SciShow Tangents - Extremophiles

Episode Date: August 20, 2019

Extremophiles are tough little guys that not only survive but thrive in the harshest environments on Earth; unforgiving places like volcanic vents at the bottom of the sea, lakes of acid, and your bellybuttonTo learn more about extremophiles and a whole universe of other microscopic creatures, check out Journey to the Microcosmos at https://www.youtube.com/microcosmosFollow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! If you want to learn more about any of our main topics, check out these links:[Truth or Fail]Single-species Ecosystemhttps://www.newscientist.com/article/dn10336-gold-mine-holds-life-untouched-by-the-sun/Extremophile Cheesehttps://www.businessinsider.com/belly-button-innie-inside-cheese-bacteria-lint-fungi-2019-7Fluffy Pink Golden Fungushttps://www.smithsonianmag.com/smart-news/scientists-discover-fungus-capable-collecting-gold-its-environment-180972293/[Fact Off]Berkeley pit extremophiles:https://medium.com/vision-2018/life-from-the-pit-70d3e0fbc0f6https://www.youtube.com/watch?v=zEnWZcG3Nzkhttps://cen.acs.org/biological-chemistry/natural-products/Scientists-mine-potential-drugs-Berkeley/97/i18PCR & Taq polymerase:https://www.genome.gov/about-genomics/fact-sheets/Polymerase-Chain-Reaction-Fact-Sheethttps://www.ncbi.nlm.nih.gov/probe/docs/techpcr/https://www.thermofisher.com/order/catalog/product/10342020https://www.yellowstonepark.com/things-to-do/yellowstone-bacteria-beer-science[Ask the Science Couch]Extremophiles:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4187170/Bacteria vs. Archaea:http://bio1520.biology.gatech.edu/biodiversity/prokaryotes-bacteria-archaea-2/https://ucmp.berkeley.edu/archaea/archaea.htmlArchaea characteristics:https://learn.genetics.utah.edu/content/astrobiology/environments/https://microbiologyonline.org/about-microbiology/introducing-microbes/archaeahttps://ucmp.berkeley.edu/archaea/archaeamm.html[Butt One More Thing]Pompeii worm:https://serc.carleton.edu/microbelife/topics/marinesymbiosis/pompeii.htmlhttp://faculty.montgomerycollege.edu/gyouth/FP_examples/student_examples/sathya_ramachandran/pompeiiworms.html

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 am joined by Stephan Chin. Hello. I'm here as always. Stephan, what's your tagline? 50 packages of watermelon flavored gum. Sam Schultz is also here.

Hello. Hi. What's that pin you got on? It's from Buckaroo Bonsai. Do you know Buckaroo Bonsai? I've heard of Buckaroo Bonsai. He's a scientist rock star, just like you. What's your tagline?

Eat my shorts. Oh, good. That one's taken, but you can borrow it for a little bit. Camp counselor Sari Riley is also here. Yes, welcome kids to camp. What are we learning about today? I can't tell you. It's a secret. Oh, it's not in the episode

title? Oh, it's definitely in the episode title. We're learning how to read. I bet there are people out there, though, that don't read the title. Sure. They close their eyes and hope for the best. Sometimes I just say, hey, Google, play SciShow Tangents. Oh, really? We got to bleep that out, though, so people's Googles don't turn on.

We'll get a lot of listens, though. Of the people currently listening to our podcast. Oh, yeah. That's not great. Sari, what's your tagline? Big, big penny. And I'm Hank Green. I'm a rock star science man.

Wow. And my tagline is forever burdened. Oh. It's just true, you guys. Just say big penny. Every week here on SciShow Tangents, we get together to try to one-up amaze and delight each other with science facts. We're playing for glory, but we're also keeping score.

We do everything we can to stay on topic, but judging by previous conversations, we won't be great at that. So, if the rest of the team deems your tangent unworthy, you have to give up one of your Hank books. So, tangent with care. Now, as always, apparently during the first part of this podcast, we can tangent as much

as we want to. I think that's okay. Just during the instruction. Now we have to get on topic, everybody, as we introduce this week's topic with the traditional science poem from Stefan. If you want to find me, check the ocean's depths, where you can see me hugging hydrothermal vents. It's hard to believe that life can live so close to magma chambers, but it's so hot that we took off one of our phospholipid layers. If you want to find me, check in nuclear reactors. As you might assume, radiation is a factor, but I have multiple copies of my chromosomes and rapid DNA repair because of a toroidally organized genome. If you want to find me, check in a pink lake. It's pretty salty here, but don't worry, I won't break.

Beta carotene gives me color and protects me. And if you didn't know, we can reproduce sexually. If you want to find me, check in the Berkeley pit. Extremely low pH and extremely metallic. But we know a thing or two about cleaning up because we used to live inside of a goose's butt. So if you want to find me, I hope you sense the theme. I am where you are not, for I am more extreme. The topic today is extremophiles.

I just love Stefan Chin's slant rhyme. It's like never quite there, like Emily Dickinson over there. Sari, what's an extremophile? What Stefan said. There's some misconceptions around extremophile. What Stefan said. There's some misconceptions around extremophile. There are two very similar things that often get referred to as extremophiles. So extremophilic organisms need an extreme condition to grow and survive. So they thrive in really high temperatures, really low temperatures, really salty, really basic, really acidic, anything like high pressure.

And then there are also organisms called extremotolerant organisms. And those are like your tardigrades of the world that can tolerate extremities and radiation or pressure or whatever. But they grow most optimally at standard times. They would prefer all things being equal to not being in extreme condition. Yes. They just can't survive them if necessary. They just want to be normal. So you're saying that's not an extremophile.

They're not technically extremophiles because they don't like extreme conditions. They can just survive them. Gotcha. They turn into like a little ball of crust that is somehow still alive. But they're not able to reproduce. They're not able to grow. They're not able to eat. Whereas extremophiles, philic, they want to be in the most extreme. Their habitat is something

that we would consider completely unsurvivable. It's the only place, if you take them out, they might die. They can't live in non-extreme environments. Extremophiles also are from all three domains of life that we know of. So there are bacteria, archaea, and eukaryotes that are considered extremophiles. The eukaryotes are like algae or fungi. So they're not any super complex. Not that we really know of.

There's going to be one that I'll mention in the butt fact. Ooh, okay. That's a little bit more complex. Yeah, just hold on to the end, everybody. By which I mean the butt. And now it's time, everyone, for Truth or Fail. One of our panelists, it's me, spoiler,

has prepared three science facts for education and enjoyment of everyone else. But only one of those facts is a true fact. The others are lies. Everyone has to guess which is the true and which is the lie. And if you get it right, you get a Hank Buck. If you don't, I get the Hank Buck. So fail, everyone, fail. A team of scientists went looking for extremophiles under the Earth's surface, collecting over

5,600 liters of water from the bottom of a South African gold mine, almost two miles below the surface. No oxygen, very high temperatures. When the scientists analyzed the water to find out what kind of things could be surviving so deep, tolerating temperatures of around 140 degrees Fahrenheit, and living without sunlight or oxygen. The results surprised them. Which of the following did the scientists discover? Fact number one.

While going through their massive amount of water, the scientists found amber that contained 20 million year old fungal spores. The spores are believed to be an early ancestor of Fusarium oxysporum, which is a pink fluffy fungus that has these tendrils that are actually decked in elemental gold. So actual gold metal.

And that may help the fungus get food from its surroundings. Fact number two, when it came time to catalog all the microbes they'd found, the team discovered several bacteria down there that are also commonly found in cheddar cheese, giving it its flavor as the cheese ages. The researchers took this a step further, creating a mix of extremophile bacteria and

normal bacteria, working with cheesemakers to create a unique extremophile cheddar. Or, fact number three, in all of the 5,600 liters of water, from which you might expect to find a whole universe of microbes living together, some might call it a microcosmos, the scientists found evidence of only one bacteria, Candidatus disulfordus audaxviator. To compensate for the lack of neighbors to have symbiotic relationships with, the bacteria has been able to meet all of its metabolic needs on its own,

even looking to dead members of its species for extra nutrients, making it the only single-species ecosystem ever discovered on Earth. So we've got amber with fungal spores, cheese making extremophiles, and number three, a single species ecosystem discovered under the Earth. So they're in

a really deep gold mine. Yes, they dug a very deep gold mine. And they found like pockets of water down there. There's like pre-existing pockets of water. From before the gold mine? Before they dug the gold mine mine yeah okay do we often find funguses and amber is this a thing that happens yes i mean you can find any like amber is full of everything like it's whatever was in the air at the time i have reservations about that one because how does the amber get down there it didn't like fall down from the surface? Tree fell in a hole.

Is there a tree growing in the gold mine? What was the other one? The middle one? Cheddar. Cheddar bacteria. I feel like this is the most human thing to do. Let's make cheese out of it. I found this weird thing. Let's make cheese and eat it.

That is a thing. We're using extremophiles to find new antibiotics and do all kinds of different research that is a thing. Like, we're using extremophiles to, like, find new antibiotics and, like, do all kinds of different research. So I could see, like, okay, like, let's make a cheese, I guess. Right, especially if they were similar. What was this elemental gold thing? So the fungus that

they found appears to be a relative of a gold loving fungus that actually, like, this is a thing that exists, that is able to dissolve gold and then redeposit it on its surface. For protection or something?

Gold armor. They think that it might be for like food eating somehow. It helps eat food. But I want it to be the last one. So I'm going to do, I'm going to guess that one and lock it in.

I also think it's a single organism ecosystem. Are we going to go all in on single species? I really want it to be true. Like, a species that makes its own food is I don't know. I have dreams about this, I feel like. It doesn't

make its own food. Like, nothing can make its own food. Right, it kills its buddy and then eats him. Well, that's a perpetual motion machine. Like, that's not possible. It probably gets some kind of energy from the environment. So either the heat or radiation down there is providing the energy.

I'm still going with it. You were going with it too? Oh, no. All three. This is risky. What a bad time. Now I'm nervous about it. We could do really well.

We could do really well. Or so badly. Go big or go home. It's too late. I already said I'm locked in. It's done. It's done. You're all fucking right.

Yeah. You looked more excited about that one than the other one. It is very cool. It's very cool. And actually, I know where the energy comes from. I just didn't want to be very specific because it would appear too real. be very specific because it would appear too real. It's from the radioactive decay actually splits water into hydrogen and oxygen, and they use the hydrogen to reduce sulfate inside of them to not generate the energy. So in a way, they are like radio synthetic, like they can use radiation

to synthesize stuff, but it's not really the radiation that they're using. They're using the product of the radiation. Like all it needs to survive is radioactive decay, which is like a physical property of the universe. Can it survive other places? It probably wouldn't effectively because anything would be more efficient at surviving than it. And when they took it out of the water, this was sort of shocking for them. And they kept like redoing the test to be like,

what are we doing wrong? But like 99.9% of the DNA was from this one species and everything else they could find that made up that 0.01% was contamination from the lab.

Oh. So there may be, like they're not like, they haven't completely ruled out that there might be some other thing living down there. But if there is another thing, it's like 5,000 to 1.

Hey, there's got to be. If those things can do that, there's got to be aliens, right? Yeah, no, definitely. That's a thing that I thought about was if there's enough carbon and nitrogen and phosphorus and whatever you need to be that bacteria. Because they use dna like yeah there's no what like they use the only stuff they have to make themselves out of is just the dissolved chemicals in this gold mine and the only way that they have to make energy is like is this where life started like no probably but like it's pretty amazing and yes there's totally aliens. There's apps.

Like, I don't want to say I've had a beer, but I've had a beer. There's definitely aliens. Yeah, I mean, like, I could talk about that all day. But there are also truths to the other ones. Yeah. So, the first one with the amber is inspired by two things. One, they have found bacterial spores in the abdomens of extinct bees preserved in amber. Sweet.

For 25 to 40 million years. Holy shit. And they claim to have revived those spores. Uh-oh. Don't do it. So that's wild. That seems like a bad idea. Fusarium made a face.

Yeah. So we'll have to talk about that one on a future episode. But there is also a fungus which was recently discovered, Fusarium oxysporum. It's fluffy and it's pink and it dissolves gold and then expresses it on its body. And they're trying to figure out how to use it to actually extract gold from ground up gold mine stuff instead of using cyanide leaching, which is how they do it now. The other one was taken from two things. One, that yes, they have found extremophiles in people's belly buttons. Whoa.

What's so extreme about our belly buttons? Nothing, but they can also live in extreme environments. And also that we have several times taken different organisms from our feet and belly buttons and other parts of our bodies and made cheese with it. Cool. I hate it. Cool. I hate it. I don't want belly button cheese. This is great.

Stefan was like, yeah! Sarah's just like, no, stop. Belly button cheese. You can have my belly button. Cheese is fine now! Yeah.

Don't make cheese weird! I'm already eating mold. It's fine. I don't want my mold to be from another person. Doesn my mold to be from another person. It doesn't have to be from another person. Maybe there's like a do-it-yourself kit that you can make cheese from your own body. I would rather do like a bacterial analysis on my own poop sample than eat cheese made from my own body.

I don't know which one I'd rather do, but can I do both? Would you rather? Tweet to us? Would you rather? Tweet to us. Would you rather? Analyze your own poop or eat cheese made from your belly button. So how do I make belly button cheese? Do I just pour milk in there? And wait.

And seal it up. Yeah. But when you're doing the poop thing, it's not like you have like a slice of your poop and you're looking at it. You like put it in something and liquefy it, right? Yeah. I don't know. You liquefy your belly button goop to make cheese, too. I'd much rather eat belly button cheese than do the poop thing. That sounds boring

first of all. I did make a boring alternate. I want to eat cheese. I'm hungry. I don't want to spend hours in a lab doing work. I just want to have some cheese. Next up, we're going to take a short break, and then it's time for the Fact Off.

We're back! Sarah, you've got one point. Everybody's got one point. Except for Stephan, who's got two, because you're both well spread out, everyone. I guess I got a chance to do some good work here, but I can't win. I can't win. I can't win.

I failed miserably, but my fact was good. Your facts were great. Thanks, everyone. So now it's time for the fact off. Two panelists bring science facts to present to the others in an attempt to blow their minds. The presentees each have a Hank Buck 2 award to the fact that they like the most. But if both facts are a giant snooze, we can just throw our Hank Bucks in the trash.

We're going to go first by the person who ate cheese most recently. I ate it for this lunch and every lunch, basically. Oh, yeah? Or like at some point during the day. At home, I just like wrap turkey in a slice of Swiss cheese and I eat that several times a day. Yeah, cheese and I eat that. Oh, yeah. Several times a day. Yeah.

Taquito sandwich, right? Yeah, yeah. It's carb free. Yeah. Did you say taquito or keto? Kind of both. It's a little bit of both. It's a taquito, keto, taquito.

So when was your last cheese? Probably yesterday because there's cheese in the work fridge. You didn't have one today? I did not have one today. Okay. So here's my fact i decided kind of to just take a loss this time sam's going for the l and take uh and talk a lot about butte montana oh the town that i'm from that has extremophiles on it so astute listeners will have heard me talk about it before probably i don't always cut out the parts where i talk about butte because i like it there. In the early 1900s, Butte, Montana had

some of the most productive and successful copper mines in the whole world. And it grew into Montana's wealthiest, most modern, most populous city. So there were a lot of up and downs economically through the years. But Butte was in pretty good shape for decades until underground mining became pretty much too expensive and too inhumane to continue. Just a lot of people died. And a lot of unions were like, we don't want to die anymore. Good call. In the 50s then, the companies in Butte started open pit mining instead, which is basically where you don't go underground.

You just rip the ground up. And this led to tons of neighborhoods being demolished. And the town's amusement park even became an open pit mine because it mysteriously burned down. And then they turned it into an open pit mine. So the largest of these mines was called the Berkeley Pit and it operated until about 1982. When it shut down, the water pumps that kept the groundwater

from filling the pit got turned off. So it started to fill with weird water. So flash forward to 1995, which was a great time for a little me. I was in grade school. I was playing video games at Silver Bow Pizza. But Butte was not maybe doing so good. No. It was just kind of like a shambling wreck of what it once was,

covered in open pit mines, basically. Is there more than one open pit mine? The whole side of the mountain has been ripped off. And it's not a pit, it's just like the side is gone. Right. And you can go

and see it for a dollar. You can go look at the pit and go look at the weird water filling it up. I've done it. So then one November in 1995, a bunch of geese

landed in the pit and they died like overnight basically from exposure to the horrible toxic water that had filled the depots full of

heavy metals and it has the pH of like Mountain Dew or lemon juice. from exposure to the horrible toxic water that had filled the depots full of heavy metals. And it has the pH of like Mountain Dew or lemon juice. So it was very bad water. And the conventional wisdom was that anything that touched it, it was basically instant death. But there were two researchers at Montana Tech, which is the college in Butte, Don and Andrea Sturley, who had been researching samples from the pit. And they had samples from early 1995 from before the geese. And then they gathered more in 1996. And they noticed that there was a yeast growing in the water that was sustaining itself with metals from the water.

And this yeast, they discovered, had only been found one time before in the anuses of gooses, which is what Stefan was talking about. So that was really cool. And it made some really cool headlines. But what the Sturleys already knew was that there were lots of fungus growing in the pit water. And for decades, they've been studying the fungi and the compounds that the fungus produced to survive in that horrible environment. And through that, they've developed or they're like trying to develop anti-inflammatories and anti-cancer medicines. And then recently, they combined a couple types of the fungus

and they created an antibiotic that has a different way of attacking Staphylococcus than other antibiotics do. And that makes it effective against Staphylococcus that has developed resistances to currently existing antibiotics. So that's all the pit stuff. It's very good that there is a bacteria that figured out how to live in Butte and it came from the Deggies. Yes. But also a fact that we've discussed as Montanans and science people. But maybe people listen to this podcast.

Oh, absolutely. That's the first time they're here. Yeah. I'm just looking at the Berkeley Pit on Google Maps. You should check it out. It's a problem. It's bad. It's better now.

I mean, the thing about it is that, like, it's so close to all these people who live there, including, like, all your friends and family. Yeah, my dad lives, like, right next to it. I don't think it'll overflow, though. I think they've figured it family. Yeah, my dad lives right next to it. I don't think it'll overflow, though. I think they figured it out. No, they'll figure it out. Unless something very bad happens to America

and we can't do anything ever again. Any other Butte questions? How's Butte now? Is it okay? Is it better than 1995? No, I don't think so. I think it's better.

The arcade, I mentioned, not there anymore. That does happen. That has happened on all the places. They all got turned into casinos. Well, you still can play games at least. Yeah, that's true.

You spend money and play games. But I guess you might win money from the casino, so better. It's an improvement. It's not an improvement. Sari, hit me with your fact. There's one extremophile that's super important to the whole field of molecular biology, fact. There's one extremophile that's super important to the whole field of molecular biology, which I'm very excited about because as previously established, I'm a huge nerd.

But I'm not sure that the story of it gets told all that much. And it was even a key part of a scientist winning the Nobel Prize in Chemistry in 1993. That Nobel Prize was awarded for a technique called PCR or polymerase chain reaction, which is a fast and simple technique to make lots of copies of one chunk of DNA. So researchers use it when they're studying a particular gene to, like, amplify it a bunch so you can look at it and put it in bacteria or do experiments with it. Forensic scientists have used it for DNA profiling, like amplifying DNA so you can analyze it. And if you had a biology lab in high school, you probably learned about it because that's how simple it is. I did it a bunch when I worked in labs because it's a really repetitive task that you give to undergrads to do when you don't want

to do it anymore. Basically, we're going to learn some molecular biology. It depends on repeating a three-step cycle over and over again for like 28 to 35 times. So it takes a couple of hours in total because each cycle takes a couple minutes. And we have machines that do this now called thermocyclers. But when it was first created, people had to like move their stuff between hot water baths. It was a whole ordeal. So step one, you denature the DNA. So DNA is double stranded and you separate it into two single strands. This you need a hot temperature for, so somewhere between 94 and 98 Celsius. That's the separation step. Step number two is you anneal primers to each of the single strands. So there are these little chunks of single-stranded DNA called primers that basically get the system set up

to replicate DNA. It's like a little, hey, start here marker. Does anneal mean glue? Yeah, connect them. So that you need a little bit colder temperature, so 50 to 65 Celsius. So that you like stick them on and that locates the gene that you want to amplify. So you you pick a specific primer that binds to the beginning of whatever gene you're looking at. And then step number three is extension of the new DNA strand, which is done with an enzyme called a DNA polymerase. And what that does is it takes free-floating nucleotides, which are the building blocks of DNA, and then starts with the primer and adds them on just like one at a time, looks at the DNA strand

as a template. And then it's like, okay, this is an A, so I better attach it to a T. This is a C, I better attach it to a G and just like puts it together. And then you repeat that process over and over again. So you've got like a new strand and an old strand, and then you denature them again. So you have four in your mixture and then you anneal new primers, and then you extend. And then you like break everything apart, anneal new primers, extend. And like over the course of this process, you get to the power of the number of cycles that you have of DNA. And that's how it like happens very simply, very quickly. It's great. But when the technique was first started, scientists used a DNA polymerase enzyme from E. coli. But the problem was the denaturing step because denaturing messes up proteins.

So it's like when you cook an egg, it gets all wibbly and like the egg proteins change shape. And so the DNA polymerase enzyme that they were using denatured too. So every time they did that third step, they had to dump in more enzyme because they ruined it every time they started the cycle all over again.

But in 1969, at the Lower Geyser Basin of Yellowstone National Park, scientists discovered a thermophilic bacterium called Thermus aquaticus that thrives at really, really high temperatures. We isolated its enzyme, TAC polymerase, which is really active around 72 to 80 degrees Celsius, 162 to 176 Fahrenheit. That's hot. Yeah. And so then like the combination of this one scientist or several scientists idea for PCR, plus the TAC polymerase from Yellowstone National Park created this like super, super good technique. And so then they like made a bunch of this polymerase. Now you can buy it fairly cheap as far as lab equipment goes it's like the most common most widely used thing in this very very

important technique that i don't know any molecular biology student is going to learn because you need it to do your research yeah you do anything yeah dna i did not know that is dna a protein no No. No. Okay. Because normally I hear denaturing as like happening to proteins, but like a bunch of stuff can denature. Yeah. But in this case, it is a protein that's denaturing, right? This is a good point.

I use denature in two separate use cases. Oh my God. Okay. Sorry. You lose a hank butt. No, you're right. You got to call me out on this jargon. No, you're right.

You got to call me out on this jargon. When you're talking about PCR, denaturing the DNA specifically refers to breaking the two strands apart. So you're breaking the bonds that hold the two single-stranded nucleic acid chains together. And then denaturing when it comes to a protein, it's a similar process in which you break all the bonds that are holding the protein together. So they become straight. They unfold, and the protein's folded structure is what gives it a lot of the function. They never fold back up the way that they should fold back up. They become scrambled eggs. The folding is the whole thing that makes the proteins good at being proteins.

Yeah, we don't understand it really. But there are some proteins that are like good at not getting unfolded at high temperatures and that's how these organisms can survive in these ridiculously high temperatures. Basically getting boiled and they're like, eh, cool, perfect. Or they're like, I love this. I can work so fast right

now. Yeah, so much energy. Yeah. So competing with each other, we've got Butte, Montana, Berkeley, Pitt, Mountain Dew, PH, Goose Butt, Extremophiles. And other we've got butte montana berkeley pit mountain dew ph goose butt extremophiles and then we've got yellowstone national park bacteria created an enzyme that was useful and pcr and revolutionized all of science oh well when you put it like that but like goose butt though i didn't know either of these things. Like, I knew about the pit, but I didn't know there were other things other than the goosebutt shit.

Surprise staphylococcus killer. Yeah. But I think I'm going to give it to Sari. Fine. I expected that. I mean, I'm also going to give it to Sari just because I feel like... That's okay. Yep.

You know. I just wanted more people to know it. And I want everybody to know about Butte, Montana. Yeah. Home of the Berkeley Pit. And now it's time to ask the science couch. We have some listener questions for our couch of finely honed scientific minds. Sam, read us the question.

At Ashley Foltz asks, Why are archaea more likely to be extremophiles in comparison to bacteria? Great. I've always wondered this too. What is an archaea? There are three domains of life. There's bacteria, there's eukaryotes, and there's archaea. And archaea and bacteria are sort of loosely put into prokaryotes, which are, they don't have membrane-bound organelles like we do.

We have these, like, we've got nuclei and we've got mitochondria and we've got other stuff. And so that's as much as I can say about this topic. We didn't realize until the late 1970s-ish that archaea were a separate domain from bacteria. We were just, I think they were called archaebacteria because they were like, ah, old bacteria. There are new bacteria and old bacteria. And then they were like, wait a minute, we actually did genetic analysis on these and they need their own domain because they're very different from bacteria, even though they're both prokaryotic, look simple from the outside organisms. One key difference between them, they have different membrane chemistry.

So they both have one outer membrane cell wall thing that encapsulates all the mush inside them. And archaea have more stability in their membrane than bacteria and even eukaryotes have, which scientists think is why more of them are extremophiles because they have these adaptations from, I don't know, their past. Are archaea actually older or is that just something we call them until we knew better? I'm pretty sure our current understanding is that like from an evolutionary perspective, a lot of extremophiles and therefore a lot of archaea are closer to the universal ancestor of all organisms on Earth. That's a powerful sentence. Yes.

And archaea were first discovered partially due to extremophiles because they were like, there's this group of weird bacteria. That's my vocal quotation marks that are so different from all the other bacteria that maybe we should call them something different and then they were like ah we'll call them old bacteria and then they were like ah no archaea they're separate okay uh so like by discovering this group of extremophiles mostly but there are archaea that aren't extremophiles so one has a more stable outer coating? Yeah. Is that it, basically?

So if you imagine a cell as like a bubble. Okay. And then the outside of the bubble has a bunch of stuff in it that makes it stronger or weaker or things like that. Different molecules that give it different properties. Okay.

The archaea are tougher, harder to pop that bubble with salt or cold or heat than bacteria or eukaryotes. Okay. Archaea strong. Yeah. Archaea strong.

Strong boys. If you want to ask the Science Couch your questions, you can follow us on Twitter at SciShowTangents, where we will tweet out the topics for upcoming episodes every week. Thank you to Natalie Wang. Anna went home. And everybody else who tweeted us your questions. Final scores. I have zero.

Sam, you got one. Stefan, number two with two. Sarah's a winner. Yeah. Everyone loves PCR. I think Sarah and you are tied now. Oh, wow. I'm climbing that ladder.

I saw Sam count on his fingers. I didn't know what was happening. That's the way I know how to do it. If you liked this episode about extremophiles, we are producing a new show at Complexly called Journey to the Microcosmos. Check it out at youtube.com slash microcosmos, where we discover all of the very weird things that happen beneath our view, all around us all the time.

These beautiful little organisms that we can observe, mostly eukaryotes because they're much easier to see than the prokaryotes. Very soothing. Yes, it's a relaxing, it's a different vibe for us. Definitely taking it down a notch in terms of the energy, but like lots of good science information at the same time. And beautiful imagery.

If you like this show, as much as you like PCR and you want to help us out, it's easy to do that. First, leave us a review wherever you listen. That's super helpful and it helps us know what you like about the show. We'll be looking at iTunes also for topic ideas for future episodes, so you can leave your ideas there in your iTunes review. Second,

tweet out your favorite moment from the episode. Also, you can tweet out whether you would rather examine your own poop or eat cheese made from your body. I'm really curious. At SciShow Tangents, let us know. And finally, if you want to show your love for SciShow Tangents, tell people about us. If you want to read more about any of today's topics, check out SciShowTangents.org to find links to our sources. Thank you for joining us.

I have been Hank Green. I've been Sari Reilly. I've been Stefan Chin. I've been Sari Reilly. I've been Stefan Chin. And I've been Sam Schultz. Sasha Tangents is a co-production of Complexly and the awesome team at WNYC Studios. It's created by all of us and produced by Caitlin Hoffmeister and Sam Schultz,

who also edits a lot of these episodes along with Hiroko Matsushima. Our sound design is by Joseph Tuna-Medish. Our social media organizer is Victoria Bongiorno. 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.

Pompeii worms are thermophiles that live in tubes near hydrothermal vents on the seafloor. Their head has red gills and sticks out of the tube into 22 degrees Celsius, 72 degree Fahrenheit water, which is pretty normal. But their pale gray bacteria covered butt is sitting in the tube in water that's as hot as 80 degrees Celsius or 176 Fahrenheit. So they love a hot butt. Why? Love a hot butt. Why do they love a hot butt?

We haven't studied them too much. Who doesn't love a hot butt? I don't really know too much about them, but something to do with like they excrete mucus that the bacteria eat and the bacteria like the hot water to something to do with a beneficial symbiosis where they need a hot butt to live.