is how nutritious was dinosaur food. So the paleobotanist, who's a co-author Barry Lomax, had had this idea for ages to grow dinosaur food plants under the atmospheric conditions that would have been around at the times that dinosaurs had lived. And we were kind of wondering, is there any way to go from that? kind of artificial dinosaur poo.

We decided there wasn't. But because of my work with modern feces, I knew about some other techniques that meant that we might be able to replicate digestion of these plants that Barry had grown in the lab. So you went about creating a sort of a stomach, an artificial dinosaur's stomach, a digester that you could feed plants into? How did you know what plants? Do we still have plants around today that were around millions of years ago? Yeah, well, we've got some that are very, very similar.

So one of the species we used was ginkled by lober. And ginkled trees today are very similar to the ones that lived at the time of the sauropods. And for the six plant species that we used in our experiments, they're all modern versions of plants that we know. lived at the same time as the solar pods. So you also had to recreate the atmospheric conditions, correct? Yeah, that's right. So we looked at the work that had been published recently,

so the most recent and the best estimates for how much carbon dioxide was in the atmosphere at different times during the Mesozoic. And the experiments we did with our plants, we used four different carbon dioxide concentrations to represent today's carbon dioxide levels, around about 400 parts per million, and then a range of carbon dioxide concentrations throughout the Mesozoic. So 800 parts per million, so twice as much carbon dioxide as today, three times as much, 1,200 parts per million, and then the highest estimate. The highest concentration was 2,000 parts per million,

which is the kind of maximum estimate for how high carbon dioxide might have reached during the mesozoic. How did you recreate what a dinosaur digestive system would look like? Well, we didn't create it from scratch. What we did was we used a technique that's been widely used in the agricultural industry to evaluate the nutritional value of new foods. So if people are trying to grow crops or look at different diet combinations

that are going to make, for example, dairy cows more productive, they can use this fermentation system to evaluate the nutritional value of the food. So we used that as our starting point, but we ran the experiments for much longer to try and replicate or to get as close as we could to the length of time that it would take a sauropod to digest its dinner.

And so what model did you use a cow, a cow digestine that doesn't have many stomachs, or did you use something simpler? It was simpler than that. So the actual experiments were carried out in gas-tight syringes and we put our experimental plants inside the syringes and we incubated the plants, the powdered plants, we ground them up before we put them in there, we incubated them with rumen fluid, cattle

rumen fluid. And that was our model for the sauropod stomach, essentially. Well, it's not really the stomach. It would have been the sauropod fermentation chamber. Why did you choose a cow and, let's say, not a horse for the rumen? Yeah, so part of the reason was that because this technique has been really widely used. There's a lot of really good data for different types of plants. So we were able to kind of use that and see how our data fitted in

and compared to other plants and a standard for all of these other experiments, standard practices to use the cow rumen fluid. But you're right. I mean, a horse would be a much, would be a closer analogue because a horse is a hindgut fermenter which means that the fermentation system is situated after the true stomach,

whereas for a ruminant like a cow, the fermentation chamber where all the microbes make the plant matter is much nearer the start of the digestive tract. And as far as anybody knows, or as most people believe, that dinosaurs, particularly sauropods, were very likely to have had large fermentation chambers but they were most likely to have had them in the hind gut position so a horse would have in some ways have been a better analog even better would have been if we could have used microbes from a modern herbivorous lizard like an iguana but in terms of actually being able to sample that material from the animal in a way that was fair to the animal and good for animal

welfare. It's much more complicated for a bit fomenta than a root. That's a euphemistic way of saying you would have had to kill the lizard to get the rumen out of it. Pretty much, yeah. So let's, let me have a drum roll please and get to the bottom line. How much does a dinosaur need to eat? Well, it depends on the dinosaur. It depends on the size of the dinosaur. It depends on the metabolic rate, there's still a lot of uncertainty about what kind of metabolism dinosaurs had. And it depends on which plants it was eating. But according to our calculations, if you took an average sauropod, a 30-ton sauropod with a metabolic rate that was somewhere in between modern lizards and modern mammals, if it was eating the most nutritious food that we could grow, which was

horse tails grown under 1,200 PPM CO2, then it would have needed to eat about 50 kilos a day of that. And if it was eating the least nutritious food that we could find, which was Aracharia, the monkey puzzle tree, grown under 2,000 parts per million CO2, it would have needed to eat more than twice as much, over 100 kilograms a day. So those are the kind of differences that we're talking about.

Wow, that's a lot of food. have to eat. It's a few hundred pounds a day of food. Now, you said at the beginning that your specialty is cuprolites or fossilized poop.

Yeah. Have you learned anything about that from what you're studying now? What have you learned? Well, it's not directly related. So it kind of, this project sort of came out of my research on

to into coprolites because through the coprolite research I got more and more interested in the digestive processes of extinct animals and of course dinosaurs are such an iconic animal especially the big sauropods it was kind of a natural progression to think about what their digestion was like and so it was really great to be involved in a project that allowed us to work on that And I noticed you did not talk about using flowering plants as food for your experiments, but the horse tails. Why is that? Well, we did use one angi-sperm, one flowering plant, which was a buttercup. We did include that as one of our six species.

But the reason that we concentrated on non-flowering plants was because during the Mesozoic, that was that was, was when the first flower and plants evolved. So the first ones came in about 125 million years ago, but it wasn't until about 100 million years ago that they really took off. And of course today they dominate

our modern ecosystems. But at the time that the majority of sauropods lived, the flora, the plants that were around were not the flowering plants, and that's why we focused on those ones in our

experiments. Fascinating. So you're happy with how this turned out? Yeah, yeah, we're really happy. So the most interesting thing really for us is that previously people had made the assumption that under elevated carbon dioxide concentrations, plants might grow bigger and faster, but they will be less nutritious. And that's because most previous experiments had been carried out on flowering plants. And also they've been They've been comparing modern CO2 concentrations with maybe twice as much, twice as much CO2. So our experiments were different because we used different plant species and we used the much greater range. And what we found was that the effect is really species specific. So you can't just generalize and say that everything's going to be less nutritious.

Wow. Under elevated CO2 concentrations because some things actually seem to increase their nutritional value under moderately or in fact quite high elevated carbon dioxide concentrations. Dr. Gil, thank you for taking time to be with us today. And good luck to you, Dr. Fiona Gill Lecter in paleontology and geochemistry at the University of Leeds in England. Okay, gather around bookworms because our sci-fry book club is kicking off. It kicked off last week, as you remember.

We're reading Stephen Hawking's a brief history of time, but maybe you missed out on how to participate. They need a little extra nudge to get started, so we're going to supply it. And here to remind you to pick up that book and start reading Science Friday producer and Book Maven Christy. Taylor, welcome back, Christy. Hey, Ira, how's it going? Fine. I'm excited to finally be knocking this book off my bucket list.

Yeah, me too. It's one of those books that really seems like everyone's heard of, but a lot of people haven't actually read yet. And it feels like a really good way to honor Stephen Hawking's legacy as he passed away this week. I'm Ira Plato. This is Science Friday from WNYC Studios. And since this is a book club, we really do want you to participate. So we have a few ways, and I'm here to give those back to you again. So the first thing to do is go to our website, ScienceFriiday.com slash book club, and that will have pretty much everything I'm about to tell you right there waiting for you in a nice list form.

But one of the things I really wanted to highlight is that we are working with artists this time around. Stephen Hawking, as you know, Ira and have spoken highly of, has some really great analysis. for how the universe works, that balloon metaphor for how the expanding universe can somehow still not have a center, for example. So they're great visual analogies. We want artists to help us visualize them. The online community, L.O. is helping us out with this. So we want people to submit their portfolios, what they've already done so far, so that we can commission a few artists to create this Stephen Hawking-themed Big Bang Galaxy universe. He wrote really simple pictures.

We might get a little more complicated and artistic one. Yeah, and we've seated it with some quotes that might help get you inspired. But all of that, again, ScienceFriiday.com slash book club. And then our guest readers, Priya Natarajan and Clifford Johnson, who are physicists, and they had a great conversation with us on the air last week. They're going to be answering listener questions in our weekly newsletter, which you can sign up for on our website. They are great science communicators themselves and physics researchers.

and we all know that there are some concepts in here that might be a little, need a little extra unpacking, so they're here to help. Other than that, we have a voicemail number that you can call. 567-243-24-5-6. We'll be having some really interesting physics conversations along the way, and we will wrap up with a big nerd fest on August's 24th with Clifford and Priya again, and you, Ira, if you have finished your reading at that point. 5-67-24-3-24-5-6.

Right, and that's where you can call in. with your physics questions or comments as you're reading along. And again, we have that weekly newsletter where Priya and Clifford are going to be helping answer some of those questions. You know, I love the book. I have to admit that somebody, I think, walked off with my copy. Oh, no. It's so popular.

I don't want to say that I lost it. It got legs and, you know. Stephen would be so disappointed. So, Ira, there's actually some good news for you. You're not, all is not lost Powell's books who always donate to our giveaway. They also are offering a discounted copy of that same edition. People still get it. Yeah, you can still get that all summer long.

And that's, again, go to our website for the link, but it's available on their website to order. And in August 24th, we're going to have a wrap-up. Right. And then actually, if you're in New York, on August 21st, we're having a time-traveler cocktail party first, where we're going to have some hands-on demos and some fun physics conversations live in New York City. So August 21st is the time traveler cocktail party. If you miss it, you can always come back in time. and attend again.

And then August 24th, on our airwaves, the nerdiest conversation that ever did nerd. That's going to be great. And once again, our website, for more information. ScienceFriiday.com slash book club, Ira. Great, Christy Taylor is our producer for Science Friday and captain of our SciFri Book Club. Thanks for taking time to be with us today.

We'll look forward to everybody participating. And speaking of great physics stories, did you know that Quarks was named after a term in the James Joyce novel Finnegan's week? You can read all about the, origins of words we use in science. It's our new summer science newsletter, science diction.

That's a great name. Sign up and read more word nerdery at ScienceFriday.com slash sciencediction. Science Friday.com slash science diction. Charles Berkowitz is our director, a senior producer Christopher and Taliatta. Produces our Alexa L.M. Christy Taylor,

Katie Heiler. Our intern is Lucy Luong, and we had technical engineering help today from Rich Kim and Sarah Fishman. And of course, we're active all week on Facebook, Twitter, Instagram, all of social media. If you have a smart speaker, you want to hear Siney Fry Podcast. You can go to our website or ask your speaker to play it for you. We've got them all up there waiting for you to go.

Have a great weekend. I'm Ira Flato in New York.