Tardigrades: Nature's Cuddly, Indestructible Microanimal

They're cute them, they're tiny that not hardly anybody knows what they are. I would say they're I would say of people listening, do not know what this is? Really? So I was under the US and that they were kind of a big hit on the internet within the last couple of years. Well, I'm not happy to that stuff. So maybe, okay, it might have been a part of a meme. I don't know what political meme. Yeah, I think I think tart grades had a had a moment. But it turns out that they they've been around for

much longer than the Internet. Yeah, yeah, hundreds of millions of years. Yeah, somewhere around the neighborhood of six hundred million years, which would make them Precambrian explosion, which makes them really old PC. Yeah, so before we get into that, let's tell you what we're talking about. A tart of grade also known as a water bear. Cute name. This is my favorite moss piglet um pigmy rhinoceros pigmy armadillo.

I don't like armadillos ever since our lepers episode. UM. They are a little tiny micro scopic animals, animals, multicellular animals that UM reproduce sexually. In a lot of cases that UM are well, they're animals. They're not just like, they're not bacteria and that viruses. They're not bugs. They're very very small. They get to be about a half to one millimeter in size depending on the species. And UM.

They're also super cute depending on your view of things. Yes, first thing you should do, if you're at home or if you're not driving, let's say, is pull at your phone or your or your desktop, pull out your desktop and look up charted grade and just look at a little picture of it, and you know, so you know what we're talking about. UM, if you ask me. People liking it to a panda bear. I don't quite get that, although the have Have Have you seen the picture of the

one on its back? No, I don't think I did. Very cute. Looks like you just wants to maratches a little belly. But it looks to me like if moth caterpillar and a naked mole rat and unholy union. That was awesome. That was the best analogy of that. That's kind of what looks like to me, um holy, I think, yeah, they managed to do it somehow. Tells uh the name tarte grade is from Latin and it actually means slow walker, which is cute in and of itself, and that supposedly

was named by um. This Italian scientists named Lazaro Spitzani. Tell him the name of his book. I love this name. His book was Oh boy, Opa scorely de Fistia and Nimala. The bield not bad, not bad. You didn't raise your your fingers though, that's right. But he named this guy he found this well, he didn't discover it. Apparently before him. In seventeen seventy three, a German pastor name Johan all Goes from gets Uh discovered it. But he is the one Spottsani is the one who named it uh, which

means slow stepper. Yeah. And the reason he called it that is because if you look under a microscope at all the stuff, which was all the rage in the late eighteenth century, look at all this stuff. After why was his name Anton von Leavin hook Am I saying that correctly? I don't remember. I'm pretty sure. Um. After he started to invent microscopes, and they there you spread, people started looking at what was in debris and rain gutters.

The added water to it, and they found that when you add water to stuff that was just dried up dust and a rain gutter, all of a sudden you saw that there was a bunch of things that came to life. And most of those things move around really really fast, just starting about like, oh, it's over here, let's go over there. I want to go over there. They have like very short engine spans, right tartar grades

lumber about. They kind of fall and flip over a lot as they're climbing over like pieces of dust and other particles. Um. And they move much more slowly and and I guess deliberately compared to their other microscopic friends in the in the rain got or debris, so that's where they got their name. Um. They have eight legs, a little little short, little stubby legs right into their rear legs are inverted right, so they're facing forward instead

of backward, and they face backwards. They face backwards instead of forward. And all their legs have little claws at the end right for climbing, for climbing, and the first three pairs of legs are used for swimming. The back are you're used for climbing only in rudder work the front with battle and they steer with the rear they make dream hands. Uh. And what are they climbing over? Well,

it depends. You can find them all over the place, um, but mainly if they're on dry land, they're they're living in moss, fallen leaves, um, stuff that you would find in a gutter lichen. Yeah, yeah, things that typically um have moisture in them because water bears tartar grades UM survive when they're surrounded by moisture. Right when they're amid moisture, freshwater, salt water doesn't matter, No, it doesn't inventil the kind

of course. Right. So there they apparently originated in the sea because the species of tartar grades that are marine based are the least evolved, I guess you'd put it. Then, Yeah, you've got freshwater ones, and then you've got ones that are terrestrial that you can find on land, and those are the ones that live in lichens and moss and stuff like that. Um, and all of them again are part of this branch of the family tree that's its

own phylum. Tarta grata is a phylum. And this article makes the point that, um, if you look at humans, where where we share a phylum Cordata with like snakes and um, every other vertebrate on Earth. Right, these guys have their own file there, in their own club. They really are. So that says two things. That they're a very ancient line and that there's a ton of them, a lot of them. Yeah. And there are there's water

bears everywhere. Yeah, and we mentioned that they're animals. And if you look at a picture, it's probably from them all. Not probably, it's definitely from a microscope. And so you know you think that again like it's just some sort of bacteria or something, um, but it's not. It is an animal. It has a brain as a nervous system, It has a little stomach and little tiny intestines, has a little tiny anus, little tiny esophagus, and uh, they

don't have heart and lungs or veins. Because I was gonna say open source, they are open uh hemail, as the lady on the internet said, which means that gas exchange and nutrient exchange happens because every cell in the tartar grades body is touching the the interior body cavity. So as food and air goes through the mouth and out his tiny venus, right, Um, those nutrients and those gases get to get passed into the cells that get pass that that it passes by. Yeah, it's like a

studio apartment. It's actually extremely efficient. Sure. So they're about a thousand species or more of tartar grades um. Six hundred or so on land, about three hundred marine and about a hundred in the fresh water. Um. They lay eggs, some of them have sex, some of them don't. Some of them self fertilize. Yeah, that's pretty interesting stuff. Else, they eat the fluids of plants or they some of them are carnivores. Yeah, the fluids of animals. There's always

got to be fluid. Yeah, they have like a piercing mouth part. I believe that can pierce cell wall and just suck the fluids and proteins and stuff out of a cell. And depending on the species that cell, maybe plant based, or it may be animal based, including other tartar grades, which is decidedly less cute cannibalism. Sure so, if you're sitting there right now and you're thinking, I don't see how this rivals and octopus, these are just tiny,

little maybe kind of cute, but tiny little animals. What's the big whoop? Uh? Right after this break, we'll tell you what the big wholp is. All Right, we're back with the big whoop about tartar grades. Despite the size of these things, how big were they? Again? Uh? In a if you look at a magazine article, they're about half the size of a period at the end of a sentence. That's a what's a magazine? No? No, that's true, you say that, but it's true. That's a good way

to put it though. So they're that tiny, and they are one of the toughest, most resilient creatures on the planet Earth. Period they're probably the most resilient animal or organism on Earth. Amazing. All right, let's talk about it. Let's talk about temperature. Yeah, they like it that like seventy degrees and nothing else. Right, So, well, what's weird is there's this longstanding tradition and biology of trying to kill tartar grades under really not so conditions. Let's see

what these little guy can take. Basically, I'm not quite sure how it started, but somebody figured out um fairly fairly early on that they could withstand amazingly cold temperatures. Right, so we're talking like down to basically absolute zero, a couple just a couple of degrees above absolute zero. And to understand how crazy that anything could survive at absolute zero.

That's where like atomic movement based ceases, because absolute zero there's no movement of atoms or molecules any longer, right, because that's what he does. Heat energies the movement of atoms and molecules, so cold, by contrast, is the cessation or the lesser movement of atoms. Right, we're talking negative to seventy two celsius negative fahrenheit. So targe grades have been kept at that temperature for twenty hours and then thought out and they said that's what you got. You

got a tickto this is great. I think I fell the fly on my shoulder. Uh yeah, seemingly unharmed. Um. They put them on ice uh at negative two hundred celsius and not absolute zero, but they've iced them down for years in a row, thought them out. They were

right back to normal. Amazing. Then on the other side, they've exposed them to extraordinarily hot temperatures like a hundred and fifty degrees celsius and um, we should say so the fact that they're surviving that's like, wow, fifty degrees celsius. That's hot. Absolute zero, that's cold. The reason why it's so incredibly just mind boggling that Tarte grades can survive this and still be animals is that they appear to

be the only life that can survive these conditions. The reason why is if you freeze and your multicellular your cells are liable to freeze themselves, and there's gonna be all sorts of cellular damage when the ice crystals form in your cells, they're gonna rupture yourselves because ice expands when it freezes. Right. It's also less to yes, we

did a frostbite frost. So the fact that they can come back to life after being exposed to these really cold temperatures means that they've got something going on that's keeping their cells from rupturing. Science has no idea why. On the other hand, with heat, tremendous heat. When you are you expose a cell to a hundred and fifty egrees celsius, which is above the boiling point of water, right you are, your proteins are gonna unfold and pool

and coagulate and be totally useless. So you can't come back to life because all of the processes and the building blocks of life are useless in your body, and you would have to start from scratch, which is tough to catch up to when you're trying to to come back alive from being exposed to high temperatures. Tarte grades do it all right. So they flash freeze them, They freeze them for years, They boil them, they try and smash them to the tune of fifty eight hundred pounds

per square inch of pressure. And the Tartar grade was like, bring it, yeah, no problem. And we're talking about pressures that are six times greater than the greatest pressures found anywhere on Earth. And they withstand it. Uh, they blasted them. They tried to suffocate them. They prepped tiny little hands around their throat. They put on tiny black gloves first so they didn't leave any of it. Now, they tried to suffocate him with carbon monoxide, carbon dioxide, sulfur dioxide,

nitrogen UM. They've shot them with gamma raise what the X rays. Yeah, they found there was a French study that found that um. It took five hundred and seventy thousand room Gin's I think that's how you say it to kill fifty of the tartar grades in a sample but still lived. And that's five hundred and seventy thousand. It takes five hundred to kill a human, but it took five hundred and seventy thousand to kill half, just

half of the tartar grades in a sample. Yeah, they shot them up into space and I think about half of those lived, right, So they literally, like he said, they're trying to come up with newer and more creative ways to kill these things. And the tartar grades take all comers basically. And there they have a couple of mechanisms. Again, science is trying to figure out one how their cells keep from freezing in a way that they would rupture

or how their proteins keep from unfolding. But like that kind of radiation exposure should do all sorts of horrible things. You should go listen to our radiation sickness episode. That was a good one, But it should do all sorts of horrible things, like break up the n A. But apparently they have some sort of mechanism to prevent this from happening, right while they have a mechanism to stitch

it back together. And apparently they also produce a protein called de s up that UH acts as a shield that wraps itself around DNA and and basically shields the DNA from radiation exposure to begin with. So um, they have all these these natural processes, but they also have passive processes as well that that include basically like going into a state of suspended animation depending on the conditions. Yeah, there are two things called um uh an oxybiosis and cryptobiosis.

Those are two of the three states where these things live. Um. The other one is just the active state, which is just a regular living normal charter grade. That's where they're doing all their daily life basically, which I don't think we mentioned. You know, there's not a lot to that part. No, And apparently researchers are like, we have no idea what role they play in ecosis. Yeah, that's kind of what

I was wondering, Like, they're indestructible. They're gonna be the only thing left maybe after our nuclear annihilation or global warming has wiped us off the face of the earth. Uh, but why nobody knows? Who knows? Maybe they're going to

grow up and be big boys one day. Well No, that's a really great question though, because if you think about it, you're like, why would these things be able to withstand pressure six times greater than what's present on Earth, or radiation like you would never find on Earth, or temperatures like you would never doesn't make any sense until you stop and think, like, there doesn't have to be

a reason. It could just be that they have strategies that they used to defend themselves against certain conditions on Earth that are just just totally unrelatedly, also happened to cover these other conditions that we humans try to launch them into that a tartar grade would never would never evolve to take on. But they can still withstand it. Like you asked the tartar grade and They're like, We're just trying to survive dude, right, Like, why you have

to lay a purpose on it? What's with your hangups? So the first one I mentioned, the an oxybiosis set s whim. If you like starve them of oxygen, they will puff up, uh in a little ball and stay that way. Basically, Yeah, I guess they lose their ability to um regulate fluid transmission in and out of their cells, and fluid rushes in and they puff up and they can stay that way I think for a few days, and then after that they die. But not bad. A

few days of being completely saturated with water not bad. Uh. The other one that's really amazing though, is a cryptobiosis. So uh, we said that they do need this water. Um. If they doesn't mean they have to live in the water, but they need water. Um. But if this water eventually goes away and you dry them up, they pull in their feet, they pull in their head, and they basically

stop metabolizing. They go into this weird state of suspended animation where they say, all right, I'm I'm basically you think I'm dead. By all accounts, I look like I would be dead, but I'm not and it's called a ton state to you in yeah, or tune. I think it might be tuned because it was it's short for um tune conform. It's got a it's a German word with an oom lot over the oh. So wouldn't it be a two? Well, it's like turn trench in form, tune in form. But I'm gonna call it a ton state.

Uh Okay, So this this ton state or tuned state, that's how I'm going to say it. Uh. Their metabolism solows down to like point zero five percent of its normal rate. Right. And there was a researcher in the forties in Italy who said that she revived a sample of tartar grades from a sample of dry moss that had been collected like a hundred and twenty years before. Well, apparently no one's ever recreated that one, but they have found that a tartar grade can survive in this teen

state for at least thirty two years. Some Japanese researchers took moss that was collected from Antarctica in three and in two thousand and fifteen, they opened up the sample and where they rehydrated it, and they found that some tartar grades came alive. It's almost like it freeze, dries itself and just needs to have, you know, add water. And they're like, all right, what what happened over the

last thirty years? Right exactly? This president The thing is, though, is if something dries out, it loses it's of its water, it's moisture from its body. I think, Okay, if something drives out like that, like your DNA needs water to If DNA stays dry, it starts to deteriorate pretty quickly. So again, nothing is supposed to be able to survive thirty years of that state, right. Um, So this has just got researchers puzzled as well, like how are they

doing this kind of thing? Apparently they have um proteins that helped stitch DNA back together, So I guess they start to come out of the tune state and one of the first things they do is stitch back this their d n A they get up the little sew machine. Yeah, well there's this one dude, and we'll take a break and talk about his a seeming obsession, uh with these

little fellows right after this. Alright, so if you want to know everything, you want, need to know about a charter grade, you should sit down and have coffee with unc Chapel Hill Coatar. Heels uh with this? Is he a professor? He's just he's a prof Thomas Boothby. This dude seems like he go to like every article I read featured him as the main uh Interviewee. Well, he likes to talk tartar grade. He does. He has a button that he wears all the time. Said, asked me

about tartar grade. People like what, Uh so, Yeah, I don't, I don't. I'm sure it's not an obsession. But he is stricken with him as I am. And Um, he's trying to figure out like how and why they're able to do all these amazing things. Um, probably more on the how than the why. He's why. He seems to do a lot of I don't know. He leaves that

to the philosophy professors. Yeah, exactly so what Thomas Boothby made his name not in the way that he would necessarily like when he was leading a team I think in two thousand fourteen, maybe maybe two fift that that did a genetic scan of a species of water bears and found some really surprising results, Right, they found that something like seventeen percent and change of genes in the water bears were associated with other things like fungi, bacteria, viruses,

that they had all these DNA stitched up with theirs, and that the the assumption was that that was how the Tarte grades were able to do all these amazing things and survive in all these ways because they were borrowing talents and traits and characteristics of unicellular life and non living life like viruses, and that that's how they were able to to survive these extreme conditions. Yeah, but it's uh, the kind of ended up being a watch.

Like he got really excited and thought, oh my gosh, they've got all this stuff, but it turns out they were just contaminated through poor experimentation. They they assumed that there was lateral gene transfer that was going on. It turns out that yeah, they had a contaminated sample. And hats off to Thomas S. Boothby because he's not like, Okay, I'm gonna go hide for the next decade like he's

he was like, Hey, it happens. It's science, man. We've gotten increasingly sophisticated machines and the increasingly sophisticated machines found that our sample is contaminated. Let's get back to work. So the Japanese researchers that follow up on a different type of tarted grade one of the hardiest around um Resuma tourists pantasma. Basically, I was hoping that's what it was, but it was like ramas odious, very natus. Here it comes this, uh, and that's one of the hardiest of all.

It's a land species. Um, the land are much more hardier. I think we already said that, right, And well there's your why, Chuck that one of the reasons why these the land um species have have evolved is because they have too They don't have these stable conditions that the marine and aquatic ones do. Right. Yeah, So, um, they tested the res ramas odious are very an odous species, and they found that they had about one percent of foreign genes involved in them, which is about normal because

lateral gene transfer can happen at that rate. It's just sort of average. All right. So, like you said, he held us head high and said, all right, no big deal. We're going to continue to search for the reasons why these little dudes are so hardy. One of the things that they found that was pretty unique is um ice is a big deal. And we talked a little bit a few minutes ago harkening back to the frost bite where ice crystals form inside a cell, tearing apart that DNA.

And there are some animals that make an anti fee freeze like protein like fish. Some fish do that to keep it from freezing. And they thought, well, maybe the chart grade is doing that, and they don't think it is. They think it can just handle it basically a right, like, maybe it's just freezing the outside of the cells and not the inside like some weird mechanism they don't understand. But it's definitely not producing in any freeze like some of these fish are. It's just like, bring bring it on,

little ice. I can take it. I can take that problem. And again with radiation exposure they have they've they've been found to have proteins that shield DNA and the ability to stitch DNA back together. Right, Yeah, so you got that covered. Yeah, And I think you alluded to it earlier. Um, it may not be the case of the Tartar grade has all these different things to survive these environments, but maybe two or three little tricks that are just you

can apply to different ways of survival. So it's not like they're evolving to go fly through space colonize new plants. That's a question that a lot of people come up with once they learn about tartar grades, is like, well, wait a minute, are these things like aliens? Did they come on an ast roid and basically gets spread like seed here on Earth? Um, they could survive space, some of them could conceivably, but um, they would burn up

on re entry, so probably not. So were they on on the back of an asteroid, they would, Yeah, they'd burn up because fire apparently can kill a charter grade I guess. Yeah. And those space experiments, they were inside the satellite, inside the capsule, protected from re entry until they were out in space, and then they were exposed to solar radiation and then they were put back in

the capsule and brought back to Earth and sound. Yeah. So, like the thing he found in common was with the heat and the cold, the common length there is an ability to repair DNA, and so maybe that's the sort of common denominator here. They're just good at it, and they're good at it because they have to be or else they wouldn't be around. Yeah, they were forced into it. Yeah, it's a pretty nihilistic you. I like it. There is another thing that stood out to me. I just love

so um. At the pressures they can withstand, the fatty membranes of their cells should be as solid as cold butter, and again should stop functioning at those pressures, or should kill them. They bounce back solid as cold butter. Yeah, I mean think about it. Like, normally, fatty membranes that make up cells, they're basically in a liquid state cold butter. That's not good for cellular function. Yeah. It's also not good when they give it to you at a restaurant,

I know, to put on the bread. You know the key to that stick it under your arm. Well, I just hold it in my hands, and you want you're gonna want to get greedy and try to do two it once, don't. It slows it down more than it longer than it takes to do two separately. And then you got butter on your hands. No, No, I mean you get the little foil rap kind. Oh I'm talking about I served you a dish with cold you leave. Yeah, I'm talking about like a you know, a real restaurant

that just has butter in a dish. That's That's what I'm saying. You leave that restaurant. That's not a real restaurant if somebody, somebody's not paying attention to detail or even the worst or the little cold butter balls that they've scooped, and it's just took that in your cheek and it's not spreadable. It's useless. Yeah, it just rolls around when you try to put it in a nerf gun. I never heard, man, have you seen those things lately?

By the way, I was watching the kid's chair on the other day and try not to get to like hysterical about stuff. But the nerf guns these days, they're they're like assault weapons. I guess I do. Like so it doesn't count, Yeah, I know, but it's I don't know. It's clearly made me think, like, huh, well, they're clearly indoctrinating young children as young as possible. You like this nerve gun, you're gonna love anyway? Uh Wow, that took

a weird turn at the end, Yeah, didn't it. If you want to know more about tarte grades or guns, you can type those words into the search part how stuff works dot com and since I said, whatever, it's time for listener mail, I'm gonna call this Aaron Sorkin rebuttal. This from Mark Frost. Hey, guys, had a comment to about Chuck's professed dislike of Aaron Sorkin. Was that you I thought that was me? That was me? Did you?

Did you gang up? Yeah? Okay? My wife and I are definitely fans, But I want to put a different perspective out there for you to consider. I don't think anyone is supposed to consider his writing to be conversational. I would kind of liken it to a musical or the place of Shakespeare, and he says, I'm not equating Shakespeare with Sorkin. Musicals aren't how people talk. Shakespeare was

definitely not representing how people talk. Back then, uh, for Willie the Sheik, it was a poetic language filled with metaphors that turns a lot of people off even today. But like with musicals, it's a stylized way of showing what people are feeling and thinking. Realizing that, yes, people don't talk that way actually makes me enjoy it more. In some ways, it makes things more compact, and that it can express feelings ideas more quickly. We can often

do so with more do so more entertainingly. Uh as the people are way more quick witted than you would be in real life. But suspending your disbelief makes it enjoyable for me, at least. I think that's the problem I have with it. It it prevents me from suspending disbelief. Yeah, me too. I definitely like to Steve Jobs movie, which we both liked. Right. You liked it, okay, I did. I actually liked how clearly artificial the construction of it was. It seemed very much like a play in several acts.

I agree with you there, sir. I did not feel like anything that was attempting to show real events or real sequences, but rather to condense a lot of what happened during periods of his life into specific scenes. I agree with all that. Then those scenes packed in the drama emotions from the time they had. Uh. We also just finished news Room, News news Room, and love that anyway. People are always up in their own opinions, um, and I tend to agree with most of your film thoughts,

just not this one. I love both your show and you guys will continue to do so. That is Mark Frost. Thanks Mark. That was very well well written, well thought out. Thanks. Yeah, I get it. People love Aaron Sarkin. Yeah, I love all that West Wing and stuff like that. Have you seen The Night Manager? No? What is that man? Where do they hear about that? Everywhere? The John Lacarre adaptation with m oh Dr House and uh, actually it's really good. Is it a movie? It's like a sixth part mini series.

Oh yeah, I like this. It's very good. Check it out. You will like it a lot. Promise. All right, that's got Josh is guaranteed. You also said it like Soyland. I didn't say that, did I? Okay, I'm just kidding. You thought you were making me think I was losing my mind. If you want to get in touch with Chuck and me, you can tweet to us s Y s K podcast or Josh I'm Clark, Facebook us at Charles W. Chuck Bryant, or Stuff you Should Know, Send us an emails the Stuff podcast at how stuff Works

dot com. Hit us up at her home on the web Stuff you Should Know dot com for more on this and thousands of other topics. Is it how stuff Works dot com