Radiolab - Shrink

Episode Date: November 24, 2023

The definition of life is in flux, complexity is overrated, and humans are shrinking. Viruses are supposed to be sleek, pared-down, dead-eyed machines. But when one microbiologist stumbled upon a GIANT virus, hundreds of times bigger than any seen before, all that went out the window.  The discovery opened the door not only to a new cast of microscopic characters with names like Mimivirus, Mamavirus, and Megavirus, but also to basic questions: How did we miss these until now? Have they been around since the beginning? What if evolution could go … backwards? In this episode from 2015,  join former co-hosts Jad Abumrad and Robert Krulwich as they grill Radiolab regular Carl Zimmer on these paradoxical viruses – they’re so big that they can get their own viruses! - and what they can tell us about the nature of life.  Our newsletter comes out every Wednesday. It includes short essays, recommendations, and details about other ways to interact with the show. Sign up (https://radiolab.org/newsletter)! Radiolab is supported by listeners like you. Support Radiolab by becoming a member of The Lab (https://members.radiolab.org/) today. Follow our show on Instagram, Twitter and Facebook @radiolab, and share your thoughts with us by emailing [e-mail]. Leadership support for Radiolab’s science programming is provided by the Gordon and Betty Moore Foundation, Science Sandbox, a Simons Foundation Initiative, and the John Templeton Foundation. Foundational support for Radiolab was provided by the Alfred P. Sloan Foundation.

Hello, I'm Lulu Miller. If you joined us last week, you met the hidden body part, stowing away inside your body. And today we have another hidden story about life, and non-life, and how the line in between them is way blur than we might think. We are talking about viruses today. This episode is rewind, but it's a lovely one. It's called shrink. And what I love about it is not just that it busts a binary between life and non-life that I always thought was hard and fast, but also that as you listen, it really feels, at least to me, like Robert, Croich, and Jada Bumrod, OG host, that they kind of shrink down into these

little boys who are so giddy with questions for Karl Zimmer. It's like they're, I picture them like two little boys at Santa's knee just taking in the knowledge. And it's a really raw, lovely glimpse, I think at what this show does best, when it does its best, which is to make space for questions and for real listening. So I hope you enjoy this kind of giddy romp through the evolution of life and non-life and all the places where that line blurs out a bit.

Here we go. Wait, wait, you listening? Okay. Okay. Yeah. Three, why? Come on, totally, you guys can't say. We want to talk to you about three things. Okay, let's do it, let's do that.

Hey, this is Radio Lab, I'm guys can't say. We want to talk to you about three things. Okay, okay, let's do it, let's do that. Okay, you have to keep up with this. Hey, this is Radio Lab, I'm Chad Abumrod. We're gonna do something that's a little bit unorthodox today, at least for us. You know, if you've listened to the show in the last 10 years or so, however long we've been doing this, you understand that like, we like to edit, right?

We like, we like a good edit. Or 70. But today, I want to play something that has Almost no edits at all. It's just a conversation Which is of course the foundation of what we do these long rambling Occasionally profane error-strune conversations that we then edit into something coherent but today I want to show you the massiness. No edits.

This is a chunk of a conversation with science writer Carl Zimmer. He came and sat down with us a while back and we talked for four hours. Two of those hours became the basis for the CRISPR podcast. That was a few podcasts ago. This was about gene editing. But then we kept on going for another two hours

and he told us this story, actually two stories, but we're only gonna play one, that I thought was really cool. And it's about this new way of looking at life. Is this a long story, a meeting story or a short story? It's not a, we can get through this a lot faster than CRISPR. Okay.

I really like CRISPR by the way. So do I. I mean, CRISPR is, yeah, it's the bomb. Yeah, that's very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very,'d say once, once upon a time being before 2003, we basically had two kinds of living things on Earth. We had cellular life and we had viruses and there was nice and distinct and clear cut. And so cells included us, because our bodies are made of cells and bacteria, which are single cells and all the other things that can grow and let their cells divide.

They have DNA, they have proteins in them, they all love that stuff. And then over here, you had viruses. And viruses were just little packages of genetic material that would go from cell to cell and use the cell to make new viruses. And so inside of them, all they had were genes and a couple of proteins that would then sort of hijack their host.

They seem like so preliminary, that they don't maybe not even qualify as life. Right. They can't grow on their own. They can't generate their own energy. So, you know, us and all other cellular life, we make a kind of a fuel called ATP. And we need that to do every little thing in our body. And viruses don't make ATP. So, you know, they're...

So, couldn't we say that life is us, cells, and multicellular beings, and then there's like sort of pseudo-life, which is these little things that live off of us? Yeah, yeah. A lot of people, a lot of scientists don't really think viruses are truly alive. They're just sort of take advantage of life to make more copies of themselves. Okay. Can I say dumb questions of viruses, they don't have a wall around them in the way that cells are walls, essentially, are walled off areas.

They might have a protein shell, and so when the flu virus goes into a cell that protein shell kind of breaks open and the genes and proteins inside come out. They do have containers that contain them for a while, I see. Isn't that one of the... Somebody who had a list of rules that make you alive and wasn't a container, was one of those rules? I... Yeah.

But they don't do the energy, they have the container at least. Right, so the problem with viruses is that they have some of the things that we think are essential for life, but not quite all of them. So it's been convenient just to say viruses are not alive, just put them over there because they don't have everything that a cellular life has. So we'll just say they're not alive. Okay. Just viruses.

Gotcha. And then? So then what happened is that there was a scientist named Timothy Robotham in England who was investigating a... Timothy Robotham. Timothy Robotham. That's a English name. In Robotham was a father.

Timothy Robotham was working in Bradford, Sydney, England. And he was looking at the kinds of bacteria that might be growing in a hospital. You know, like they were having some problems with pneumonia outbreaks and so on, and he was like, okay, what's growing around here? And so he went to a sort of cooling tower for water on top of the hospital, and he took a sample, and he went and put it under his microscope and he's like, hmm, some interesting bacteria here. Oh, here's a very interesting bacteria that doesn't really look like anything I've seen before. Wait a minute, this guy would just kind of

crawl around to weird places and just snatch those snippets of scum or what would he, yeah, what was he? What was his job? He's a microbiologist. Oh, of course. So, you know, it would be good to know. Does that what microbiologists do? They just go scrape little bits of rock or water towers. They search the world. Yeah, I mean microbes are everywhere. So microbiologists go everywhere to find microbes.

So they're even, you know, in a water tower on a hospital. Was he, did was he in a kind of an investigatory role? He was trying to help them figure out which bacteria are making music? That was one of the hopes, but he was thinking of doing a survey because their diseases like legionnaires disease which can grow in these sort of containers of water. There's some concern about that, so better to get to know what's growing. So, he's particularly taken by one thing that he assumes his bacteria,

and it's got an interesting kind of round his shape. And he went bacteria around, you can call him coca-eye or cocus. So, he names this Bradford cocus, gives it a name. That's why the cocus name comes in. It's referring to the shape. Like strep to cocus, is it because it's round? Why did not know that?

It's the things you learn. The things you learn. The things you learn. Oh my God, okay. So he's trying to study this thing, You are my God. You are my God. Okay. So he's trying to study this thing and he's trying to... So when you're a microbiologist, the way you study bacteria, you get them to grow. And he can't get this to grow.

He's feeding at things and it's like, it's not growing. Why is it not growing? I can't figure it out. And eventually, you know, he just hits a wall. And unfortunately, his lab got shut down and so he basically said, okay, I don't wanna throw this stuff out. So I'm gonna give it to some of my colleagues in France.

It wasn't dying, which wasn't growing. Yeah, so he gave it to a scientist named Bernard Lascola and his colleagues. And they kind of put him... Bernard Lascoda. We, and he just says, he just sets it aside for a while and doesn't, you know, it's just more bacteria, you know, and it's for some reason he decided to, you know, take a look at this Bradford caucus. What was this thing that Robotham was talking about?

So he looks at it and he says, okay, this is the size of bacteria, but it looks like a gigantic virus. What is a virus? It's usually very small. Exactly. So a bacteria to a virus is like... Like hundreds of times bigger. Hundreds of times, okay.

So it's a Queen Mary to a small thingy. Yeah, right. So he looked up close and he was like, what is this thing? This doesn't look right. This, this, if I didn't know better, I'd say this was a virus. He's saying this based on its internal orientation.

It's appearance. It's because it had the protein thingy and had the stuff. So a lot of viruses, they have a shell made a protein. And the shell is kind of composed of plates. So it kind of looks like a soccer ball. Ah. So it's a very distinctive look. Okay.

And it looked like that. It looked like that. It didn't look like bacteria. Oh, interesting. It was like, wait a minute, could this be a virus? So this would be like, maybe like finding an enormous soccer ball in the woods. Yes.

So he'd found the Leviathan equivalent of a virus. Right. It didn't make sense. It was kind of crazy in that microscopic realm to say, maybe this is a virus. Right. It didn't make sense. It was kind of crazy in that microscopic realm to say, maybe this is a virus. Wait, so didn't so Brad Mumford, what's his name again? Timothy Robotham? Robotham.

Didn't have this realization? Nope, he hadn't looked at it closely enough. He looked at it. But he just didn't somehow put the this is a virus. He didn't click for a Tuesday. Was a Tuesday, you know? Wednesday is that's a virus day and it was Tuesday. And it's likely that other people were looking at the same things in years before.

I'm thinking they're bacteria. They're realising. Here's a big, here's something the size of bacteria. Well, in fairness, because viruses are always small, then you wouldn't think a big thing would be a virus. Well, viruses are always small in the sense that they were discovered because they were small. So basically, what scientists did was they discovered viruses by filtering fluid from

a sick plant or a sick animal through a filter, porcelain, actually. And it was so small that anything, the size of bacteria got trapped in the porcelain and anything smaller came out. Oh. And lo and behold, they could find things that could cause sickness in that fluid that passed through the filter. Well, so the discovery of viruses meant it was innately small because that's how you filtered for them.

That's what they were looking for. That's interesting. So there were probably generations of scientists who were looking in through microscopes, saw some interesting round thing and assumed it was bacteria and it was probably a virus. What the fuck is this giant, giant Leviathan virus? I assume that was his question.

Well, I mean, he first he had to really establish that it was. And so what happened was that he looked very closely at it and kind of worked out its chemistry. And the more he looked at it, the more it looked like a virus. He started actually looking at it's DNA, which hadn't been possible before. Turned out that it's a DNA resembled the DNA viruses and not have any known bacteria.

It didn't have, it actually didn't have the equipment for making fuel inside of it. Then the real kicker was that he found out how to grow it. What he had to do was he had to stick this thing inside of Amoeba. And then out of the Amoeba would come more of the, more Bradford Caucus. Just like a virus. Exactly like a virus. So he needs to change the name from Bradford Caucus

to something else. Right. So they named it Mimi virus. Mimi virus? Mimi virus? Because they were in France and Mimi is in a French opera. But because it was a mimic. It was a mimic.

It was a mimic. Yeah, interesting. Mimi. Is that a little like a mini me? Mimi. Is that like a French word for me? I think they just took the beginning of mimic and added a device.

Mimi virus. Very nice. I guess it's the same thing twice. Mimi. It's like mimic. Yeah, OK. I get it. So interesting. Yeah. Yeah, okay. I get it So interesting. Yeah, so this so this was I mean this was really bizarre when they published

The report on this in 2003 and men people really scratch your head because remember, you know ordinary viruses have you know Maybe ten jeans. This one had 1,000 and 18 jeans 10 genes. This one had a 1,000 and 18 genes. Wow. When you have 10 genes, those are the genes that sell you have a protein capsule and so you can swim through the thing. So when you land on a cell, you can burrow in and then explode and then make babies. So there's not much to being a virus, so you just need a few genes for that. Why was he a thousand? Does this thing have particular talents that the other viruses didn't have? Yes, maybe a virus and just need a few genes for that. Why would you use 1,000? Did you say? Does this thing have particular talents that the other viruses didn't have?

Yes, maybe it was like... It does. It does. What is that? Okay. Well, so one thing that's really interesting is what happens when it goes inside, it's host and amoeba. It goes in, but instead of kind of shedding off that protein code and just spilling out its contents,

it actually goes in and stays as it was. You mean it stays in a container and everything just started. Yeah, it's called the virus factory. Once it's inside there, it's this thing they call the virus factory. And it basically is able to, things, components come into it, and then it sort of has enzymes that can refashion them, and then they outcome the components for new, John, as far as-

Does this one has a nucleus of the already- or the existence cell? No, it just floats in there. Oh, interesting. So it, what does it do like that? Oh, it's a little portal, and No, it just floats in there. Oh, interesting. So it, it, what does it do like that? Oh, like, it opens up. It opens up a portal and it sucks up some stuff in there. Yeah, it has this beautiful sort of,

they call it a stargate. Because it's shaped like, it's a doorway shape, like a star and things come in. And then, and then I, I'm not, I'm not another stargate. The, the, the, these sort of manufactured things come out. And then in the cell, they assemble into new giant viruses. So it spits out the raw materials

and then self-assemble into a giant Leviathan? No, baby giant Leviathan says, which then how do they get out of the, do they explode through the surface of the cell? Yeah, they just blow out. That's like a totally, that's a totally different thing. Never heard of that. Yeah, I thought normally viruses

just go into the machine that's already there because they're parasites. They use the living things. This thing is, I'm, I have a weird kind of respect for this thing. Oh yeah, it's, it's amazing. And you know, one of the amazing things about it is that it can get, it's own viruses. It gets, there are, really? Yes. So there are its own viruses. It gets, there are viruses. Really? Yes.

So there are viruses of viruses. These things are called viral fages, and they actually go into the virus factory and hijack it. Oh, interesting. And instead of outcome viral fages. Oh. Oh yeah. As soon as you have a virus factory, that's what a virus wants.

It's none of the virus has its own virus factory. Well, it's going to get, it's going to be viralized. It's viralized by the other viruses its own virus factory. Well, it's going to get, it's going to be affected. Viralized by the other viruses. Right. Weird. Yeah, weird is the right word, I think. Right. Now, in 2003, you could say, well, this is one weird virus.

But the scientist said, well, I wonder what else there is. Like, yeah. Well, that's creative basic. So they said, OK, it's got all this extra genetic genetic Power but he's doing this sort of special circus act here. It's building its own factory And it's just behaving differently for the so maybe it just needs all those genes to do this special thing It's the problem was that when they looked at these you know 2018 genes most of them didn't match anything anyone had found before Hmm these are new genes.

Genes, yeah, that you couldn't even guess at what they were at. This has got to be from what, this is like an alien, it's from Saturn, this thing. Is that where you drive them with a story? Not quite, but kind of. I mean, so what you're saying, so they look at all the genes, they look at the chemistry of life as it's known, and they don't find any matches for this little thing, this big thing really. For most of the genes and they don't find any matches for this little thing. This big thing. For most of the genes, they couldn't find a match.

You know, you can look at, I mean, Well, that's a double mystery. Like, what is it? What is this? And where does it come from? Because it doesn't seem to have the smell of earth life. Yeah, except that it uses DNA. I mean, it uses protein.

It uses our chemistry, but it's it's doing something weird And so these scientists said well, okay, they looked in an English Hospital, you know water cooling tower. Let's go look at one here in France And so they looked and they found another giant virus, which is even bigger than the one that they already found We're in the hospital in France in the year conditioningonditioning Tower. It was another cooling tower. Cheese is like a, this is a cooling tower phenomenon so far. Roof top biology.

Well, it's excitement galore. It's more like the drunk looking for the keys under the lamppost, you know. It's like, you know that, Oh, this is wherever you look there. It's like, we know that we know there was giant virus that's found in one water tower. So let's go look in another water tower. Like's our safest bet and hey look we found an even bigger one

You know which they which had even bigger it was even bigger. Yeah, so instead of a thousand eighteen genes It had a thousand fifty nine genes So they named this one mama virus Mimi's first cousin Mama. Right, right. Did Mama do in things in the cells that Mimi didn't do? Or did it also build the factory? Yeah, it was making a virus factory.

So there's something, there's a common theme here with these two, now you have two giant viruses doing the same thing. Isn't this the whole stargate and everything? Yeah. What's weird is that the Mama virus has a bunch of genes that Neemee virus doesn't have. So it's like, and again, don't match anything that... So they don't know what these extra ones do? Some of them look like they're involved in building proteins, which doesn't make any sense

because viruses are not supposed to do that. So it's, this is all completely confusing. But then they say like, okay, maybe we need to kind of get away from the whole water power thing and widen our little... Where would you go? Like since the opposite of a water tower would be like the bottom of a well, or do you go to a library and look in the interior of old parchment books? Now you start looking at places like you look, you look in the ocean or you look in sediment

or you look inside animals or you look in the soil and they start finding giant viruses over and over and over again. Really? In all those places? In soil inside of animals, like in animals tummies or something? Yeah, so they went to, these researchers went to Brazil and said, let's go look at animals and see if we can find giant viruses.

And they found a new species in cows and they found a new species living inside of a monkey. And these were were they finding giant or giant viruses? Yeah, the numbers of genes were going up and up and up. Yeah, they would keep finding new record breakers. So the biggest one right now is called mega virus. That's the summer movie. Yeah. Mega virus. I mean, there's, you know, bigger than Mimi, bigger than Mama. Mega in a world. In a world. You got it. That's right. It's like the

truck of Sores, you know, it's like this is like I'm wondering what they're going to do as they keep finding bigger ones because you keep having to find super narratives for these things. Well, where was mega found? What was what? Mega I believe was found in the ocean. And how many genes does mega have? Mega has 1,120 genes. Okay, so we're but it's not actually the big the so it has the most genes, but it's not actually the physically the biggest giant virus.

Which was. So this one is called a Pandora virus. They're still. We found in a box. Let me guess. You know, in a sealed box and then they opened it and oh my god. Well, it's, it has this bizarre shape like an urn. Uh-huh.

Which is completely nuts. There's no urn-shaped viruses. This is crazy. And the urn, did that remind somebody of the myth of what the word, the word? So Pandora's Box was actually an urn. Oh, it was, okay. Yeah, I see.

Oh, kind of, it might be Pandora's Box then. God, that's a very learning. Just to make you happy. Very learning. Because you love where they found it. Where do they find it? So what they did was, these Russian scientists, they were collaborating with Doug up,

Frozen Tundra, that had been frozen for 30,000 years. And they said, let's saw this out and see what's in there. What kind of things have been asleep for 30,000 years? It does, like, the beginning of a sci-fi movie right there. Among other things, they found Pandora. They found Pandora virus. Not only did they find it, but when they let it warm up a bit, and then they gave it some amoeba to check out, they did it's thing. They did it's thing. Wow. And how much bigger, if the first giant virus you introduced us to was like an elephant-sized mouse, compared to that elephant-sized mouse to how much bigger is this one, maybe it's

more specific than you want to be. I need to look at the numbers, but you're kind of going from, I don't know, elephants to dinosaurs. You're getting bigger and bigger and bigger. You know, we're not talking about, you know, Pandora virus is bigger than a lot of bacteria. Wow. So these things are now being found everywhere.

You look, I mean. They are incredibly common. They've even been able to get giant viruses out of people. Really? Yeah. We do what's up. What are we really, you find them in a person? In our intestines or something?

I believe they found one sample in somebody's lungs. And another sample was found in someone's blood. But it's really hard to tell whether they're actually like actively invading us and making us sick, you know, maybe so if invading amoebas, they can invade human cells. Because amoeba and human cells are surprisingly similar. Or is it just kind of along for the ride with some amoeba that infect us, or does it kind of drift in and when people are sick, their defenses are down. So we don't know if giant viruses have anything to do with

human disease, but... It's true, we have a category problem here. Yes. If you've got a giant virus that's virus like in its general shell, but it's making proteins, it's got a bunch of genes that viruses don't have. You're already bigger than some bacteria. Shouldn't we call it as its own separate thing at this point? That's what people are arguing about right now. Do we keep that line between viruses and cellular life and just put the giant viruses with the viruses or do we kind of blur the

line a bit? This feels like it's on its way from one category to the other. So that's one of the big questions is like what way did this thing go in evolution? What does that mean? Well, how do you get a giant virus? How do you? Well, that's so... So we'll get to the potential answer to that question, which I think is totally fascinating after the break.

What's the answer to that question? What's the answer to that question? I think it's totally fascinating after the break. Hey, Chad here, Radio Lab. So we're going to return to our conversation with Science Writer Carl Zimmer. It's an unannoted conversation. And we were talking about giant viruses

and what they can teach us about life, which really starts with a simpler question of like, where the hell did they come from? How do you get a giant virus? Like, how do you? How do you? Well, so one clue comes from those genes. So now that they're finding more

and more of these giant viruses, they're finding enough variety of them. They can look for a source and some common genes that they share, some common mutations in genes. And they're finding actually that it looks like giant viruses might actually belong to one lineage. Oh, interesting. So they're cousins. They have a common ancestor?

Yeah, it's a tribe of us. Right. And if that's true, it could be an incredibly old tribe. These giant viruses could be a lineage conceivably that goes all the way back to the early stages of life. The dawn of time in the world. It's really old, like back to the very beginning of life on Earth. To that era, yeah. I mean, maybe when cellular life was getting started. But the question is, well, what were the giant viruses like then?

Now, some people have said, well, no, giant viruses actually started out as teeny tiny viruses, and they've just been gathering up new genes through time and just been getting bigger and bigger and bigger. But a number of the people who actually genes through time and just been getting bigger and bigger and bigger. But a number of the people who actually study giant viruses and have really helped us to understand the most, they're saying, no, we don't think so. We actually think that these things started out as cellular life.

They were cells. They were full-blown cells. Well, you mean they were from the other side of the road? They were cellular life. And then they switched sides. Yeah, they changed teams. Yeah. How?

No, that, like I can't have a plant that becomes an animal. How did they, so they started off as like what we would call creatures. Right. And then they started out truly alive. You know, they, they, like free standing out there in the air or the water or the ground or, yeah, just some, like some free living microbe.

Yeah. And then, well then why would they be, why would you go demon yourself? This is, this is your problem with parasites. You keep saying mean things about parasites. Well, how many years have we been talking about parasites? Where do I tell you nothing? If I had a choice between being a...

having my own integrity and choosing to make a living on my own, or to suck off you, I would just live on my own. Excuse me for... I know you like parasites, but honestly... Could you not use that passage that we really accordingly? It's already been cut. So, so wait a second. So you according to this theory, you have a man's true never the left. We have a micro that is that is doing its thing and then something happens. Okay, what is the something? It becomes a parasite. something happens. Okay, but what is the something? It becomes a parasite. It becomes a parasite. Or at least, you know, maybe a symbiont. Here, basically what it does is it starts living inside another cell. You need to give up its integrity as a free

life form, a free standing life form. Just so we understand what that means, that means that it's got a shell, it's got a border, it's making its own energy, it's replicating in the way that we think. At the beginning, at the beginning, it can make its own energy, it can grow, it can divide. It can do all the things that living things do. Yeah. And then for some reason, it chooses to require some other creatures' existence for its own. It has to become dependent on some other organism for its very, very existence. Well, let's flip it the other way and say,

it discovers a wonderful new home inside of another cell. It's a, it comes in and it's like, it's like I love leaving Laipaacov a new apartment for a dark cave. It's a new and exciting opportunity. No, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, your deer, you're starting your own fires, you're going on and on and on and you do that for like a few years and then and you're walking through the jungle and then It's very very skinny Not going well, so Robert Crowe which that the Haggard hunter

And let's say you're doing this in Minnesota, right? So it's like cold, okay, and then suddenly like And let's say you're doing this in Minnesota, right? So it's like, hold, okay? And then suddenly, like, there's a break in the forest and you come across a giant mansion and you're like, what is this place? And you open the door. And inside, there's like conveyor belts

with ice cream and steak. And, you know, and there are slippers waiting for you. And, you know, anything you need, it's somebody else is taking care of it. There is one thing you left out, when I walk into this magical kingdom of soda, it doesn't let me out. I can't leave ever again.

It shows that I am become so dependent on its natural wonders that I lose my independence, my integrity, and the very, very thing that I walked in with is now gone. We did literally have this conversation a few years ago. We did, it's true. We did, and I did point out to you at the time that you are quite dependent on other species. Do you want me to bring it up? No, no, no, no, no, no.

With Vita. I will just say, see episode 32. No, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, is a great way to go because you have all these things taken care of for you. Now, according to this theory, these mysterious ancient microbes started going into these cells and reproducing there and then going out again and then finding another host cell to infect. Where are they making their hosts sick? Probably, yeah.

Probably. Yeah, because giant viruses are not good to get. We'll see, this complicates your mansion metaphor just a tiny bit, because what it means is that you go in the conveyor belt and you're feeding yourself and having a good time, but then your filth starts to muck up the place and it starts to collapse from within.

That doesn't sound so nice. To strain the metaphor a bit. Go boy, go boy. Robert, pro-witch. No, I've done it probably for him. I was gonna have him. Okay, Jim, start understanding. So you spend some time in this wonderful mansion.

You rest, it's warm, it's comfortable, so on. You eat, fill it with your filth. You start a family, you know? And then also in you and your descendants, you know, leave the mansion. The mansion just collapses from all the damage you did to it. But you know, actually you see in the distance there's another mansion. Let's just go over there. Now you feel like rest it and ready and like, yeah, all we got to do is get over there. So let's just go there. We don't have to, we don't have to stop to kill a

deer. We just go to that next mansion. The ice cream is waiting. I is get over there. So let's just go there. We don't have to stop to kill a deer. We just go to that next mansion. The ice cream is waiting. I still got a walk. So I need my legs, so to speak, to get to the next mansion. But I don't need the powerful muscles that I would have needed to kill the deer.

I can let go of those. You don't even need, you know, let's say that you don't even need the knowledge of how to kill a deer. You would be blind, dumb, and fat. So these things, these things, these things, they start getting rid of these genes. And how does that happen? Just, you know, a random mutation comes along and just cuts out a bit of DNA.

That doesn't need them. You're fine. Yeah. You're like, that's okay. Is it a moment where, oh, there goes a big chunk of me. God. Yeah, I don't need that. I mean, that's a regular kind of mutation.

That happens all the time in cells. Oh, yeah, yeah. But then your successor being just travels a little bit lighter and is able to succeed just as well. Right. So, you know, if we are born with a part of our DNA that's deleted that had some, you know, like hemoglobin genes in it, like, goodnight, like that's bad. But, if you cut out a gene that this giant virus no longer needs because it's got everything supplied to it and it's host Fine, so let's chuck that chuck it out. So you have this so the idea is that you that these viruses they're giant viruses

But they're actually been shrinking Huh and at a at a how fast is a giant like the And at a how fast does a giant like the Imagining back in the beginning there was there was not mega Gino Cellular being oh, I sell you a guy right. Okay, so this I mean cellular be All the privileges and joy independent life Size wise. It's a blimp. It's a massive thing and then suddenly it starts to shrink bit by bit by bit by bit. What rate does it start to shrink and shed itself?

Well, it could be that these giant viruses we're finding, but these giant viruses that scientists are finding could be shrinking very, very, very slowly. It could be that there are other viruses that made this transition that shrank faster. So maybe, maybe, it's a race to the bottom, maybe some tiny viruses are just former giant viruses that just shrink really fast. Race to the bottom. It's such a different way of thinking about life. You generally assume being a multi-cellular organism yourself that little things in some deep sense, you're not supposed to say this, want to be big things.

You don't want to say this. I know, I know. But most people, unlike you as whole, most people think that it's better. I'm more than the podcast. It's better to be more complex than to be simple. But here, you're talking about a different voyage altogether. It might just work out for you to be simple rather than complex. just work out for you to be simple rather than complex?

Well, given that viruses are insanely abundant on this planet, I mean, by some estimates, 10 to the 31st power of viruses on Earth, think about that, like it's a, you know, it's a one with 31 zeros after it. I mean, it's inconceivable how many viruses there are on Earth. So it's their world. So apparently, you know, nature has not agreed with you. But you know, it is interesting, like thinking about how life gets smaller and simpler. It is just saying, yeah.

If it's true that this trajectory is as as common as you say, that things start out sometimes, start out big and then learn to live inside other things. And in the process, get smaller and smaller and smaller. And this is actually maybe what happens to a lot of viruses, not just some viruses. In a way, it gives the virus an honorable history. I don't know why I feel that way.

This boy isn't going to sign up for that. No, he's not going to sign up for that. It's okay. Well, an honorable history, but then it abandoned its free living path. It did. It gave into the temptations of the mansion full of steak and ice cream. It's true, but I've always assumed, and this is not something one should assume, that viruses were a kind of proto-organism.

They were somehow at the beginning of something, and they never quite got going. Yeah, but you're actually saying that these viruses are in a way at the end, not at the end, but they're at the, I don't know how to quite use the words that I want to use. There's, they feel somehow at the end of something out of the beginning. Like you've just took, you just took what I consider to be the beginning, and you've now made it an end, end, end. And that's interesting. I never, I just, that's interesting. Yeah, very interesting. So, so life can go in different directions. And how far can that reverse journey go? I mean, can you go from like, how big did that?

Was it ever like a turtle with things? Or, no, like a giant dinosaur? No. Sorry. There are things called, I believe they're called mix of zones, which started out as free living animals and have become parasites. And they're just down to just a few cells.

Maybe, maybe, mixes zones. Mixes zones, you say we're free living animals. You don't mean animals in the way that anyone would think of animal. Like a jellyfish. Oh, look, my pet, my pet's lovely, not like that. Well, my pet jellyfish. Really?

Really? Yeah. So you're saying a jellyfish. Really? Really? Yeah. So you're saying a jellyfish-sized thing has now reduced itself to a tiny spec? To a giant microscopic parasite of fish. Get the f*** from. Someone even say it because you can't do it if you're that small. That's insane. Really?

Like going from something you can see and would want to avoid while swimming down to something that you might even just breathe in without even knowing it. Wow. Oh, you're blowing my mind. Shrinking my mind. What was it called again? Mixes. Mixes Owen.

I'm mixing Owen. Yeah. How do you spell that? And why X, Z, O, A, N? I'm trying to in my mind to construct a scenario where we like the mix is Owen could begin to shed Like if we were living inside that like not the iPhone but the eye Home the eye universe. Well, you know, but the fact is that we you know, we have Cast aside some things, you know, what if we cast aside well, we can't I mean we used to smell better

I know I know that I know better We used to be able to make our own vitamin C in our own bodies. Our own bodies were vitamin C factories. Really? Yes. What changed that? Why did we want to let go of that? That sounds great.

Sunshine vitamin C. Yeah, making your own vitamin C. Well, if you are sitting around eating fruit all the time, fruit which is loaded in vitamin C, then if you get a is loaded in vitamin C, then if you get a mutation on your vitamin C gene, well, you're fine because you're getting your vitamin C from somewhere else. You don't feel that lack, you know. You don't start getting scurvy because you're treating yourself on fruit and then that mutated gene may then spread out and end up being in every member of your

species, which seems to happen to us. I mean, you can literally like see like these, we have these broken vitamin C genes. Yeah. So sometimes we shrink too. Yeah. Okay, so there you have it, a raw conversation with Science Writer Carl Zimmer about shrinking shrinkage in life. Now, usually what happens to these conversations is because you're just talking and because you don't really have like an encyclopedia sitting right next to you, you get a lot of the

little things wrong, little details, little facts, names, dates, whatever, and because you don't really have like an encyclopedia sitting right next to you, you get a lot of the little things wrong, little details, little facts, names, dates, whatever, and then, you know, you fact check it later. Uh, so in fairness to Carl, as we were fact checking, we gave him the chance to listen back to the raw conversation, make a couple of amendments. This is fact checker Carl, uh, scolding, uh, rambling carol. Okay. So, okay. We were saying that this microbiologist Tim Robotham took his samples to France, but actually

there was another microbiologist named Richard Bertels that did it. Gotcha. Small but important. Sorry Richard. Our apologies. And Mama Virus turns out to have a thousand twenty-three genes, not a thousand fifty-nine genes's our apologies. And Mama virus turns out to have 1,023 genes, not 1,059 genes, but apologies. Then I started talking about mega virus.

At the time in 2011, it was indeed the biggest virus known. 1,120 genes, okay? However, there was in 2013, a another virus found called Pandora virus. Now, I was saying that this was something found inside between Tendra, wrong. This was found in the ocean. And this virus has a whole lot of genes.

How many? It has 2,500. Whoa. 2,500. I mean, that's way more than a lot of bacteria. Also, at a certain point, and we do refer to Pandora viruses being the biggest virus in size, actually, that distinction

goes to Pitho virus. And also, it seems that since we talked, there's evidence that there might actually be a couple separate lineages of giant viruses. One may have evolved from big to small as we talked about, but another one might have gone in the usual direction from small to big.

There's one last thing that I see. So apparently, apparently I didn't quite spell Mixes Zone correctly. Hey. This is High Spell Mixes Zone, and M-Y-X-O-Z-O-A-N. Apparently I missed one of those O's. I can't remember.

I mean, I'd be lying if I say I didn't think a little bit less of you. No. Okay, extra O, back in. And the Ross duPidet. That goes into Radio Lab. Stupid people interviewing stupid people and reviewing stupid people about smart things that's funny that's a great tagline okay uh that's our new tagline I'm Chad Abumrod thanks for listening Radio Lab was created by Chad Abumrad and is edited by Soren Wheeler, Lulu Miller and

Lottip Nasser are our co-hosts. Dylan Keith is our director of sound design. Our staff includes Simon Adler, Jeremy Bloom, Becca Bressler, Aketty Foster Keys, W. Harry Fortuna, David Gable, Maria Paz Gutierrez, Sindu Nyanasambadam, Matt Kilti, Annie McEwan, Alex Nisen, Alyssa John Perry, Sarrakari, Sarah Sambak, Aryan Wack, Pat Walters, and Molly Webster. With help from Timmy Broderick, our fact checkers are Diane Kelly, Emily Krieger, and Natalie Middleton. Hi, my name is Michael Smith.

I'm calling from Penn H. Indus, Jersey. Middleton. condition.