Tiny Matters
Take a dive into the genes, microbes, molecules and other tiny things that have a big impact on our world with Tiny Matters. Join scientists Sam Jones and Deboki Chakravarti as they take apart complex and contentious topics in science and help rebuild your understanding. From deadly diseases to ancient sewers to forensic toxicology, Sam and Deboki embrace the awe and messiness of science and its place in the past, present, and future. Tiny Matters releases new episodes every Wednesday and is brought to you by the American Chemical Society, a non-profit scientific organization advancing chemistry and connecting the broader scientific community. Tiny Matters is produced by Multitude.
Tiny Matters
Stories trapped in ancient teeth: Reconstructing megalodon’s diet and retracing the steps of woolly mammoths
How often do you think about your teeth? In this episode of Tiny Matters, we talk about how the atoms trapped within teeth can reveal what an animal ate and where it lived, and how studying teeth has helped ecologists reconstruct prehistoric food webs of megatooth sharks and retrace the steps of woolly mammoths across the Arctic. And hopefully, we’ll give you a few new reasons to appreciate your own pearly whites.
Send us your science stories/factoids/news for a chance to be featured on an upcoming Tiny Show and Tell Us bonus episode and to be entered to win a Tiny Matters coffee mug! And, while you're at it, subscribe to our newsletter at bit.ly/tinymattersnewsletter.
Links to the Tiny Show & Tell story are here and here. All Tiny Matters transcripts and references are available here.
Hey Sam, how often do you think about your teeth?
Speaker 2:Outside of brushing my teeth and going to the dentist. Not a whole lot. Why do you ask?
Speaker 1:Maybe I've been watching like a few too many crime dramas and History Channel mysteries, but I've recently become sort of entranced by just how much a single tooth can tell you about a person.
Speaker 2:You mean, like using tooth DNA to figure out who it came from or how people with a sweet tooth might have more cavities than others?
Speaker 1:Yeah, that's definitely part of it, for sure. But as a former chemist in practice and a forever chemist at heart, I recently went down a rabbit hole, looking into how the tissues that make up teeth actually store a ton of information about the diet and movements of the animal that grew them.
Speaker 2:Yeah, so those are not the sort of thoughts that I previously had about teeth.
Speaker 1:Okay, well, in that case, I am very excited to go on this dental adventure with you.
Speaker 2:Welcome to Tiny Matters, a science podcast about the little things that have a big impact on our society, past and present. I'm Sam Jones and today I'm joined by guest co-host Ariana Remmel, who also joined me back in episode 70.
Speaker 1:Ari, welcome back, Thank you so much for having me. I'm so excited to be back and I'm psyched for this episode. I'm so excited to be back and I'm psyched for this episode. So today on the show, we're going to talk about how the atoms trapped within teeth can reveal what an animal ate and where it lived. We'll see how studying teeth has helped ecologists reconstruct prehistoric food webs of megatooth sharks and retrace the steps of woolly mammoths across the Arctic, and hopefully we'll give you a few new reasons to appreciate your own pearly whites.
Speaker 2:In order to understand why teeth keep such good records of their bearer's life history, we need to start with some basics. So most of us are familiar with the fact that vertebrates use teeth for all sorts of behaviors like eating, chewing, biting and fighting. Though teeth are hard and bony, they aren't actually classified as bones due to a few important anatomical differences. For example, all of the tooth's blood supply and nerve endings are located at its core in a soft tissue called dental pulp. Dental pulp is super sensitive, so it's surrounded by two protective outer layers called dentin and enamel, which form the part of the tooth that sticks out from our jaws.
Speaker 1:That being said, dentin and enamel are both largely made of the same biomineral found in bones, a calcium-based compound called hydroxyapatite. Dentin is a mix of hydroxyapatite and proteins like collagen, while enamel is almost pure mineral, which actually makes it the hardest substance in the human body, and if you think about how much physical and chemical strain we put on our teeth, it makes sense that these tissues need to be really hard and resilient. Here's how geoscientist Daniel Sigman at Princeton University explained it to us.
Speaker 3:Our mouth is a very acidic environment. Sometimes when we're eating, it has to deal with many different chemical conditions, and we often have to use it to crunch relatively hard materials, and so bone is really just not over. The life of an organism is often not strong enough. This is why organisms evolved to have enamel teeth.
Speaker 2:It's also why teeth show up so prominently in archaeological and fossil records. That super durable mineral component means enamel can stand the test of time, sort of like our body's equivalent of an airplane's black box. In fact, for some extinct organisms, we owe most of what we know about their life histories to fossils of their teeth. Megatooth sharks like the notoriously massive Otodus megalodon are a great example.
Speaker 1:As listeners may know from pop culture lore, megalodon was once the largest shark to ever swim the high seas. As I was looking for sources to put the size of these behemoths in context, I found a Smithsonian Institution article that describes Megalodon as being about, and I quote, the size and weight of a railroad car and up to three times the length of a modern day great white shark. So massive, just astonishingly large. And like great white sharks today, megalodon's skeleton was largely made of cartilage, which doesn't fossilize as easily as hydroxyapatite. So paleontologists make these body size estimates for Megalodon based on what they can extrapolate from fossilized teeth, which average about four to six inches in length, though folks have found specimens more than seven inches long, which brings me to another fun fact. The scientific name megalodon actually derives from the Greek for giant tooth, that is very fun and also very apt.
Speaker 2:There's a lot that we can learn about what megalodon ate based on the shape of its teeth, which are triangular, flat and serrated. It clearly wasn't an herbivore, which typically have broad, flat teeth for grinding tough vegetation, and sharks that primarily eat fish tend to have long piercing teeth, which leads paleontologists to believe that Megalodon was probably really good at hunting marine mammals like baleen whales. Plus, those giant teeth were bound to leave a mark.
Speaker 3:One of the ways we try to tell who ate who in the paleontologic record is by looking for scars on bones, so evidence for bite marks and these are great and they can indicate connections and events of feeding, but they don't integrate over the lifetime of the organism.
Speaker 2:Daniel told us that we sort of have to take each bite mark with a grain of salt, because a single event can't tell you if this was a common predator-prey interaction or a rare treat. Without a more complete picture of a megalodon's dietary habits across its full lifespan, as opposed to the snapshots that we see in the fossil record, it's difficult for scientists to wrap their heads around how this terrifying predator and its basically mouthful of knives actually functioned within its past ecosystem.
Speaker 3:So evolution is directly tied to ecosystem function. So if you want to understand why, let's say, a given class of organisms evolved, you need to not just know about the temperature that they were experiencing, not the rainfall or the salinity of the water. You also need to know what kind of ecosystem they were living in.
Speaker 1:Figuring out Megalodon's place in the food web, or what ecologists call trophic position, could help us understand not only how it evolved, but also why it went extinct around 3.5 million years ago. One possibility is that Megalodon lost access to important prey that they needed to sustain their massive bodies, especially since there's evidence from the evolutionary tree of marine mammals that the size and diversity of baleen whales was also changing around the same time. It turns out that we may be able to glean new clues to solve that mystery by analyzing the nitrogen atoms preserved within the enamel of fossilized megalodon teeth.
Speaker 2:Say more about that.
Speaker 1:Well, you've heard the phrase you are what you eat, right?
Speaker 2:Of course, meaning the foods that we eat have a direct impact on our health, since we use the nutrients in our food to generate energy and build and maintain muscle and all of our other body tissues.
Speaker 1:Yeah, exactly Because our body mass has to come from somewhere, right, and that somewhere is all the stuff we eat, which again makes sense when you think about it. Athletes are always talking about getting enough protein in their diets to build muscle. Milk cartons even advertise that they contain calcium to build strong bones and teeth.
Speaker 2:So some portion of what we eat literally does become a part of us, which is so cool to think about, but most biomolecules like proteins, fats, sugars, even minerals they're all made from the same handful of elements, right Like carbon, oxygen, hydrogen and nitrogen. So even if we can detect atomic traces of these materials in a really old fossil, how can Daniel and his colleagues figure out where they came from?
Speaker 1:That is a great question that's going to require us to get a bit technical, so bear with me. Let's think about the periodic table of elements for a second. Which, oh, I'm just as a chemist, I'm so excited. Okay, every atom found in nature has a place on the periodic table based on the number of protons in its nucleus. For example, all nitrogen atoms have seven protons and all oxygen atoms have eight, and so on down the table.
Speaker 2:But in addition to protons, an atom's nucleus contains neutrons, and atoms of the same element can have a different number of neutrons. Like nitrogen, atoms sometimes have seven neutrons or eight. So they're called nitrogen 14 and 15 to distinguish them by mass. An atom's mass is just its number of protons plus its number of neutrons, in this case seven protons plus either seven or eight neutrons, correct?
Speaker 1:So elements that have the same number of protons but a different number of neutrons are called isotopes, and I know that all these numbers can be a mouthful. So when talking about two isotopes of the same elements, chemists will sometimes use a shorthand and refer to them as either light or heavy. So in this example, nitrogen-14 is the light isotope, while nitrogen-15 is heavy.
Speaker 2:Yeah, that definitely helps.
Speaker 1:Some of these isotopes are unstable and only stick around for anywhere from several millennia to a few seconds. For now, we're going to focus on stable isotope analysis. Isotopes of the same element are basically the same in terms of how they function within molecules and behave in reactions, but chemists and geoscientists have developed highly sensitive methods to distinguish isotopes by weight and detect subtle differences in their abundance within samples.
Speaker 2:For example, daniel explained that by about the 1950s paleoclimatologists realized they could reconstruct the temperatures of ancient seawater by analyzing the ratio of oxygen-16 to oxygen-18 isotopes from ocean sediments and fossilized marine organisms.
Speaker 3:In my work in paleoceanography, my big interest is to understand the role that ocean biology plays in the carbon dioxide concentration in the atmosphere and thus the greenhouse effect over time and especially over glacial and interglacial cycles.
Speaker 2:Biological cycles are all about organic materials, but most of these isotope-based data about past ocean climates come from fossilized microorganisms whose soft tissues are long gone. But megalodon teeth they're famously giant and have a full coat of protective enamel.
Speaker 3:We are super excited about this organic matter that's trapped within these biomineral fossils, but by design there's very little of that organic matter. So one major part of my research program is to make isotopic analyses of nitrogen. Nitrogen is a critical nutrient for all organisms.
Speaker 1:So everything from plankton to sharks needs nitrogen for DNA, rna proteins, all sorts of stuff. About 99.6% of the nitrogen on Earth is the isotope nitrogen-14. But there's still about 0.4% that's found as the heavier, rarer nitrogen-15, both of which are stable, got it?
Speaker 2:So, if we think about proteins that contain a lot of nitrogen that's coming from our diet, those proteins will contain a mix of both light nitrogen-14 and heavy nitrogen-15. But are they mixed in the same ratio as we see on the rest of the planet?
Speaker 1:Thank you so much for asking. No, we and I'm using the royal we here to mean all vertebrates we don't use all the nitrogen we eat, so we have to get rid of that excess somehow. And though nitrogen-14 and nitrogen-15 are nutritionally identical, our cells tend to hold on to the heavier isotope and throw out the lighter one.
Speaker 3:That leaves us enriched in N15 relative to N14, relative to what we ate. This is known by ecologists as the trophic enrichment factor. You know how much higher an N15, N14 ratio we are than what we ate.
Speaker 1:So let's try putting that in context. In a marine food web At the very bottom trophic level we've got microscopic algae. They're hanging out in the water column, photosynthesizing until along comes a shrimp that gobbles it up. Now that shrimp is going to repurpose some of the algae's organic matter to maintain its own body tissues. But the shrimp's metabolism will have a slight preference for keeping the heavy nitrogen while disposing of mostly light nitrogen.
Speaker 2:So the shrimp ends up with a higher ratio of N15 to N14 than the algae at eight?
Speaker 1:Yeah for sure, it's one link up the food chain. So it's slightly more enriched in heavy nitrogen compared to the trophic level below. So let's say the shrimp is also just hanging out munching on algae until it gets got by a small fish by eating shrimp. That fish is already starting out with a heavy nitrogen-enriched food source, but it is once again going to preferentially hold on to the N15 for its own tissues.
Speaker 2:So every trophic level in the food web has a slightly higher heavy nitrogen enrichment, up until you reach an ecosystem's apex predator, which in today's ocean would be the great white shark.
Speaker 1:Yes, exactly. So this is where the magic happens. Daniel's team developed a new technique to make super precise nitrogen isotope measurements from really small samples, including the tiny amount of organic matter preserved within the fossilized teeth of megalodon and its megatooth relatives.
Speaker 2:Wait, did you just make a tiny matters pun? Oh, I for sure did.
Speaker 1:But it's just because I am really excited, because in a study led by Daniel's former graduate student, emma Kast, they revealed a fascinating new mystery when they compared the trophic enrichment measurements from fossilized megalodon teeth to that of modern white sharks.
Speaker 3:It seems to have been at a higher trophic level than white sharks.
Speaker 1:So this, to me, is wild. What Daniel is saying is that if you count the links in the marine food chain today, starting at the bottom with photosynthesizing microorganisms all the way up to white sharks as apex predators, daniel's and Emma's results show that Megalodon's ecosystem had at least one, but probably multiple additional trophic levels below it that are unaccounted for.
Speaker 2:Daniel shared a possible few explanations for this difference. One is that Megalodon was actually eating white sharks or whatever shark sat at the equivalent trophic position as our great white sharks do today. Another is that mature Megalodons were actually cannibalizing juveniles of their species. And there's a third secret thing.
Speaker 3:It's also possible that we're missing a prey type. You know, the fossil record is not ideal for capturing every type of organism that might have existed, and so we may be missing or underestimating some critical higher trophic level that was somewhere above the fish-eating sharks and even the great white ancestor sharks of the time.
Speaker 2:Another fascinating implication of Megalodon's remarkably high trophic level is that these sharks weren't relying entirely on baleen whales for the bulk of their prey, after all, since these marine mammals are so much lower in the food web. So whatever caused these legendary fish to go extinct was probably independent of whatever evolutionary changes were going on in those whales.
Speaker 1:This is just one example of the cornucopia of insights that might now be within reach, especially since we've got fossils of organisms that date back more than 550 million years, and Daniel is hopeful that these techniques might even be applicable to some really, really old samples that could shed light on Earth's nitrogen cycle going back billions of years.
Speaker 3:And we are going to be getting other types of information from this fossil-bound organic matter, for example about its chemical content. That will together yield a richer and richer picture of these ecosystems through time and potentially revolutionize how we think about how the earth has evolved.
Speaker 2:As mind-blowing as it is that we can learn so much about marine ecosystem interactions millions of years ago from fossilized tooth enamel, there's actually a whole lot more that scientists are discovering from stable isotope analysis of dentition on dry land, from stable isotope analysis of dentition on dry land. So we're headed to the Tanana River Valley near Fairbanks, alaska, which is where scientists have uncovered an ancient archaeological site called Swan Point. And at the end of the last ice age, swan Point would have boasted a panoramic view of rolling grasslands that were once the stomping grounds of woolly mammoths and indeed, about 14,000 years ago, Swan Point became the final resting place of a woolly mammoth known today as Elma.
Speaker 1:So we spoke with paleoecologist Audrey Rowe about what she's learned from Elma's tusk, which is actually a specialized kind of tooth.
Speaker 4:The tusk itself is from a 15 to 20-year old adult female mammoth, and so, oh, we ran the gamut of tests on this tusk because we wanted to learn everything we could about her, about her life.
Speaker 2:Audrey is a PhD candidate at the University of Alaska, fairbanks, and she's part of a team working to understand migration patterns of both extinct woolly mammoths and modern caribou via isotopes in their teeth. The team's findings could have big implications for wildlife management and the de-extinction movement.
Speaker 1:To understand how researchers can gather location data from tooth isotopes. We've got to take a step back to you are what you eat. As we talked about before, the minerals in teeth collect traces of what an animal is eating as its teeth grow. In addition to atoms like carbon and nitrogen from organic matter, in those meals there are other important elements like calcium and strontium that originate from inorganic minerals in the ground itself.
Speaker 4:So it's all about the bedrock. I'm not a geologist, but it's all about the bedrock. That's where it starts out. So why does bedrock matter to mammoths or caribou? It's because the bedrock is what forms the mineral fraction of soil. It decays into soil over time. That soil is then taken up by plants and then herbivores like mammoths or caribou that eat those plants.
Speaker 2:The specific mixture of elements within soil depends on the age and composition of the underlying bedrock, which gives geographic regions their own unique isotopic signatures. In particular, geologists have found that strontium isotopes in a rock, fossil or tooth can provide a pretty good clue as to where it came from, because the ratio of strontium-86 to strontium-87 is tightly linked to whatever type of bedrock made up the landscape where the specimen formed. Researchers have even created maps of these isotope distributions that are called isoscapes.
Speaker 4:It's a portmanteau of isotope and landscape. So isoscapes are just models of isotope ratios that vary geographically over a landscape. So with strontium we have models of bedrock ages and types that we then use to make models of what we think the strontium 87 to 86 ratio should be at any given point on that map.
Speaker 1:Geologists have created isoscapes for a lot of different elements, but the strontium isoscape is particularly handy for calcium-based biominerals in teeth. So, if you can humor me with a final reference to the periodic table, strontium sits right below calcium, which means these two elements have similar chemical properties and our bodies as I speak once again for all vertebrates aren't always great at distinguishing between the two. So sometimes we'll stick a strontium atom into our dental tissue where calcium should be. And because the strontium isotope ratios in plants mirrors that of the underlying bedrock, the mammoth's tusk sort of logs where it ate as it grew, and though there's not nearly as much strontium in tusks as there is calcium, there's still enough to be measurable and useful for Audrey and her colleagues.
Speaker 2:Another useful feature of tusks is that they grow continuously throughout the mammoth's life, so every day she was alive. Elma added a very thin layer of dentin to the base of her tusk, which would incorporate a smidge of strontium from her latest meal, though the tip of Alma's tusk seems to have worn off over time. The growth bands within her tusk record what are essentially strontium geotags from every location she visited, starting from the first few years of her life to the day of her death, and today, more than 14,000 years later, scientists can decode those isotopic signatures.
Speaker 1:To start, Audrey and her team split the tusk down the middle to get a clear view of the growth layers inside. Then they use a technique called laser ablation mass spectrometry. The laser basically blows up a tiny spot on the tusk into plasma, just a tad smaller than a grain of table salt, so that the mass spec can weigh all of its components and determine the sample's isotopic composition.
Speaker 4:With the laser ablation we're taking phenomenally high-resolution measurements of strontium isotopes along the entire length of the inside of the tusk.
Speaker 2:These high-resolution strontium measurements work out to a geotag. For nearly every consecutive week of Elma's life, and because Audrey also has access to an isoscape for all of what is now Alaska and the Yukon, she trained a computer simulation to translate the strontium data to a literal walk across the isoscape map. She has the computer model backtrack from Swan Point where Alma died and take a random step in any direction within about 50 kilometers, which is about the most a mammoth would have walked in a given week.
Speaker 4:And then we look at that strontium value on the map at that new point and we look at the measurement at the next point on the tusk and we compare those two. Are they the same? Are they close enough to be feasible? If they aren't more or less the same, we have the computer model.
Speaker 2:Take another random step from there, and the computer model keeps going from there until it either proposes a possible location for each strontium measurement on the tusk or it hits a dead end. Audrey had the computer take around 20,000 of these walks, then winnowed down the conceivable routes using other elements she'd measured in the tusk, including oxygen and sulfur.
Speaker 4:She told us that this data is not as precise as the kinds of GPS trackers that we use on migratory mammals today, but all of them do sort of map out a lifetime of spending several years, first half of life more or less, in that southeastern Yukon area and then, for whatever reason, walking westward for about two years into Alaska and then spending the last couple years of life just puttering around interior Alaska in like the Fairbanks-Tenina Valley area, and it ends.
Speaker 1:These data suggest that Elma spent most of her life in the interior highlands of Alaska, and she appears to have frequented the same regions as other mammoths and early humans alike. At the end of the Ice Age, alaska's climate was becoming warmer and wetter, which promoted the spread of trees and shrubs in regions that had previously hosted lush grasslands. What remained of those grassy habitats would have been in the highlands, so Audrey says it makes sense that this is where Elma spent most of her time. So far, this is only the second mammoth tusk that's been analyzed by this method, the first being a male named Kick, who lived about 3,000 years before Elma. Kick's tusk revealed that he hung out in many of the same regions as Elma, but he covered a much greater range, which is somewhat expected, given that juvenile males likely separated from their maternal herd to establish their own territories as adults.
Speaker 2:This is the kind of information that gives researchers a sense of what woolly mammoths needed not just to survive but thrive on a long-lost landscape.
Speaker 4:But that's just two animals who we know so much about and we're starting to get a little glimpse, a little picture of what mammoths lives, their life histories would have been like. But we need more. We need more so it's not just n equals two, so that we have a more general sense of what they did, not just what these individuals did.
Speaker 2:And that kind of data is going to be crucial if any of the existing projects to de-extinct mammoths actually come to fruition. But there are also benefits nearer term. Today, audrey is putting the techniques her team developed, studying massive mammoth tusks, towards measuring location data stored in much smaller teeth of Alaskan caribou that once traveled in herds of more than 500,000 individuals, according to some historic accounts. By retracing the past migration routes of these animals from their teeth, audrey hopes that she can help land managers conserve an iconic animal that still roams Alaska today. It's tiny show and tell time. Do you want to go first? Do you want me to go first?
Speaker 1:Well, I feel like you went first last time, and so I will, you know, take one for the team and go first this time. So, given that this episode was a little bit about rabbit holes, do you have your own experience going down rabbit holes, perhaps on Wikipedia?
Speaker 2:Oh, I think it used to be one of my favorite activities. There was this game on Wikipedia where you would start with a term and then you'd I forget what it was but essentially you wanted to end up back with that term. I can't remember.
Speaker 1:Ah, yeah, yeah, yeah, yeah, no. I similarly remember playing some sort of version of a game of like six degrees of separation or something, where you could always end up with some weird Wikipedia page, and anyways, that is why this story in Nature magazine stood out to me. This is by a reporter named Helena Kudiabora I hope I'm pronouncing that right. She was reporting on a new study that was a collaboration between researchers at the University of Pennsylvania and the Wikimedia Foundation that analyzed different search styles in Wikipedia, which is like the different ways that people tend to engage with that open access data source to find information, and they have basically identified three primary styles. The hunters you know, the people who go into the website are like I know what I need and I'm going to follow links until I find the thing.
Speaker 1:Then you have the busybodies, which I think is kind of what we're.
Speaker 1:You know, the game of the game version that we're talking about, where you go in and you're like, okay, this is the thing that I wanted, but also this thing seems interesting and there's kind of a loose knowledge network that's represented there.
Speaker 1:And then there is a third one which is called the Dancers, which I can't remember if it's in the paper itself or the story that describes dancers as people who take creative leaps in their kind of search parameters right as they're moving between these links. Previously, people's Wikipedia search habits have been studied in like confined laboratory conditions, but this time around they were using data from like nearly half a million people across 50 different countries and 14 different languages, and so, while hunters and busybodies had kind of been defined before, this is the first time that we're seeing these dancer search types showing up in the data and I think it's really interesting. They talk about, like maybe some reasons that different people might prefer one style over the other. You know, like sometimes I go to Wikipedia, as I said, to find a specific piece of data, and sometimes I'm like oh you know, let's just see.
Speaker 1:Let's see where I end up just by clicking all of these links. But I just thought this was really, really fun, yeah. So like, what would make someone more of a dancer? Like if you're going there to look for something specific or look for a broader kind of category of knowledge, or if you're like you know what, why is there in this tooth isotope story a link to a megalodon fossil, right, you know? And then you go, you bounce to all of these different things, I, you bounce to all of these different things. I think that's where you start to see the dancers. So sometimes maybe we're dancers and sometimes we're hunters. Yeah, I love that.
Speaker 2:And sometimes we're busybodies. I know the naming is great too. I really enjoy the naming. I'm going to be thinking about this now every time I go on Wikipedia.
Speaker 1:I'm looking forward to the Wikipedia article about this research. I know I know.
Speaker 2:So I have a, I think, fascinating but also kind of silly tiny show and tell for you today. A paper just came out in Trends in Ecology and Evolution and it is kind of sort of about drunk animals. So ecologists are challenging this assumption that it's accidental when wildlife eats fermented fruits that contain a significant amount of alcohol and then behave quote drunk. Yes, they argue that since ethanol is naturally present in like pretty much all ecosystems, then it's probably consumed all the time by fruit and nectar eating animals. I wish that one of them had made a quote that's like I think these animals are getting sloshed regularly. They didn't say that. I said that Just to clarify, not quoting anyone but myself.
Speaker 2:Okay, so ethanol first became abundant around a hundred million years ago, that's when flowering plants started producing that sugary nectar and fruits, and then yeast could, of course, ferment that sugary nectar, those fruits, and I didn't know this, but I guess naturally fermented fruits usually reach around 1% to 2% alcohol by volume. Oh, didn't realize that, but concentrations can be as high as 10.2%. Oh, my gosh, in specifically overripe palm fruits in Panama. So it seems like some yeah, some fruits, like as they start to ferment, are incredibly alcoholic, and so of course it's really hard to figure out are these animals trying to get drunk or not? Because there are a lot of reasons that they might benefit from ethanol consumption, from alcohol consumption. So first, it is a source of calories, but researchers will also say that animals can't detect the ethanol the way that we do. Like there's such a specific taste where it's like oh my gosh, this is. But I wonder if that's also because it reminds you of like really terrible vodka or something I don't know.
Speaker 1:Yeah, yeah, yeah.
Speaker 2:Yeah, and then ethanol also could have some medicinal benefits. Fruit flies I didn't realize this, but they'll actually lay their eggs in a lot of substances containing ethanol and I guess it protects their eggs from parasites. Oh, so that makes a lot of sense. And the fruit fly larvae actually seem to increase their ethanol intake when they become parasitized by wasps, which is like fascinating. And then also, on the cognitive end of things, one of the behavioral ecologists who was involved, anna Boland, who was actually the first author and she's at University of Exeter, said on the cognitive side, there's this idea that ethanol can trigger endorphins and get the dopamine system going. That can lead to relaxation, have benefits in terms of sociability, which is just so funny to think about, like within the animal kingdom broadly. But yeah, they haven't tested that. They need to know if ethanol is really producing a physiological response in the wild and that is TBD. But I just thought this was a really fascinating one and I was shocked by how much alcohol some fermented fruits can have.
Speaker 1:Yeah, okay, that for one a lot, but I, you know, I think that this point of kind of tying in the evolutionary history, of when this, you know, ethanol started appearing on the landscape, does add kind of this new perspective of is this a thing that animals today have just kind of learned how to do, or is this a thing that has, like a behavior that's evolved over time? And I especially think the idea of the social lubricant that we humans use alcohol to be is really fascinating.
Speaker 2:That's so cool. Yeah, it's so fascinating to think. Is this tipsy fruit bat just trying to like be cool around the other fruit bats?
Speaker 1:Yeah, I mean it's possible. We need the scientists, and inquiring minds want to know where's the research grant for this, honestly, a tiny little drunken fruit bat also sounds like very cute to me.
Speaker 2:Adorable, it's like very cute to me Adorable.
Speaker 1:Thanks for tuning in to this week's episode of Tiny Matters, a production of the American Chemical Society. This week's script was written by me, ariana Rimmel and edited by Michael David and Sam Jones, who is also our executive producer. It was fact-checked by Michelle Boucher. The Tiny Matters theme and episode sound design is by Michael Simonelli and the Charts and Leisure team.
Speaker 2:Thanks so much to Daniel Sigman and Audrey Rowe for joining us. A reminder that we have a newsletter so you can sign up for updates on new Tiny Matters episodes, video clips from interviews, a sneak peek at upcoming episodes and other fun content that we think you'll like. I've put a link in this episode's description. We content that we think you'll like. I've put a link in this episode's description. We'll see you next time.
