SciShow Tangents - Metamorphosis

Episode Date: July 30, 2019

 When you think metamorphosis, you might think a beautiful butterfly coming out of its cocoon. However, lots of things metamorphose in much less graceful, much more sticky, gooey, unsettling, and potentially dangerous ways!Follow 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]https://www.eurekalert.org/pub_releases/2008-01/uoc-sbb010308.php http://news.bbc.co.uk/2/hi/science/nature/4460030.stmKind of gross but very cool, highly recommend this video: https://www.youtube.com/watch?v=GCo2uCLXvhk[Fact Off]Cryptometamorphosis:https://www.nytimes.com/2018/07/11/science/snail-metamorphosis.htmlhttps://royalsocietypublishing.org/doi/full/10.1098/rspb.2018.1099#sec-3Figure from paper: https://royalsocietypublishing.org/cms/attachment/12748a2e-c968-4fff-912a-9f9cd2c3d514/rspb20181099f01.gifWax moths and plastic:https://www.npr.org/sections/thetwo-way/2017/04/25/525447206/a-worm-may-hold-the-key-to-biodegrading-plastichttps://www.ncbi.nlm.nih.gov/pubmed/28441558[Ask the Science Couch]Grasshoppers/locusts:http://mentalfloss.com/article/57104/whats-difference-between-grasshoppers-and-locustshttps://www.scientificamerican.com/article/when-grasshoppers-go-bibl/(includes picture) https://www.sciencemag.org/news/2009/01/serotonin-makes-locusts-swarmhttps://science.sciencemag.org/content/306/5703/1881

Hello and welcome to SciShow Tangent, 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 Stefan Chin. Hello. Stefan, what's your tagline? Tomorrow's a new day. That sounds sad. I'm happy.

Why did they say that? Why are you so sad? I'm not. Okay, good. I'm glad you're happy. Sam Schultz is also here. Hello. Sam, what's your tagline?

Oh, my allergies. Oh. Everybody. My mouth is so itchy all the time. Oh. Sari Riley's also joined us. Yep. How are you doing? Uh, I'm okay. Do you ever get so stressed out that you're nauseated?

Yeah. Whoa. That's like what I am. Yeah, sorry. This is very cheery. Tomorrow's a new day, as Stefan said. Yeah. Oh, my allergies. What's your tagline? Doing my best. Doing my best. And I'm Hank Green. And my tagline is feet for feet. Your last one was feet are neat. Oh, shit. I gotta mix it up. And my tagline is balls to the wall, motherfucker.

What? That's the kind of energy we need. Yeah, the energy we're bringing to the podcast today I like it should I have I should have said tomorrow's a new day motherfucker

yeah I didn't go hard enough yeah we should have all done that doing my best motherfucker oh jeez every week here on

SciShow Tangents we get together to try to one up a maze and delight each other with science facts we're playing for glory and we're also playing for Hank Bucks

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 a tangent unworthy, we can force you to give up one of your Hank Bucks tangent with care. Now, as always, we introduce this week's topic with the traditional science poem this week from Stephan. This poem's called The Dragonfly. Changing changes, Poem's called The Dragonfly. Changing changes.

Pieces shift places. Aging in stages. Now freedom it faces. As a baby it squirted water out of its anus. But now it has wings and can fly to new places. Does that make sense? That's good. I feel like if you have the ability to jet yourself around with your ass, don't give that up.

Imagine if baby human swimming lessons were that different from adult swimming lessons. It was just like, let him go! We have a whole different pool for this. Yeah, you would need a different one. The water's gotta be more dangerous than the air, though, right? Like, if you're in the water, there's more

fish to eat you than there's stuff to eat you if you're flying around in the air, right? Right. Maybe. Yeah. Well, yeah. Dragonflies, when they're adults, they're predators. I think the dragonfly niffs, though.

They're pretty mean, I think. I think they also eat stuff. Yeah. They eat baby fish, I'm pretty sure. But they definitely get eaten by fish. Also, shooting water out your butt gives you more propulsion because it's more mass per unit of volume than shooting your wings can do it. Shooting air out of your butt. I wish that there was an insect that shot air through its butt in the air,

but that seems very inefficient. No, yeah, definitely not good. Airplanes kind of do that. It's where they keep the generator on the plane. It's in the back and then it's got exhaust out there. That's not for thrust.

No, it's not for thrust. It's probably adding some little amount, maybe. Maybe the tiniest amount. Yeah, anything that pushes any mass. Just as much as a human fart would accelerate a human being. Right. If you're not in space, it'd push you backwards.

And if you fart, it'd push you forward. So he's gotta do both at the same time. And then which is stronger? Like an immovable object? We have a lot of experiments to do up there. I apologize for this entire beginning of the episode. Stefan's got a point for his poem.

Yes, thank you. We didn't even talk about what the topic was. Now we have to talk about what the topic is, which is metamorphosis. Sari, help. So I couldn't find a very precise definition, but metamorphosis seems to be any sort of extreme physical transformation in the morphology of an organism. And this physical change also affects their behavior in some way and also usually their ecological niche. For example,

caterpillar turning into a butterfly or a tadpole into a frog or a dragonfly nymph into a full-grown dragonfly. Tadpoles swim in the water and have gills and then they grow lungs and have to breathe air as frogs. And they have a sort of a whole different survival strategy and also a different body plan. And that drastic transition in a short period of time is metamorphosis. I would love it if there was, there has to be, it's a big universe, a sentient species that does metamorphosis. Instead of like, coming of age, we're going to have your quinceanera or your bar mitzvah,

like, no, you you are gonna go in a cocoon and you're gonna come out an adult yeah that's just that'd be so wild that's basically pokemon are pokemon sentient oh okay if you look at like me too i don't know he talks you two can speak the human language yeah pikachu they all understand words okay i didn't know about this i'm old too old for pokemon lore yeah and i'm worried about the whole setup now oh yeah you imprison sentient species in your balls and make them fight for you like a squirtle is as smart as like a toddler at least well yeah because they knew knew enough in the TV show to fight fires and help out. And wear sunglasses. They had friends.

Yeah, so there you go. Who started this one? Oh, it was me. It was a thousand percent me. Okay. Well, Sarah has negative one points. But I can tell you more about metamorphosis. I know it won't make up for it. That's probably for the best.

So there's complete metamorphosis, which is like a caterpillar to butterfly where the body plan significantly changes. But there's also incomplete metamorphosis, which I learned about called hemimetabolism. So that is certain types of insects where the nymphs look like smaller versions of the adult and they just like keep shedding their exoskeletons like russian nesting dolls and those increasingly bigger nymphs or larvae are called instars instars which is a very cool name that is nice why doesn't a human growing up count as like incomplete metamorphosis we don't shed our skin i think kind of we do i think if we were to change metabolically like have hormones level change, and then as teenagers, we like shed our exoskeleton and then a slightly bigger version of ourself popped out.

That would be metamorphosis. But our change is too gradual. Okay. I think I got a sunburn in high school where that happened. Well, because like snakes don't undergo. Right. I don't know. Some reptiles do, but I don't think like snakes shedding their skin that's not metamorphosis not even incomplete metamorphosis

i don't think so oh boy yeah so it turns out it's fuzzy it's always fuzzy there's always a blurry line i'm metamorphosizing yeah i'm doing it right now the non-science couch is convinced that everything metamorphosis yes so we'll just present that to the audience and see which couch they'd like to go with. Yeah. I used to be a little version of me. You did. Look at me now. Okay.

So for the purposes of this episode, extreme quick growth into something different-ish. Yes. Yeah. And different-ish in appearance, behavior, things that it eats or eats them. Maybe you're constantly undergoing very slight states of hemi-metamorphosis, Sam, every time you lose a skin cell and get a little bit bigger. I'm like a goldfish. I just keep growing until I match the surroundings. That doesn't even work for goldfish. But I do, I will keep your office the same size for that

reason. I don't want to get too big or too small. They can't shrink again. They just sag. Yeah, they can't shrink. They can just die. So I guess that means it's time for Where one of our panelists, it's me this time, has prepared three science facts.

But only one of those facts is real. And the rest of you have to guess which fact is real by deduction or wild guess. And if you do, you get the Hank Buck. If you don't, I get your Hank Buck. And this week we're talking about a metamorphosis. We're talking about a beautiful blue butterfly, the Alcon blue butterfly, which likes to outsource the work of raising its young to their friendly neighborhood Myrmica ants. Mimicking the ants' surface chemistry,

the butterflies trick the ants into taking care of the young caterpillars. So the caterpillars basically change the chemicals they're expressing on them so that they look to the ants like ants. And then the ants get, like, super invested in them and feed the caterpillars at the expense of their own young. The caterpillar can live for up to two years inside the nest before turning into a chrysalis and eventually emerging from the nest into a fully formed butterfly. But in that time, things can go a bit wrong. Which of the following is the worst case scenario for the Alcon butterfly caterpillar?

Number one, the parasiter becomes the parasitee. While the ant colony may not know that there's a caterpillar in ants' chemical clothing among them, a parasitic wasp does. It enters the nest. The wasp releases a pheromone that incites the ants to fight each other, and then in the confusion it injects its own egg

into the caterpillar's body. The colony seemingly returns to normal after the wasp leaves the nest, but when the time comes for the caterpillar's body. The colony seemingly returns to normal after the wasp leaves the nest. But when the time comes for the caterpillar to pupate, the wasp grub eats out the inside of the chrysalis. And then instead of emerging as a beautiful blue butterfly, out comes a wasp. Or, number two, the ants catch on.

As the caterpillar begins to enter the chrysalis stage, some of the ants continue taking care of it. But in one of the species, the spell begins to wear off. Recognizing the changing chemical signatures from the chrysalis, the ants have evolved to take advantage of the meal that has been taking advantage of their hospitality, striking early while the chrysalis is still soft. They consume the inside of the chrysalis, providing a nice cold dish of revenge. Or number three, raised by ants, the Alcon butterfly undergoes a bit of an identity crisis that stays with them through adulthood. Even after flying away from their host homes, the Alcon butterfly has been observed trailing around the ant nests, even when it isn't

trying to offload its young. It's most striking during the annual nuptial flight of the ants. It's likely due to the common chemical signatures it has evolved to resemble the ants. The Alcon butterflies have been observed trying to join these large mating swarms so that they can unsuccessfully court the queen ant. I hope it's that last one. And nobody has to die. Yeah, nobody dies there. So your facts are, one, that the parasitic wasp lays an egg inside of the caterpillar, and then as it turns into a chrysalis, it eats the inside and is all happy. Or two, the ants turn on their parasite and consume it.

Or three, the butterfly gets a bit horny with the ants because it gets confused by chemical signatures. It misses its friends. I want to go back with my friends who raised me. Yeah. So they get a big old grub and they're like, this is our big baby now. This is our big, big baby. We love our big baby. They don't want to discriminate.

It's just a chunky boy. But they kind of do because they're like, all our other babies aren't as cool as this one big baby. Yeah. And it eats so much. It's always hungry. You said they can live there for two years, but how long do the ants take to grow up? Oh, multiple generations of ants, maybe. So they're just like hanging out there.

That's my grandpa's baby. This giant caterpillar has been here my entire life. And it's just my job to feed it. And I love him. it smells so good i mean it just reminds you that like ant brains right like how they decide what to do with their lives is all chemical signatures yeah if you can mimic those chemical signatures then you can get like fed for two years straight i also just like that there's some things that their babies look like ants so they can blend in. This one doesn't even bother.

It just smells like ants. It's a big old chunky one. I'm pretty stuck on the last one. I don't want it to be the other ones, so I'm going to go with that one. There are wasps that parasitize all kinds of things. Parasitic wasps will lay their eggs on anything. So that makes me feel like it could be true.

So watch out, Sam. And me, too. I don't know. Probably no humans. I think just insects. The second one sounds plausible because it's just like you have a little smoothie in there. It turns itself into goo so you don't have to. So it's just like, oh, this is not a baby anymore.

It's a snack. The first one does seem kind of unbelievable to me. It's like a secret spy mission. Like you have to sow confusion and then sneak into the nest so you can inject this one thing. I'm going to go with the second one. I'm going to go with. I thought you already went with the second one. Oh, yeah.

Okay. I can go with the second one. No, it's fine. No, I'll go with the second one. Okay. I'm sorry. You're all wrong. No.

Is it the wasp? It's the wasp. It sows confusion. It plants a chemical bomb and the ants are like, ah. And then in the meantime, it's like, I'm going to stick my egg inside of this caterpillar. There's other caterpillars out there that aren't living in it. But this one doesn't go anywhere. It's just always in the same place, always with these ants.

You know it's going to be safe, I guess. You know it's going to be there. They're going to take care of your, yeah. They're going to take care of your food food sack your baby's food sack for years so are there nuggets of truth and the other ones yes there are some nuggets there is a species of ant that has changed its surface chemistry particularly to outsmart this caterpillar but it doesn't they don't eat them wait a species of ant that changes its yeah so there's a piece of ant that has changed its surface chemistry so it no longer matches. Okay.

It's like an arms race thing. I see. But it doesn't do it like spontaneously once the caterpillar is there. They've just evolved out of being tricked. Yeah. Okay. And the other one is a thing that happens with ducks. So brood parasites are also a thing in birds where a bird will come along and lay an egg in a nest.

And there are, let's quote here, male facultative interspecific brood parasitic ducks mistakenly courted females of the host species instead of their own. So they're parasitic ducks? Parasitic ducks! Next up, a short break, and then the fact off. Welcome back. Hank Buck totals. Sarah, you're coming in last with negative one. I've got three. Sam's got're coming in last with negative one. I've got three.

Sam's got zero. And Stefan's got one. I need to tangent a bunch, you guys, because I'm killing it. There's still one point behind me. What the heck? Now it's time for the fact off. Two panelists have brought science facts to present to the others in an attempt to blow our minds and yours listening at home the present easy to have a hank buck to award the fact that they like the most and now it's time and we will go by the person

who most recently got a piercing oh that's a kind of metamorphosis of your own body yeah a very fast change i got one in third grade i got my my ears pierced, and then I realized that I hated the feeling of metal going through my body. And so then I cried a lot whenever I had to twist them, and then I eventually took them out. I did not like that feeling when I had piercings. When you have to twist them? Because you have to keep the hole open long enough to make sure it stays open. For it to heal up? Yeah, it was a very bad feeling.

Oh, never. I never have. Never have? I've never gotten a piercing. No, no piercings on this body. Wow, I would have beat all of you, but it's not me. When's the last time you got a piercing?

High school. Oh, okay. I think after third grade, I decided I didn't want piercings anymore, and I was like, tattoos is what I want as an adult. Yeah, I've never seen Sari. She's covered in tattoos.

Yeah, you know me. Head to toe. Wild. Okay, so when we think about the major body changes that happen with metamorphosis, you think about like very visible or obvious things, like a tadpole looks very different from a frog. But I want to talk about something that was discovered in a deep sea snail called Gigantopelta chesoya in 2018, and it's called Cryptometamorphosis.

So when these sea snails are babies below five millimeters or so in body length, they look and behave like a lot of snails we know. So they have normal guts and a chitinous scraper called a radula, like a tongue teeth. I couldn't find exactly what they eat, but it seems fairly herbivorous because they said graze in the paper. So algae, small organisms eat, digest poop. But right between 5.1 and 7.88 millimeters in body length, their esophageal gland grows explosively and becomes what's known as a trophosome, which is a specialized organ where chemosynthetic bacteria move in and then use things like hydrogen sulfide and oxygen to make energy, some of which goes to the snail. And as far as I can tell, the radula and the guts,

like the stomach, intestines, and other things basically stop growing. So they're proportionally very tiny because the snail grows to be like 50 millimeters or two inches in size. So I brought a picture that'll be in the show notes, but like the yellow is the organ. Oh, whoa. So its whole body basically becomes a bacteria house all of a sudden at some point,

but the outside doesn't change. So it looks the same from the outside. It looks the same from the outside and just like keeps growing bigger and bigger. Is that what crypt metamorphosis is? It means that it's like secret inside. You don't know what's happening. Yeah.

So it's hidden metamorphosis. I thought it was like a Bitcoin thing. Bitcoin. And these snails. Mine for Bitcoin. Crypto metamorphosis is what happened to all of my money. So then they basically become bacteria houses. They stop eating altogether and like get their energy from

these bacteria that create it from gases and other chemical compounds and then they like grow and mate and exist as adults but like the most interesting conclusion from this was that the researchers were like we don't know how many other sea creatures forest creatures whatever could be undergoing crypto metamorphosis right yeah because the the way they discovered this was finding adults that look like they didn't eat. And they're like, this is a weird ass snail. Its digestive system is not set up for eating like a normal snail. And then they looked at babies and they're like, well, these ones look normal and it eats. So when does it not? And they did a bunch of x-ray scans at all different stages. So does it not eat at all? Yeah, so it's like any sort of symbiotic relationship

where bacteria consume chemicals and then give energy to their host organism. And as far as they can tell, the adults don't eat. Are there anything else that cryptometamorphoses? Not that we know of so far. This was only in 2018. This is the only cryptometamorphosis that we know of. Yeah, but there could be other things

out there secretly metamorphosizing. Gotta start cutting everything in half until it gets to the bottom of it. But at all life stages, too. I want a bacteria sack that feeds me. I think I do, too. Replace all your intestines with it. Well, I could keep my intestines.

What if I want a piece of pizza? But I won't need it. Sam. Do you want to hit us with your facts? A few years ago, a beekeeper in Spain discovered that her hives had a big problem. Human-made beehives might seem like fairly secure places because they're enclosed, they're sturdy,

they're probably really sticky, and they're filled with guards that have built-in spears on their butts. But to many types of parasitic animal, they are a valuable target. Filled with nutritious food like sweet, sweet honey and helpless little baby bees. One of these animals is the wax moth. So female wax moths sneak into beehives and lay their eggs in like some out-of-theok or cranny and then when the eggs hatch into wax worms is what their larva is called they start eating the wax of the the hive and they chew through like the honeycomb and they ruin all the stored honey and they like kill the babies indirectly because they get rid of the little brood thing that they're in and as they go they

spend webs behind them that can tangle up the bees and the baby bees, and they just make a huge mess. And then they go into their cocoons in the hive, and they come out as moths, and they go to find more hives to lay eggs in. So this beekeeper named Federica Bertaccini discovered that some of the hive panels that she had in her operation had a waxworm infestation. So she grabbed a plastic bag, and she cleaned all the panels. But then when she was done, she looked at the plastic bag and it was filled with holes and all the waxworms had escaped. So for a lot of beekeepers, that would just be an annoying thing. But she is not just a beekeeper, but a researcher at the Spanish National Research Council. So this occurrence made her wonder if the wax worms had eaten the plastic if they just

chewed through the plastic or if they had eaten it like they eat the beeswax so they crunched up a bunch of uh waxworm larvae and they spread it on plastic and it melted the plastic into ethylene glycol which is used in antifreeze i think and breaks down naturally after 10 days so then they put a bunch of living worms on it and they did the same thing. They ate the plastic like of their own volition and it didn't seem like they had any health problems or anything like that. And even the silk that they spun and the cocoons that they made themselves also melted the plastic.

So right now they're trying to figure out how it happens. Like it's obviously the same thing that lets them dissolve and digest wax wax but they don't know if it's an enzyme or if it's a bacteria but they're trying to recreate it for mass whatever you call it mass production so we can just spread it on all our garbage bags uh-huh so this is my second one in a row about dissolving plastic this one's kind of familiar well come on we gotta save the world that's right i'm out. There's too much plastic around here. Yeah, I guess to like consume wax would require some particular biochemical machinery. Yeah.

Eating wax is not a normal thing that things do. It's very... We can't even do it, right? Oh, yeah. It's not a good food. What's in it that would be helpful to them? I couldn't really figure it out. Oh, wax definitely has a lot of energy in it.

Okay. So like you can burn it, obviously. Oh, right. Candles, for instance. You seem very rowdy. Just like... Uh-huh. Like a little bunch of little rowdy boys

running through the hive like chomping, like breaking all the walls down. Yeah. Smashing things, eating the grubs, eating the honey. Pooping in the honey.

Yeah. Pooping the honey. They don't eat any bees. They don't eat any bees or anything like that. They eat like their skin, their shed skin. What? Sorry. The. They eat their skin, their shed skin. What?

Sorry. The bees? Shed skin? Eat their skin? They eat the shed exoskeletons. Oh, that's wild. That's chitin. That's also a really difficult to digest.

But they don't ever directly harm any bees or attack any larva or anything like that. They're just garbage eaters. Yeah. Well, they can be in the hive for six months, too. So they're rowdy boys for a long time. Why don't're just garbage eaters. Yeah. Well, they can be in the hive for six months, too. Whoa. So they're rowdy boys for a long time. Why don't you just go eat plastic? There's lots of plastic around.

If you can do that, why are you, like, searching for beehives, which are basically, like, nowhere? Well, nobody told them. They don't know yet. Guys, plastic!

Yeah. Can you hear me? Do you listen to podcasts? Yeah, we gotta teach all the moths to speak human languages and then give them iphones and give them iphones subscribe them to itunes itunes doesn't exist oh sorry apple podcast

stitcher they could use whatever i don't care what podcatcher they use but they need an account no matter what. I don't know if the system can handle that with more new accounts either. It'll be like Moth 1, Moth 4, Moth 4008, you know? There's got to be a lot. There are more people than wax moths.

Really, though? I don't think so. There are so many of us. When people talk about a lot of insects, then they talk about beetle species collectively, not just one. Yeah, but I bet all wax moths have the same name,

and that name is wax moth. So they would need a lot of numbers after their names. Well, there might be some edgy wax moths that's like W at sign X M 0 T H. Yeah, that's true. Yeah.

Also, the great thing about numbers is that there is an infinite number of them I'm just saying it might be a load on the system I don't know how

these things work not my primary concern with the thought experiment but it's good to explore all angles okay do you get

Dr. Point for this? I don't know let's do it oh okay fine take him down with me oh man the longest episode ever i know so we have sari's crypto metamorphosis where your digestive system turns into a big bacteria sack for a snail so it never has to eat again which is freaking awesome and

sam's a scientist lady was cleaning her beehive and her bag dissolved yeah and then they destroyed a bunch of wax moths and rubbed them on plastic and it dissolves plastic

which is also freaking great those are both great I mean the crypto metamorphosis thing is pretty cool yeah and we've never found it before we just found it 2018 was last year

yeah well mine was in 2017 so that was just two years ago uh i'm gonna go with sam because it uh when i was in in school one of the things i did was try to figure out like ways to break down lignin which is the stuff trees are made out of and it's just organisms on this planet are so good at making compounds that are super durable and hard to consume. And then something is always like, but I could consume it. And I just love that there's a thing that has figured out how to eat wax. And then it might actually be like super useful for us.

Why are you trying to melt trees, Hank? There was a good reason. Okay. That sounds pretty evil so i guess now it's time to ask the science couch listener questions have been sent in to us and our couch of finely honed scientific minds is going to take them on stefan what's our question at birana ella asks has there ever been a metamorphosis where scientists originally thought the two forms of the species were separate species depending on what you mean by scientists, like, yeah.

Like, we used to think that about, like, everything. But scientists now, like, more recently, I bet, yeah. But I don't know. Sari? Didn't they think that the caterpillars and butterflies were having sex with each other or something? Was that a thing? There is a conspiracy theory from someologists conspiracy theory that caterpillars and butterflies were two separate species very few people believe this but the ones who believe it are like super into it that there were separate

species not like caterpillars and butterflies but early on in the evolution of like of metamorphosis that like a wormy thing and a flyy thing did it figured out and like somehow got all their stuff together and became one species yeah but it's like people don't even like to bring it up because it's appealing to non-scientific folks but there are some biologists who like but we should look into it and see if maybe but it is a tiny fraction that's a science who are okay who can lend any credibility that idea at all is it okay that i brought it up i think so yeah is that forbidden it's kind of forbidden oh no it's like you don't want to mislead more people like you don't want to plant that idea into anyone

else's brains. So I was trying to find a concrete example of a modern species where this happened. And the most interesting one that I found was the desert locust. So locusts are just short-horned grasshoppers. So all locusts are grasshoppers, but not all grasshoppers are locusts, if you think of it that way. And desert locusts are a very big pest in Africa and the Middle East and Asia. Eat tons of crops. And most of the time, the desert locust is greenish. So it looks more like what we would picture as a grasshopper.

But there's something that causes a big physiological shift to make it like much darker like sandy colored black and like spotted and the biggest change is behaviorally so instead of being solitary and hopping around they swarm so they change colors yes they look different they go all black and spotty and then they're like we're gonna work together now boys and we're gonna eat everything i heard about this one when it was news so that's recent that we've yeah like they thought they were we're going to work together now, boys. And we're going to eat everything. I heard about this when it was news. So that's recent that we found out? Yeah, like they thought they were two different species of grasshopper because they look and act totally different. With the desert locust specifically,

people did a study and they found that serotonin was the key compound. So as a juvenile, as the green docile form, they don't have a lot of serotonin. But when they injected serotonin into the grasshopper, that's when it physiologically and behaviorally changed. And if they added serotonin blockers, then it didn't. Would it change back? I don't think it would change back, but it like kickstarts the transformation. And so I think this falls under the umbrella of metamorphosis because it is like a big behavioral and physiological change. And it seems like it can happen within one generation.

It can also happen over multiple generations. So it's like they gradually become locusts. You just wake up one day and you're like, you know, I'm not a nice grasshopper anymore. If you want to ask the science couch, follow us on Twitter at SciShow Tangents, where we will tweet out topics for upcoming episodes every week. Thank you to Actually Gimli and Bob Zerker and everybody else who tweeted us your science questions. It's so exciting to have Gimli watching. Yeah, it's really him, too. And finally, before we move on to our final scores, we have a quick bit of listener mail from Logan, who is studying disaster and emergency management and has an important clarification to make re our definition of natural disasters.

A disaster, he says, is generally defined as a hazard event which overwhelms a local population's ability to cope with the impacts. So a tornado that ruins a few houses is terrible, but not a disaster. If it wipes out half a town and the province, state for you, has to step in and help rebuild, that's a disaster disaster. Overall, if every hazard event that interacted with humans was a disaster, we would be absolutely fucked. Thank you, Logan. Thank you, Logan. That's a very good clarification. If you want to clarify our definition of metamorphosis, please send us an email.

Oh, yeah. I'm doing my best here, but we can get some of your bests here. So our Hank Buck final scores. I come out on top with three. Stefan, you've got one. Sam and Sarah, you've got one point, but you also lost one point each during this process. I honestly feel like we were the most on topic the whole episode.

And that YouTube just tricked us a couple times. Yeah, well, you know, that's the way the cookie crumbles. Life isn't fair. If you like this show

and you want to help us out, it's easy to do that. You can leave us a review wherever you listen. That's super helpful. It helps us know what you like about the show. It also lets other people know

that the show is good. We'll be looking at iTunes reviews also for topic ideas for future episodes if you want to leave those there. Second, tweet out your favorite moment from the episode. And finally, to show your love for SciShow Tangents,

you can tell people about us. And if you want to read more about today's topics or see some good pictures of snails and locusts, 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 Stephen Chin.

And I've been Sam Schultz. SciShow 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. One time a scientist was like, what would happen if I grafted an eyeball onto the butt of a blind tadpole? What? Just don't.

Well, what happened? Well, first of all, the tadpole's nervous system figured out that it was an eye and the tadpole was able to see out of it. Whoa, he's modular. And its mind was like, yeah, that's how eyes work. I've never known any other way for eyes to work. And then the tadpole underwent metamorphosis and there was a eyeball on the butt of the frog. That's my whole fact.

An eye butt frog. And that's my butt fact. My computer literally just ran out of batteries.