SciShow Tangents - Build-A-Human Compilation

Episode Date: August 12, 2025

For all you aspiring Frankenstein's out there (that's the scientist, not the monster, you know we gotta be accurate on Tangents), may this compilation guide your mad scientist tendencies as we learn about some of the most essential body parts (butts obviously included).Episodes in this compilation:S2 E4 - Bones, original airdate: December 3, 2019S2 E14 - Hearts, original airdate: February 11, 2020S3 E30 - Brains, original airdate: September 21, 2021S3 E48 - Butts, original airdate: February 15, 2022S4 E20 - Skin, original airdate: August 9, 2022Sources for each episode can be found in the descriptions of the original episodes on your preferred podcasting platform.SciShow Tangents is on YouTube! Go to www.youtube.com/scishowtangents to check out this episode with the added bonus of seeing our faces! And go to https://complexly.store/collections/scishow-tangents to buy some great Tangents merch!While you're at it, check out the Tangents crew on socials:Ceri: @ceriley.bsky.social@rhinoceri on InstagramSam: @im-sam-schultz.bsky.social@im_sam_schultz on InstagramHank: @hankgreen on X

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen this week. As always, I'm joined by Stefan Chin. Hello. What's your tagline? The back of your leg is always clean. Boom, take that haters. Sam Schultz is also here.

Hello. What's the longest thing you can think of? A blue whale. That's good. Yeah, blue whales are pretty long. Yeah, I bet they're like, there's some walls that are like the great walls. The great walls, big. Human intestines.

They're super long. DNA. But not as long as a blue whale, right? How big are they? Blue whales are longer than intestines. Uncoiled. They aren't, though. They're like 20 feet.

Oh, okay. That's pretty short. You guys are thinking small, though. I was like the length of the time that the universe has been around. That's time. That's not a thing, though. Try again. One more time.

What do you mean? Longest thing you can think of. Intestines. Say, what's your tagline? Hey, Colgan, man. Sarah Riley has joined us today, too. What's your tagline? Big City Farts.

That's my type of tagline right there. What's different about a big city fart? Versus a country fart. I don't know. You know, the microbiome's different. You leave the country. You go into the big city. You have big dreams.

You have big farts. And I'm Hank Green. My tagline is darkness is always waiting for you. Oh, come on. True, but depressing. Every week here on SciShow Tangens, we get together to try to one-up a maze and delight each other with science facts. We're playing for glory, but we're also keeping score and awarding Sam Bucks from week to week. We do what we can to stay on topic, but judging by previous conversations, we suck at that.

And so if your tangent is real bad, we can dock you a Hank Buck. Now, as always, we introduce this week's topic with the traditional science poem this week from me. I wrote this poem about a real-life event that is happening right now in Montana. In Montana, a rancher once found, two dinosaurs dancing around. A company called and said, Quite appalled, those are our minerals in your ground. Years ago, you see, the rancher had talks. A company paid them to sign several docks.

And now the company cries, when the bones fossilized, they were no longer bones. They were rocks. So when you own a bunch of land in a place where there might be coal or oil or natural gas, you sign away your mineral rights, but you keep the surface rights. so you can keep having the water and all the stuff to make your crops and your cows and stuff. So the rancher didn't actually find the bones, but this amateur paleontologist found this amazing dinosaur fossil find. Two dinosaurs locked in battle, died together, were fossilized together, different species, and it's like a million dollar find, and more than that. So the Supreme Court now has to decide whether these are bones, which would mean that they are part of the surface rights, or if they're minerals, which would make them part of the mineral rights.

because it changes who gets the money for the sale of the dinosaur bones. Oh, my God. How much do you get for signing away your mineral rights? A lot. But also, what you really are hoping is that they find something, and then you get very rich. They'll get a portion of the sale of the dinosaur bones if the Supreme Court decides that they're minerals, which I don't think they will. I think they're going to look out of them and say, those are bones. But, like, if they find natural gas on your land, like, if there's good fuel deposits of some kind, this makes you quite rich.

So it's a good idea to sign away your mineral rights generally. It's right there in the name, fossil fuels. They can add a comma. Fossils, fuels. The topic of today's tangents is not fossils or weird Supreme Court cases. It's bones. It's just bones generally. But I found out about that story, and I had to make a limerick about it.

Bones are... You should know this. You didn't. Yeah, they're mineralized... The sticks that keep us together. They're the sticks that keep us together. But you can have sticks that keep you together that aren't bones. Oh, yeah.

Like cartilage. Cartilage. And then you also have other skeletons that aren't bones, like outer skeletons like those have. Exoskeletons. Yeah. But bones are mineralized. They're basically mineralized cartilage. And they have stuff inside of them that makes stuff?

They have stuff inside of them that makes more bone and also that makes your blood. Thanks, bones. Well, we just ran out of places in the body to put. but the blood factory. And so we're like, well, all right, inside the bones. It is weird. Now that you say it,

it's very strange. It's like, what's going to make the blood? Oh, the bones? The creepiest thing. We'll make the other creepiest thing. We'll use the skeleton for that. I feel like it's also a very safe thing.

Like, you need your blood. So where are you going to hide it? In your bones. No, that's where I want to put my brain. Your brain should have been in your bones. Put my brain in my bones. The brain is in your bones. That's right in my bones.

I want it all the way. in my bones. But we have our spines, which are like bone and brain too. Our spines are kind of bone brain. So, Sarah, am I right about what bones is? Yeah, I think so.

I do have etymology of bone because I do look at that now. I only have a half answer for us. So if any linguists know the real answer, that would be great. It seems like the word bone is from an old English word for fuck.

No? I should have looked up how to pronounce it because I don't know how to do old English, but it's B, A. with a line over at N, which also seems like it would be pronounced bone, which is related to the Dutch bean and the German bine. Those are all in the same family. So, like, trace back to Germanic roots. But then, separately from that, in Greek, bone was osteon. And the proto-Indo-Europeans, which are hypothetical people for linguistic terms, use the root from the Greek word, like ost. So that's why we have osteoblasts. or osteocytes or osteologists or things like that. And I don't know how aust and bone became two separate things. They probably, it sounds like to me that we just named them twice.

Like the Greeks had it and we're like, here's a bone. And then the Germanic peoples were like, bone. And then we've merged. What do you guys call it, bone? Why do you call it that? Bone. What else are you going to call it? The bone's just a freaking bone.

Yeah. And now, it's time for... One of our panelists has prepared three science facts for our education and enjoyment, but only one of those facts is real, and the rest of us have to figure out either by deduction or wild guess, which is the true fact. And if we get it right, we get a Sam buck. If not... Then Sam gets a Sam buck. Then Sam gets a Sam back because it's Sam this time.

Hey, Sam, what's your facts? Giraffes are basically the biggest, boniest weirdos around. Okay. And to top it all off... This is just some giraffe facts for you. And at that but all off, they've been observed performing one of these very strange bone-based behaviors. Which is it? Number one.

They commonly gnaw on skulls, antlers, and other bones that they find just laying around. Number two, they can make low-frequency sounds at other giraffes here by conducting the vibrations in the ground through their skeletons and up to their ear bones. Or number three, the earth is a bell. Drafts have so much calcium in their bones that their skeletons glow through their skin if exposed to UV light. Ooh. That's cool. So our three facts. Giraffes gnaw on those bones.

Love them bones. Two, giraffes can hear low frequency sounds or make them. They can pick it up through the earth into their ear bones. What's making the sounds? Other drafts. Okay. So they're communicating through the ground, through their bones. And final number three, they have so much calcium that their skeletons glow.

through their skin. Does calcium glow under your blood? Well, I would Google that, but I'm not allowed. Not allowed. I will say all bones glow under UV light. Okay. But they have so much calcium. You got to have a lot of calcium if you're a giraffe

because you're very heavy and you stand on stalks. You made some poor decisions evolutionarily. No, they got to eat those leaves. Yeah, they just stretch them to get to those leaves. They need long bones. I know that animals gnaw on bones because it gives you those minerals. They crave that mineral.

Is that why dogs not on bones? No, I think they're looking for the nutritive value. They like the marrow and the sinew and stuff on the outside. Dogs had other dogs on TV chewing bones. Yeah. Got to get it on that. There's also just a chewing instinct, things like that. I like to chew myself, Doritos mostly.

You wear your teeth down on Doritos. If bones were made of Doritos, I would be a bone cruncher. Love that. But like really hard. Have you ever had a Dorito that's like three Doritos stuck together and it was like a mistake at the Dorito factory? And you're like, ah! Ah!

That's what it be like if bones were made out of Doritos? I would love it. Would it just be layers of Dorito like that? Or would it be like one thick Dorito? How many Cs in that? Two. Okay. Yes, that.

So I know animals not on bones. I know that happens. Herbivores do that too. Two, they can talk through the ground seems unlikely. That seems like something could do, but you're so long when you're a giraffe. That won't transmit. Yeah, all the way up all my bones. But you can feel, like, you can feel vibrations.

If, like, this couch was shaking, I could feel it in my bones. Yeah, but how do I, a giraffe shake the ground enough for you to feel it in your footbone? No, for sure. But what if it was like a whole family of drafts, like all running on sand together, then you can be like, Oh, my friends are here. My bones are telling me. That'd be nice. It seems like it would be hard to parse out giraffe noise from all the other things stomping around.

Maybe that's their special ability and their bones. I don't like that you guys think that that one might be it, because I thought that was one we could definitely write out. They also, like, they have very thin skin. Like, there's not a lot at the, like, base of their legs. I also love the idea of someone going out studying scorpions or something. I don't even know if the territory overlaps. And then accidentally shining. it up and be like, look, I can see a whole giraffe skeleton.

Well, you should probably answer. Okay, I'm going to go. I feel like gnawing on bones is kind of boring. I'm going to say the weird vibration one. Oh, wow. It sounds unrealistic, but I love the vibrating giraffes. I'm going to go with the gnawn bones, I think. I'm going to go with gnaw and bones, too.

I did this last time. I went with Stefan and I got it wrong. Well, it's the boring old non bones. But there's lots of really cool pictures of giraffes with entire like impala skulls in their mouths. They like suck on the bones and nobody's really sure why they do it. So the common thought is that it is to get minerals, but they have tested the dissolving quality of giraffe spit and they couldn't figure out a way that it would like get enough of anything out for it to be helpful. Huh. Yeah.

So they think that it might just be because they're bored. But they've also found that taller draps chew on bones more frequently than shorter draught. So it must be mineral-based. They must crave that mineral. They must crave the mineral. But they're not eating it, either. So they're not eating it? They're just gnawing on the bone.

Well, but some of it gets in there. Yeah, but not like, I don't think they think enough of it gets in there. That's for intimidation. Yeah, I mean, if I see some guy chew it on an impala skull, I will not walk up to him. What you just said reminded me of something I read, apparently camel bites dissolve bones, which is weird. Camel bites dissolve bones, which is weird. What? Is that even me? I don't know.

So there is a paper from 1989 where they said there are four cases of severe osteolysis, so like bones breaking apart after camel bite. What the hell? I don't know. Unliving people? I think unliving people. Is that what happened to Harry Potter? Is that how they make his arm go jiggly?

They had a camel in their trouble. They spit all over it. And so I was looking at how related camels and giraffes are, like maybe at some point an ancestor could dissolve the bones. Yeah, draughts just like a little crunch, evolutionary in their system. Number two, the low-frequency sound thing is actually elephants. So there's this biologist named Caitlin O'Connell, who has been studying this group of elephants since 1997. And her theory is that elephants use bone conduction to receive messages from further away than they could with just vocal communication. So she'll do experiments when she'll put speakers above ground and below ground and play different elephant calls.

And she'll look at how they'll react. and they can hear the underground calls and seem to actually position themselves so that they can hear the underground calls over the actual above ground sound. So they seem to prefer that method maybe of listening. My feet ears. Yeah, they have like a big pad of fat in their feet

that they can squish down, it seems like, to make them bigger on the ground, and the sound goes up to their feet and then into and rattles their ear bones. So they might be able to talk from like 20s, miles away with their like this like low rumble that they can do. My penis turned to green. I'm weeping pus from near my ears.

Dad, what is this? I'll be right there, son. It happens to everyone. And then the see-through bone glowing is chameleons. You can shine a UV light on chameleons and their bones seem to purposefully, like they have patterns that seem purposefully set up to, for things. things that can see UV to be able to see. So they'll have like bones pop through their face in certain places that make ridges and stuff. And like you can see their ribs right through them.

Yeah, I can. I'm looking at a picture of it. And they just found a type of frog called the pumpkin toadlet that has big plates of bones on its back that look like they make patterns too. But they're not quite sure what all of this means yet. They're not quite sure what all of this means yet. The story of human existence. Next, we're going to take a short break And then it'll be time for the fact off

Welcome back, Sam Buck Totals. Sarah, you have nothing. Sam and Stefan are tied with one, and I've got two. I haven't been winning in a long time and I'm really lucky no one docked me from my weird Doritos tangent I was into it. I was thinking about it but I do know the

scores. Me and you are tied at five and Stefan and Seri are tied at seven. Oh. Never mind that. I was like how are you both ahead again? No, no. We're tied for last. Oh, okay. Yeah. And now it's time for

the fact off. Where two panelists have brought science facts to present to the others in an attempt to blow our minds We each have a Sam Buck to award to the fact that we like the most. And this week, it's Sari versus Stefan. And who goes first to be determined by who can tell me the average human baby has how many more bones than the average human adult? 112. 112.

More? In a baby than an adult. Yeah, I think it's a lot. I'm going to say 64. The answer, 94. So you went over, Sari. So Stefan gets to choose who goes first. I pick Sari.

So, Sarah, what's your fact? There's an extremely weird caprid, which is a subfamily of bovines. And this particular one is actually more closely related to a sheep, but it's called a goat, called myotragus, bellericus. That's now extinct. And this goat lived exclusively on what's now the island of Majorca for what seemed like 5.2 million years until humans arrived on the island around 3,000 years ago. and killed them. And scientists are kind of confused as to how it lived so long because the adult myotragus were around 18 inches high. The babies were around the size of a large rat and took maybe 12 years to grow up. They had relatively small brains and tiny front-facing eyes to save energy.

And their skeleton-made scientists think that they weren't able to run, jump, or move fast around. But their likely were predators on the island because there wasn't a lot living there because it was so nutritionally poor and barren and blah. And so even weirder than all that, all mammals and animals that can generate their own heat, have uninterrupted fast growth of their bones because we eat and grow pretty much continuously. But the bones of this goat were different because they had interrupted growth and what's known as lamellar zonal tissue in the cortex of their bones, sort of like the rings in a tree, which is a trait that was otherwise just in ectothermic reptiles. So basically these goats had the growth and metabolism rates of a crocodile

where they adjusted to the food and temperature available and like sunned themselves and their growth changed based on the resources available. And this probably let them survive times of scarcity, which is why they could survive for millions of years on this very bad island. I am so mad that we can't look at one of these things and study it.

Are they sure that they just don't have weird? bones? I think they're pretty sure. I think they're because they were studying doing micrographs of them and really looking at them on a molecular level. And the scientists were so shocked because it's like this is not typical mammalian bone tissue. This looks like a lizard. And it explains like the big mystery of how did these very bad, bad, bad goats live for so long on this island. And it's because they didn't need that much food or they, I don't know, just slow. Man, I want these goats so bad. Stefan, what's your fact? So a team at MIT wanted to create a device that's kind of like Siri or Google Assistant, but that was like more seamlessly integrated into you. I felt like more of an extension of your brain. So they developed this headset that goes around your ear and extends down to the jaw.

So it's not over the ear, it's not in the ear, it goes around the ear. And using this device, you can silently interact with different things. Like they have a video that shows someone like controlling their Roku. But they had people like playing chess, like doing math, like all kinds of stuff. So to someone who's not wearing the device, all of this interaction seems silent. It's completely silent. So what's happening is when you read silently to yourself, you're doing something called sub vocalization. Even if you're not mouthing out the words, your intent to speak is creating tiny muscular movements.

It's not even movements necessarily. It seems like, so in the paper, it says that this thing is picking up on ionic movement caused by muscle fiber resistance. And I don't really know what that means. Sure. But they pointed out that this is better than EMG. Like, EMG can't. What's EMG? That's normally how you would read like muscle activation.

Oh, okay. It's like the electrical activity happening. But they describe it as, it's sort of similar to how, like, some modern prosthetics work where you sort of think about what you want to do. and the device can interpret that motion and, like, move the prosthetic. So it reads those signals from your jaw, which apparently is the strongest and most reliable place to read that. And then it performs the action. But then to communicate back to you, it uses bone conduction headphones. And so that's the part that's around your ear is it's just vibrating the bone behind your ear.

That's part of your skull, and that goes right into your ear. And so you can hear the little Google Assistant or whatever speaking to you, but it's completely silent. And this is apparently how we can hear underwater is through this bone conduction. Like, because without the air, like, apparently our eardrums are not are pretty useless. Which is just like elephant feet. And elephant feet. And baleen whales, which I think we've talked about before. Oh, yeah, because it vibrates some kind of goo inside of their neck or something.

Yeah. And it's also, apparently, they communicate at such low frequencies that the wavelengths are, like, longer than their bodies. And the tiny eardrums are too small to pick those up. And so they have to, like, use the whole skull as, like, the thing that receives that, yeah. Yeah, that's cool. So I have a Google assistant and I communicate with it, but I don't like it. I don't want to. I don't want to say the words and I don't want to talk to this thing that I know is not a person.

I find it weird and I feel weird not saying thank you to it, even though I know it's not a person. I don't know. There's something weirdly social, even if I'm alone about talking. I want to be able to not say it but control it So this makes a lot of sense to me All right, you want to give your point away? Sure, do you want to give your point away? I do.

Okay. I thought it was going to be easy, but Stefan made it hard. Three, two, one, Sary. Well, not that hard, apparently. It was so good. I thought when you said that you were going to give it to Stefan, so I was going to give mine the Sari. Oh, okay.

You can't gain the system anymore. You can't get the system. You just have to admit that you love these goats. I do love to protect them with your whole life. Now it's time to ask the science couch. We've got a listener question for our couch of finally honed scientific minds. It's from Hippie Jack 3 who says, how did bones evolve? Like, specifically, how did tissue come to incorporate calcium?

Did teeth evolve separately, or are they somehow different from other bones? The evolution of bones, I found, is very contentious. Ooh, wow. Almost, like, a sliver of hope in me was like, there has to be an answer. It's all over the place. So once upon a time, the bone fairy came to Earth and was like, some of you have bones now. But the bone fairy was really tectonic plate shifting. What?

5 billion years ago. Yeah. No, that's what they called the bone fairy. So those shifted, which resulted in a lot of minerals like calcium carbonate, ending up in the ocean, which then at some point organisms started to incorporate into them, which made things like shells and spines and other hard body parts, which led to a huge increase in organism diversity. And then, question mark, question mark, question mark. Fast forward a billion years.

Bones. So one paper that I was reading said that all types of mineralized tissues found in living vertebrate, so bone, cartilage, enamel dentine, seemed to appear fairly simultaneously on the fossil record around 420 million years ago. Parentheses, blaze it. I know that joke. Parentheses blaze it, she said. I'm so proud.

But the big source of a lot of controversy is a material called Aspidon. People have been arguing for at least 160 years about what it is. Basically, it's a tissue in, I think, a paleozoic species or a group of animals called the heterostrachan. Fossil, armored, jawless vertebrates. Oh, okay. What kind of fish you're talking about? They have the ones with the helmets on their head, kind of? Yeah. Okay.

The tissue forming most of their skeleton is called aspidin. And on a microscopic level, aspidin is crisscrossed. It has like a bunch of tubes inside, like little holes. That is what scientists are arguing about. Like, are they cell spaces for bones? So like in our bones, there's room for marrow and bone cells inside so that you can generate more bone. Are they spaces for dentine? Are they like super, super tough?

Do they have like attachment fibers like collagen inside? Do they have other things? So, like, without knowing what is inside it, we don't know how to classify it. Like, is it a precursor to all the tissues, the mineralized tissues that differentiated? Or is it, like, the original bone? And no one seems to have come to a conclusion, but it's very interesting to hear, like, all the arguments one way or another if you care about this kind of thing. I do. People just, like, get really firm in their papers.

It's like, this is wrong. Instead, we propose that aspidin is the earliest evidence of bone. And you can hear, like, their scientific mic drop. There's another person being like, no, no, no. It can't be. But aspenin is not something that still exists. No. There's also some discussion about accellular bone versus cellular bones.

So cellular bone being bone that has bone cells that produce more bone inside versus a cellular bone where the bone cells are like away from it and then they deposit the cells elsewhere is from my understanding. Anyway, teeth are even more complicated. You don't know when they came about relative to the other parts of the skeleton. We've been studying tooth-like structures and jaw bones and fish.

Like, fish is where all this research is being conducted. There are two big camps that I could find. The inside-out hypothesis is that teeth came first, and then exoskeletons of fish came later based on the teeth. But then other people are like, no, it's the other way around. We had jaws first and then teeth.

If only we were around 420 million years ago, we could just look. But we weren't because bones didn't exist yet. But this is making me think, so if you found a planet that didn't have tectonic activity to deposit all that calcium in the ocean, then you're just going to have a bunch of soft, squishy creatures living on that planet. Though there's nothing wrong with a squishy creature. There's still plenty of squishy creatures out there. So the answer is there's no answer. The answer is we do not have a good idea.

We just not a fish for the original bone havers one way or the other. Yeah. Okay. And there's probably just like there was a bunch of calcium around. And so at some point life accidentally mutated to absorb some of that calcium. Oh, there's a part of my body that's hard now. And that is helpful. Every teenager's experience.

Oh, God. If you want to ask the science couch your questions, you can follow us on Twitter at SciShow Tangents, where we'll tweet out topics for upcoming episodes every week. Thank you to at I'm going to take a nap and at Shanna Gecko. And everybody else who did it is your questions this episode. Sam Buck final scores. Seri with two. Me with two.

Sam with one and Stefan with one. That's all right. That's fine. That's okay. I don't care. I'm back with a vengeance. Yeah. If you like this show and you want to help us out, it's really easy to do that.

First, leave us a review wherever you listen. That's helpful, and it helps us know what you like about the show. Also, we'll be looking at iTunes for topic ideas for future episodes, so you can leave those in your reviews as well. Second, you can tweet out your favorite moment from this episode. And finally, if you want to show your love for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green.

I've been Sarah Riley. I've been Stephen Gin. And I've been Sam Shultz. SciShow Tangent is a co-production of Complexly and the Wonderful Team at WNYC Studios. It's created by all of us and produced by Caitlin Hofmeister and Sam Schultz, who also also edits a lot of these episodes, along with Heroku Matsushima. Our editorial assistant is Deboki Chakravardi, and our sound design is by Joseph Tuna Mettish. Our social media organizer is Victoria Bonjourno, and we couldn't make any of this without our patrons on Patreon.

Thank you, and remember, the mind is not a vessel to be filled, but a fire to be lighted. but one more thing the tail the beautiful bony crown that makes a butt really shine but sometimes the tail can be a liability and that's why lizards some lizards have developed the ability

to detach their own tails in emergency situations also known as autotomi which means self-amputation and then they can grow them back later however and this may be something that everybody else knew but it never occurred to me. They can't grow their bones back in their tail. So they basically just have like a weird dumb tail.

It's just a tube of cartilage with like bad skin on it. Because they can't, they haven't figured out how to actually regrow the bones. Huh. And I couldn't figure out why they even needed it again in the first place. Just in case they need to throw it off again. Well, there you go. They store fat in it. I guess that's true.

You have to have the stick to put the fat on. Like a but corn dog. Hello and welcome to Syshow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series Syshow happen. This week, as always, I'm joined by Stefan Jen. Hi. What's your tagline? Give me the fizzy. Sam Schultz is also here.

Hello. What's your tagline? Sweet little grandpa. Sarah Riley is here as well. And what's your tagline? Unicorn piss. Oh, shit. That's the best.

That's a direction. I don't look in my brain. That's the way to do it. All you people come in and prepared, violates the sanctity of the tradition. The panic and then say something. My tagline is, the sanctity of the tradition. Yeah, but one time your tagline was like yellow pants or something. Yeah, and then the next time I was like, green pants.

Every week or unsouchoed tangents We get together to try to one-up a maze And Delight each other with science facts We're playing for glory But we're also keeping score And awarding Sambucks from week to week We do everything we can to stay on topic By which I mean not really

But if you go on a tangent And the rest of the team deems it unworthy We can dock you a Sambuck So tangent with care Now always we introduce this week's science topic With the traditional science poem This week from Stefan Step into this atrium

of inquiry and science. Ooh, I like it so far. And let's take a look at one of the organs that's inside us. It's wondrous and constant, this four-valve appliance, upon which we've got quite a dire reliance.

Our steady hearts carry on, keeping up the pace, delivering oxygen and removing metabolic waste. A regular hum of badam-badam, pushing blood through the veins. A hearty thanks goes out to this

pump for maintaining such consistent flow rates. But the heart's where you feel the burden when love goes down the drain. And it also sometimes gets to hurting when you eat too many spicy chicken wings. But if you decide you want to run, it also picks

up its speed, because it knows that I've got a ton of hungry cells to feed. That's right. Thanks heart. You just rhymed drain with wangs. Hell yeah. Well, that's how I say it in my everyday life. Yeah, you do. I need some chicken wangs. Yeah.

You'd say that all the time. Yeah. So it is Valentine's Week here in the world, in America. I don't know how widely Valentine's Day is celebrated, but we wanted to do a Valentine's Day-ish thing. So we're doing hearts, but not like the metaphorical kind, the physical ones. And what is a heart, Sari? It's like part of your circulatory system. It is made of cardiac muscle, which is different than the skeletal muscle on your bones and different things.

It has four chambers like Stefan's poem. Not always. Well, okay, the human ones too. Mammals, many birds. Reptiles, you start getting into three, other organisms. You get like five squeezy bits that you call a heart. Yeah, and sometimes you get more than one heart in an organism. Octopi have three.

What about animals that have that hemolymph stuff? Yeah, sometimes animals move their blood around with hearts, and sometimes they move their blood around other ways where they just contract their body tissues to shove. blood around. But that like a heart is a sort of a centralized system for moving like oxygen containing fluid through a body. Or to get that fluid to be oxygenated. Yeah. Yes. That is an important part. Yes. Because your heart like system like pumps it from your body into your heart to your lungs back into the heart back out into your body. This feels like one of the only episodes where we've like been able to definitively say this is. This is what this thing is. It's hard to argue about what it

Yeah. I'm sure that there is somewhere in the animal kingdom, some animals that have, like, weird, not quite heart tissue stuff. That's like worms and stuff. We'll talk about them later. But they have like heart-ish tissue that squeezes and that helps move blood around. And so some people call them hearts and some people are like, meh. Why not distribute the heart and just have all of my arteries and veins do like, blah, blah. That's what our intestines do.

Yeah, the way my intestines do it. Some peristalysis. That's the word I was looking for. Wow. I think it's because the heart is so energetically taxing. So our cardiac muscle cells contain way more mitochondria than the rest of our muscle cells because our heart never stops. We can contract our muscles, but we can relax the rest of them. But if your heart stopped contracting, you would die.

And that's like what happens during cardiac arrest. Well, that's like rhythm getting messed up. But the energy it takes to have our inhumans for chambered heart that can contract so regularly is a lot. So we have mitochondria generating a lot of ATP. And if all of our blood vessels were aligned with that, we would probably need to eat so much and probably also sleep a lot to recover from that. I love both of those things. You got the entomology of the heart? I did look at that.

It all sounds like from words that look and sound sort of like heart, but it has relatives beginning with card and chord from Greek and Latin and French. So that's where like cardiac comes from. But also other words like accord and discord and record. Those come from relationships between people. So like accord is harmony between people. And so it's like an agreement of the heart. Oh, that's lovely. Never touch your heart to another person's heart, though. Will they, like, shock each other? No, it's just gross. You've got to open your whole rib cage. It's hard. Which brings me to my...

We've got a panelist. It's me who's prepared three science facts for our education and enjoyment, but only one of those facts is real. And the other panelists have to figure out either by deduction or wild guess, which is the true fact. If you do, you get a Sam Buck. And if you don't, then I get your Sam Buck. and I would like to tell y'all about open heart surgery. So this started being done a while ago and really sort of gained prominence and was done frequently starting in the 50s.

So here's the thing. Open heart surgery, just for clarity, it's not when the heart is open. It's when the chest is open. So it is open heart surgery. You're usually doing heart surgery on the heart or the circulatory system when you're doing this. But there's a problem, which is that you don't want to do a surgery on a thing that's moving around. So you stop the heart during open heart surgery, but you don't want to stop a heart because

that and people die. So the patient's heart has to be stopped, but then you have a machine called a heart-lung machine that takes over the job of circulating and oxygenating the blood. One of the pioneers of open-heart surgery was Dr. Clarence Walton Lilla Hay, who performed his first open-heart surgery in the 1950s. And while techniques since then have come a long way, thankfully, it made the process safer, Dr. Lila Hay took advantage of what was available at the time to make his life-saving surgery possible, including one of the following strange but true approaches. Back number one, Dr. Lila Hay enlisted the help of a local ice cream parlor studying their soda fountain because he wanted to understand how it moved liquids around and combined it with the carbon dioxide gas, adapting that soda machine into a machine that would transport an oxygen.

oxygenate the patient's blood during the surgery. Number two, Dr. Lila Hay would cool down the operating room to a frigid temperature before beginning surgery. So the patient would lay in the room as their body temperature decreased, allowing for them to have more time to do the surgery before the brain damage would occur. And then it would come in and all the nurses and doctors would be dressed warmly to do the surgery. Or fact number three, Dr. Lila Hay recruited a person to serve as the human heart-lung machine connecting the patient to the donor through a pump so that the patient's blood flow would be routed from their body into the donors where it was oxygenated by their lungs and their heart and then pumped back into the person who was having the surgery done on them. That is the one that I hope is the one. So we've got, he was inspired to create a heart-lung machine by an ice cream parlor soda fountain or fact number two. He cooled down the temperature to keep the patient hypothermic so that they wouldn't go brain dead as quickly.

Or number three, he used a person instead of a heart-lung machine to be a living blood oxygenator. Can you explain number two to me why that helps? So when your body slows down, like your metabolism slows, and your body doesn't use the oxygen up as fast. So the existing oxygen in the tissues would last longer, allowing them to do like 15 minutes of surgery instead of five minutes of surgery. So they still have to work really fast. And we do that now, sort of. With some things, slowing. Yeah, I feel like you've talked about it in previous brain-related something maybe.

It's like in like, like, hardcore trauma situations. Right. When you have to do a lot. Yeah, a lot of stuff to fix the people. And things are broken enough that you can't just stick them on a machine. Okay. So that sounds plausible. I really wanted to be hooking up to a different animal, though.

I just imagine, though, like that. It's a person. A person, right? When I was running through it in my mind, I was like, you could do it like a cow, like whatever. Yeah. Whatever. They got so much blood. Yeah.

It would have to go into their arteries and veins, so the blood would mix. Yeah, well, that could be good. Yeah. Well, yeah, get some cow blood in there. That never goes wrong. Don't put cow blood inside of you. I'm not a doctor, but I know that that's bad. Well, it'll happen.

It's probably okay. That one where you hook somebody up to you sounds very familiar to me, but I feel like it's from like a Star Trek or something. Yes, man, Mad Max. Maybe that's what I'm thinking of. But I feel like if you were hooked up to someone, like if you were the human blood machine, person, you would have to breathe a lot more, right? And your part would be pumping harder.

Oh, yeah. Seems like you got more distance to go. You've got to be some hazard pay maybe. I don't know. Siri, what seems to the most plausible? Yeah, you're being really quiet. I don't know. I'm only trying to wrap my head around these

because I'm getting two in my head about them. Like, this sounds plausible, but this part sounds fake. And that's how I lose truth or fail every single time. You really should get this one right, I feel like. I feel like I should, but that is the pressure that I feel every episode. The cold one makes sense to me.

me for the reason Stefan described but that also feels like it makes a good lie I'd be worried about open heart surgery being cold like maybe the emmergyzor burning your dang heart oh and like the surgeon like when I'm trying to play games and my apartment is cold ooh like you lose finger dexterity

like oh you're right you're right it's bad I also think that the human sounds really cool I feel like it wouldn't be additional strain beyond like exercise and there are probably family members that'd be like oh yeah I would give my blood i would stand in the surgery room is that too complicated a thing for them to have done back

then probably not i guess i don't know we did almost on the moon that's true we were a decade off from the moon or two or whatever i don't know yeah i feel like people did blood transfusions just like person to person instead of like blood bags so they would be like here's my blood that is now used for trauma medicine but used to be like the standard for that kind of treatment the soda one it sounds so dumb It doesn't even sound like you'd have to, like, go ask somebody who own an ice cream parlor. You'd just read about it in a book. Be like, oh, he's a doctor. He does a dude would know how it would work, right?

No, that's not. That one sounds like something that would happen in the 50s. When I didn't have the internet? Like, doctors are not engineers. And so, like, you'd have an engineer and designs a sodium machine. And then the doctor's like, how does this work? Maybe I can do something with tubes to let me work on the heart. I don't know.

I believe it even less than I did it before. Specifically, the dissolving. Like, how do you get carbon dioxide in? to soda versus how to get oxygen and I don't know where they would get if they had just like vials of oxygen probably I know nothing

the history is like squished into like one plane everything happened at the same time everything that happened before I was born it's the same so yeah I don't know I'm gonna make you guys guess I'm not going first you go first

I'm gonna choose the human pump man human pump man I'm gonna choose Oh, freak. The human heart man. Human pump man. Oh, no.

I'm going to choose. I don't like it, but the cold one, I guess. I don't want to give Hank three points. Sarah, you convinced them the right answer. You did it, and then you didn't get it. Oh, no. Well, not only did Sarah, you got it, like, it was almost always a family member. Yeah.

Oh. And, like, you had the whole, and it was like exercise. It was like a little bit of extra work. You're so smart. Yeah, you had everything right. I just didn't want the risk. I overthought it. Oh, man.

I thought my effects were so good this time. I mean, I was all on board with the SOTE fact. I thought that sounded super right to me. It fell apart under scrutiny, I feel like. So he did help create the bubble oxygenator, which went on to replace the human body pump. But it was not inspired by a Soda Fountain. Number two thing, they did used to, before,

Dr. Lila Hay, they would sink the patient into a horse feeding trough full of ice before doing open heart surgery. So that is pretty real, but they didn't probably, for practicality reasons, and maybe they didn't want to get their hands cold and, like, be bad surgeons. They didn't cool down the whole room. And then, yeah, so the real person, it was called cross-circulation, and he did over 45 heart surgeries on children using that system. And the donor was typically the parent. Little body. It'd be easy to support a child.

Yeah, no, no worries. They have very little blood. So the blood was rather from the patient's heart through a single pump to the donor's femoral artery and then fed back into the patient with the same pump. And that is similar to how a fetus

is kept alive inside of a pregnant person. Now part of the reason this works is because you don't need to have like 100% blood flow. So during the procedure, it was about one-third, to the normal rate of blood flowing through them. And 62% of the people who came in for this surgery were discharged from the hospital, which means that a lot of people did not live through it,

but they were people with very serious conditions that he was operating on. And 49% of those people were alive 30 years later, which is extremely impressive considering the severity of the conditions he was working on. But they moved away from it because of safety and ethics concerns for the donor, because it did turn out to be fairly dangerous. And one of the donors had some kind of an embolism, so like an air embolism that led to its stroke, and I think survived but was disabled because of it.

That had developed because of the process. Because of the donation process that they were using. So they invented the bubble oxygenator so that they could oxygenate blood without a pair of human lungs. I think we use those in fish tanks, too. I mean, yeah, it's actually very similar. Next up, we're going to take a short break. Then it's time for the fact off.

Welcome back, everybody, Sam Buck Totals. Seri has none. I'm tied with Sam with one and Stefan Scott, too. Now get ready for the first. Fact off. Two panelists have brought science facts to resent to the others in an attempt to blow their minds. The presentees, each have a sambuck to award the fact that they like the most to decide who's going to go first. We've got a trivia question. The blue whale has the slowest heart rate of any mammal. The fastest heart rate in the animal kingdom goes to the blue-throated hummingbird.

What mammal has the fastest heart rate of any mammal just slightly slower than the hummingbird? one, the mole rat, two, the hedgehog, three, the shrew, or four, the gerboa. Sam, you go first. What's a gerboa? It's the mammal with the fastest heart rate, in fact. Is it? You're going with gerbola? Sure.

Okay, he's going with gerboa. What do you think, Sarah? A shrew, maybe? Yeah, I would have said shrew. The answer is a shrew. Hey! Nice. There is an object that was put in a glass jar filled with maybe cognac or some

Brownish alcohol. It was not a gerboa. It was smuggled from Paris, France, to Warsaw, Poland in 1849, and as pretty much remained sealed in a pillar in a crypt at the Holy Cross Church until close to midnight on April 14, 2014, when 13 people, including an archbishop, a culture minister, and just two scientists, were allowed to look at it, taking over a thousand pictures and adding wax to the jar seal to keep it tight. That object is Chopin's heart because on his deathbed he apparently wanted his heart to be buried in Poland even though his body was in France because I don't know symbolism he wanted his heart to be in his home country and then it's very precious to them now because it's been protected this whole time and even this inspection was mostly kept secret with no released public photographs and those

two scientists getting to go were mostly because they were bugging it seemed like them to look at the heart because they wanted to answer a key question, which is what he died from. He was a sickly man throughout his life, but it's sort of a mystery of what disease killed Chopin from things like cystic fibrosis or tuberculosis. And ultimately, it would be great to do genetic tests to figure out what happened to the tissue. But for now, this like couple hour glimpse at his heart in the dark of night in secret in a crypt is the best we've got. The researchers say that the heart was massively enlarged and floppy. That's a quote. And had whiteish... It's a hundred years old. And had whitish fibrillary covering around the heart tissue,

which they attributed to a condition called pericarditis, which is inflammation that could have been the result of long-lasting tuberculosis. So the two scientists that actually took pictures of it and wrote a research paper as of 2017 said mystery solved, probably tuberculosis. That's where I thought my fact would end, but I was like double-checking just to make sure. There's a 2019 paper that says the things that the 2017 paper used to diagnose his death with tuberculosis need a closer examination. So like histology, some sort of tissue analysis, or even something non-invasive, like a high-magnification microscopy or a CT scan, or just like tipping the jar around to help tell whether the whitish deposits happened before or after the death. That doesn't seem allowed. Yeah, they're just trying to get in there.

That's what it seems like to me. This person's like, I want to see the heart. I want to see Chopin's heart. And shake it around. Why are these people see the freaking heart? To Polish people, it is like a very important artifact because he was such a great artist. That's fine. They'll be careful.

The Statue of Liberty is very important to America and we let people see it. Yeah, we hang out in their head. It's a little bit big, though, to like. Hide away. Or like drop on the floor. Yeah, I guess so. Hard to break. I think they're worried that the alcohol inside will evaporate.

That was my next question. I got to drink it. I just want to get drunk on Chopin's heart alcohol. That would be extremely powerful. Oh, my God. Excellent. Thank you. And it's Sam's turn?

Yeah. So I have a fun story that turns into not a fun story, very suddenly at the end. Cardiac catheterization. Is that he sick? Catherization. Yeah. There we go, is a procedure where a teeny catheter, aka a tube, is run through an artery or vein all the way to your heart. And there are lots of life-saving and preventative uses for this procedure, including installing pacemakers.

You can also perform angioplastys with it, and a variety of tests and measurements can be performed using a catheter. So basically, it's a vital part of heart medicine, but in order to convince the medical establishment that it was possible, its inventor had to go to extreme lengths. So Werner Forsman was a 24-year-old recently graduated doctor. He was like less than a year out of medical school, working at a hospital in Eberswold, Germany in 1929. And he was inspired by a medical illustration of a horse having its veins catheterized. And he started like scheming up ways that he could do that to people because he saw what it was helpful for on horses. Did it? They were using it actively on horses? They were doing stints and stuff in horses.

They could blow up balloons in there. So you'd think that if they were doing it on horses, that they would say, let's do it on people. But at the time, it was a commonly held belief that any tampering with the heart was basically insta death for people. I guess I thought their hearts were more important than horses' hearts. I mean, I guess they are. It's probably stuff with like the soul in human hearts. Maybe. What year was this?

1929. But that belief was something that had carried over from like the middle of the 1800s. Somebody had written something like, don't mess with this or you'll die. And then since then, it seemed like everybody was not messing with the heart. So pretty much there was like no progress made in heart research for a long time. So he tried it out on some cadavers and it was working okay. And when he was ready, he asked his superiors if he could start doing it on patients. And they said no.

So he conceived of a little plan. They said, no, you're 24. Yeah. Well, then he did what a 24-year-old would do. He convinced the OR nurse with the keys to the medical equipment storage room that his idea was really good and that she should help him. so she agreed to secretly help him in the middle of the night and she offered herself as a test subject

so he strapped her down he anesthetized her arm and made a cut then unbeknownst to her he sliced his own arm and started doing it on himself because he couldn't make himself do it on her I think like he didn't feel right about it so she was strapped down

and saw him doing it and she was like freaking out and he was shoving the thing up his own vein and he had cut a length that he thought was the length that would take to get to his heart and when he got to just about that length he unstrapped her from the table and they went to the x-ray room together

and they stood in front of the fluoroscope which is like a live x-ray and she held a mirror up to it and he finished shoving it in all the way because it was only to his shoulder so he had to keep feeding it and he could feel it hit his heart and he said it made him feel like he had the cough

and while he was doing this one of his friends found out he was doing it and they ran in and they tried to pull it out of his arm but then he quote overpowered that person And he got it in when I liked the chambers And it worked They didn't die instantly

So he told his bosses And he got in some hot water But they let him start trying it on patients And eventually he went to a bigger hospital To continue his work But he had been publishing papers That some people in the medical community didn't like And he was kind of fired with that explanation

So then he floated around Working at other hospitals Until World War II When he joined the Nazi Party I was wondering when the bad twist was coming. And he got captured by the U.S. really early on, I think, in hell as a POW until the end of the war. But during his imprisonment, a French and American doctor were using his research to, like, build upon. And they started to come up with all kinds of ways to use this process he had made up.

And then when he got out of being a POW a few years later, he won the Nobel Prize. So I guess he never really got in that big of trouble for being a Nazi. So that's the end of my story. We did it to himself. He strapped a lady down. He was 24, though. You're not making great choices. There's probably a lot of 24-year-olds

who listen to this podcast, and I just want to say, you're doing great. I hated being 24. That was a bad time for me. Like, my mid-20s were very bad. So I'm sorry. 24 was maybe my worst year, too.

24 was last year. Oh, no. How's it going? It was actually, like, pretty shitty, so 25 is better. Yeah, 24-year-olds out there. Yeah. It gets better. From a rifle age of 25, I can tell you.

So we've got Sari with Chopin's heart, treated as a holy relic, and inside of a pillar, and it was floppy and massively enlarged. Or is Sam with Dr. Werner Forciman, who created catheterization. He did it on himself first, and he also fought off a person who wanted to stop him, and then he became a Nazi. Or maybe he was a Nazi the whole time. He's probably an Nazi the whole time. Yeah, yeah. I suspect. Then won the Nobel Prize.

Yeah. Still a Nazi, though. Yeah. All right. You ready to vote? Yes. I'll count you down. Yeah.

Three, two, one. Sarah? What the one? What on earth? I know. I was surprised. I was pretty sure. I do enjoy thinking about catheters.

But, yeah, the enlarged heart in a jar. His heart was already dead. And what were the heart juice, Sam? Join us. I disagree with this. I'm going to start a poll. Yeah. I think that I bet.

I bet if you took, like, the whole average of the world, you would have come out on top. But in this room. This is a classic case of, like, important medical discovery versus weird old fact. Weird things. And I have lost several fact-offs to weird old facts. Yeah, Sarah's going weird. I mean, yours is a weird old fact, too. He thought off a guy.

He tied a woman down to a table for some reason, sliced her arm open and didn't use it. I know. I told the story. I know it already. It's a conspiracy It's the curse of the same buck And now it's time to ask the science couch We've got a listener question

For our couch of finely honed scientific minds That comes from at club jaw Squids octopi and worms can have multiple hearts What advantage would we as humans gain By having multiple hearts? Also, where would you want your second heart to be In or outside your body? So it can be anywhere inside or outside my body

If I had a second heart, I would want it to be inside of cognac in a, in a can inside a pillar in Poland. I would want mine to be in like a fake android body somewhere that's pumping blood through it to keep it alive so that when my heart fails, I will have a replacement there waiting for me. And they're just like ship series second heart to her, wee, we, we, we, we. And then the android just dies? Yeah, what's going on there? Why does it need an android? Why is it being an android? I don't know.

Why did you create a life? Just to kill it. It's just like, okay, I missed so because Andrew. Human-shaped box. Right, okay. Human-shaped box. Why is that hard to be human-shaped? Yeah, it's creepy.

Why don't you make it adorable baby seal-shaped just so it can be more freaked out about it? Check this idea out. Yeah. I kind of want like a little compartment maybe near the, you know, on my flank. Uh-huh. Just a little compartment and I can open it up and like stick different organs in there. So if I need an extra kidney or. Or if I'm like going out to the bar, I'm like, double up the liver, let's go.

Yeah. Or if I'm going to exercise, double hearts, let's get it. Yeah, I love that. It's like, it's modular. You know that horses have a heart in every foot, kind of? What? Yeah, they have like a little cushion system that when they hit their foot on the ground, it pushes blood up their legs. So, like, when they run, they sort of like have assistance in pushing their blood around.

There's a adaptation that appears to help them run longer. I think my feet actually sounds like the best one. Let's do it. Is there an advantage of having multiple hearts? It doesn't seem like it. So it seems like any animal that has multiple hearts has it because their heart is not as powerful as ours. For example, octopuses have three hearts. They have one central systemic heart that supplies blood to the body, and then they have two branchial hearts that push the blood toward the gills.

So they have, like, separate hearts for each part of the process. Like a pulmonary heart. Yeah, our four chambers handle, like, pumping out to the lungs and pumping to the body. Worms have five aortic arches that squeeze blood into different vessels, like either to the front body vessels or the back body vessels, they just kind of like squeeze. So it seems like nature does do multiple hearts, but human hearts have evolved intentionally and are pretty much going at the max capacity they can. We're doing it good. We're doing it good. But we can't get much bigger.

No. Someone asked a physiologist this, and so I'm just going to steal his answer, where it's like adding a second heart probably wouldn't do much. Sometimes heart transplants, you don't actually get the whole heart replaced. You get like a piggyback heart grafted on to help. So the donor heart does most of the beating while the original heart pumps less. There's two hearts in you. Yes. But if you just like had two hearts in you, your body might get used to the second heart. And then your muscles might get more blood and you might get stronger over time. time, like, it would just mean pumping blood more. Let's Phil Steffing up with hearts. See what happens. Can't have enough. And then there's, like, one sort of experiment, but I don't think scientists pursued it

very long. But when we're embryos, our heart is actually two. It's called the primordia is what the heart is called at that stage. And then eventually fuses into, like, the four-chambered thing that is in our chest. There's probably certain circumstances in which humans could develop two hearts. if, like, something goes awry during development, but there are probably other things going to rye that would not lead to the most robust health as an adult.

So mostly, like, even though we have really good places to put our second hearts, a second copy of our heart probably wouldn't do much. But if we had, like, squeezy tubes, like a worm or, like, a horse does in its feet, that might help because that just, like, helps squish blood where it needs to go a little bit faster. And now Stefan has a correction. It was pointed out to me on Twitter by at Emily Janet 6 that in our music episode, I mentioned that, or I said that 440 Hertz is Middle C, but it is not Middle C. It is the A note that is above Middle C. I really blew it.

I was too excited to be on the science. I knew it was wrong, but I was too embarrassed for you to correct you. Yeah, all of us, all of us knew it. Yeah. You are all laughing at it. Just let them be wrong. If you want to ask the science couch your questions, follow us on Twitter at SciShow Tangents, where we will tweet out topics for upcoming episodes every week.

Thank you to at Emma Ferry 11, at Crystal R99, and everybody else who tweeted us your questions this week. Final scores, Sari and Stefan are tied with two. Me and Sam came out with one, which means that Sari and Stefan are tied for the lead overall. What the heck? Yeah, I came in three points under them, and Sam, points under me. Oh, wow. I could have been tied with you. Interesting. If you like this show and you want to help us out, it's very easy to do that. You can leave us a review wherever you listen. That lets us know what you like about the show. Also, you can put topic ideas in your

iTunes reviews. We look for those there. Second, you can tweet out your favorite moment from the episode. And finally, if you want to show your love for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sarah Riley. I've been Stefan Shane. And I've been Sam Schultz. SciShow Tangens is a co-production of Complexly and the Wonderful Team at WNYC Studios. It's greeted by all of us, and produced by Caitlin Hofmeister and Sam Schultz, who also edits a lot of these episodes along with Heroga Matsushima.

Our editorial assistant is Deboki Chakravardi. Our sound design is by Joseph Tuna Meddish. Our social media organizer is Victoria Bonjourno, and we couldn't make any of this without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. When you have a really big, satisfying poop, the stool could activate the vagus nerve,

which is involved in the parasympathetic nervous system. So it can cause your heart rate and therefore blood pressure to drop, which leads to mild, lightheadedness and good feels, called pooforia by Dr. Ednich, chef. in his book. But if there's too much, what's your poo telling you? Listen to your poop. I've heard of this book, actually. But he warns if there's too much lightheadedness, it could potentially lead to fainting while pooping called defecation syncope. Poophoria, according to the internet, is also called a stool high. Don't do drugs, kid. Just get poo high. Yeah, just not a mucal, man. This episode of SciShow Tangents was made in partnership with Gates Notes, the blog of Bill Gates.

diagnosing Alzheimer's disease as early as possible isn't just important when it comes to caring for individual patients, but also in clinical trials and research that could lead to new breakthroughs in Alzheimer's treatment. Go to Gatesnotes.com to learn about promising new advancements in the early detection of Alzheimer's disease. Hello and welcome to Sci Show Tangens. It's the lightly competitive knowledge showcase. I'm your host, Hank Green, and joining me this week, as always, is science expert, Sari Riley. Yehah. And our president, everyman, Sam Shultz. Hello. I wasn't crazy about that. I'm going to try out some new interjections. I say hello all the time, so get ready. People love hello. Look, look, look. We need to mix it up a little bit. We've had a lot of the same over the last two years. we need some y-haws. I want next time for me to say

and our resident every man, Sam Schultz, and for you to say, wow, motherfucking who? Oh, sometimes I say, what's up? I know, I want Wahoo. Like, Mario, okay, I'll try. Yeah, and I'll do a Yoshi noise. I'll do yoshu.

Oh, no, that was really good. Wow. I can only do like two impressions. I can do Yoshi and I can do a beagle howling, and that's it. We're going to save the beagle howling for next week. Every week here on Sisho Tangents, we get together to try to one-up a maze and delight each other with science facts while also

trying to stay on topic. Our panelists are playing for glory. They're also playing for Hank Bucks, which I will be awarding as we play. And at the end of the episode, one of them will be crowned the winner. And they will be able to brag about that. And it will be all worthwhile. Now, as always, we introduced this week's topic with the traditional science poem. This week, it's from me. I can think about my body parts. That doesn't bother me. I've got parts that run in circles and parts that make my pee. I can think about my hair that grows in patches here and there. I can think about my eyeballs that move and look and stare. It doesn't bother me one bit to think about my knees. They bend and push and hurt sometimes after I climb trees. There's only one part

of my body that I like to just leave out, a part that if it's all the same, I'll just not think about. If you think about it too much, it'll drive Amanda drinking, because the thinking part is thinking about the part that does the thinking. That was very cute. Thanks. So the topic for Today's episode of tangents is brains, the thinking part. And there are all kinds of different ways that thinking parts do the thinking. But, Sari, do we know what a brain is? I think so. I think we can draw a circle and say most of the things inside the circle are brains.

Well, yeah, I mean, there is some debate about how far the brain extends. Yeah, that's true. But we know that, and in humans and by extension, all vertebrates and most invertebrates. and most intervertebrates. It is the center of the nervous system. It's an organ. It is in our heads, usually close to other sensory organs, like our eyes, ears, nose. Other animals have different versions of sensory organs.

And it's just chock full of neurons and chock full of glial cells, which are the overlooked, underappreciated cells that stick our brains together and help with a lot of supporting functions. Part of my fact off is about glial cells, and I could not figure out what the hell they were for the life of me. So, what are they? Well, they're like, so like neurons are usually the considered the most important cells in the brain. They're like the ones with the axon and dendrite, and there where nerve signals get sent along. And then glial cells are just like around.

They don't have, like, different ends. They don't transmit electrical signals. But they're just like the cushioning around the neurons. And if the neurons need a little structural support, they give that. If they need a little biochemical support, they, like, sprinkle some biochemicals. They, like, insulate everything so that the electricity stays in the correct wires and they don't get crossed. They're just like the every man kind of cell, Sam. Okay.

So the ways in which, like, a brain becomes unclear. Octopuses, cephalopods, where you end up with a bunch, when there's, like, multiple brains stemming out. the whole nervous system occasionally is decision making as well as so and also this happens in us there are ways where that our nervous system makes decisions without involving our brain and then it's like well at what point is it brain then in us it's pretty clear this is a big complicated mass of decision making but in other organisms it's like well there's like one end of the nervous system that's like enlarged a bit does that count as a brain and then there's the other confusing part is where do you draw the line in our own bodies between the brain and the rest of the nervous system.

There are people who argue about whether the eyes and optic nerves count as brain, or if that's just sort of a separate thing, which reminds me, if you ever want to have a good, creepy giggle, just Google brains and eyes and look at all the image results. It makes you think, how on earth does any of this work? We made an episode about eyes being brains on SciShow very recently, and like your spinal cord might be part of your brain and stuff like that or all kinds of stuff. Yeah, where does it go? Where does it end?

Where does the start? Terry, what do you think? Oh, I don't know. I'm not going to weigh in on this debate. We just got the squishy bits and then we've got the harder parts to protect the squishy bits. And that's how it all works. And I don't think about it too hard. That's what the science couch is for.

Yeah. I just sit here recording my silly little podcast on this silly little rock with my silly little friends. And don't worry where my brain stops and ends. That's probably for the best. Oh, God. Do you know where the word brain comes from? So what's funny about the word brain is that it is not connected to a Greek root. Like the Greek root for mind is friend, which is like phrenology or frenetic.

So that is the mind or thought root. But in old English and Germanic languages, the word brain, or other forms of it, seems to have arisen from who knows where, influences from other cultures. But any way you trace it, it seems like it is a homonym for words for mush or goop or filth or like pulpy mass.

Because we didn't realize what the brain did. We just cracked open skulls and then it came out and we were like, gross. What's that brain? It says nothing. Yeah. It's just the goop you keep. in your head.

Yeah, we just had a head full of mush, huh? That's what we were saying? Like, other organs were more, like, rounded. I don't know, you could, like, pull them out of a body, but then we only saw brains when you, like, really obliterated someone, and it was like, look at that body goop. That's a brain. Wow. That's wild.

You really obliterated someone. Yeah, I guess it's like it was what comes out when you have a particularly violent interaction with a foe. Yeah. And it's, like, excrement, basically. like garbage. It's just mush. Yeah. Yeah. That's wild. I always wonder if like the seed of conscience, so like when I think, I feel like I'm thinking out of this part. Yeah. Did not everybody throughout time feel that way, I guess? Nope. I've read a book among the history, the history of like our

understanding of consciousness and like understanding of mind at one point and like they felt that in their chest. Wow. Which I can some, I can get like sometimes I like when I'm having strong emotions, you feel it in your chest. Yeah. Yeah. I think a lot of it was heart based and And that's where, and I'm just guessing at this point, but, like, humors came from because, like, oh, your heart pumps your blood and your soul is, like, bound up in that system. So you've got to adjust the things that the heart does to your body to make yourself feel better. Okay. Gosh, that is a shocker of an etymology. I did not expect this.

Yeah, we really undersold the brain, and now it's stuck. And this is, like, the word that's stuck, which I think is hilarious. Like, this word where we don't know where it came from, and it means mush. And it's like, this is the center of all human consciousness. It's the mush. Yeah. And we use it to just make iPhones and yell at each other. Wow.

What a thing. Yeah. Real bummer on that one. I don't know. iPhones are pretty cool. Okay. Yes. iPhones are cool.

The yelling not so much. Unless it's like fun yelling, like, ha ha, I'm razzing my friend. Then worthwhile. Yeah, yeah. Unless it's like butt his legs yelling. Yeah. Are we all on the same page regarding butt being legs? This is the origin of the butt and legs conversation as tangents.

This was something I was thinking about when I was putting together our bonus episode for this month was I couldn't remember what your stance was on it. Me? Yeah. That's what I thought. I mean, I'm in the same boat as you, yeah. But it couldn't be anything else. I'd be ridiculous. I'm indifferent at this point.

But his legs, sure. Again, just here making a silly conversation of my silly friends. Don't need to think about where things start and end. It's me. Yeah, Sarah Riley, head empty. Yeah. Head empty, just talk. All right, well, get head full because now it is time to move to the quiz portion of our show

where you will have to think hard because it's time for... We use a lot of algorithms every day, and some of them are in our computers. Yes, there are brain algorithms. In fact, many computer algorithms are based on brain algorithms. So when researchers want to improve computer algorithms, they look to brains sometimes and sometimes to animal brains. Which of the following, three tales of algorithms and their animal muses, is the true fact. So we've got three things where an algorithm was inspired by an animal. Two of them are fake.

One of them is true. Are you ready to find out and tell me which one is the thing? Oh, yeah. Yeah. Fact number one, researchers created an improved search engine that's better able to sort information by designing an algorithm inspired by how fruit fly neurons sort and label smells as edible or not edible when they're foraging for food. So that's fact number one. Fact number two, researchers developed a more effective Spotify recommendation algorithm that layers information aggregated from external reviews and from in-app usage.

That was inspired by snakes and how their brains layer infrared and visual information to parse their surroundings. Or you have fact number three, researchers created a cloud drive that is able to efficiently store more information across multiple servers by designing an algorithm that mimics the way the distribution of neurons and multiple brains throughout an octopus's body allows it to operate its arms independently. So is it the fruit fly search engine, the snake maps, or the octopus server drives?

Well, God bless Spotify and hello to everyone listening on Spotify, but I feel like my Spotify recommendations have gotten worse. So it makes me be the best. Maybe that's what happened. Maybe they're like, let's choose this snake stuff, but then it turned up to be real bad. Thanks, I don't know anything about music. Fruit flies, that seems like a lot of work for a fruit fly to me.

I would think they'd think everything smells food. Is that not the case? Well, no. It's not everything is food. If you're a fruit fly, you can't just go to anything that smells, or you'd have them all up in your armpits. Oh. Do I smell with their feet or something weird like that?

I'm sure there's like chemo receptors. They don't have a big old schnaz on there, I don't think. But I think some receptors on their body. Isn't it like house flies taste with their feet? And then they can like detect chemicals other ways. Yeah. Okay. So here's my guess with a housefly.

I think lands on a thing. It goes, ew, not food. Flies away. And then goes, I already forgot what I was just doing. So they don't, they don't sort anything. That's my guess. But it's a fruit fly, not a housefly. Well, what are both?

Both of them do the same thing. Okay. One's just smaller. And what do you think about cloud storage, Sam? Well, I'll tell you what I think of cloud storage. That one seems too obvious to me. The octopus brain thing is like the first, I feel like that's one of the first things you think about when you're thinking about like animal brain. It's like, oh, octopuses have weird brains.

So now you tell me what you think. Sam's ruled all of them out. Yeah. I know they're all wrong. I know which one I like, but. I also, this is where you could convince me of anything. I understand algorithms so loosely that you could tell me you based it on anything and be like, oh, you base this on bees swarming, you base this on the groundhog popping up and down out of the ground.

Sure. I agree that the octopus one feels too on the nose. It's like, oh, look at the octopus that has different brains and then there are different servers. and they're all linked together in the cloud, which is the octopus's head. But great metaphor. Yeah, but when you say it that way, I mean, it makes a lot of sense. So I don't actually know. I don't really use Spotify.

I listen to the when I run, but I have the ads version because I don't listen to enough music. So I get an ad every third song or something. So know nothing about recommendations. I guess there's multiple inputs. There's like what you're searching and whatnot. I'm writing that one off because I don't understand Spotify. I'm leaning toward fruit flies because it feels like a search engine is something that people, like search algorithms are something that people try to work on a lot of the time.

Like in my computer science classes way back when we had to learn different ways to sort things. And so I could see scientists tinkering with that. So I'm going to go with fruit flies. Okay. I'm going to go with the snake one. I don't know why. That one just feels like something somebody would try. It may very well be something that someone would try, but so far it is not something that anyone tried.

But the correct answer is the fruit fly search engine. Yes. Congratulations to Sari for getting early point here on SciShow Tangents. This was a pretty complicated computer science situation that went down in 2017 at Salk Institute in California for the design and algorithm based on how fruit flies fire up their neurons when trying to figure out whether or not something is edible. So typically in a search engine, an algorithm is based on what's called a similarity search where you reduce your dataset down to a few key traits and you tag them and then you put them into, you sort them, as sorry I was saying, into buckets, but with like similar tags on them. But fruit flies do that differently.

They actually spread things out into like a ton of buckets instead of just like a few different tags. They gather a ton of information using a ton of neurons and then sort from there. a researcher described the difference like this. If a computer scientist was trying to study relationships within 100 different people, the typical similarity search method would be sticking them all in a crowded room

with a fruit fly method spreads them out over a football field. I don't really get its computer science and its hashes and its algorithms. But they definitely did this. And when researchers created an algorithm based on the fruit fly method of sniffing out food into a way to search through a dataset,

the algorithm was performed just as well and sometimes even better than a normal computer science solution. Wow. All our fancy technology and a little bug beats us. That's right. Well, it turns out that the ways that brains figure it out is probably pretty good because they work

well. Yeah, sometimes. The Spotify thing was fake, but snakes do do this where some of them have special pit organs that are separate from their eyes and create a heat map. And then the snake is able to sort of like look at the heat map.

and the visual map that its eyes give it somehow at the same time either like referenced to each other or literally stacked on top and like we don't know how this works because we're not snakes and we cannot perceive the world the way that they can but it's very cool that they can they sort of have two different sets of inputs like that are basically visual though it's one's infrared and they come from totally different organs and then they can see them together and then the octopus thing y'all were right uh it's just octopus brains really cool Yeah. Do they work similarly? The cloud and octopus brains? No. Okay. Hank apparently does understand cloud computing and just doesn't want to tell us. You're right.

It could be. I mean, definitely, like, things are stored. Like, my email, like, my Gmail is not all stored on one computer, you know? Right. So there has to be some way that it figures it out, but I don't heck and know. All right. So we're headed out of Truth or Vale with Sari with one point and Sam with nothing. we're going to take a short break, and then it will be time for the fact off.

This episode of SciShow Tangents was made in partnership with Gates Notes, the blog of Bill Gates. The way we currently diagnose Alzheimer's is one of the biggest hurdles standing in the way of developing Alzheimer's treatments. See, by the time patients know to get tested for Alzheimer's, their cognitive decline is too far. advanced for drugs to work on them so they can't volunteer for clinical trials. A cheap, non-invasive way to diagnose patients early is key to finding an effective treatment for Alzheimer's. The good news is that all over the world, technologies are being developed that will allow doctors to do just that. From a blood analysis being developed in Sweden to eye exams being researched in Seattle, easy to administer tests could be widely available in the next couple

years. You can learn about some of these promising advancements in Alzheimer's diagnostics and more about the future of treatment for Alzheimer's and the new blog post and a video at gatesnotes.com. Welcome back, everybody. Get ready for the fact off. Our panelists have brought in science facts to present to me in an attempt to blow my mind. After they have presented their facts, I will judge them and award Hank Bucks in any way I see. see fit. And to decide who goes first, I have a trivia question. The hominid that can claim the largest brain is homo-neanderthalensis. The average Neanderthal brain was about 200 cubic centimeters larger than the average Homo sapiens brain. How big was the average Neanderthal brain in

cubic centimeters? So it's 200 cubic centimeters bigger than the average human brain. So just go, based on that, how big do you think a Neanderthal brain was? Oh, how big? How big? of human brain. It's this big. Oh, shit. Yeah, I'm trying to figure out what my head is in centimeters. About 200 cubic centimeters

could mean literally anything to me. Well, I mean, like, so you know that a Neanderthal's head is not like three times bigger than yours. Right, right, right. So math your way from there. I'm not, I'm going to let Sarah do it first. I'm going to guess that a Neanderthal brain

was 1,200 cubic centimeters because I can do 10 times 10 times 10 really easy in my head. You're like, okay, all right. Close enough. Oh, gosh, what did you say? 1,000. 1,200.

So I'm guessing that our brains are 1,000 cubic centimeters and plus 200. Oh, that's 1,400. Sam is the winner through just cheating. No, just being really smart, please. The answer is 1,600 cubic centimeters. which is substantially bigger than a human homo sapiens brain. So if only they were around for us to be like, what's up, that would be cool.

But they are not, why? Don't ask too many questions. Don't ask questions you don't want to know the answer to. So Sam, that means you get to decide who goes first. I guess I'll just go first for once in my life. So whales and dolphins have big old brains. We were talking about big old brains, they got even bigger damn brains. sperm whales in fact have the biggest brains on earth and many dolphins have a larger brain to body ratio than primates including humans so one conclusion you might draw from this fact is that since whales and dolphins have big brains that they are really smart possibly even smarter than humans however they don't really seem smarter than humans they don't have like underwater cities or anything like that and the brain to body ratio could i guess hypothetically be useful in determining intelligence i guess especially like ape intelligence but

The mammal with the largest brain-to-body ratio is the tree shrew, and they aren't. They ain't that smart, probably. So taking these details into account, a paper published earlier in 2021 proposes an alternative explanation for why whale and dolphin brains are so huge. So the first thing you need to know is that mammal brains have to stay 98.6 degrees to function right. Anything below that can make bad stuff start happening real fast, up to an including death. So one way the animals keep their brains the right temperature is with brown fat.

So when the brain starts to get chilly, brown fat produces proteins called uncoupling proteins or UPCs. And when these proteins hit mitochondria, I'm getting a lot of my depth. This is what I understand. When they hit mitochondria and brain cells, the cells start making heat instead of ATP, which is a chemical that helps the brain function by helping ions travel on the brain. Is that what ATP does? Does anybody know? ATP is like a chemical energy. you can use it to do whatever inside your body.

Okay, my next sentence is, I think it basically makes the way your brain create energy less efficient and more heat producing. So it's like just a different energy it's making. So the researchers looked at the brains of three species of cetaceans, which are whales and dolphins, and 11 species of land-dwelling mammals closely related to cetaceans, like hippos, pigs, and giraffes,

and found that 90% of the neurons in cetacean brains had UPCs in them, so this extra heat-causing molecule. and only 35% of neurons and land mammals had UPCs in them. And cetacean glial cells, which we talked about before, I won't tell you what I wrote that they are, but mine was a little different than yours. I just said there's support cells in the brain.

Is that right? Sure. That's good. So they are also full of UPCs, like 30 to 70% of them have UPCs, while on land species there aren't any UPCs in glial cells. And then also the nerves that control production of UPCs are way denser than land animals.

So based on these findings, the team proposes that cetaceans of all the big old brains because they needed to basically be have their brains be chock full of like heating elements. So their brains wouldn't freeze in the cold ocean. And a brain that's processing UPCs

instead of ATP's is probably not working at full efficiency. So the size of the brain is not a good way to tell how smart the animal is. It just needs to be big to be hot. And this all probably happened a long time ago when early cetaceans moved from like closer to land waters out into the cold ocean. of millions of years and Earth's cooling climate,

but, of course, millions of years of gradual, delicate evolution are no match for 100 years or so of clumsy man-made climate change. So the researchers concluded their paper by saying that if the oceans continue to get hotter, we'll probably have a lot of whales and dolphins with really hot brains, and that will be good for them. Well, in the short term, it would be bad for their brains. But in the long term, if it's warmer, then their giant brains could turn extra-powerful because it don't need to stay warm all the time.

they could get super brains that's true and then they can make an underwater civilization hopefully they don't just all their brains don't just all cook instantly probably that's what's going to happen yeah but who knows there is billions of years left and maybe not for us and or whales but just in general like the universe will still be around yeah there'll be more whales on some other planet somewhere else somebody else can help someday yeah they'll figure it out one one way or the other yeah all right that's quite cool sam i liked your facts Thanks. What does Sarah have for us? Okay. We all know our brains are important because our central nervous system keeps our bodies going and that importance comes with a cost, which is energy,

as Sam was talking about with his fact. So in healthy adults while resting, so not after a hard test or a bunch of exercise, it's generally thought that around 10 to 20 percent of the volume of blood being pumped out by the heart goes to the brain because those hardworking cells need a steady supply of oxygen, biochemical signals, and other nutrients carried by blood. And a lot of brain studies use fMRI, which is functional magnetic resonance imaging, which basically relies on this fact that brain cells need oxygen and detects changes in blood flow when people are using their brains in different ways. And I've always considered fMRI like a pretty modern development, and it is generally credited

to Seiji Ogawa and Ken Kwong in the 1990s. But about a century before then, the Italian physiologist Angelo Maso created a device. called the Human Circulation Balance, which was sometimes nicknamed the metal cradle or machine to weigh the soul. And those names sound a little bit mad scientist, but the idea was actually pretty good. He was studying how blood pressure and blood flow changed when we use our brains by strapping people to what was basically a carefully balanced seesaw table. The idea being tested was that if someone used their brain and that increased blood flow to their head, he could measure that because their head would get heavier and tip the table. And Maso's results got a little hand wavy, since his notes claimed that the table tipped clearly when he rang a bell to stimulate the patient's brain, presumably like

you're hearing something as opposed to not hearing something, and that it tipped less extremely when someone was doing light reading like a newspaper and more when they were reading a difficult philosophy booked. Oh, come on. And those are such subtle differences to measure. So even with a highly sensitive technology like fMRI. So his table, eh. But what is incredible to me is that the overall strategy of this machine to weigh the soul is pretty good that brains need blood flow to work. And scientists thought so too, because two of them, David Field and Laura Inman, recreated a version of this table for a 2014 study using a scale to measure any slight tipping of the table rather than relying on their eyesight. And there was a difference of force around 0.005 to 0.01

newtons when participants were in silence and blindfolded compared to listening to music and looking at the wiggly graphics of Windows Media Player. That's fun. So the initial takeaway here is go humans. We understand the basics of the brain and blood flow, even a hundred years ago. But the deeper takeaway is that even though we've come a long way, we constantly face problems with brain measuring devices. In Mosso's device, for example, to balance it, he had to use pressure monitors to account for normal things like breathing, changes in heartbeat, and humans just being fidgety when we're lying down. And in FMRI, we have to understand that brain regions serve multiple functions, and we have to decide what normal blood flow is

relative to, like, statistically significant shifts. So maybe to our future selves, fMRI will seem as quaint as the machine to weigh the soul, because while blood flow is sort of quantifiable. Our brains are just weird mush. Well, now you have an unfair advantage where you can tie in your fact to the definition because you wrote the damn definition too. Oh, yeah. Sarah has an unfair advantage because she did more work. I connected it back using my own brain because in my script that I wrote for myself, I said our brains are so freaking complex. But then I just decided, woozing my...

What's the word? Improvisization. Improvisational skills. Please cut out all the bad takes. There wasn't a good take, Siri. They're all bad. You should have just said improv. Using my improv skills.

I wowed you. We are wowed. I'm wowed. That's for Dancer. Oh, boy. Oh, that's super cool. Like the TikTok frame, which one of these makes a better TikTok makes this so much easier.

Because, like, I can sense out, like, story to tell. And both of those would be great TikToks, but Sarri's is a better TikTok. Yeah. That is really weird because it's got, like, mad scientist vibes. But it turns out that the mad scientists were kind of right. And that if you look at, if you listen to music, that your head gets heavier. Yeah. Uh-huh.

All right. Well, congratulations, Sarah. That means you are solidly the winner for this episode with the 200 points that you got for this versus Sam's 180. And that means that it's time to ask the science couch where we've got listener questions for our couch of finally honed scientific minds. This one is from at Dr. BFF.

Is there any evidence that a brain or brain-like organ evolved multiple times independently or are all brains related? Definitely not all related. Brains have, in fact, I believe, by some crazy evolved multiple times, right? I don't know. Maybe. I think it's very contentious is what I found.

Oh, all right. It's a fight. Yeah. So we know what side of the fight you're on. I have found, at least, more readings and more literature from the people that are all brains traced back to a central ancestor. Just like a worm with like an enlargent nerve spot. Exactly. Yeah. And it's not only just a worm with an enlargent area of thought, but it is a made-up worm. It's one of those situations where people, like, trace back taxonomic trees, and they're like, there is probably an ancestor here.

We probably will never find one. There was a worm. Yeah, we won't find it in the fossil record, but there was a worm. And they've named it the erbilatarian, or erbilateria, bilateria, meaning bilateral symmetric, because they think it's the, or this proposed ancestor is the ancestor of all animals that have bilateral. symmetry. So like vertebrates like us, but also other kinds of flat worms that now have brains, like the invertebrates that have brains, as opposed to radial symmetry, which is like jellyfish that have nerve nets or. Yeah, and worms. Worms are radially symmetrical. Oh, yeah, yeah. Not all. Flatworms are not really. Well, I mean, worms are a lie. There's no actual group. Oh, we just point to tubes.

Yeah. Well, yeah, then some tubes are radially symmetrical and don't have brains. Anyway, the urbilateria, there are multiple different hypotheses of what it might look like, either if it's like a very simple worm or like it actually started differentiating body parts more similarly to like more complex bilaterally symmetric animals. Most people are in the camp of the simple blob, which makes sense because there's a lot of complex things going on in evolution. I guess the main counter argument to this being the one time brains evolved or the original brain from where. which all other brains diverged is the fact that other bilaterally symmetric animals that we were joking about, but like acorn worms or nematodes or that are also radially symmetric, that don't have a brain. So if they all came from this common ancestor, then maybe it didn't have a brain

and then brains evolved multiple times. Or it's possible that they evolved and lost their brains because it was not energetically favorable to have one around. And all the worm scientists seem to say, we have simply have no way of knowing, but it is very controversial to say that there is a worm ancestor that had a brain. And worm scientists are up in arms of that concept, that you would say something so bold and so definite. All right. Well, see, I was of the opinion that maybe this doesn't count, that the urbilitarian nerve cluster at the front of the worm, is that a brain? I don't know. There's just very different brains, but it does make sense to me to sort of like start at a nice solid spot, which is like, when did a nervous system first happen?

And then when did a sort of centralized location of that nervous system first start to develop? Yeah, as opposed to like scattered neurons around your body. There's like a clump. Like C. Elegans neurons, which are just like basically evenly distributed throughout the organism. Sam's looking like he's not a huge fan of this line of hot. I don't know anything about this. there's a worm maybe might have had a brain might not you don't know is that what you said

yeah yeah in so many words and it kind of sounds like the scientists were also just like don't worry about it is this a little worm living in its little worm life well they're worried about it they want to know the answer but sometimes you you gotta say like we don't know you gotta just let it go yeah and maybe we'll find it I think it's fine I don't know what I don't know anything about pneumatodes or brains I got nothing to offer you

Would you time travel to find the first organism with a brain, Sam, or would you time travel to something more interesting? I had time travel to be considerably more interesting. I had time travel forward as far as I could. Skip past some bullshit. I think that's probably what I'd be doing. Wow, that's bold. That's brave.

I think time traveling any more than 100 years is like, will there be anything there? Oh, when did Star Trek happen? I'd go 500 years, minimum. Sir, Star Trek isn't like a definite. Yeah, well, maybe, though. You don't know until you get there. It's true.

I'd rather go someplace definite, where, like, I know what I'm signing up for. And I like the idea of going back to Earl Balletaria because there's nothing's got teeth thin. Nothing's going to eat me. You got to be so careful. You're going to squish something that's important. They're everywhere. This whole area is covered in them. Okay.

They'll just squirm all up my legs and I'll be like, hello, little buddy. I'm taking you back to the present. I'm going to get a Nobel Prize. It'll just be a planet of Hanks. And you'll all be like, good job, Hank. Thanks, Hank. Here's the Hank Prize. That's how it works.

Oh, Lord. Well, if you want to get the science couch to answer your question, you can follow us on SciShow Tangents, where we tweet out topics for upcoming episodes every week. Several people did that, including Dr. BFF, but also at FF558 and at Harth Holmes and a bunch of other people. So thank you for your questions. If you like this show and you want to help us out, you can do that in a bunch of different ways. But the main one,

and that you will like this because you can get access to things like Poopi-Pee-Pee-Pedia, our patron-only podcast, and Q and Biday, our other butt-focused patron-only podcast. Look, we love butts here at Sajotan. And you can become a patron and get access to those things.

Also, we have a newsletter for you. We've got illustrated poems that Sam does. The newsletter has an extra answer to a science question from Siri. It's great. Yeah. So much. information packed into it.

You can also leave us a review wherever you listen. We're approaching, I think, a thousand reviews on Apple podcasts, and I love to read them. I don't know if you know this, everybody, but SciShow Tangents is climbing up the charts. People are discovering us. They love us. We're amazing. People are talking about that little science podcast. Yeah, nobody can shut up about it.

It's so good. And finally, if you want to show your love for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sarah Riley. And I've been Sam Shultz. Saishotangins is created by all of us, and produced by Caitlin Hofmeister and Sam Schultz, who edits a lot of these episodes along with Heroku Matsushima.

Our social media organizer is Paola Garcia Prieto. Our editorial assistant is Debogicavardi. Our sound design is by Joseph Tuna Meddish, and we couldn't make any of this without our patrons on Patreon. Thank you, and remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. When talking about brain sizes, like Sam was saying, scientists try to take body mass into consideration. So a given animal might have a big or a small brain on average relative to its size. And it turns out, the current record holder for vertebrate with the smallest brain compared to its body is a deep-sea fish called the bony-eared ass-fish.

I feel like we talked about this guy before for different reasons. I feel like I've heard about the bone of year at ass fish, too. There was some other humiliating thing that was wrong with him. That was not his brain, I don't think, though. But the ass part, as far as we can tell, comes from its scientific name. Acanthonis, armatis, Armitus referring to the weapon-like spines on its head. Acanthos referring to prickly.

an onus, either meaning relative of a cod or donkey, which is also known as an ass. Anyway, the wrinkly preserved specimens do kind of look like pieces of shit. Well, this was our dumbest episode. Yeah. Hello, and welcome to SciShow Tangents. It's the lightly competitive science knowledge showcase. I'm your host, Tank Green. And joining me this week, as always, is science expert, Sari Riley.

Hello. And our resident everyman, Sam Schultz. Hello. I'm thinking that we may need to pivot here at SciShow Tangents. I'm thinking that the thing that gets attention is talking about whatever. not is the most interesting science thing, but the internet is currently arguing about. Because last time we did that intro about NFTs,

and I think it did fantastically. And I have to tell everyone that there is an illustrator named Rachel, who has made a bunch of board Pelican Yacht Club NFTs. I should just start out by saying that. They're beautiful. I want one. Well, it may be too late because she had a sign-up sheet that I think got a little overwhelmed. Well, I should be on there by default.

Now you're talking with a podcaster privilege, Sam. Uh-huh. Yep. Look, maybe I will splurge and I'll, I will commission a pelican for each of you and for tuna if you want one. Do you want one, Sari? Sure. I would do it for the bit.

I'll change back for sure at some point because I don't want anyone glancing at my profile and really thinking that I'm an FTA person. Well, as long as it's not a hexagon, you're good. Yeah. They look too good. They look too good. to be real NFTs, unfortunately. That's true.

They're very stylish. Anyway, did I introduce you both already? I think I did. Yeah, you did. Okay. And you want to talk about something the Internet's fighting about. Yeah. So these days, the Internet's, I don't know if you've caught this,

but it was mad about Wordle for a little while. Mad about Wordle? Because Wordle is going to become part of the New York Times now. Oh, yes. Because we all thought that, of course, wordle was just sort of, a sort of community co-op communist experience. It's a natural resource.

It's just a forest. And the New York Times, of course, purchased it, which I think means really what they have purchased is the right to do a wordel without people being as mad at them because they, of course, could have just done one. You can't copyright the idea of a wordle. I think it's great that they did that,

but Sam disagrees with me. Because what if it costs money eventually? I don't want to pay money for my wordal. I don't want to pay money from my wordal. I would watch a little ad, before it for a fine sponsor. Either you pay money for Wordle or the Wordle answer is always a brand. That would be fine with me too.

However many five-letter word brands, it's just Pepsi over and over again. So I'm saying, the New York Times can do whatever it wants and so can the Wardle guy. And I, that's my. No, stupid. You're stupid. Yeah, and then Sarah, you're the voice of reason. Go. I stopped playing Wordle anyway.

This is what the internet goes to the voice of reason. It's going to exit people's public consciousness in the way very soon. That's it. The end. Yeah. But, you know, we can all be happy for the wordle guy. I'm happy wordal exists. It's made my life better.

I love co-wordling. I wordled with Catherine. No way. I saw my dad and my mom doing a wordle together. That sounds nasty, doesn't it? And I was like, no, you had to do your own wordle. Wordles are sacred. You can't have somebody looking over your shoulder being like,

Oh, no. Try a, A, try a B. Are really good together at wordle. Our score goes up if we are working together. Interesting. Rachel won't show me the wordal. She, like, makes me go in a different room when she's doing it, and I can't look at it. Wow.

Yeah. Sylvia also hides the wordal from me, but we crossword together because that gives us a significant advantage. Crossword is all, like, I hate doing it. crossword by myself. A social crossword is the only way I crossword. Every week here on SciShow Tangents, we get together to try to one-up, amaze, and delight each other with science facts while also trying to stay on topic. Our panelists are playing for glory, but they're also playing for Hank Bucks, which will

be awarded as we play, and at the end of the episode, one of them will be crowned the winner. We have finally arrived at the end of season three. It's the season three finale, and I mean, end fairly literally, as the exploration of our body parts concludes with this episode. And so we're going to introduce this week's topic with the traditional science poem this week from, I think it's from me, right? It is from you. Thank goodness, because I did write a poem. Okay, there's a topic we're always talking about. Even if the whole episode's about trout, we can't keep ourselves away from it, the thing on which you are likely to sit. Not a chair or a couch or a bench at the park. This thing, no, I fear we keep it in the dark.

You see, you don't see it that much. It's quite hard to see, if only because it's where your eyes can't reach. But you know that it's there and you really do care. You wouldn't ignore it. No, you wouldn't dare. It has to stay healthy for you to keep up your strut. That thing, you know, you're, you know what, your cushion for sitting, the end of your gut. Your wonderful, marvelous, beautiful but I love that that's a kids book for sure

I can't do any kind of poem anymore I read a lot of kids books the topic for the day is but Sherry what is a butt

because I have some strong opinions as you know so a butt I guess a butt as we So a butt A butt

Turns out Sarie hasn't known this whole time when a butt is oh no I've just been making it up. I Google butt and then whatever fact pops up. But that's why I want to start with, we end each episode, as Hank said, with a butt fact. And for that, we usually lump it into

anything that involves an anus, which is like a hole at the end of a digestive system, or a cloaca, which is a different hole, also at the end of the digestive system and reproductive system, or poop, which is the stuff that comes out of that hole, or any sort of, sort of like opposite of head end of an animal. Like I think we've done butt facts that are just about tails or like anal glands that are next to the anus or like anything in the rear rump booty area. Yeah. But the word butt specifically is mostly used for human anatomy. Like technically a lot of animals have butts because it's where the gluteal muscles are.

So like the gluteus maximus, the gluteus medius, and the gluteus minimus muscles. And in humans, the gluteus maximus muscle, so like the big butt one, is extra developed because of us walking on two legs. So like a cat has a gluteus maximus, but it's just a tiny, a little pathetic one. They don't have big cheeks. I think at least apes, like great apes have bigger proportionally gluteus medias and gluteus minimis. is. But the size and strength of those muscles is relative to, like, pelvic position and how they intertwine with the leg movement. So, yes, all animals, I think, or all mammals, I would say, have all three muscles, but just in different arrangements. And humans are the one where the

gluteus maximus is, as the name suggests, amped up to big. But we still, do we call it the gluteus maximus and the other animals because it's the analogous muscle, but it isn't the max? We still call it that in other animals because I think it's useful. So what I'm hearing here is something that I have maintained for a long time, which is that regardless of whether but his legs, butthole is definitely not butt. I feel that way. I guess though, yes.

Butthole is a subset of butt. No, butthole is not butt. But is the fleshy flesh. Butthole is just an area. It's just a thing that exists around the butt. Sarah's not going to allow this. You seem to be saying that butt is like a person thing. And then when we look at other animals,

we say like a fish doesn't really have a butt because it has a butthole. Got a butt hole for sure, though. It has to. But it doesn't have like the fleshy lumps. And a horse has a big butt. They have big butts. You see it. It's like that's a butt.

But it's because it's the big fleshy round things. They have a but hole too. But they also have a butt hole. I'm just saying that like you can't have. have a butt and you can't have a but hole. You have to have a butthole. Everything has a butthole, but not everything has a butt hole. Not everything has a butthole. There are some animals with no excretion. Well, okay. Okay. Yeah, you're right. You don't have to have a butthole. Yeah, you don't have to have a butt. But that's, I think it's like,

butt cheeks and butt hole. Yes. So all of them share the word but, whether or not they're connected. So you're saying there's butt cheeks and there's butt hole and then there's But, and butt includes but hole and butt cheeks? Yes. But we don't have butt cheeks because we have a Venn diagram. Cheeks, hole. Then in the middle, but. It's even butt-shaped.

What's butt-shaped? Oh, the Venni-a-Vat diagram is. And in the middle there's a butt hole. No. And the side there's a butt hole. That's too bad. Yeah. Not a perfect analogy in fact.

Where did that great word come from? What butt? Yeah. Well, everywhere. I think butt meaning. like our physical but came after the word the root word for butt.

So the root word for butt in English is the proto-Indo-European root B-H-A-U bow or something which means to strike. And so like head budding, it's like that

meaning of butt. Or like two things budding up against each other or you're re-budding an argument. So like all those words are related But then at some point Attested by 1860 in U.S. slang at least So like pretty recent

It became used It's like the most recent word It's like this is the last one we came up with Buttox came slightly earlier I think that's just they like the fancy version No one thought to make it shorter Because it's like you got two buttocks there Same thing, but cheeks

you're referring to both of them was used around 1,300 maybe in old English. Why is the word for strike a butt word? Why were they like, oh, that word is for like

supporting or hitting something and that was what we will call the big round flesh globes? Is it because you got two cheeks right next to each other? They hit each other? So I strike. Yeah.

My first thought was because you spank him. You know, like that? Give a little pat. That's what those are for. That was also my first thought, but I think, unfortunately, I think it has to do with the support factor in that, like, you push two things up against each other. And so your butt's kind of like what you push against things. It's like abutting itself.

It's keeping us standing up. So what the medieval people want me to do is to hit things with my butt. Yeah. I won't say no to that. You can do a head butt. You can do a butt butt, you can do, like, whatever you want. I guess. I guess with consent.

Consensual headbutts. They happen all the time. It's very common in human society. Pro-social behavior. All right. I feel as if I am now an even more of an expert on butts than I already was.

We're going to move on to the quiz portion of our show this week. We're going to be playing a game related to all the other games that we've been playing for the last few weeks. It's called

Whose butt is it anyway? Butts have a lot of amazing purposes in our lives, whether it's something as simple as sitting on or something as essential as creating exit for all of the stuff that went into your mouth. And yet, there are so many possibilities for what butts can do, possibilities that other animals have uncovered. And unfortunately, we have not yet. Let's work on it, everybody. We've got to unlock the power of our butts. For today's edition of Whose But Is It Anyway, we will be drawing on some of the creative posterior choices that have arisen in the animal kingdom.

I will describe to you a feat of ingenuity that involves an animal's butt and it's up to you to guess what animal I am describing. Whoever gets closest to guessing whose butt it is will win the point. Are you ready?

Yeah. All right. Our phones come with face ID now. But these animals, if they had a smartphone, maybe it would come with butt ID because that is how good they are at recognizing butts,

including the red butt of an ovulating female. This ability might help this animal because it often walks closely together in groups, And on four limbs, putting each other's rear ends close to each other's faces. So they got really good at identifying each other by butt. What animal is it? Whose butt is that? What's that?

Some kind of an ape, right? A monkey. A baboon. Is that the one that has the red butts? Yes. There are a lot of apes that have like weird bulbous butts, calloused butts to sit on and whatnot. Not as fleshy as humans, but colorful, et cetera.

It's like a little toe pads of a dog, but it's on the butt. Yeah, yeah, very... Do they smell like corn chips? Do they smell like corn chips? I don't know. You'll have to ask an ape scientist. I must know. Well, baboon seems too easy, but I'm going with it.

He's going with baboon. I feel like a different direction. I'm going to go with a goat. Still in the mammal family, but I feel like I'm not going to play the monkey game. Well, that makes it easier for me because the answer is chimpanzee. Very close to a baboon. Very close. Certainly closer than a goat.

Research has shown that chimpanzees recognize each other through both their faces and their butts, though the specifics of how that recognition happens isn't really well understood. Maybe it's just because they look at the butt and they say, that looks like Steve. In 2016, a team of researchers in Japan and the Netherlands investigated one specific property of this recognition by drawing on a very human behavior called configuring. recognizable recognition. In humans, this refers to the way that we process the entire structure of the face to recognize other people. That's why it's harder for us to recognize faces when they're upside down than when we're looking at other objects when they're upside down.

The face has to fit into our idea of what a face looks like. The researchers wanted to see if chimps experience something similar when looking at butts, so they showed them pictures of primate butts to get them to match identical butts together. And when one of the butts was flipped upside down in the picture, the chimps took longer to match them suggesting that they processed butts in a similar configurable fashion to how we process faces. That's very cute. They've got a little butt computer in their brain going, that's the cheek link. Yeah.

So round number two, the butt as a tool of seduction is not unique to any particular species, but this animal takes it one step further through a very thorough inspection. When mating, the males of this species will gather together in groups to display themselves. when a female approaches, he will boldly display his rear, allowing the female to poke around in what researchers hypothesize maybe a diagnostic tool to check out the male's health. So, whose butt is it anyway? Huh, poking, eh? You can poke with many different parts of the body.

This could be literally any animal. I would believe it about so many things. Like, they just look at the butts. Sure. Okay. I feel like I have something fun to poke, though, you know? Like a bird doesn't have anything fun to poke back there, do they? Oh, you can poke around?

I guess they got big feathery butts. Okay. I'll go first. I'm still going to stay in the mammal zone, I think, because I feel like they're more defined butthole and butt cheeks. I'm going to guess goat again. You're still going to say goat every time. Okay.

I'm making this a thing now. Stand around, poke the butts. Hyenas. I'm trying to think of something that the males would be comfortable. standing around with each other. I think hyenas are more female-dominated. So we had goats and we had hyenas. Which of those is more similar to the great Bustard, a bird in the Bustard family?

Nothing. You'd have to go back to the primordial ooze, I believe. So who's got goats? Neither of these live in the same. Well, I'm going to go with the goat. Because I feel like Bustards live sort of in places that they don't live. live where hyenas live, for one thing. I think they sort of have like a more similar kind of like stuff that they eat,

like a habitat and such to a goat than to a hyena. Congratulations, Sarah. You got lucky. You didn't deserve it. But okay. I'm a sad person. Let me have this win. Okay.

Sarah gets all the points from now on because we don't want to be a sad person. Yeah, that's okay with me. So the Great Bustard is the heaviest flying bird And when it comes to mating, the male puts on what researchers have called a Reiterative and almost obstinate exhibition of the cloaca Oh, oh, that's cute. It means to suit the demands of the picky female Great Bustard who will look for a white, clean cloaca With no signs of diarrhea that may indicate infection.

Isn't that what? That's the least you could ask for, really. To try to present the least infected cloaca possible, the male great bustard might even be self-medicating. Researchers from the Spanish National Museum of Natural Sciences studying the bird found that around mating time, the great male buster ate a surprisingly large amount of blister beetles, surprising because the booster beetle produces a poisonous compound called canthardin. And when the researchers tested the compound,

they found that it was able to kill bacteria, leading them to hypothesize that the male great busters might be eating the beetle to kill off diseases and increase their odds of mating. Oh, man. That's wild. It's like, I know my butthole is really stinky and bad. I'm going to eat these horrible beetles so that I can find a girl. Yeah, I need a better butthole.

I desperately, desperately need a better butthole. Bro, your butthole is whack. Number three, these animals have a thing in common with Sir Mix a lot, which is their inability to lie about their big butts. In fact, during a period of their life cycle, these animals will line up from biggest butt to smallest butt for an important part. of the next step in their life, which I think is adorable. Whose butt is it anyway? So this is like the, instead of showing them their anus, they're just like, kind of like you line up kindergartners, it's like line up in alphabet and order,

line up in butt size, and let's get ready to rumble. And there's a reason, but I'm not telling you the reason, because it's going to give it away. And they got to be friends, I'd imagine. Yeah, yeah, yeah. They're not butt fighting. They're just arranging themselves by butt size. That takes a lot of coordination that you're not going to cheat. You're not going to lie.

You don't want to. You're not going to lie by, I guess. I think I know. You think you figured it out? I think I know too. I think I know a little guy who's very butt-centric and likes to have a lot of friends. And it's, yeah, deep inside of the psychotangents lore for some reason. It's associated with me very deeply, even though I don't really care about them all that much.

our friends, the hermit crab is my guess. The hermit crab is Sam's guess. This is also my guess. Sam's best friend and favorite animal of all time, carved it into stone, the hermit crab. You got it. They arranged themselves by butt size so that they can switch their shells more efficiently

when they grow out of them. Oh, well, you should maybe start arranging ourselves by butt size. Maybe we'd find something in common with our fellow people. If when we went to a new place, we were just like, ah. similar but so shells are precious real estate for hermit crabs so when a large shell appears they will gather around to see if it fits

but if the shell is too big that's not a big deal of the hermit crab because it knows another larger hermit crab might come along and need it so the small hermit crab will sit and wait as more hermit crabs gather around the new shell and as they wait for the right-sized hermit crab to appear the crabs will form a line arranged from smallest to largest

so that when the right-sized one does appear and take its new shell, the next crab in live, can discard that crab's shell and then pass it down to the next and the next and the next and the next and the next. What the hell? How are they so aware of their bodies? You tell me, you are the one who loves and knows everything about hermit crabs. Okay, I'll hit the books.

It's wild to me that they wait, too. It's like, I know this is a good shell. Yeah, they're like, somebody's going to come by and take that, and they're going to leave a great shell for me. that's adorable well that was fun and that means that we have a tie going into the next round because you got one and one and then you both got hermit crab because you're a bunch of smarty pants we're just a pear butt cheeks next we're gonna take a short break you're the butthole Hank everybody knew that and then it'll be time for the fact off

All right, get ready for the fact off. Our panelists have brought science facts to present to me in an attempt to blow my mind. And after they have presented their facts, I will judge them and award Hank Bucks to the one I think will make a better TikTok. To decide who goes first, I have a trivia question. A meta-analysis published in the Journal of Pain Medicine found that music has charms to soothe the savage butt. The average person across 14 countries had lower heart rate, less pain, and greater satisfaction if music was playing during their colonoscopies. But not during their bronchoscopies. So that's interesting.

It's so relaxing that in one study, fewer people asked for extra colonoscopy sedation when they had music. So what percent? Fewer people needed extra sedation when getting a musical colonoscopy. Hmm. That seems like it would just be human nature. So 75%. That's so many. I guess that makes sense.

A lot of people listen to music while they exercise, too. And I feel like that's just a keep. Yeah. You were one of the 25%, sorry. I'll say 40%. Nice safe answer. It was 12.5% fewer people after sedation when having musical colonoscopies. This is very interesting to me because in the U.S., we always 100% sedate colonoscopies.

We put people 100% to sleep. Whereas in other countries, you just stay awake for it. And then if you have hard time, they'll put you to sleep if you want. Huh, I didn't know that. Wild. Because in other countries, they're like, why would we spend a bunch of extra money on that? But in America, we love to spend money on health care. Why wouldn't you?

As expensive as you can make it. So, anyway, that means that Sarah gets to choose who goes first. I'll go first because it's related. So we'll have the hermit crab transition. Okay. So many quarrels are colonial organisms that stay. put and let biodiversity come to them. They construct sprawling calcium carbonate structures for aquatic creatures to live in, on, and around, the coral reefs we know and love. But not all

corals are social beings. Some of them don't want to live in a huge community. They're loners, wanderers, such as the genuses, heteropsamia, and heterocyanthus. They don't look like much, kind of like an egg, which is the calcium skeleton, with some gooey tentacles sticking out on top, which is the invertebrate organism that can sting and eat and whatnot. Their common name is walking corals, but they don't have luxurious gams to do the walking. Instead, they find just one friend and hitch a ride on their butt. In most cases, we found walking corals attached to the butt

of a small marine worm called a sepunculid or a peanut worm, apparently because they look kind of like a gushy peanut, but I don't see it. And the coral skeleton provides shelter from predators, and as the worm crawls to new places, up to a couple meters per day, the coral attached to its butt gets dragged along. And as an added bonus for its tentacled protector, the worm brushes off extra sand and whatnot from the coral's body so it doesn't get all dirty and buried. It's a pretty good mutualism, two friends that grow up together over time. However, some other creatures are budding into this relationship and trying to offer the corals a better or just as good deal.

The hermit crab, Diogenes, heterop samicola, is kind of an oddball. It's super long and scrawny, and unlike most hermit crabs, has a butt that is not an asymmetrical spiral designed to squish into a snail shell. In fact, their butts are symmetrical, perfect for nestling right into a walking coral skeleton and whatever twists and turns lie within. So this is the first time researchers have seen a hermit crab that uses living coral as a house that it can grow alongside. And on top of that surprise, it's the freaking exact same mutualism as the sepunculin worms. So the hermit crab gets protection and can squish itself up into the coral cavity for protection like any other shell. And in exchange, the coral hitches a ride on the hermit crab's butt as it ambles around the ocean floor, though I don't have distances to compare with the worms. I assume the hermit crab can go farther.

And the real kicker is that the hermit crab brushes off extra sand from the coral to give it a little extra teal. see stealing the worm's signature friendship move. So somehow, this hermit crab has evolved to take over a really specific ecological relationship from a super unrelated species with a very different butt, which is very biologically weird. And walking corals, it seems, we'll take whatever butt they can get. So who knows what other creatures might try to offer a better deal in exchange for the coral protecting their backside? Hermit crabs are very perceptive. That's what I'm learning today. I mean, the more I learn, the more I love them. It's just so much interesting stuff about hermit crabs. I have so many questions about, I didn't even know that walking coral

existed. Explain again what the heck of walking coral is. So it's an invertebrate organism and they scatter polyps quite small. Yeah. And then once the polyp lands somewhere, so like it can be on a rock or in this case, it's usually like a little piece of detritus, like a shell fragment or something. Then it just sits there, plants itself, feeds, and then excretes the calcium carbonate skeleton. And so many corals live in colonial organisms where a lot of the polyps plant themselves in one spot. But walking corals are where it's only like one or two polyps that plant themselves on a small shell and then just grow big enough. They get big. Yeah. And then they stay kind of small. And then the worm like crawls into that shell into their skeleton and just drags them along.

But they're, like, way bigger than a normal colonial coral. Yeah. But walking coral is like, you know, like, they look like a shell. Like, it's like almost like a C-enemone, but it's got this like calcium carbonate thing surrounding. I'm looking at pictures and I'm just like shocked that these exist and I had no idea that they existed. They look like C-enemones, but they're corals. Oh, the hermit crab's so tiny as well. The hermit crab is real little and he's got a funny butt that fits into that walking coral.

And did they develop the little hole for the worm specifically? That I can't quite tell. It seems like it's a combination. It's like as it's growing as it's exuding the calcium skeleton, the worm is like, ah, protection. And so then it doesn't grow the skeleton for that, like over that hole. And then the worm does some maintenance to like keeping it carved out as more gets exuded as the coral grows. Okay. Okay. But if you see, like, the underside of a walking coral, then, like, there's a perfect little hole. It looks like someone drilled it in.

Well, I'm delighted, Sari. Sam, what do you got? Well, continuing the theme, mine's about wool worms. Wow. Plants, branch, fungus branch, but you know what's not generally known to branch? Animals. Yeah. We generally make do with one mouth, one butt. Why fix what ain't broken? Well, a handful of marine worms are brave enough to challenge that prevailing viewpoint. They're known as branching marine worms due to the fact that they branch. And they're marine worms. And they're also worms and they live in the ocean.

Everything seems pretty normal when you look at their heads. Got normal, just worm heads. Move up the body, still pretty normal worm body. But then when you get to where you might assume its ass would be, what you find instead is an expansive branching structure of tuby worm hind parts. And not just a couple. But hundreds or potentially even thousands of butt branches, each connected to the same main digestive system and each with its own anus. Why?

Well, hey, that's what I wrote next. Why so branchy? These little guys live inside of sea sponges and they grow to fill as many of the holes in the sponge as they can, which sounds disgusting. They want to poop around the whole sponge. Feels like the wrong end. I want to poop everywhere. You guys don't even know, and I'm about to tell you why you don't even know. you're talking about.

Most likely they're doing this to gather food, but there's another weird thing about them. No food has been found inside of these worms, but their gut seem to be fully functional. So what it eats and how it gets energy, if it doesn't eat, it's still a mystery. There's some speculation that the outside of the branching worm's bodies could be capable of digesting food just as well as the insides of their bodies,

based on the fact that their exterior is covered with like the kind of cilia that you find in intestines. signs and intestines. So basically, their entire body might be dedicated to branching out as wide as possible and touching and digesting as much like free-floating ocean crud as it can. But when you get right down to it, the unfortunate thing is that they've got all these anuses, but they don't need them for pooping. So it's a total waste of an anus, it seems like.

They don't need to, because there's nothing ever inside of their digestive system? Well, they must poop, but we haven't seen them poop. I think they'd be pooping all over the case. I feel like we would have seen them poop. With that many butt holes? You're looking at that many butts. One of them's got to be pooping. So since we can't figure out what they're eating exactly,

it's not also clear what relationship the worms and the sponge have, like if it's parasitic or symbiotic. It seems like it'll be parasitic. It doesn't seem fun to have a worm and you're poking all the little butts out. Every single place, yeah. Yeah, but that's not even all the weird butt stuff because sometimes their butts come to life. So branching marine worms can't leave their sponges because they got a sweet deal going on.

So instead, they grow a special butt, and this butt has eyes. and it has rudimentary guts and genitals, and then their butts break off and they swim off to have sex with other worms' butts. This is my favorite thing about marine worms is that their genitals become free-living organisms. This little guys. It's beautiful.

It doesn't mesh with our idea of what an organism is. It's like, so what's that, though? And it's like, that's just its genitals. That's my penis. See you later. It's doing its own thing. It has its own to life. No, I'll ask the genitals. Don't ask too many questions. Stop asking questions. It's the genitals.

It sounds like no longer a butt. It sounds like floating genitals with eyes. Well, it's a butt adjacent if you ask me. Okay. You've got to tell me if it poops. And what I'm hearing is it doesn't. Well, oh gosh, if it doesn't poop, is it a butt? Anyway, I have one where there's three species of these worms that we know of. One, cilius romaosa was found by the ancient. HMS Challenger in the 1870s when they dredged up some CBC sponges and they were like, ugh, these are filled with worms.

And then another one, Ramosilis, something, multi-Qaeda, was found in 2006, so pretty a long time later. And then a third was found in January of 2022. And it's named Ramosilis King Gidorae after Godzilla's three-headed hydra-like arch enemy King Gidora. And I had to mention that only so I could talk about King Gidora on Sishotangans. Though I don't know The episode of the day is butts

And Sam did bring a worm That has like a dozen A thousand butts Has a thousand butts You know it's not cool One butt You know it's really cool A thousand butts

He just did a little dance Everybody My story had at least two butts Worm butt Crabbutt And crab butt It's true Worm butt

A worm butt crab butt And you had a butt hole On a walking coral a special butthole that for an animal that doesn't even have a butthole. It's not a butthole. It's a butthole. It's a hole for butts.

This is difficult. So you guys tied coming into this. So it really is about whose fact is better, which you've made it very difficult. Sam, I would 100% be on board, except we don't, like I want to know, I want to be able to say how these butts work. Okay.

If I can find you video, you evidence of this worm pooping, you'll overturn this decision at a later time. It's the fact that we've never seen them with anything inside of their guts, which makes me think that that's not how they work. They just absorb nutrients. And so they're like trying to branch out as much as they can inside the sponge to absorb nutrients through their cilia. And they just absorb nutrients. They don't have to do digestion. But you also say that they have a functioning digestive system, but it's never full of food. There's too many questions for me. Oh, no. That's fair.

But they have so many butts. And also one of their butts breaks off and goes and makes babies. Sari says that's not even a butt, though. Now you're being sad and now I feel bad. Which is I know what you're trying to do. I'm very easily manipulated. It's Siri. Seri's the winner.

We're not going to let it happen. Congratulations. I love that I now know what walking corals are and also that they walk only aided by their little friends. Man, I feel like I've been for the ringer. That was very difficult. Congratulations, Sary, on your win of this episode of Sysot Tangents. And now it's time to ask the science couch,

where we've got listener questions for our virtual couch of finally honed scientific minds. It's from Connor on Discord, who asks, is there a scientifically best way to wipe? Like, material, stance, pressure, also posture, etc. The only science thing I know is front to back, particularly for people with vulvas. You don't want to get that close to the urethra.

You want to get that away. And then as far as anything else beside that, I'm just like bidet. Yeah, I was going to say. Scientifically, it's got to be best. I recently heard that there's 64,000 times more bacteria on the hands of people who don't have bidetes, which is something that I just made up.

Well, why would you do that? You didn't make up. I didn't. It was something like that. It was the butt fact from last week's episode. And it was exactly 64,000. But it wasn't what I said. It was like directly after wiping or something.

Yeah. Yeah. Not like generally just walking around town. Non-Baday people are covered in butt germs. Nasty. Yeah. Yes, it was after wiping. It was like four sheets of toilet paper compared to bidet.

Yeah. And then the bacteria on the gloves of wiping. Right. There it was. So is there a best way to wipe. wipe. Well, I think you hit on some of the big ones. So one of the big tenets of wiping is preventing infection and actually trying to clean it. So wiping away from your urethra, great idea, prevents the bacteria from going. We learned last week on the butt fact about poopy butts versus

bidetes. And so in general, what I could find is it all comes back to bidets or a little bit of water or moisture can help get into various crevices and clean up the poop residue better than a dry thing. But you also want to make sure that you're not leaving your butt extra moist because that creates just an environment for fungal stuff or other irritation in the skin. Also, it might lead to you ever saying the sentence or the words extra moist butt, which you never want to Swampass to use the common tongue. So that's like one

bit of it. I guess that sort of answers material question of like you want something sturdy, a little bit damp. I caution, I'm not a doctor. So I want to preface this, I'm not a doctor, ask your doctor about your butt decisions.

But wet wipes, which you might think be helpful with both cleanliness and washing vigor. And they can be in certain situations like babies have so much poop, an unfathomal amount of poop. You got to wipe it up with whatever you can. Yep. But wet wipes may introduce chemical irritants instead and create contact dermatitis in both adults and babies or any aged humans, specifically ones that contain methyl isothiazylinone. Oh, wow. Methylchloroisothiazillinone. Oh my gosh. Are two

two compounds. Why don't the wet wipes just have water on them? Yeah, I don't know. There's plenty of them that include like antibacterial, antiviral agents. These are, I think, often preservatives that keep the wipes moist and I don't know exactly, like the ins and outs of preservatives, but keep them fresh on the shelves.

So you want to walk away from the toilet with a slightly wet butt? Is that what you're telling me? No, you should not have your butt be a little wet. You should wipe a little wet and then make sure to dry it. Good. Yeah. The other part of this question is like stance and pressure. Stance doesn't really matter.

It seems like experts say whatever is accessible for you, however you can get your arm or limb or whatever down there. Wiping is better than not wiping. Yeah, I could feel that. Yeah. So wiping too little can lead to skin irritation, but also wiping too intensely also leads to too much irritation. It can mess with... Just got to find that goldilocks zone of the wipe. Yeah.

And I thought the American Society of Colon and Rectal Surgeons has given a name to people to the condition when you wipe too much and too hard. Can't wait. The technical term is called paritis oni, I think. But also the casual term is polished anus syndrome. Oh, no. Those birds have that.

The busters. We just really overzealously clean, whether it's through blister beadle or through rubbing toilet paper. Don't do that. Apparently dermatologists deal with this or like colorectal surgeons are like, you just wiped the heck out of your butt. Wow. Trying to clean it. And so just use a little bidet or a little water, and that could solve your troubles more than wiping so vigorously. I just have a question to ask to Hank Green.

When you Google polished anus syndrome, why would you click on images? I'm just going to leave that one for myself to be pondering forever. Like, is that just what I do now? I'm like, if I'm recording tangents, I'm like, show me a picture of that cute little worm. And I was like, nope, that's a bunch of irritated buttholes. Well, Sarah, thank you for doing the hard work here today. of helping us get to the bottom of the bottom. And we had an absolutely delightful time.

If you want to ask the science couch your question, you can follow us on Twitter at SciShow Tangents, where we'll be tweeting out topics for upcoming episodes every week, or you can join the SciShow Tangents, Patreon, and ask us on our Discord. Thank you to At Boots and Guitars on Twitter, Emily 17 on Discord, and everybody else who asked us your questions for this episode.

If you like this show and you want to help us out, super easy to do that. You can go to patreon.com slash SciShow Tangents and you can become a patron of the show. can get access to things like our newsletter and our bonus episodes and our cars to commentary. Very silly and very fun. And also, if it weren't for patrons, we literally couldn't make the show. Second, you can leave us a review wherever you listen. That's helpful and helps us know what you like about the show. And finally, if you want to show you love for SciShow Tangents,

just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sarah Riley. And I've been Sam Shultz. SciShow Tangents is created by all of us and produced by Sam Shultz, who edits a lot of these episodes along with Herokamatsushima. Our story editor is Alex Billo. Our social media organizer is Paola Garcia Prieto. Our editorial assistants are Dubuki Trakravardi and Emma Dauster. Our sound design is by Joseph Tuna Mettish. Our executive producers are Caitlin Hofmeister and Hank Green, who is me. And we couldn't make any of this, of course, without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be led to.

but one more thing the hoopoe bird is a beautiful striped bird who lives a very butt-centric lifestyle from cradle to grave the female hoopoe has a big sack under her tail feathers that swells up with liquid during breeding season oh no it's not just any old liquid it contains chemicals that make it smell like rotten meat and eggs oh worse so what could you possibly want to do with a butt sack full of stinky liquid well she rubs it all over her eggs of course the butt goo acts as a protective layer against bacteria and also as a way to signify to its mate that it's a good mother. And that's not even the only way that these birds use their butts. Hoopo chicks are able to shoot a stream of liquid shit right into the faces of predator's supersoaker style. And there's videos of it and it's great. It's H-O-O-P-O-E. If you want to watch a baby bird, just laser shoot some crap face. It's great. Oh boy.

I think if you just like coated your eggs in this in like foul smelling goop, it would be good for a lot of things. Like I would not, for example, try to make an omelette out of that. Yeah. I don't want this egg. No. Great. Congratulations. I don't know why we all haven't evolved that.

We need to do more with our butts. We haven't figured it all out yet. There's something going on down there. Of the powers that we heard about today, which one would you want to have? Well, our power is having a big butt, which is the. not a very fun power. It's fine. We can walk. You got to trade walking. You trade your big butt. I would like to have a corkscrew butt that fits into a shell. I actually like my butt just the way it is. I wouldn't choose to switch it for the world. Even if you could shoot a big laser beam of shit out of it? I don't want to do that.

I think I would want a wombat butt because they're just really sturdy and strong. And I could smash people with them if they got to. close. Hello, and welcome to Hello and welcome to The Lightly Competitive Science Knowledge Show Showcase. I'm your host, Hank Green, and joining me this all this week, as always, is science expert, Sari Riley.

Hello. And also a resident everyman, Sam Schultz. Hello. I would like to ask you to a personal question that's become increasingly important in my life, which is, when does it stop being fun for me to be pedantic? Because we all have seen it. We're like, here's the 93 reasons why this movie is wrong. And it's just like, no, no, no, no, that's not.

not good anymore, but there's, there's a place for it. How do I know when I'm being intolerable? Are you asking at what age you think you'll outgrow this or in a social context of like, no, I need, I need a boundary to stop me before I become one of those guys. I see, I see. Okay, because my age where I outgrew, it was like 18. As soon as I switched from high school to being in the real world. That sounds like it was a big win for for you and everyone you know. Yeah, my social. And yet I'm out here analyzing the predator's face and thinking, there's no way that those jaws could close because there's no, there's no, the musculature isn't there. On his little outside teeth. Yeah, on the outside teeth.

Yeah, on the outside teeth. I think it's maybe more fun if instead of saying this couldn't work, maybe trying to explain how it could work. Does that make sense? Yeah, I'd be like, here's where, here's where there would need to be some flesh on the predator's face in order for those outside teeth to be able to do any real damage. Because I'm not saying, like, there could be little muscles in there that could sort of, like, hold things in place. If you don't know, the predator's got two sets of teeth. He's got the big outside teeth. He's got little inside teeth.

The idea, I think, is the big outside teeth would, like, hold on and then feed the prey into the predator. But the real idea is that when he takes his mask off, he looks really scary to the people watching a movie. Yeah, it's good to have two sets of teeth if you want to be pretty upsetting. To double roar with. Yeah. Does he double roar? I think when he first takes his mask off, you're like, oh, this guy is not so scary. And Arnold Schwarzenegger's like, oh, I could take this guy.

But then he's like, I have another mouth under my mouth. And then I was like, no way. No way. The aliens have two mouths, too. They do. That is an interesting parallel. Yeah, which I think happens sometimes in nature. Like, aren't there some animals that kind of have a second set of teeth?

There are animals with multiple rows of teeth. Like sharks have multiple rows of teeth. But I don't know if there's like a second jaw. There's some fish that have like a mouth that bites and then inside of their throat they have like grinders. Yeah, they got some more teeth down in there. Sort of an extra set of like doing mouth like work. You're right. Pharyngeal jaws in a moraineal.

Don't put your hand down in there. Don't put your hand deep into an eel. See, now it's fun because you're teaching us something. Right, right. And then there's that I saw the tweet about this and it said, When the jaws open wide and there's more jaws inside. That's a moray. Which is my poem for the...

No, it's not. Anyway, we're here on SciShow Tangents. It's a show where we get together to try to one-up a maze and delight each other with science facts while also trying to stay on topic. Our panelists are playing for glory and for Hank Bucks, which I will be awarding as we play. And at the end of the episode, one of them will be crowned the winner.

But to start the episode out, after you guys have made me feel a little bit better about myself, we're going to have the science poem. this week from me. An important thing when life begins is to keep outside out and inside in. That's really almost the whole basis of a little thing we call homeostasis. There's a border between living and dead between what you see and the eyes in your head. For you, it's about two square meters from the top of your head down to your feeders.

The largest organ you have in your body. Yet if I can see the whole thing, it's a little bit naughty. Keeping the outside in, keeping the outside out and the inside in, it's all eight pounds of your wonderful skin. That was good because you gave no indication that you were about to do a silly rhyme like feeders. And up until then, it was so straight late.

Well, I was having a problem. All right. Yeah. There's not a lot that rhymes with meters. And I wanted to talk a little bit about the sort of specifications of our topic for the week. which is skin. Sarah, what is skin?

It is an organ. It is a protective organ, and it has a lot of other stuff in it. But skin is only skin on vertebrate animals, which I thought was interesting. So, like, biologically speaking, skin is skin invertebrates, and it is not scales, it is not feathers, it's not hair. Okay. What? Right, right, right. Yeah, okay.

But all those things stick out of it. Oh, but birds have skin underneath. Yeah. Invertebrates either have, like, a. an arthropod exoskeleton, or a shell, or if you get to the goosy bits that are like a slug or a snail or a sea cucumber, that's just tissue. I don't think it's specialized enough to be considered skin, like a barrier. Right, like a jellyfish doesn't really have skin, it's just like a...

Just got goo. The tissue actually has to be different from the other tissue in some way. Yeah, to be considered skin. So one thing I know from teaching anatomy and physiology once, even though I was not very qualified to do that is that um so there's epithelial cells is like the kind of cell that we have on our skin we also have it in non-skin places we have it sort of on all the places that sort of experience the outside in some way and so i'm curious at the points where we transition from having like the caratinous like the place where the epithelial cells uh like leave behind dead

like hard carotin stuff that is the stuff that like makes up skin that's like hard and it's harder to like cut through or scratch through versus like the inside of our lungs which do keep outside out and inside in like they're still doing that work or the inside of our digestive systems which our digestive systems are covered in epithelial cells but like it's not really skin it's wet it's delicate you can easily scratch it and and have it bleed uh what it is basically i'm asking is my tongue covered in skin it's my throat covered in skin is my rectum covered in skin It's my colon covered in skin. It's got me more like a slug, right?

Your rectum and colum is a slug. And that's tissue. Is that right? That's what I would think. Not about it's a slug, but that it's like a separate tissue. I'm glad to hear that my rectum is not a slug. Your rectum is a hollowed slug. Yeah.

Which is basically a worm. No, I think it's because, like, your tongue is an organ and it's muscle tissue in the way that, like, your heart is muscle tissue or your intestine is. It is epithelial cells, but it's different than the epidermis. It's a muscle covered in epithelial cells, which is just like my calves, too. Yeah, but there's other stuff. The composition of their epidermis is different than the composition of your tongue in that. It has elastin and keratin and other proteins in it and glands. So sweat glands, sebaceous glands, like oil glands, hair follicles, and layers like that that you don't have present in other organs.

And I think in the way that an organ is a collection of similar tissues, your skin has those elements as a part of it. Right. I bet that there are some people who would argue that all of the whole digestive system is kind of skin. And I would love it. To what end, though, Hank? This is your new is buttlegs, is lip skin. Where does your skin stop? And where does the rest of your inside begin?

Is rectum skin? So, Sary. I feel like we got a fairly good idea of what skin is. Do you have anything else to tell me about it? I do. I have some word origins because it's kind of a mystery. A linguist said the answer lies hidden in the depths of civilization. Sure, sure.

That sounds right for a lot of these things. But as far as I can tell, there are two different words for like the covering of our body. One category of them. So the root word of cuticle and the, the root word of hide, like the hide of an animal, are the same, which is S-K-E-U, which means to cover or conceal. So it's like the idea of this coating that is concealing you and is like your outer layer. That makes sense in the way that we refer to like a cuticle, mostly like an insect cuticle or something like that. But the word dermis or like any sort of dermatology, dermal, epidermal, and the word skin both come from root words that mean to flay or tear or cut, which is like a very violent origin and action.

Right. Like the verb to skin. Yes, like the verb to skin. And I think that's because as we trace these words back, they kind of converge with the idea of. of, like, human skin is equivalent to non-human animal skin. And the way that we processed that was to, like, cut it and flay it and turn it into clothing. And we just used the same word, even though we didn't cut and flay humans as often. I guess it did happen. Humans are violent to other humans. Much less frequently. But, yeah, but we're like, oh, we're made of the same stuff.

The exception to the rule. So it's the stuff that tears. It's the stuff that can get split over. We had a word for the thing that was useful and the process of acquiring the thing that was useful. And they were like, oh, I guess, like, we need a word for this. Now we'll use that one. The doctors need a word. Here you go, doctors.

Yeah. And then from there, I think once we had the word for human skin, then skin was then extrapolated even further. So we had animals first, and then we were like, oh, we're an outer layer that can be flayed. And then we looked at pudding and we're like, oh, that's a skin. Or like, this fruit, like, oh, that's got a skin. too, I guess. Yeah, yeah. It became any old, any old soft covering.

Yeah. Okay. Ew. Now that we know what we're talking about, it's time to move on to the quiz portion of our show. Today we're going to be playing skin, truth, or fail. Being self-conscious about your skin can feel like a very human experience. But actually, other animals have to contend with the superficial issue of how their skin looks to potential mates. and also to predators, and even to prey.

The following are three stories of animal skin, but only one of them is true. Which one is it? It could be fact number one. Fish scaled geckos use their large overlapping scales to gather and store future meals, luring unsuspecting insects with scents produced by their skin and trapping them with their scales until they scratch their meal out. Lovely. Or it could be fact number two.

When trying to attract female bats, the male wrinkle-faced bat covers the bottom half of its face with a flap of white furry skin that they only take down when it comes time for copulation. Great. But that could be fake. It could be fact number three. To ward off sharks or other predators, the octopus granuladone Pacifica, maybe, craft fake warts out of ocean debris with the goal of making their skin seem infected and thus unappetizing. So it could be fact number one. Geckos trapping their meals with their skin and scales. Fact number two, ugly bats using a face mask of skin for mating or fact number three,

Creative Octopi making their skin a warty for protection. Ugly bats. They're probably okay. Yeah. Well, I don't know. Why else do they hide in? They're just self-conscious. They're like every protagonist of a Y-A novel of like, I'm secretly, I'm beautiful, but I hide it.

Right. Behind my skin flap. Do you take the glasses off and it's like, oh, she was pretty the whole time. Gosh, the gecko one, is that it as a gecko of some sort? It's a gecko. That one seems like something that we absolutely would have made an episode of syshow about. So I just can't believe that we. That's a dangerous road to go down.

Why? Yeah. Because we're all, like, we frequently get sci show episodes from tangents. Well, yeah, but happens all the time. We would have seen this guy. I would know about him. A little guy who keeps snacks under his scales. Yeah.

Yeah. A little, like a top pocket, but a bug scale, you just... I would have seen this by now. So the octopus one, not to tip my hand too much. That one seems like it would really require an understanding of, like, disease, like, what being sick means and stuff on the part of the octopus, I guess. Not really. It just on the part of the shark.

Like, if it works, then the octopus is going to eventually. maybe figure it out, but the shark does need to be like, ew, gross. I don't want that gross octopus. And I could see it being an extension of camouflage in some way, like octopi, octopuses already change skin texture when they can, or cuttlefish do, I think. Some sort of cephalopod can change skin texture. And so I could see them also modifying that way, like, I'm going to stick some sand on me, stick some rocks on me and it works for some reason but and and like the humans are extrapolating

that it looks diseased rather than the octopus headed into it with that mentality of like don't let me go to school today don't eat me please I also don't think sharks are discerning enough eaters for that to matter but I don't know I don't know anything about sharks but all that being said, I'm going to go with whatever the middle one was. The bats? Yeah, the bats. Yeah, the bats with a masked bats. That seems very not real also, but oh, well, I've already decided.

I don't like choosing the same thing as you, but I'm also leaning towards the bats because it feels like something unnecessary. There's so many things that feel like unnecessary mating rituals. Like, ah, I just have like a big green feather. Oh, look at my large black wings. And so all of the dumbest things are sexual selection. Yeah. And so it'll be like, oh, he has a very good face flap.

And it stretches so big. It covers so much of his head. That means biological fitness, maybe. So I think it's that one. And bats have really fucked up faces anyway. So they probably, you know. Again, you don't even get onto the bats. These are wrinkle-faced bats, though.

And if you Google them, you will see that if not true. Traditionally attractive. They're cute. Are they? No, they're horrible. They look like the predator, but with only one mouth. They're a living nightmare. They are very sort of like roar shock test of a face.

Yeah, that's not what you want for your face, generally. No, I don't want it for my face, but I think it reminds me of being cute in the way like a pug is cute, where it's like, oh, you feel a little bad for it. Yeah. No, there's too many ridges on this guy. Yeah, that's a face only an echolocator could love. And the fact, you guys, is true. Two winners doesn't happen often. Yeah, I can see his little flappy right here.

You can see his little flappy. So, Riggle-Faced bats live in forests in Mexico, Central America, Venezuela, and Trinidad and Tobago. But sightings of them are very rare. So bat researchers were excited in 2018 when a pair of nature guides stumbled on a rare group of them. When the researchers went to watch them, they found that there were as many as 30 male bats perched in a group

trying to attract a mate. But, oh, God, they're lecking. Lecking also is a thing that when, like, males gather to, like, display to a smaller group of females, that's what you get so many weird situations of display. Like, it's always the weirdest displays are from lecking males. Anyway, what is especially weird

is that while they were trying to grab, a female bat's attention, the male bats would cover the bottom out of their face with a weird flap of skin covered in white fur, and then they'd chirp through the mask. The skin face mask would remain in place until they found a mate, at which point the bat would lower their mask until done. That's what it says. The female bats don't have the mask, and researchers aren't quite sure why the male wrinkled face bats have this mask. One theory is that it could be a way to signal females that they are ready for mating or it could be a way to trap olfactory secretions that will be released during mating. So just get all the secretions all jumbled up and held in there

until it's time. Unfortunately, it's been hard to find these bats again since the 2018 sighting, so it may be sometime before we know for sure. So the geckos is very weird. We almost could have used this as the fact because I think it is significantly weirder. It was so weird that, I don't know, Maybe you wouldn't have guessed it. But there are fish-scaled geckos. They are notable because they have very large scales that can reach up to around 8% of the gecko's body length. And unlike other geckos, whose scales lay flat against their bodies,

these scales are super large, and they're only partly attached to the body. And the scales are notable because one species has been observed jumping out of them when trying to escape predators. When a predator grabs the gecko, it can jump out of this. skin holding its scales into skate and then it will regenerate the scales and the skin and i'll put up for our video viewers put a picture of this up if we can get one because it is awful they look like oh it looks like a chicken like a little chicken breast my little chicken breast yeah just like a chicken breast so just horrifying horrifying animals for this week's episode of

tangents. They're so cute when they have their skin on, though. Yeah. Then they're just like, whoops. Yeah, which is true. I mean, it's true for most things. When you lose your skin, you get a little less cute. You're significantly less cute, yeah, I suppose.

As for the octopuses, there are, there are warty octopuses, but this is only notable. They have, like, really little ones because it's a way to differentiate between two very similar species of Pacific Ocean octopuses. But no, no fake warts just word on. off the sharks. Sharks ain't doctors. They're not going to know. They don't have any idea. All right. It's one to one. We're going to take a short break and then it will be time for the fact off. Bad dogs. Our panelists have brought science facts to present in an attempt to blow my mind, and after they have presented their facts, I will judge them and award Hank Bucks any way I see fit,

with preference going to those who are giving me good topics for sci shows and TikToks. But to decide who goes first, we have a trivia question. Are you ready to answer it? Yes. This is my favorite part of the whole show. Sebaceous glands are small glands and mammalian skin that open up into a hair follicle. These openings also serve us away for the body to release sebum, a mixture of fats and cellular debris that keeps our skin from losing too much water. These glands begin forming when we are developing as a fetus coming after the formation of hair follicles and epidermal tissue. What is the earliest point in weeks of fetal development at which these sebaceous glands begin developing? Sam's over here multiplying nine by four.

Yeah, I don't know that, first of all. I have so little experience with babies and pre-feet, pre-babies. I'm going to guess 22 weeks. Okay, 22 weeks. These usually get picked when the answer is shocking. So I'm going to say like 32 weeks. Oh, like really late. Yeah.

I thought you were going to go a little earlier. I thought you were going to run away with this one because it's 13 to 16 weeks. of fetal development. After we're born, we don't usually develop new glands. Instead, they just get bigger as we get older. So they're in there, ready to go. So we've got all of our sebaceous glands, which is wild, because we get quite a bit larger. We get so big, yeah, but we just still got a lot of holes, the same holes. Yeah, a lot of holes. Don't say that. Well, you know, We just have the one mouth. So at least there's that.

Okay. I'm hungry. I would like a pocket cookie right now. I'm also really hungry. All right. Do you, Sarah, do you have a fact that can make me not hungry anymore? Oh, no. It may make you thirsty.

So I'm ready to go first. All right. You want to go? Yeah. Straws and other kinds of drinking tubes are marvelously convenient invention. Have soda. a cup that you want in your mouth, suck it through a straw, have water in a backpack that you want in your mouth, suck it through a rubber tube. Even trees kind of have

straws inside them. Their xylem extends from their roots to the leaves, and they create suction to help draw the water up. But humans aren't the only animals that have figured out the power of the straw. And in fact, some lizards basically have a bunch of straws in their skin. The thorny devil is one of these lizards, a super spiky ant-eating reptile that lives in the Australian desert. The morphologically weird things that we can see are the caratinous spikes all around its body, but those are covered in a watertight layer of skin called the Oberhauschen, which I think is great. German scientists got there first. And a layer of small scales. And if you take a closer look, like with a microscope, beneath their scales, shaped from

the skin cells of the Oberhausen, there's a network of five to 150, micrometer-wide grooves, all leading right to their parched little mouths. And so even without suction, water can sort of crawl its way along certain surfaces, like partway up a straw or along a paper towel. This is called capillary action, and is because water molecules are pretty good at adhering to other surfaces and cohering to other water molecules. So when a thorny devil stands in some wet sand, the water travels through capillary action into those grooves and its skin and eventually to its mess.

mouth. And when researchers have plopped thorny devils in little puddles of water, they just sort of stand there and open and close their mouths because they're drinking with so little effort like a beer can hat but built into their body and the beer doesn't have to be in cans. They just got to stand there. And this so-called skin capillary system has been measured to contain water that amounts to around 3.19% of the thorny devil's body mass. And it works no matter where the water hits their body, which is why these reptiles rub their bellies in dew-covered sand and flick it on their backs, not for a dust bath, but to prime their skin with water so that they can suck up even more thanks to the stickiness of water molecules.

So it's not easy living in a dry, dry desert and conserving water, but apparently having skin straws is one way to do it. Ah. That's awesome. They look great. Is there any, the thorns have nothing to do with this? No. Surprisingly, they don't. Those are all just like, I think, intimidation factor. Maybe something to do with eating ants, yeah. But it's all beneath the thorns, beneath the scales.

It's in their skin that this is happening. It's in the skin. How does it get to their skin if it's beneath all their scales? I think there's gaps in the scales. Like they're not as tossing them away as the fish scale gecko, but they're not like totally locked together. like body armor because their pointiness keeps things away probably if i was going to be some kind of species from other planet i think i might like to look like that just like a big guy who looks like that yeah you'd be like i could just like walking around on two legs that would

be pretty cool just like super scaly and thorny and also if i want a beer i just pour it on my back you could sit in a big puddle of beer drink it to your butt opening and closing? Knaop, nap, nap. It's like, I get out with my father, and I'll have put my hand in the beer. No, gna, no, no, mom. That was good.

All right, that was great. Sam, what do you got for me? Oftentimes, a luxury beach vacation will include a visit to the spa, where your skin is pampered by things like seaweed wraps, pumice stones, lotions, little cucumbers on your eyes. I've never been to a spa,

so this is just kind of what I guess it's like. Yeah. You ever been to a spa, anybody? Oh, no. Yeah, but I've never gotten any of that. Never got the cucumber eyes? Just a back rub. Well, anyway, there are some creatures for whom every day seems like a luxury beach vacation, like dolphins, for example.

And according to a May 2022 paper, they also may be treating themselves to the occasional spa day. A diver and dolphin researcher named Angela Ziltner has been observing dolphins in the wild for a long time. But when she was diving in the Red Sea, she noticed the dolphins there were doing something that she'd never seen before, rubbing and scratching themselves on coral. This isn't totally unheard of behavior in cetaceans, but dolphins are not observed doing it very often. And as Ziltner watched them more, she noticed that they weren't just scratching willy-nilly like a dog scratching his butt on the carpet or something. They were rubbing very specific areas of their body with very specific types of coral. So coral is super weird, to me at least, in that it looks like rocks, but it ain't rocks. And one of the least rock things that it does is excrete mucus.

And it does this for lots of reasons, like to avoid drying out if it finds itself above water somehow, or to block UV light, or, and this one's important, as protection against outside pathogens and sediment? And what is a dolphin, if not a big, weird, sediment-y pathogen, if you really think about it? So the researchers got really up close to dolphins rubbing themselves, and notice that as they rubbed, the coral started producing mucus that would end up smeared all over the dolphin. And they seemed to use two different types of coral to treat different types of skin. Rushy Gorgonian coral for sensitive spots and a type of large, ridged, leather coral for harder areas like their foreheads. And both types produced mucus when rubbed.

So they took the coral back to the lab and found at least 10 compounds in them with antibacterial effects and 17 total compounds that are hypothesized to do things like balance a dolphin. skin microbiome, hydrate their skin, or improve the elasticity. The researchers also observe these dolphins visiting the coral after waking up from a nap, like they were waking up in the morning and going to go take a shower, but just at the coral, and they'd even line up and wait to use the coral and wait their turn for it. So the next step of the research is figuring out if this is a natural impulse, like the aforementioned dog butt scratching, or if dolphins know that the coral contains

some kind of medicinal thing and seek it out consciously. But, I mean, either way, we can find yet more commonality with the animal kingdom in our mutual urge to hit the spa and treat ourselves. Are the corals okay? I don't know. Sometimes I said that they got so excited, the dolphins, that they would, like, bite chunks off the coral and go, like, woohoo. I'm like, oh, my head feels so good. Yeah. That they, like, really would get amped when they were visiting this coral.

So probably, you know, sometimes you get in a back rub and you just kind of, like, just let them have it. Yeah, I suppose. What do you mean? Just punch him in the chest. Yeah. You're like, oh, that felt good. Woo! I would guess the coral.

You grab the oil and just sort of sling it around the room. I guess the coral doesn't love it. I know. It seems like it might be a little, well, it's producing the mucus to protect itself. Yeah. And it often is like, yes, more. This is what I want. The good goo for me, please.

You need that goop. This is one thing we should remember. That other animals will totally exploit nature. if given the chance. Sure. We're bad, but everybody would be. If you, like, let dogs have as much power as we do, they'd wreck the whole planet. That would be a really big disaster.

Sure. No doubt. Now, the second, to protect the corals, if this is a problem, can we just put, like, some good lotion down there? Oh. The other thing I'm worried about is if people are, like, you know that it were, like, three like telephone messages away from the beauty industry being like dolphins yeah have been using this since the dawn of time to soften their supple foreheads yeah and now you too

can have a soft dolphin forehead that's no good if only we just irritate coral industrially yeah yeah i was thinking that as i was reading it maybe we need to censor this episode so that the secret is not but it's like say if anybody does this You can come back here and know that we preemptively called them a bad person. Yeah. So I have to choose between our two facts, which are Thurny Devil with Capillary Skin Action or Dolphins having Spot Ais. Everybody loves dolphins. You guys are tied right now, too.

Everybody loves dolphins. Everybody loves coral. Everybody loves stras. No, everybody hates. Sure, everyone hates straws. That's true. But maybe that's a voting in favor. It's like, here's a new way to do straws.

You don't have to use a straw. You can just kill a lizard. What's just more fat? Oh, it's the lizard. Like, there's been a number of times I've heard about dolphins, like, doing weird tool use now. And so I'm a little bit more used to it, whereas a lizard that can drink just by sort of like, belly and up to a moist patch of sand. and then making its mouth go funny. It's just funnier, and it's more surprising.

I'm sorry, Sam. Sarah's the winner of today's episode of Sideshow Tangents. Think her judgment is slipping. All right, well, that's an extra Hank buck to Sarah. No. You can't give Hank bucks in anger. All right, that means that it's time to ask the science couch, where we answer listener questions for our virtual couch

of finally honed scientific minds. Vita Bjornin on Discord asks Is the skin on different parts of your body Different like big skin moisturizer wants us to believe My wife has an entire skincare routine And I use the same soap for my head, face, body and teeth Not actually teeth It's great news

And it is on dolphins at least we just learned huh Yeah, I got different forehead skin for sure on a dolphin Yeah Skin is different on different parts of the body And that's all I know It does vary across your body. It's not just big skin moisturizer. It's big anatomy and physiology.

They want us to believe it, too. There are generally two types of skin, but then, of course, there are subcategories. But it's, there's, like, the thin skin that has a lot of, like, a variety of glands and hair follicles. So, like, thin and hairy is how one source described it. And then there's the rectum. Yeah. Well, thick and hairless. There's the other, which is like hands, feet, face is kind of like thin, like mixture.

I don't know. Lips. Do you say thick and hairless? Pretty hairy. Yeah, I guess. Thick and hairless. But yeah, it's like depends on what the skin is, what the skin's main purpose is. Like, is it for protection or is it?

coming into contact with other surfaces like paw pads do or our hands and feet do. Yeah, paw pads. Right. And the different areas of our body have different like compositions of, I mean, you can look at like how hair follicles differ across skin. Like that's the most visually striking difference in different parts of our skin is the different kinds of hair follicles that grow. But when you look at the glandular level as well, then there's quite a big difference.

So, like, your hands and your souls of feet don't have any sort of glands except sweat glands. So they're really good at getting sweaty, but they can't really get oily. They can't really get hairy. They can't get smelly in the same way. Because they don't make the sebaceous stuff. Yeah, they don't make the sebaceous stuff. And I don't think they have the apocrine sweat glands, which are the smelly ones that are in, like, armpits, genital area, puberty places. Sari did kind of just say that feet can't get stinky.

They can just differently. Yes, they just get differently. They get stinky because all your sweats there and then there's bacteria. It's not because the glands are. And skin cells. And skin cells, yeah. The bacteria are making it sweaty as opposed to, like, the sweat being smelly in and of itself, I think. I don't know.

Even in the apricrin, in the case of apricon glands, it's mostly what you're, I think, mostly what you're spelling is the bacteria, the byproducts of the bacteria could. consuming the stuff that the African glands make. Yeah. I think. So is it okay to use the same soap on your whole situation? I think that there are small differences that probably matter a little bit. And I definitely have been criticized for using body soap on my face, but I still do it.

Yeah, I think it depends on what you put your body through and also like, So much of so much of skin care is advertising in some way, like companies trying to make us feel self-conscious about a thing to then fix that problem. That wasn't necessarily a problem. And so, yes, there are different treatments for different parts of skin. And I like to default to medicine because that feels more concrete than like something subjective, like acne in a non-medical sense. But aloe vera, for example, has been used for centuries upon centuries of human care for, like, burned skin or dry skin because it's mucusy. And we already produce mucus to help moisturize things. We produce oils and other things.

So, like, adding that onto your skin helps fix a problem that you identify with either your environment or, like, some damage that you caused. So in that way, skincare is a science. much of modern skin care is just like inundating people with products. And so the people who are doing the real science work are everyone with their little spreadsheets of like, okay, what does this do to this kind of skin? Yeah. It's also very personal. Like different, like skin is very like individual people's skin is all very different. So like the kind of idea, especially the idea that one person would say to another person, you're doing it wrong is I think something to avoid

because we are all all have our different situations and if it's working and it's not too expensive and it's not like a clear placebo effect I think that's fine all right thank you for your question Vita if you want to ask your question

to the science couch you can follow us on Twitter at SciShow Tangents we tweet out topics for upcoming episodes every week or you can join the SciShow Tangent's Patreon and ask us on Discord. Thank you to at Organic Bypass, at How About That Jazz and everybody else who asked us your questions for this episode. If you like this show and you want to help us out, super easy to do that. First, you can go to patreon.com slash SciShow Tangents to become patron and get access to things like our newsletter and our bonus episodes. You can also watch us on YouTube at

YouTube.com slash SciShow Tangents if you like it that way. But whichever is great. Or both. Or both. That might be a bit much. You can also. Also leave us a review wherever you listen. That's very helpful, and it helps us know what you like about the show. And finally, if you want to show your love for Sci Show Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sarah Riley. And I've been Sam Shultz. Sy Show Tangents is created by all of us and produced by Sam Shultz, who edits a lot of these episodes, along with Seth Glicksman. Our story editor is Alex Billow. Our social media organizer is Paolo Garcia. Our editorial assistants are DiBoki Chalk Rivardi and Emma Dauze. Our sound design is by Joseph Tuna Meddish. Our executive producers are Caitlin Hoffmeister and me, Hank Green. And, of course, we couldn't make any of this without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted.

But one more thing. Parasitic. blowflies lay eggs that hatch into maggots that burrow into an animal's skin, causing an infestation called a fly strike. That's the real name for it. The stuff of nightmares.

My friend of mine had one of these, and she just loved to, she loves to tell the story. It's her favorite thing, and I'm like, no one else likes this. This is especially a problem for Marino Sheep, so not just my friend Bethany, but also

for Marino sheep, who grows so much fluffy wool on their butts that poop and pee gets crusted on and it attracts blowflies, causing nasty infestations and even death. Oh, no. So a common but controversial way that Australian shepherds have managed fly strike is by, I don't know how to pronounce this word, mule sing, M-U-L-E-S-I-N-G, cutting away crescent moon-shaped slices of skin off of sheep butts so that it grows back as scar tissue without hair follicles. These bare butts without poop stink

are much less likely to be appealing to blowflies. They cut their butts off? I hate that a lot. They cut their butt hair off. There's got to be a better way, Australian Shepherds. There must be a better way. Oh, get them diapers.