SciShow Tangents - Mating

Episode Date: February 14, 2023

In honor of Valentine's Day, that most cherished day of beauty and love, the Tangents crew gets real down and dirty by telling you more than you could ever want to know about sex harpoons, cannibalism, living sperm, and some other utterly un-romantic methods of copulation employed by the animal kingdom! SciShow Tangents is on YouTube! Go to www.youtube.com/scishowtangents to check out this episode with the added bonus of seeing our faces! Head to www.patreon.com/SciShowTangents to find out how you can help support SciShow Tangents, and see all the cool perks you’ll get in return, like bonus episodes and a monthly newsletter!And go to https://store.dftba.com/collections/scishow-tangents to buy your very own, genuine SciShow Tangents sticker!A big thank you to Patreon subscribers Garth Riley, Mike A, and Tom Mosner for helping to make the show possible!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @im_sam_schultz Hank: @hankgreen

Hello and welcome to SciShow Tangents, the lightly competitive science knowledge showcase. I'm your host, Hank Green. And joining this week, as always, is science expert, Sari Riley. Hello. And our resident everyman, Sam Schultz. Hello. Last episode, we talked a little bit about the little cursor zoo where we keep our cursors at the top of our document. Faith seemed to have just had a big change of heart and made it into a cursor prison. And I don't know, there's three, there were three of us in there and i assume that's us oh you think it was us oh interesting if it's just drinking her kombucha over there like no no i was not what i was thinking at all so uh i i immediately opened the document and then i pulled i pulled all of us out of there there is a fire right now which

is somewhat concerning i pulled i just generated more people and then put no signs to create a little protest outside the prison. And then Tuna created a bottle with a fire on top for a Molotov cocktail. Oh, a Molotov cocktail. I see. And then I just showed up and freed everyone. Yeah. Like, it's done. We're out.

You can't imprison the hosts of scishow tangents yeah what have we ever done a lot of stuff not deserving of prison a lot of people haven't have done a lot of stuff it's true not deserving of prison true so the question is what's the thing that you did that would most likely end you up in prison i'll tell you mine. Wow, okay. I had this fun idea for a way to encourage people to vote. I think maybe it was like you get entered into a sweepstakes or something. Turns out you can't give people rewards for voting. That's really not cool. That's one of the things that people do very intentionally to manipulate the outcome of elections.

You can tell people to vote. You can help them vote. You can give people to vote. You can help them vote. You can give them all the tools that they need to vote, but you cannot give them things in order to vote. Even a percentage of a chance of winning a thing, not allowed. And I figured that out just in time. Good. Before you went to-

And then I was like, you're right. Got in trouble for bribery. That's a good rule. That's a good one. I think that that was probably the right for bribery that's a good rule that's a good one i think that that was probably the right call to have that rule in place i didn't think through the full implications of my idea that never happens anyway i'm not going to make you guys incriminate yourselves for the things that you did to send yourselves to prison yeah my mom will be mad at me yeah mine was like civic engagement yeah mine. Mine was definitely falsified identity, but for the sake of prank as opposed to like broad.

So I never applied for insurance or credit card or anything. I just pretended to be other people using my technology skills. Who did you impersonate on the internet? I used to pretend to be people who were interested in egg and sperm donation. When people would put high-priced ads in student papers of like, we are looking for top SAT score, AP test, fives, chemical engineer to donate biological materials, I would create fake email accounts and message with them because I was curious how unhinged of a person they were. But I think I was also unhinged to do this.

Yeah. That's weird. Like create these fake personas. And then I would always back out. I would say that I had some sort of, like, oh, I have, sorry, I didn't disclose that I have any glasses. And then sometimes I would be like, oh, that's a deal breaker.

Wow. And sometimes. But what if they said, okay, we don't care, come in. Then would you just start sweating bullets or what? I also have congenital glaucoma. That's why I've got the glasses. Then I would either make up more lies or ghost them and delete the email account forever.

No, backing out doesn't seem like a weird thing to have happen. Right. From their perspective. The sperm of healthy MIT students. It's because you went to MIT. I was like, this never happened on my college campus. Yeah. No, mine either.

It's like, well, we were really looking for a bunch of guys who do so much weed. Yeah. No, the eugenicists go to the fancy people's schools. And they're really like, we need the social elite. And then I'm like, but how racist and elitist are you? I see. You're doing some investigative journalism. It's great.

Yeah, it would have been journalism if I had actually written anything instead of me just showing the emails to my friends and being like, look at these weirdos. If you'd found something really juicy, you would have written about it. But you never know what you're going to find until you look.

That's the true journalist's heart. You got to look under every rock. Well, watch out, egg donor searchers, eugenicists, I'm coming for ya. So every week here on Tantrums, we get together to try to one-up amaze and delight each other with science facts while trying to stay on topic.

Our panelists are playing for Glory and for Hank Bucks, which I'll be awarding as we play. And at the end of the episode, one of them will be crowned the winner, and it won't matter at all. Now, as always, we introduced this week's topic with the traditional science poem.

This week is from Sari. Roses are red and Valentine's Day is commercial. So let's talk instead about pollen dispersal. For some flowers, you've got stamen and pistil in one. Self-fertilization makes seeds and you're done. Because there's two gametes, the egg and the sperm, it's still sexual reproduction, I'm here to confirm. Though there's potential to find an external mate when wind, water,

or bees help set up a blind date. Animals aren't that different from our planty friends, so let's look at mating through the same lens. It takes two gametes to tango these meiosis-made cells, though the methods of merging can have more whistles and bells. Some social, some savage, some weird mixing of genes, with one mate or several or thousands for queens. The heart of the matter is that heart doesn't matter. For most living species, they breed just to scatter. So tis the season for chocolates and rituals complex but

remember we don't know why evolution led to sex oh you can't say that without me talking a lot but yes congratulations that was very good but you can't say that i'm gonna fight about it i can't believe we could do one episode about mating which is it's big it's very big the topic of the day is mating um and sari i guess i need you to tell me what this is so i guess we we are calling it sexual reproduction i think so i think to narrow it down slightly because if you include all the accoutrement that comes with mating and i guess we will probably talk about the the social rituals around it sure because there are a lot of it but at its heart i think the topic of this episode is sexual reproduction which is the everything that goes on with either opposite sex or hermaphroditic

organisms or yeah it doesn't have to be opposite sex either because sometimes there's like more than two. Yeah. That lead to the fusion of two gametes. Right. And so we've got gametes, the gonads that produce the gametes, and then copulatory organs that vary from animal to animal, plant to plant, eukaryote to eukaryote. And all of these systems work together to help organisms reproduce. And it would be easier, is definitely true, if you could just bud. If you could just be like, and there's a thing on my shoulder, and it falls off, and it's a baby now.

But we don't do that. And sex, I think, has evolved several times. There seems to be some significant evolutionary pressure towards sexual reproduction rather than asexual reproduction where you just make a copy of yourself, which is totally possible. Lots of organisms do it. So it's not like it's not possible. It's easier in every way than sex. it's not like it's not possible it's easier in every way than sex but sex is obviously selected for because it is a burden to the organism but continues to be selected for over and over again

continues to happen over and over again we have a pretty good guess of why that is right why sex specifically as opposed to other methods of genetic recombination evolved to facilitate genes transfer is very, very weird and not as easily explained by like the gradual process of Darwinian evolution, because the forming of the egg and sperm cells is a lot of energy to go to a process that doesn't happen for any of our other cells. And like the specialization of all

these body parts it's hard to pinpoint at what point in the single-celled uh part of our evolution that spawned the first eukaryotes sex happened and in what way was it like a viral infection or was it something what caused there to be these germ cells these gametes as opposed to the somatic cells that make up the rest of our bodies and how did those systems like proliferate and specialize in so many different ways it's like a very weird question that we can gloss over with the idea of like yes it is advantageous to mix up our genes, but like why this multilayered way to mix up our genes, we can't explain biologically. So you don't have to have two different sexes to have sex. There are lots of organisms that are hermaphroditic and so they enter into copulation and they both get pregnant or one

of them gets pregnant and it depends on how it sort of mixes out and so like that's a separate and equally difficult to answer question of like why the differentiation between two sexes happens um and yeah why not one and why not more than two because sometimes there are more than two but like and i've read science fiction in which there's more than two for like sentient species, which is always an interesting thing to explore. But very unusual for complex organisms to have more than two sexes. Wild. Wild. And I guess the sort of like, we understand that just because there's benefit doesn't mean that we understand why it happened or how it happened.

There are ways for genes to be mixed that aren't sex, where two single-celled organisms come together, they mix their genes together, and then each of them leaves genetically different, but there is no offspring. It's very weird. It's like you kiss someone and become a different person. Conjugation, if you want to look it up yeah and so like why didn't that become the the dominant force by which we share genetic material there are probably plenty of reasons but i don't i've never read that science fiction book where like people were like like sex happens and then it's like it's a time in your life where you're like i'm tired of being this person i want to have some of that person's genes and see how it goes you'd be so squishy you'd be picking up all kinds of dirt on your in the rest of your life i don't think you wouldn't have to be squishy necessarily

it depends on like the mechanism by the way like if you if you swap stem cells in some way where like it goes from your infects your whole body like it's a virus bone marrow or something yeah or infects your body in some way and then just. Bone marrow or something. Yeah, or infects your body in some way. Like you'd have sex, you'd get really sick, and at the end of it, you'd be like,

I'm Steven now. Anyway. Well, anyway. I feel really on topic right now, you guys. Do we have anything etymological to discuss? So I couldn't really figure out what

we use before mate uh in scientific literature beget siring like those are the old old english words yeah yeah yeah whatever you see in translations of the bible you might assume are previous versions of it but it seems like the word mate started out as a noun for like a buddy and specifically someone who you eat with which i think is funny because it's a similar root as uh mate and meat are similar words like you sit at a table you share some meat with someone and so then it went from like a companion or partnership as it has always been the case in human society we are obsessed with romantic partnership and sexual partnership so we were like oh a mate is like someone you spend a lot of your time with so

a sexual partner uh and then we were like we just imprinted that onto animals as we do when we study animals we're like ah they mate too and then we started using around the 1500s uh the word mates to describe animal pairs as well i've always wanted to write this book but it's just it's too big volume one volume two yeah i've heard both of you talk about writing this book before which explains why this definition is so long and that this episode will be forever. I'm so sorry. All right. Well, then I guess it's time to do the game.

I've got a game for you guys. Do you want to do the game? I think so. Yeah. We're going to do the scientific definition. If there was one perfect strategy to find the ideal mate, we would all be doing that by now. ideal mate. We would all be doing that by now. Instead, all across the animal kingdom, mating brings out the strangest and most undignified behavior in all of us. And today, we're going to explore those behaviors with a game of the scientific definition. I'm going to name some

kind of mating behavior to you, and it's up to you to try and guess what that behavior entails only based on the name. We're going to get in trouble. And what animal does that type of behavior? So you can give me both of those. Whoever gets closest to the actual answer wins a point. Okay. We're going to start out with nuptial pads. Oh no.

No, Sarah's very, was excited about that one. Sam was terrified. So I think Sarah should go first. Yeah. So nuptials obviously it's like uh there's nuptial gifts i know in in the animal kingdom where you give a little present or you give your little sperm in a packet to to your mate and so i assume nuptial pads are similar uh i assume it is a sea creature i'm gonna say sea creature because they got lots of gushy stuff and it's like you create a little gentle place to lie down and and mash nasties you know

i wasn't ready for that at all you were so technical until the end there so it's just like an area you create for the act. Yeah, you create it. Yeah. Give me a specific sea creature. I'm going to say

it's a type of fish. Like a bony fish. It's a bony fish. Okay. I think it's just like padding around your genitals when it's sex season

to protect from all the smooshing that's going to happen. On maybe like uh some kind of frog if i have to go that specific you do and you did and you got the right animal sam yes what yeah i didn't know that but i know frogs do all kinds of weird shit oh my gosh i they also do a lot of pad stuff they're always on those lily pads but those that's not what these are okay nuptial pads are on the thumb and forearms of male frogs and they

help them grip onto female frogs during mating so frogs mate via am am plexus which involves a male getting like a piggyback ride as he grasps onto the female's back and it helps coordinate the frogs through external fertilization lining up the the egg uh deposition and the sperm transfer happening as it's happening uh they don't they don't actually like insert anything uh so nuptial pads are often spiny they also have glands below the surface that secrete various substances that are thought to either make a glue-like chemical that enhances the grip or to release pheromones. In some frog species, the skin of females will actually show abrasions where the male frog's nuptial pads held them, suggesting that they might even be receiving those pheromones

through the skin as like an injection. The heck? You're doing too much frogs. Come on. You do. You have to take it down a notch. That's not necessary necessary you're not even having sex yeah all that work you're just squirting down on the ground all right word number two

is the spermilege i guess i need to go first probably this is like a little it's like you know like mech cartoons it's like something that the sperm hitches a ride in and it's like a robot and it helps the sperm get to where they're going in a little some kind of cell with with with legs or something gets inside a bigger cell it's yeah it's like a sperm carrying device of some kind for a little thing what give me like a kingdom i would have this something aquatic like a fish maybe like a okay a shark i don't know okay shark sperm carrier sari sperm allege to me sounds like something pointy i'm not like a, not like a mecha, but like a weapon that you use.

And I know that some insects do traumatic insemination and jab each other. So I'm going to say it's like what the implement is called. Like I'm going to inject my sperm with the spermal edge. Sure. And it is a beetle of some sort sary that was very close i love it you're the winner there for sure it's it's a bed bug thing and bed bugs do do traumatic insemination but instead of being the device that actually stabs the sperm in uh it's a V-shaped area on the abdomen,

so it's kind of pointy in that way. And apparently it makes the act of sex less traumatic, even though they don't have a way for the sperm to get in. It actually has to go through their carapace or whatever. So male bedbugs directly inseminate the body cavity of female bedbugs by piercing them through the body wall. And that's upsetting. The process could pose a risk to female bedbugs. It's got infection worries. There's hemolymph leakage where it's just like bleeding, basically. Immune responses against the sperm. It also takes time and energy to repair the cuticle. Well, in 2003, scientists hypothesized that the spermal edge is an adaptation that helps

female bedbugs mitigate those costs by keeping the damage restricted to one area and reducing the amount of hemolymph that can leak out. So they have the spermal edge. Yeah, the females have the sperm allege. It's like a specific area that's maybe adapting to become a place that's easier for the whatever that's called to go through. They noted that different species have different sperm allege structures. In some, the sperm allege even forms a tube that leads to the oviducts. They're re-evolving it. They're figuring out how to do vaginas.

Again. Just more. Everywhere you look, they're doing it again. Just figuring out the same systems. That's how evolution works. All right. That's one win for each of you. Here's our last one to see who's the winner.

What is the love dart? to see who's the winner. What is the love dart? I feel like I've heard of this before. I think it's gastropods. So like a slug or a snail thing. What it sounds like, but I don't know what. So it's a dart.

So it's a dart made of whatever their shell is made of, is my guess. And they stab it into each other to secure their position whilst mating. Because they kind of goose all over each other. And so it's like a stay where you are. Like a cramp uh or like an ice ice pick yeah ice axe hold on so that we can goosh we can goosh together better yeah so we should we can goosh uglies all right sam i think sari's right but i'll make something up maybe it's a you could still get it more right. Okay, it's the snail thing, like Sari was saying.

But it's not a crampon. It is a... Gosh, it's just their penis. I don't know. Okay. Do they have one of those? That could totally be it. I'm going to read you what a love dart is.

It is a structure that is used by at least nine families of land snails to make sure that their partner's body won't break down the sperm. So, let's keep reading. I'm pretty sure Sam pulled this one off. Even though Sari,

but Sari knew a lot. So, for example, it is indeed made of the same stuff that the shell is made out of. So that's a big win, which is calcium carbonate. And then other species do have softer love darts made out of chitin though. So I don't know. That's two votes in favor of Sari. Land snails are hermaphroditic.

And when they find a mate, they typically circle around each other, inspect each other for like, are you a sexy snail? What's your body look like? How big are you a sexy snail what's your body look like how big are you and then they will settle on a mate and one of the snails will then puncture its mate with their love dart which is made of a muscular sack in the body that can force the contact through uh and then some species will shoot only one love dart others it's a bit more repetitive one species use the same dart to poke their mate over and over again for about an hour. The important part of the

love dart is that it is coated in mucus, which acts to close off a particular organ called the bursa copularatrix in the punctured snail's body that normally would break down sperm. The act goes both ways, with the punctured snail turning the tables and puncturing its

mate with its own love dart so that they can eventually pass sperm packets to each other and mate. So it's not for holding on, which is what Sari said. It's more like the penis where it is actually delivering the sperm. So I think I'm going to give it to Sam, even though Sari really had a lot. Yeah, and I wouldn't have even known it was snails without her saying that, so. Oh, well, if you tell me that.

No, you can give it to Sam. Cut that. I didn't know that. Now we're going to take a short break, and then it'll be time for the Fact Off. Hello and welcome back, everyone. It's time for the Fact Off. Our panelists have brought in science facts to present to me in an attempt to blow my mind. And with this topic, you better.

After they have presented their facts, I will judge them and award Hank Bucks any way I see fit. But to decide who goes first, I have a trivia question. Porcupine mating is understandably tricky. But the quills are actually easy enough to get around. The male porcupine just makes sure to respectfully display their interest first by standing on their hind legs and peeing at the female porcupine, who then decides, based on this display, whether or not she would like to reveal the quill-less regions for reproduction. The real challenge is, in fact, the timing. Porcupines tend to live on their own after they are grown up, and the female porcupines only have a short window during

which they're fertile at its longest how long is the female porcupine's fertility window how short is it pandas are pretty short i feel like they're a couple weeks so i'm gonna say seven days i feel short i'm gonna say days and have time to find each other, right? So I'm going to say three days. Eight to 12 hours. Wow. Oh! So it went. What the hell?

I thought it was going to be Sari, but it's Sam! Who goes first? I guess I'll go first. Okay. Milkweed butterflies are a genus of butterfly so named because of their relationship with plants in the milkweed genus. They lay their eggs on the plants and caterpillars feed on the leaves of the plants, which contain a toxic sap. The most famous example of a milkweed butterfly is also probably one of the most famous butterflies of all, the monarch butterfly. It's well known that the butterflies and caterpillars use the toxin from the plants to make themselves toxic to deter predators.

But adult male butterflies also use the chemicals to make mating pheromones that they present to females in what is known as a nuptial gift, which Sari mentioned earlier. So the male butterflies retain a lot of the toxins that they ate as caterpillars to make these pheromones for their gifts. But they also use an interesting method called leaf scratching to collect more of these chemicals when they need a top off. So leaf scratching is basically what it sounds like. The butterflies use their tiny little claws on milkweed leaves and they make the leaves release their toxic sap, which they lap up with their cute little tongues. And they also have another way to collect more toxin. The leaves of a milkweed plant are a perfectly fine place to get more of this toxin when they need it but there's another source

of even more concentrated toxins in their environment a big slow chubby defenseless one that's just sitting right there all full of toxins caterpillars so in 2019 researchers in indonesia observed several species of adult milkweed butterflies drinking the precious toxin-filled goo out of wounded and dead baby caterpillars and the culprit of much of this wounding were the adult butterflies themselves who were observed scratching open the backs of living caterpillars including caterpillars of the same species as the adult i'm just thinking if this isn't what they should be doing these these caterpillars should be a little tougher like oh like they'd they'd have evolved to be tougher but maybe it's advantageous for the species as a whole for the adults to be able to suck the blood

of the young that's just what i'm thinking continue maybe nobody else ever thought of it until now you know it just seems odd for a butterfly to be able to injure a caterpillar. Seems like it'd be pretty easy to evolve out of that situation. That's true. So the researchers weren't sure if the dead caterpillars being fed on were killed in some other non-butterfly way, or if they had simply been drank to death by their elders. And some butterflies were also so focused on drinking the caterpillar juice

that they wouldn't stop even when the researchers would like touch them or like brush them away one slightly more innocent explanation for this is that the butterflies are just accidentally scratching open caterpillars when they're scratching leaves but you know they're still drinking the goo out of their own babies until they die i don't buy it i don't buy it those are pretty different things. I guess when there are babes on the line, you got to occasionally get a little weird. SciShow Tangents just continues to prove me wrong about stuff.

There's always another worst thing about butterflies. The depths of their depravity will never be truly plumbed. Yeah. Okay. Sorry. Took a very different direction, but similarly weird because this, yeah, so many options for it.

For centuries, people have been postulating about soulmates or other mysterious ways of communicating between two specially linked organisms. And it's been a minute

since we've delved into some historical pseudoscience on tangents. So I have the perfect thing for this romantic episode, the mating of garden snails. This is why I knew a little bit about love darts. Gastropods have all sorts of ooey gooey mating practices and common garden snails, which are cornu aspersum, previously classified as helix asppersa, are no exception. They are, as Hank said, hermaphroditic, which means individuals produce both sperm and eggs, and after a several-hour-long mating session where they inspect each other's slime, and I think in this species shoot a love dart,

like we were talking about, they line up their genital pores and inseminate each other. It's a very romantic, goopy, special connection. So special, in fact, that around the 1850s, the French occultist, and that's the epithet I found for this man, Jacques Benoit, thought that after swapping mucus and gametes, a mated pair of snails would be telepathically connected.

How? I have no idea. Animal magnetism was in at the time yeah yeah but he he might have just said they were something special in the slime i read all the texts i could find on this uh he didn't give a good clear explanation uh he ran with it anyway to create what was known as the sympathetic snail telegraph. And people like Samuel Morse were working on a boring old electric telegraph with wires around the 1830s. So I think he wanted to offer up some competition to that. And his invention was based on the previous pseudoscientific idea of a flesh telegraph, which is even grosser than a snail telegraph basically you and your friend trade pieces of arm skin in a surgical transplant and you tattoo the alphabet on both of your skin graphs

and then you can forever send messages to each other ouija board style by poking the letters in sequence with the needle so benoit was like brilliant and mated 24 pairs of snails and split the pairs up in bowls around 10 feet apart. Apparently, his goal was one for every letter of the alphabet, but there are 26 letters. And I was too busy researching the fake science to look into contemporary languages. Oh, my God. This is an unresolved discrepancy. scene. Anyway, he ran around poking snails in bowls on one side of the room while his friend interpreted

the message based on the wiggles of the snails on the other side of the room and a journalist watched this whole thing. It was sketchy at best, but the journalist wrote about it anyway as if it worked and there was big press about it. Wow, snail telegraph. The snail's love

shall never be conquered. So telegraphs already existed. Yes. You gotta have the pair and you gotta never be conquered so telegraphs already existed yes you gotta have the pair and you gotta pull them apart so you gotta like go to my house get my snails and then we have just snails for me to talk to you i can't talk to anybody but you so it's less good but you can send your secret snail messages definitely good No, I'm not saying it's bad. But then after this got publicized, people, maybe not even scientists, asked Benoit to test his snail telegraph more rigorously, like over a greater distance, not in the same room, you know, like basic communication things. That sucks. And then he disappeared from the public case. Okay.

I love that. Oh, no. Well, here's the situation. From the public case. Okay. I love that. Oh, no. Well, here's the situation. Sam kind of is only in the lead through duplicity. Oh, come on. We would have tied at best. At worst, whatever one is applicable in this situation.

But the snail occultist is so good. Like I love, I could see either of these being a kick-ass TikTok that gets a million views. But the snail occultist is the true winner of my heart this episode. All right, well. Oh God, so good. Fake science, fake science.

Fake science. Yeah, I just looked up some real science as well. It was always all gonna be about sex. All right. Now it is time, now that uh know that sari is the winner of the episode it's time to ask the science couch we've got a question for our couch of finally home scientific minds mike a on discord and at nano book review ask based on what i've read mating is always about pairing two organisms slash gametes why two would more than two be too biologically difficult so

i have heard that there are species that have multiple like more than two sexes and and like funguses i think um are that can be this way i'm not entirely sure what this means though what what i think it means is that like this this individual cannot reproduce with other individuals of its sex and that happens like a bunch of different times there's a bunch of groups but any one of them can reproduce with each other but they're all different and so there's like borders you can draw of this individual cannot reproduce with these ones. And there's a bunch of different kinds. That's not really what we mean

because they can reproduce with any of the other ones. But then as far as why that would be better or this would be better, the thing that most organisms do where there's two sexes, I have no idea. Is this question like, why isn't there something where three things have to have sex

to have something yeah or or anything like there could be a bunch of different circumstances where there's more than two sexes right you could you could imagine like a sort of like i like this organism needs to be present but isn't actually involved doesn't donate any genetic material um versus like i guess it does seem a little weird. Like, I don't know what you would do if like how you would take genetic material from three organisms and mix them together. Like that seems like biochemically complicated. Sarah, do you have anything? You must've done research. I did research and I led to a lot of these same questions where it's, it goes back to kind of

what we were talking about at the beginning of the episode which is we can explain why sex is evolutionarily favorable now but the weird variations on it and how it came to be are difficult questions without jumping back in time or like finding fossil evidence or molecular evidence or things like that. So there are organisms that I found that work kind of like what you were describing, Hank. There is at least a nematode and an algae that have three biological sexes in that, but the biological sexes are male, female, and hermaphroditic. So the hermaphroditic can mate with either the male or female based on the parts. So it's not quite like three separate categories.

It's like, how many of the gametes do you produce? Do you produce egg, sperm, or egg and sperm? And I guess there are algaes maybe or plants that have a lot more sexes, but I haven't dug into exactly what that means. I don't know enough about genetic recombination and cell types, but I think it's more what Hank was saying where we define sex as your cells can genetically recombine with another member of your species cells but not others and yeah that is just i think a weird consequence of evolution because this whole idea that you can offer some genetic material and someone else can offer some genetic material and those can merge fairly seamlessly and then create a new organism is a very weird thing. And so my guess as to why more than two hasn't happened is because we either haven't observed it or it, it just like,

it was such a weird thing that two things come together, that three is even more weird. And yeah, nature doesn't do good with odd numbers. Yeah, definitely that. So you have to jump right to four yeah it's it's almost like this is a vibe uh yes not a statement of fact but it's it's very difficult to evolve sex in the first place and all of the advantage you're gonna get from sex you get from two individuals and and so like as long as you're getting the variety you don't need to evolve any new complexity so it's like the simplest thing

that gives us the advantage of faster evolution i'm not sure how having three sexes would speed up evolution yeah and having the core like there are organisms where there are more than two participants to be, like have successful mating, whether because of competition, like for example, there are those snake masses where it's a bunch of males

and one female, and all in competition, there are creatures, I think even chickens that can be inseminated multiple times and there's like competition between the sperm there's some agency exercised by the vaginal canal etc to do it and then there's also like whales i think uh at least gray whales that help brace each other during mating like there's a third that's just kind of there. Floating around in there.

Floating around. It's hard to squish together in the water. It's hard to get leverage in the middle of the ocean. So there's a third. Or like in some birds, there's this behavior. Like a true wind man right there. Yeah. So there's all these like social and structural, social and behavioral structures around sexual reproduction that involve more than an egg and a sperm coming together because that's where it starts getting complicated.

Whenever you introduce more variability, there's always more of a chance that something's going to go wrong. It's like that song lyric. Everywhere I go, the more I see, the less I know. I thought I knew stuff about this topic, and now I know more and I know less. You just scraped the surface. So I'm going to struggle through that. Sari and I need to write this topic. And now I know more and I know less. So I'm going to struggle through that. Sari and I need to write this book. If you want to ask

the Science Couch your question, you can follow us on Twitter at SciShow Tangents, where we'll tweet out topics for upcoming episodes every week. Or you can join the SciShow Tangents Patreon and ask us on our Discord.

Thank you to at the fruit robot, Melanie Roy, and everybody else who asked us your questions for this episode. If you like this show, you want to help us out, it Roy, and everybody else who asked us your questions for this episode. If you like this show, you want to help us out.

It's super easy to help us out. First, you can go to patrion.com slash slash show tangents, where you can be a patron. It acts as a newsletter and a bonus episodes and a special thanks to patrons, John Pollock and less acre. Second,

you can leave us a review wherever you listen. That's super helpful and helps us know what you like about the show. And finally, you want to show your love for SidesShow Tangents, just tell people about us. Tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. Hey, happy Valentine's Day, everybody.

I've been Sam Schultz. SciShow Tangents, created by all of us and produced by Sam Schultz. Our associate producer is Faith Schmidt. Our editor is Seth Glicksman. Our story editor is Alex Billow. Our social media organizer is Julia Buzz-Bazio. Our editorial assistant is Debuffy Chakrabarty. Our sound design is by Joseph Tuna-Medish.

Our executive producers are Caitlin Hoffmeister and Lee Hank Green. And of course, we couldn't make any of this without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. The palolo worm lives in coral reef burrows around islands in the South Pacific Ocean, like Samoa or Fiji. Its front body segment contains all the essentials like its eyes, its mouth, and its gut. But once or twice a year, these worms grow a special long butt segment called an epitope, which is a bright teal or tan packet of reproductive gametes.

tan packet of reproductive gametes. During a spawn, these epitopes are released all at once at night, and they even have a rudimentary eye spot to help them wriggle towards the ocean's surface. At sunrise, the epitopes dissolve, the eggs get fertilized, and they hatch into larvae that settle down into the coral reefs. But these marine worm

butts can also be scooped up in nets like noodles and cooked as a local delicacy. They have eyes and stuff? They're like little alive guys that come out. It like, it, it messes with your definition of alive. Like,

is that alive? It has agency. It seems to want things. It's moving to like, if a single celled organism is alive, then it's just, it's just not, it's a new individual.

And it's doing reproduction too, which is one of the things that they always put on the lists, which is why the list is a bad idea. Always a way to get around the list. Yeah. Yeah, you just grow another little version of you that's just reproductive organ and say, go off into the world, my son.

Wouldn't that be a fun way to do it? Just like, just take off your finger and it just like sort of hops around there goes my little sex boy it looks like a little it's a Sour Patch Kid commercial we just grow a little Sour Patch Kid to ourselves and then they run

yeah