In short
Why animals have such different tongues, and how tongue shape evolved for feeding, swallowing, and sensing.
Guests/backgrounds
Dale Althoff (listener in North Carolina, asked the question; observes papillae on his tongue and differences on dog/horse tongues). Jessica Ray (lead keeper, birds team, London Zoo; works with macaws). Nick Garrett (hoofstock keeper, London Zoo; works with giraffes). Kurt Schwenk (professor of ecology and evolutionary biology, University of Connecticut; explains tongue evolution from fish suction to land feeding; also muscular hydrostats). Callum Ross (professor at University of Chicago specializing in feeding systems; compares herbivore/carnivore/nectivore tongues; explains mammal tongue muscle mechanics and swallowing). Ben Tapley (curator of reptiles and amphibians; explains king cobra tongue-flicking and Jacobson’s organ).
Key claims
Tongue variety comes from diet and feeding/sensing needs. Parrots have a bone inside a finger-like tongue for dexterous shelling. Snakes use split tongues for chemical sensing (“stereo” smell) via Jacobson’s organ, not taste. Mammal tongues are fleshy, bone-free muscular hydrostats that shape-change for chewing and swallowing. Tongues are crucial for safe swallowing; impaired tongue movement can cause pneumonia after strokes.
Notable examples
Macaws shell nuts with a bony, finger-like tongue; cows use keratin papillae to grab grass; king cobra Arthur flicks a split tongue to sample scents; giraffes have long, dark, antiseptic-saliva tongues that wrap branches and strip leaves; humans rely on tongue movement to push food past the oropharynx into the esophagus.
Written by AI. May contain mistakes. Listen to the episode to check what was said.
Chapters
Tap a time to open that second in VOExploring Tongue Diversity
0:00 to 1:00
Listeners share their observations on different animal tongues.
“This BBC podcast is supported by ads outside the UK.”
Exploring Tongue Diversity
1:20 to 3:21
Listeners share their observations on different animal tongues.
“We're feeding macaws because we want to get a glimpse of a tongue to help answer a question from one of you lovely listeners.”
Macaws and Their Unique Tongues
3:21 to 6:15
Discussion about the structure and function of macaw tongues.
“Tongues aren't something I've ever given much thought to, but they are incredibly important.”
Evolutionary Insights on Tongues
6:15 to 10:22
Kurt Schwenk explains the evolutionary development of tongues.
“it's just proven to be so successful that they've continued it.”
Special Adaptations of Animal Tongues
10:22 to 13:54
Callum Ross discusses various animal tongue adaptations.
“In some animals, they became highly specialised, like the sticky tongue of a frog.”
Exploring Tongue Variations in Mammals
15:02 to 17:06
Discussion about the evolution of tongues in mammals and their adaptations.
“the show that chews over your science questions.”
Giraffe Tongue Adaptations
17:06 to 21:08
Insights from a zoo visit about giraffe tongues and their functions.
“and make all these incredible shapes I imagine a giraffe might struggle with.”
The Functionality of Tongues in Swallowing
21:08 to 26:48
Detailed explanation about the mechanics of tongues and swallowing processes.
“So when we move an arm or a leg, it's very understandable.”
Evolutionary Significance of Tongues
26:48 to 27:35
Understanding the diverse adaptations of tongues across species.
“The variety is particularly surprising when you consider all tongues evolved from the same basic structure in an ancient aquatic ancestor that first ventured onto land and suddenly needed a new way to eat.”
Introducing the Global Story Podcast
28:25 to 28:56
Learn about the Global Story podcast and its focus on American influence.
“The United States is about to mark its 250th anniversary.”
Transcript
Automatic transcript. May contain errors.0:00Kurt Schwenk:This BBC podcast is supported by ads outside the UK.
0:30Kurt Schwenk:at Whole Foods Market. Your phone is your lifeline. Calling your kid to say goodnight, waiting on a job call back, or just sending a meme to your best friend when it's been that kind of day. Wherever life takes you, the TextNow app keeps you connected for free. Get a real phone number, unlimited talk and text, and 5G data for your favorite apps, all for$0 a month. No fixed contracts, no hidden fees, no panic when bills pile up, just phone service that's there when it matters most. TextNow. We've got your back. Download TextNow in your app store today.
0:58Caroline Steel:Wireless plans require the purchase of a SIM card. Visit textnow.com for terms and conditions.
1:07Caroline Steel:Working with parrots is so fun. You're listening to CrowdScience from the BBC World Service, the show that answers your science questions. I'm Caroline Steele, and I'm on a fun day out at the zoo. First stop, some very lively parrots. Why is he making so much noise? He wants nuts. I have nuts in my hand. He sees other than... Should we give him a nut? He's still going to yell though. We're feeding macaws because we want to get a glimpse of a tongue to help answer a question from one of you lovely listeners.
1:44Kurt Schwenk:Hi, I'm Dale Althoff. I live in North Carolina in the United States. My question for crowd science today, why do different animals have such different tongues? like my tongue has these uh i guess they're called papillae that are on your tongue and i was looking at my dog's tongue when uh he was licking me and he seems to have them but they're much smaller
2:10Caroline Steel:so what a papillae i don't know should i look up a photo let me let me do a quick search are they're the sort of small bumps you see on the surface of your tongue and they contain taste buds whereas I'd always assumed that the bumps were our taste buds but they're not so you've noticed that your dog hasn't got them either she hasn't got them or they're smaller
2:37Kurt Schwenk:it's not clear and I was looking at my horse's tongue the horse seems to have a very smooth tongue.
2:46Caroline Steel:Okay, so you've got up close and personal with a horse's tongue. You've noticed your dog's tongue. Got any other tongue observations?
2:54Kurt Schwenk:Oh, yeah. I had a parrot for a while. And her tongue was more like either a tentacle or your finger or something. It was kind of round and dry and she would use it to manipulate things a little bit. When she opened her beak, she would reach out and use it that way.
3:11Caroline Steel:Okay, well, we will do a deep dive into tongues, find out what's going on, and hopefully make some sense of it. Tongues aren't something I've ever given much thought to, but they are incredibly important. They help us eat and speak, and across the animal kingdom, they can get pretty extraordinary. From the chameleon's lightning-fast tongue to the sandpaper-like tongue of a cat. So why do we see such variety? Why are tongues so far from one size fits all? To answer listener Dale's question, I think we need to see some tongues in action. Which brings us to London Zoo in the UK, where Jessica Ray, a lead keeper on the birds team, is introducing me to some parrots.
4:03Caroline Steel:We're stood next to a huge aviary. What birds are living here? So we're at our macaw block right now. So basically a bunch of different macaw species. We've got green-winged macaws, blue-throated macaws, great green macaws, and hyacinth macaws as well. So a nice variety of macaw species. Okay, so we're here because we want to learn more about different animals' tongues. Because our listener wants to know, why do animals have different tongues? What's a macaw tongue like? It's actually very strange. As you'd expect, I think. Like the most important thing about a bumcow tongue is that like all parrots, they have a bone inside of their tongue.
4:38Caroline Steel:Ah, there's a bone in their tongue. There's actually a bone inside. So it's actually really, really cool. So it looks a bit like your index finger if it's kind of curved. And what it does is allows them to manipulate their food. So they'll crack through the nut with their beak and then they'll use their tongue to manipulate the food inside of their mouth. So they basically can peel the skin or the shell away and spit all the stuff out that they don't want. So what do their tongues look like? Do they look like a sort of pink fleshy tongue with a bone inside or do they look more like a finger? I would say it looks the shape of a finger, but it's kind of leathery and really dark.
5:12Caroline Steel:It's very strange. Yeah, that sounds bizarre. So we've got some macaws next to us. Any chance we can feed them a nut and see if we can see this tongue in action? Yeah, yeah, yeah. Let me grab some nuts quickly. Okay, great. We're suddenly joined by a hungry looking macaw. Here you go, you can have a nut. Oh, wow. Okay, you can see his tongue quite clearly. He's a gorgeous blue macaw with a yellow eye. And then, oh, he's biting into his nut. And using his tongue, yeah, like a finger. I mean, it's impressive. Imagine being given a nut and then shelling it with your tongue. Yeah, and he can do Brazil nuts very easily.
5:50Caroline Steel:He can shell the almonds and everything. I'd say Brazil nuts tend to be his favourite. And so do all macaws have bones in their tongues? Yes. So why do you think they have tongues like this? Do you think this is sort of an evolutionary advantage? Exactly, yeah. I think it's mostly based on their diet and who was the most effective at eating it. So if you want to eat a lot of seeds and nuts rear your offspring, it's quite helpful to have a bone inside of your tongue. So over many millions of years, it's just proven to be so successful that they've continued it. A finger-like tongue. It almost sounds like the stuff of horror films.
6:25Caroline Steel:No offence to McCaw's. But somewhere deep in our evolutionary history, macaws and humans shared a common ancestor. So how did macaws end up with basically a finger, while we humans ended up with a flat pink muscle? Where did tongues begin?
6:44Kurt Schwenk:Since we evolved from fish ancestors, and those ancestors fed in the water, that when eventually they transitioned to life on land, they needed to find a way to both capture food and manipulate it in the mouth that didn't involve water.
7:01Caroline Steel:This is Kurt Schwenk, professor of ecology and evolutionary biology at the University of Connecticut in the US.
7:09Kurt Schwenk:So in water, things like the prey are buoyant. They'll float around in front of you. There's no gravity to worry about. and the vast majority of fish and even other aquatic vertebrates use suction.
7:23Caroline Steel:So all life began in water and most of life in the water vacuums up dinner.
7:29Kurt Schwenk:So they actually rapidly expand their mouths and throats and they suck water in and anything like a small fish or prey item that's caught in that bubble of water that gets sucked in also comes into the mouth.
7:45Caroline Steel:Sort of like a straw, kind of like using the fish mouth as a straw?
7:49Kurt Schwenk:Yeah, in fact they make the mouth opening fairly small, which like a straw, it can accelerate the speed of the water into the mouth. But by doing that, they're essentially exploiting these characteristics of water, which is the fact that it's viscous and that things in the water are buoyant.
8:07Caroline Steel:Water is quite dense and thick, or viscous, so things like tasty algae can float around in it, rather than dropping straight to the bottom.
8:16Kurt Schwenk:But in the air on the land, the air is not viscous at all.
8:21Caroline Steel:Which means no floating food for our newly land-based ancestors.
8:25Kurt Schwenk:I mean, maybe you could suck a mosquito into your mouth, but not much else. And there's gravity and the prey has weight. And so it has to be lifted and physically pulled into the mouth. And so my feeling is that the tongue became elaborated from musculature that was already present in the fish to take the place of water.
8:49Caroline Steel:So tongues developed from muscles that were already present in fish, gradually taking over the job that water used to do.
8:56Kurt Schwenk:Instead of suction, they protrude the tongue, capture prey on the tongue, draw it into the mouth. And then once it's in the mouth, they can lift it and move it back and forth and push it into the throat. swallow. Again, all the things that water did ancestrally.
9:14Caroline Steel:Tongues have been around for hundreds of millions of years. They began as a simple way of getting food into the mouth, but evolved into everything from the finger-like tongue of a macaw to the long, soft tongue of listener Dale's horse.
9:29Kurt Schwenk:The main reason animals have different tongue shapes is that they use them for capturing prey or acquiring food in different ways, and then they use them for moving the food around in the mouth while they chew it in different ways.
9:42Caroline Steel:This is Callum Ross. He's a professor at the University of Chicago in the US, specialising in feeding systems.
9:51Kurt Schwenk:Herbivores have a different kind of tongue to carnivores. They're different from nectivores, animals that survive by eating nectar. So, for example, a cow tongue has got a lot of keratinous protrusions on it, papillae.
10:08Caroline Steel:Those are the tongue bumps that listener Dale noticed. Turns out they can be made of keratin.
10:13Kurt Schwenk:Keratin is the same stuff your hair is made out of. And it's the outside layer of your skin. And so cows have modified papillae that enable them to grab the grass and crop it using their tongue.
10:25Caroline Steel:Oh wow so kind of acting a bit like scissors sort of break the grass up
10:31Kurt Schwenk:Yeah tongue anatomy is very important for acquiring food and bringing it into the mouth and manipulating it If you don't have hands then you're going to need to have some way of acquiring the food item And so lizards use their tongue for acquiring prey Amphibians do and mammals do like anteaters for example have a really long tongue
10:53Caroline Steel:So after our ancestors hauled themselves onto land, tongues evolved to make capturing food and eating easier. In some animals, they became highly specialised, like the sticky tongue of a frog. Which sounds like a genius plan, but evolution doesn't have a plan. It's just the variations within a population that give some individuals a better chance of surviving and passing on their genes. Which is particularly important for the organ that helps us eat. But tongues are about more than just food. In front of us is a lovely large snake. Could you introduce me to the snake?
11:33Kurt Schwenk:Yeah, this is a male king cobra. His name's Arthur and they are the largest venomous snake on the planet.
11:42Caroline Steel:I'm back at the zoo to meet a king cobra and Ben Tapley, curator of reptiles and amphibians. Wonderful. I have to admit I'm not a fan of snakes but I mean this guy's quite pretty and quite chill
11:55Kurt Schwenk:I'm going to try and turn you around today
Read the full transcript
11:57Caroline Steel:so we are answering a question from one of our listeners who wants to know why different animals have such different tongues and actually this king cobra is a perfect example because I think he did just stick his tongue out for us are you going to do it again?
12:15Kurt Schwenk:They're constantly kind of just scanning the environment, seeing what cues they can pick up on. And that's part of the tongue flicking, is they're kind of looking for scents in the environment.
12:27Caroline Steel:Oh, there you go, he's stuck his tongue out. It's quite long, it's quite dark, and then it famously has that split at the end of the tongue. What's the split for?
12:37Kurt Schwenk:So the split in the tongue is basically when they flick the tongue out, they're looking for chemical cues in the environment. And by having the split, they can scent things differently from either side. So they're kind of sensing in stereo.
12:53Caroline Steel:And when you say they're sensing things, how are they using their tongue? Can they taste the air? What can they do that we can't?
13:02Kurt Schwenk:So what they do is once that tongue goes back into its mouth, they've got an organ on the roof of the mouth called a Jacobson's organ. And that interprets what the two forks are picking up on. So it's more smelling the air rather than tasting.
13:17Caroline Steel:So why do you think snakes have evolved to have a tongue like this? What kind of advantage does it give them?
13:23Kurt Schwenk:I mean, each species will have different kind of constraints along their kind of evolutionary path.
13:30Caroline Steel:Yeah.
13:30Kurt Schwenk:And this is the way that snakes have cracked sensing their environment.
13:36Caroline Steel:So snakes have long tongues with a split at the end, not to help them taste, but to smell. It feels like we're a bit short-changed as humans. No forks in our tongues for stereo smelling, bones in our tongues for incredible dexterity, or sharp papillae to help us chop up food. Is there anything special about our tongues? That's coming up next. This is summer at its peak.
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14:27Caroline Steel:Is the American dream still possible? I'm Asma Khaled, one of the hosts of the Global Story podcast from the BBC. One of the most successful exports the United States has ever sold the world is the American dream, that tantalising promise of a better, freer, richer life. But is it still attainable?
14:46Kurt Schwenk:I feel like the American dream is alive, but not well.
14:49Caroline Steel:For more, listen to The Global Story on BBC.com or wherever you get your podcasts.
15:01Caroline Steel:You're listening to CrowdScience from the BBC World Service, the show that chews over your science questions. Our listener Dale wants to know why there are incredible differences in tongues between species. So far, we've visited a king cobra with a long skinny tongue and some noisy parrots with bony tongues. Now it's time to turn to us mammals. Have mammals evolved any unusual tongue adaptations?
15:29Kurt Schwenk:Most mammals don't have bones in their tongue. It's all muscle.
15:34Caroline Steel:This is Callum Ross, our expert in feeding systems.
15:38Kurt Schwenk:You lose the ability to protrude like a bony skeleton with the tongue around it, but you gain the ability to have very dexterous tongue movements within the oral cavity, within the mouth. So that's important for manipulating the food while you are chewing, positioning it between your teeth.
16:01Caroline Steel:I guess I never really thought about the fact that, because you do it so subconsciously, that you're using your tongue to get the food between your teeth. So if you were just sort of going to randomly chew and hope for the best, it wouldn't have a good success rate. So you need a tongue to kind of get the food in the right location.
16:18Kurt Schwenk:Yes.
16:19Caroline Steel:Our tongues are remarkably coordinated, which becomes very obvious the moment you accidentally bite on your tongue instead of your food.
16:27Kurt Schwenk:Mammal tongues are very fleshy. They've got a lot of muscle and the muscles range in a very complicated way. The muscle fibres are imbricated.
16:37Caroline Steel:Which means the muscles in our tongues overlap.
16:40Kurt Schwenk:Kind of like a basket work of muscle fibres. There's vertical ones, there's transverse ones, and then there's longitudinal ones. And those are inside the tongue. And using those, you can change the shape of the tongue in very complicated ways. and so that's something that mammals have that most other lineages of vertebrates don't have.
17:01Caroline Steel:Yes, it's kind of impressive that not everyone but a lot of people can roll their tongues and make all these incredible shapes I imagine a giraffe might struggle with.
17:11Kurt Schwenk:Yes, well a giraffe can certainly stick it out a long way and roll it.
17:16Caroline Steel:But they probably can't go like this, you know. It's a shame this is audio only. I'm currently showing off my tongue rolling skills.
17:24Kurt Schwenk:No, they probably can't, although I don't know if you've ever asked one.
17:28Caroline Steel:I haven't, that's true. Well, it's time to remedy that. Let's go back to the zoo. Oh my goodness, I don't think I've ever been so close to a giraffe. It's maybe half a metre away. Oh, and I caught a glimpse of its tongue. We're stood in front of two giraffes. And they're leaning over towards us. Is that because you've got some leaves in your hand, do you think? Yeah, definitely. They're like, excuse me, why are you holding my breakfast? Yeah. This is hoofstock keeper Nick Garrett. And we are trying to learn about different animals' tongues because our listener wants to know why different animals have such a range of tongues.
18:08Caroline Steel:I don't think I know much about a giraffe tongue other than it's grey, is that right?
18:13Kurt Schwenk:Yeah, so it's sort of grey, purpley, black colour. Basically, when the sun's out, they're feeding. and obviously in Africa they need some protection from the sun. So yeah, that's why the tongue is that colour so it doesn't get sunburned when it's out browsing all day.
18:30Caroline Steel:Whereas if it was a lighter colour it might get burnt. Okay, and then do they feel like a human tongue? Have you ever felt a draft tongue? Yeah, no, I've been licked a few times. Very, very slobbery tongue, so they have a lot of saliva on the tongue
18:44Kurt Schwenk:and it's actually got antiseptic properties. so obviously in Africa they eat a lot of acacia so lots of thorns so occasionally they do get
18:53Caroline Steel:cuts and scrapes on the tongue but yeah they've got antiseptic saliva so helps it heal quicker oh they're saying hi to each other that's very cute and they have quite long tongues is that
19:05Kurt Schwenk:right yep so yeah about sort of 45 centimeters yeah should we have a look should we yeah yeah feed some of these leaves to...
19:16Caroline Steel:Whoa, her tongue is so long! And she's sort of wrapping it around to pull the leaves off.
19:22Kurt Schwenk:Yep, so they're fully prehensile, so they can grip things. And why do you think giraffes have such long grey tongues?
19:32Caroline Steel:Do you think it's an evolutionary advantage to be like that?
19:34Kurt Schwenk:Yeah, I think it just helps along with the neck. They can already reach stuff that other animals can't, but then they've got the tongue as well. It just helps them pull the branches closer to their mouth and grip the leaves, pull the branches in.
19:49Caroline Steel:So they can access food that's even more out of reach.
19:53Kurt Schwenk:Yeah, and they can wrap their tongue around a branch and then pull it back, taking all the leaves with it.
20:00Caroline Steel:Sort of strip the... Yeah, just strip the leaves. Which is exactly what's happening now. You handed her... Oh, there we go. You handed her a bit of branch with leaves on and she's just dropped a completely bare branch now. Oh, wow. The way she uses her tongue is incredible. So cool. Could I have a go at holding the leaves? Yay, I'm going to feed a giraffe. I'll give you a smaller bit. Thank you. Would you like some leaves? Hold quite tight. Okay, holding tight. Pull it all out of your hands. Oh, my God, her tongue is so strong. So she's pulling. She got the whole branch.
20:37Caroline Steel:feeding a giraffe is an experience i'm definitely going to remember they coil their long tongues around branches and then strip off the leaves with remarkable speed and precision mammals tongues can
20:50Kurt Schwenk:be incredibly impressive if you think about that a moment and think about both how much they can move and how complexly they can move and their ability to elongate and to change shape they do it in a way that's completely different from the kinds of movements we're used to.
21:08Caroline Steel:This is evolutionary biologist Kurt Schwenk again.
21:11Kurt Schwenk:So when we move an arm or a leg, it's very understandable. We have bones and muscles. Muscles move the bones. The bones are hinged at joints. And so we have a simple lever system that is familiar to most people who are using levers every day, you know, whether they're conscious of it or not. The point being that for most movement, muscles and bones interact to create movement. In the case of tongues, there are no bones, no joints, no levers. The tongue is pure muscle, and yet it's able to elongate, change shape, exert force, do finely controlled manipulations. and it's doing that all on its own.
21:59Caroline Steel:Our tongues are incredible shape-shifting structures, a bit like an octopus's arm or an elephant's trunk.
22:06Kurt Schwenk:Organs that do these kinds of movements using only muscle, they're called muscular hydrostats. But we can simplify that and just think of them as something like a water balloon. So imagine yourself holding a balloon that's kind of a long, narrow balloon. and you filled it with water. And it's important to recognize that balloon, it's elastic and stretchy, right? And it's filled with fluid, but water, you can't squeeze water and compress it, right? Like it doesn't matter how hard you push on it. It's not going to get any denser or smaller or compact. It's going to stay exactly the same. The water in your water balloon, no matter how much you squeeze on that water balloon, the volume isn't going to change.
22:55Kurt Schwenk:And the only way it can go is to stretch the balloon out and make it longer. So when you make it narrow, it gets long. When you make it wide, it gets short.
23:09Caroline Steel:Yeah, so your tongue sort of has a set volume. If you want to make it stick out, you have to make it narrower. And if you want to flatten it, you have to make it shorter, a bit like a water balloon it has a sort of fixed volume.
23:23Kurt Schwenk:Exactly that's exactly right and so all of this dramatic tongue protrusion we see in giraffe tongues comes from these kinds of internal manipulations of the musculature that changes its shape.
23:37Caroline Steel:So when a giraffe tongue is resting in its mouth it's short and fat and it narrows and lengthens when reaching for leaves. But mammals tongues aren't only for capturing and chewing food. Here's Callum again.
23:51Kurt Schwenk:One of the things that the tongue does is push the food back across the oropharynx into the esophagus during swallowing.
23:59Caroline Steel:Our esophagus is the tube food travels down from our mouths to our stomachs. And the oropharynx is the shared passage at the back of the mouth.
24:09Kurt Schwenk:So the oropharynx is important because it's the place where the airway and the foodway cross. You breathe through your nose and that goes down into your trachea, which is in the front, through the larynx. But the oesophagus is in the back, so evolution has seemed fit to have this crossing area.
24:28Caroline Steel:Yeah, it doesn't seem like a good idea.
24:30Kurt Schwenk:Not the best work it ever did. The tongue is super important for quickly pushing the food across the top of the oropharynx and into the oesophagus.
24:37Caroline Steel:Yeah, I mean, we have our tongues to thank for not sort of constantly, accidentally inhaling our food.
24:44Kurt Schwenk:Yes, exactly right. And the timing is super important. People who've had strokes who can't swallow properly, they can get pneumonia because they inhale food particles into the lungs. So the function of the tongue during swallowing is very important. And we wanted to know what was the mechanism whereby the tongue pushed the food back across the top of the oropharynx.
25:07Caroline Steel:Callum uses a technique called XROM to study tongues. It involves using x-rays to reconstruct the movement of tongues in 3D.
25:16Kurt Schwenk:One of the mechanisms that's used in swallowing is this kind of narrowing of the tongue. And if you constrict it sideways and it's in this closed box, some of the tongue has to go out the back. If it's closed in the front, right? That's why you can't swallow with your mouth open.
25:35Caroline Steel:I didn't know you can't swallow with your mouth open
25:37Kurt Schwenk:It's really hard
25:38Caroline Steel:Why not give it a go? Open your mouth and try to swallow Yeah it is really hard isn't it? I didn't realise quite how important tongues were for swallowing But yeah sitting here now trying to swallow with my mouth open I'm like Good luck Very difficult We could probably do a whole episode on why you can't swallow with your mouth open. But here's the top line. When you swallow, your tongue has to go backwards so food can go down. It does that by pushing against your front teeth, which is much easier when your mouth is closed.
26:17Kurt Schwenk:Better understanding tongue mechanics will help us treat people who have various kinds of dysphagias. So dysphagia is difficulty swallowing or disordered swallowing. and that is associated with a fair amount of sickness and death because people get pneumonia because they're not pushing that food across the top of the larynx properly. So a better understanding of tongue mechanics will help us develop different ways for treating people who've had strokes or tongue cancer and had pieces of their tongue taken out.
26:47Caroline Steel:Listener Dale, you wanted to know why you've come across so many different animals' tongues. The variety is particularly surprising when you consider all tongues evolved from the same basic structure in an ancient aquatic ancestor that first ventured onto land and suddenly needed a new way to eat. Since then, tongues have evolved to suit an extraordinary range of diets. Dale, your parrot had a finger-like tongue reinforced with bone to help manipulate and crack open nuts. And for us humans, tongues are essential for swallowing safely. and understanding them better could help improve the lives of people with difficulty swallowing.
27:25Caroline Steel:From swallowing to chewing to catching prey and even smelling, tongs are one of evolution's most versatile tools and they're critical to survival. And finally, over to you, Dale, for the credits.
27:38Kurt Schwenk:That's it for this episode of CrowdScience from the BBC World Service. The question was from me, Dale, in the United States. The show was presented by Caroline Steele and produced by Joe Glanville. If you have a question on any subject in science and you want the team to investigate, why not email proudscience at bbc.co.uk? Goodbye.
28:05Caroline Steel:Thank you, Dale. Plus, one more thing. Excitingly, we now have a WhatsApp number. Please send us your questions or even send us a voice note. Our WhatsApp number is plus 44 8000 314 773. That's plus 44 8000 314 773. Right, this really is it. Goodbye.
28:32Caroline Steel:The United States is about to mark its 250th anniversary.
28:37Kurt Schwenk:And so on the Global Story podcast from the BBC, we're telling surprising tales of American influence on the world stage and in ordinary people's lives all across the globe. We have this ability to export our story and a lot of people have bought it.
28:53Caroline Steel:I feel like the American dream is alive but not well. From the BBC, it's the United States at 2.50.
28:58Kurt Schwenk:Listen on bbc.com or wherever you get your podcasts.
From the publisher
Why is there such a variety of tongues in the animal kingdom? CrowdScience listener Dale has observed that his dog’s tongue is different from his and so is his cat’s. He’d like to know the reason.
Caroline Steel visits London Zoo in the UK to find out more about the different types of tongues - from giraffes and birds to lizards.
She talks to evolutionary biologist Kurt Schwenk, who explains that the development of tongues made it possible for animals to make the leap from the sea to life on land. Fish could rely on water to help them swallow food, but air and gravity required a whole different mechanism for having dinner.
But why is there such a variety of tongues between species - from the forked tongue of a snake to the rough tongue of a cat? And does it all come down to our diets?
Researcher Callum Ross reveals how he’s pioneered a new technique for investigating how animals use their tongues when they eat and drink, and why tongues are so important for swallowing.
Presenter: Caroline Steel
Producer: Jo Glanville
Editor: Ben Motley
(Photo: Giraffe licking its lips - stock photo - Credit: laurenepbath via Getty Images)