SciShow Tangents - Eggs

Episode Date: December 11, 2018

Eggs have tons of different sizes, textures, and protective shells, from giant ostrich eggs to squishy fish egg clusters. But, scientifically, they all boil down to the same thing: an egg is just a re...productive cell that can be fertilized by a sperm to make an embryo. This week, we’re cracking the science of eggs wide open![Truth or Fail]Brown trouts:http://www.bbc.com/earth/story/20150214-fake-orgasms-and-other-sex-lieshttps://www.sciencedirect.com/science/article/pii/S0003347200915859?via%3DihubOctopuses:https://www.mbari.org/deep-sea-octopus-broods-eggs-for-over-four-years-longer-than-any-known-animal/https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0103437Trilobites:https://www.sciencedaily.com/releases/2017/01/170124124905.htmhttps://pubs.geoscienceworld.org/gsa/geology/article-abstract/45/3/199/195237/pyritized-in-situ-trilobite-eggs-from-the?redirectedFrom=fulltext[Fact Off]Stick insect eggs:https://www.eurekalert.org/pub_releases/2018-05/ku-tsi052318.phphttps://www.sciencemag.org/news/2015/10/stick-insects-lure-ants-fatty-knobshttps://www.nytimes.com/2018/06/05/science/stick-insects-eggs-birds.htmlHumsters: http://www.stillhq.com/pdfdb/000360/data.pdfhttps://onlinelibrary.wiley.com/doi/abs/10.1002/mrd.1120230307https://link.springer.com/chapter/10.1007/978-1-4471-3310-0_5https://www.ncbi.nlm.nih.gov/pubmed/1725451[Ask the Science Couch]Egg shape: https://galapagosconservation.org.uk/whale-shark-reproduction/https://scripps.ucsd.edu/centers/cmbc/2018/05/15/hydrothermal-vents-incubators-for-deep-sea-skate-egg-cases/https://books.google.com/books?id=zg1mDwAAQBAJ&pg=PT158&lpg=PT158http://science.sciencemag.org/content/356/6344/1249http://www.bbc.com/earth/story/20160304-one-animal-has-more-babies-than-any-other

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Starting point is 00:00:00 Hello and welcome to SciShow Tangent, the lightly competitive knowledge showcase starring some of the geniuses that make that good old YouTube channel SciShow happen. Today we are joined by musician and artist and producer, Stefan Chin. Hello. What's up? What's your tagline? PickleBob. And we also got over there, Sam Schultz, also artist, also grandfolk. What's your tagline?
Starting point is 00:00:44 What's a grandfolk? You're just a good person. I thought you weren't going to say any nice things about me. You were just going to say Sam. So maybe that's just my tagline. Sam. Sam Schultz. It's Sam. And over here on the science couch with me is Sari Riley, science communicator and MIT
Starting point is 00:01:02 graduate. We got that degree on the science couch. What's your tagline? Shipping and handling not included. And I'm Hank Green, creator of SciShow and general YouTube person, I guess. My tagline today is pant balls. Every week on Tangents, these four friends get together. We try to one-up each other and amaze and delight each other with science facts.
Starting point is 00:01:26 We're playing for glory, but we're also keeping score, awarding Hank Bucks from week to week. We do everything we can to stay on topic, but judging by our previous conversations, this group will not be good at that. So if someone on the podcast wants to go on a tangent, they've got to give up one of their Hank Bucks. No Hank Bucks, no tangents. We all start with none.
Starting point is 00:01:46 So let's stay on target. Okay. And as always, we introduce this week's topic with a science poem. Overduct, overduct. Release your prize. Oh, gosh. How many spheroids can overduct supply? No nest in sight.
Starting point is 00:02:07 We must improvise. A frying pan will do. Salmonella, goodbye! I wasn't comfortable with the accent. But I like that. I was trying to read it as if I was casting a spell, sort of. Ah, that's good. Which is not related to the topic this week, which is eggs.
Starting point is 00:02:25 Which is, our topic is eggs. But I do like, eggs are kind of magic. And I especially think that like, a fried egg is magic. Because can you,
Starting point is 00:02:35 wow, what a thing. This beautiful encapsulation of some of the best food. And you know, I used to think that eggs were like
Starting point is 00:02:43 a lot of like, fat and calories and stuff it's 80 calories an egg you know when we were younger I feel like TV was really trying to tell us
Starting point is 00:02:51 that eggs were bad for us remember that they used to be like jokes in the Simpsons about how bad eggs were for you and stuff yeah
Starting point is 00:02:57 they're gonna give you all the cholesterol and it's true that if you have cholesterol problems you might want to avoid eggs also it's true that the US government
Starting point is 00:03:03 categorizes eggs as meat because they have enough protein, I guess. Huh. All right. But they are not by vegetarians considered to be meat.
Starting point is 00:03:14 Sure. What else would they be? They're, what? They're, I don't know. They're food. Okay. They're like, uh... Don't yell at me.
Starting point is 00:03:21 Animal products. Milk is not considered. They're like milk. Yeah, milk is not meat. They're like milk. Where yell at me. Animal products. Milk is not considered. They're like milk. Yeah, milk is not considered. They're like milk. Where they come out of an animal, a hole of an animal, and then it goes into our mouth. Right. So for the world, can we get a good definition of what an egg is?
Starting point is 00:03:39 It's like the piece before the sperm comes along that's going to make the baby. Yeah, it's like a really cool weird cell. All eggs are just one cell. They're squishy. They got a nucleus inside and that's where the sperm fuses. They combine their genetic information and then they can start dividing to become a new organism. But they can come in all shapes and sizes like fluid-filled sacks or some of them get laid with a mineral coating to protect them from the weather. And now it is time for
Starting point is 00:04:07 Truth or Fail. One of our panelists this week, me, has prepared three science facts for our education and enjoyment, but only one of those facts is a true fact. The others I made up. And the other three panelists are going to have to figure out either by
Starting point is 00:04:23 deduction or wild guesses which is the true fact. If they do, they get a Hank buck. If they are tricked, I get a Hank buck. Would you like to hear my facts, you guys?
Starting point is 00:04:33 Oh, yeah. I think this is going to be hard because it seems like none of us know very much about eggs so far. Number one, there's a species of trout. It's actually here in Montana
Starting point is 00:04:41 called the brown trout. And it carries, get ready, two different kinds of eggs. It has real viable eggs and it has fake eggs that are just like fluid filled sacks. Why would that happen? Well, trout have courtship and they make babies by like having sort of like a little interaction. And if the female thinks that looks like a good male she will
Starting point is 00:05:07 leave her eggs in the water and he will inseminate them just like release his sperm and that's how the eggs get fertilized but if she doesn't like the look of the male and he keeps bugging her she will release some of her fake eggs and he will
Starting point is 00:05:23 just do his thing and then swim away and stop bothering her. That's like, I promise this is my real phone number. Fact number two. It can be good to give your little ones a chance to grow in their egg. So give them some time to do that thing.
Starting point is 00:05:40 But a species of deep sea octopus takes this to a crazy extreme with eggs that go from like laying to hatching takes more than four years. The mother also spends that entire time like hanging out over her clutch, making sure that nobody comes to bother them. And she does not eat during that time. And also, this is especially weird because most octopuses only live for two years. So this also makes this the longest living octopus
Starting point is 00:06:13 because she spends more time guarding her eggs and not eating or moving than most octopuses spend being alive. And finally, number three, eggs are super packed with nutrition because you want to give your baby that chance at life. And so you want to give good food in there.
Starting point is 00:06:30 But that also makes them a delicious snack. So there are different strategies that animals use to protect their eggs. This is a weird one that I hadn't heard of before. Trilobites did this by laying eggs that are like spiky sea urchin looking things. And they're like spiny chitin covered balls
Starting point is 00:06:49 that they had to push out of their cute little trilobite selves, which probably wasn't super fun, but I don't know because I am not a trilobite and I can't ask them because they've been extinct for 250 million years. So we have number one, fake trout eggs. Number two, long-lived octopus eggs. Or number three, spiny trilobite eggs.
Starting point is 00:07:07 I think it's number one. That seems... I feel like I've heard of similar strategies before, though I can't remember what the specific example was. And the octopus thing, I also feel like I've heard about an octopus that made the ultimate sacrifice to take care of its eggs. But I don't know.
Starting point is 00:07:30 Four years seems like a long time, especially if it's like twice as long as other octopus. And then, I don't know, spiky eggs don't make any sense to me. That one sounds so boring, I feel like. Boring. That one sounds so boring, I feel like. Boring. But also trilobites are like, I don't want to call them basic, but they're just doing their best. That was a long time ago.
Starting point is 00:07:55 Yeah, a long time ago. They've got spiky eggs to it. I'm also leaning towards. Do you think spiky eggs is too advanced for a trilobite? No, I think it like fits with a trilobite. Like if I was a trilobite and I had a random mutation to make my eggs special, spiky eggs seem to make sense. Like let's bump them around. Seems like a big leap. Yeah. I think it's, the fish one sounds really familiar to me too.
Starting point is 00:08:18 Because I know fish make fake eggs in their body sometimes. And sometimes the babies eat them too. fake eggs in their body sometimes and sometimes the babies eat them too. So if they, before they lay the eggs, they're like fake eggs and the fish hatch inside them and then eat the fake eggs
Starting point is 00:08:31 and then are birthed. What the heck? Wait, what? So the fish aren't in eggs anymore. Yes. They break out of their eggs and then they like, there's these extra eggs
Starting point is 00:08:45 that are just nutritional support for the fish that are swimming around inside their mouths. Yeah. I see. Yeah, their bodies make lunchboxes. But that awesome.
Starting point is 00:08:53 Little lunchbox. It's like a gusher. Yes. Oh. One egg for baby. It's caviar for them. They're fancy. A little caviar.
Starting point is 00:09:01 Yeah. But because it sounds real, that makes me want to say it's fake. Because I don't trust Hank. Yeah. That's how I feel about that one too. What was the middle one again? Octopus.
Starting point is 00:09:12 Octopus. That one's bullshit. I don't play that one at all. Yes. Yeah. If you had said that the baby octopus eat the mom, I would have been like, yeah, that makes sense.
Starting point is 00:09:22 But just like sitting there for four years, I'm like, no way. They can't do that. I say the fake eggs. Fish. Fake fish eggs. Fake fish eggs. Sam. I say the fake fish eggs. Octopus mom. Octopus mom. Sari is correct. No! Octopus mom.
Starting point is 00:09:40 Dang it. That sounds so boring for them. Okay. Let's start with octopus moms. So this is at the Monterey Bay Aquarium Research Institute. MBARI, I think, is what it is. And they went down. They saw this octopus mom sitting on her eggs. And then, like, a few months later, they went down.
Starting point is 00:09:57 She was still there. What? A few months after that, they went down. And then years later, they've been watching, going on the exact same spot. This octopus mom is not moving, dying slowly. Her eyes are filming over. Her body is shrinking. Her skin's getting all saggy.
Starting point is 00:10:14 And then they go down one day, four and a half years later, 53 months after they first spotted her. And she's gone. They assume dead. And all 165 octopus eggs have hatched and some of the octopi or octopodes or whatever are around and are like the most developed baby octopuses they've ever seen.
Starting point is 00:10:36 How recently was that? This was 2011. Okay. So she could have been there for longer than four and a half years. Yeah, potentially, probably not much longer because I think that they had been
Starting point is 00:10:44 to the spot where she was. They even tried to give her a crab, which is the food that they eat, to see if she would eat, like, because, you know, they're not down there all the time, so they don't know. She may have eaten something. She may have eaten, like, an egg that died.
Starting point is 00:10:58 She might have, like, nommed on some of those. And it was, like, deep sea. So metabolisms are very low down there. It's like three degrees Celsius. So you can live a long time. And like the creatures in the deep sea in general have weirdly long lifespans. But like this is the longest
Starting point is 00:11:15 from fertilization to hatching or being birthed of any animal we've ever seen. Any animal ever? Yeah. Whoa. Yeah, because elephants are like two years or something, and that's one of the longer ones.
Starting point is 00:11:31 Have they observed this in any other octopuses, or was it just maybe this one octopus? Well, they think it's this species, but this is the only example that they've ever seen of it. It was just sort of a luck thing. Do they know where she went, Or is it just like disappear, probably went off to go die somewhere? I think she just died.
Starting point is 00:11:48 Yeah. And floated away. And that's common in octopuses, like that mothers will sort of guard the brood and then die. Was the first one based on any true things or did you just make up the fish? Oh, totally.
Starting point is 00:11:59 The brown trout actually fakes orgasm. Oh, weird. No, that's even weirder. It'll like go through the motions of laying eggs, but it won't actually do it. It'll like do all the same body movements. And then the male will be like, that looked right.
Starting point is 00:12:17 And we'll release its sperm and then walk away. And then trilobite eggs just look like normal eggs that we do know what they look like, which is pretty cool. We have fossilized trilobite eggs. But like normal eggs, though we do know what they look like, which is pretty cool. We have fossilized trilobite eggs. But also there are some really weird-shaped eggs, particularly sharks. So some species of sharks will lay screw-shaped conical eggs. The goal is to get them sort of wedged somewhere where it's harder for something that wants to eat them to get them out.
Starting point is 00:12:43 But they think that they're screw-shaped so they're easier to lay. Like, they want them to have edges and stuff, but they don't want them to, like, be impossible to get out of a body. Right. So they sort of, like, screw themselves out of the shark. Did you find shark egg sacks a lot when you lived down south? We found, like, skate— Mermaid's purses? like mermaids purses.
Starting point is 00:13:05 Yeah, mermaids purses. Those are skate egg pouches. But those are a shark, aren't they? And sharks. They're in a class called chondrichthys with sharks and skates
Starting point is 00:13:13 and all the other cartilaginous fishes. So I think they're like ghost fishes are in that category too and they all have these pouch-shaped eggs. Okay.
Starting point is 00:13:22 Anyway, that's my facts, you guys. I got two hang bucks. You nailed us. You facts, you guys. I got two Hank books. You nailed us. You got two. Which means I got one now because I already spent one in the beginning. Pre-spent.
Starting point is 00:13:32 After our break, we're going to go to our fact off with Sam and Sari. But first, let's talk to our sponsors. So I have two Hank bucks, but I spent one earlier in the episode, so I have one. Sari has one. Our panelists over here, Sam and Stefan, have zero. It's time for our Fact Talk. Two panelists bring science facts to present to the others in an attempt to blow our minds.
Starting point is 00:14:10 The presentees each have a Hank Buck to award to the fact that they like the most. However, if both facts are giant snoozes, the presentees can choose not to award their Hank Buck and instead throw it in the trash, which we're not going to do. Don't be ridiculous. We're going to choose who goes first by asking
Starting point is 00:14:26 who touched a chicken most recently. I bet I know. Probably me. I touched a chicken like two days ago. You guys touch chickens so frequently. I was like, Hank touched one last
Starting point is 00:14:41 Friday. I did. Well, me too. I touched a chicken also. It was a good chicken touched one last Friday. I did. Well, me too. I touched the chicken also. It was a good chicken. It was a really good chicken. It was such a sweet chicken. Maybe I have to rethink a bunch of stuff. Yeah, really smart chicken. Also, I did not realize how big a chicken poop is.
Starting point is 00:14:55 Oh, my God. Did it poop? Yes. It pooped into Jesse's hands. Did it poop? It pooped like an egg. It was like an egg. It was like an egg shape and size.
Starting point is 00:15:03 Was it solid? It was solid enough that Jesse just caught it and it was like. That's weird. Yeah. So bad. I didn't get a whiff of it. If you're confused, this was while we were filming SciShow Talk Show with Jesse, who brings in some animals for us to see.
Starting point is 00:15:17 The chicken being probably one of the more quotidian ones that we hung out with. But also one of the more like amazing to look at. Yeah, beautiful. And his eyes were so like thinking about the stuff going on around it. that we hung out with. But also one of the more like amazing to look at. Yeah, beautiful. And the eyes were so like thinking about the stuff going on around it. It was like talking and it was very calm. It was a moving experience. It was a beautiful chicken.
Starting point is 00:15:37 Yeah, there's beauty all around us if you know where to look for it. That's my science fact. Stick insects are insects that look like sticks they spend most of their time trying to look like sticks so that might not seem like they have very interesting lives but their eggs
Starting point is 00:15:50 are super interesting first of all they're parthenogenic so they can basically like clone themselves is that what that means pretty much
Starting point is 00:15:57 yeah okay if they aren't viable males around the females can just lay fertilized eggs which they do by going to the tops of trees laying the eggs and then kicking them with their to the tops of trees, laying the eggs,
Starting point is 00:16:05 and then kicking them with their feet so that they rain all around the forest. They all lay eggs that look like seeds, and a lot of them lay eggs that look like seeds that have a little nub on them called the capitulum, which is a fatty structure that mimics the part of seeds that ants are attracted to, and so the ants find their seeds
Starting point is 00:16:25 chomp on them bring them back to their nest put them in their garbage bin after they eat the fatty part off which is not important to the stick insect then they hatch
Starting point is 00:16:34 in the trash part of the ant's nest they're just safe in there and they look like ants when they come out so then they sneak out of the nest because they look like ants
Starting point is 00:16:42 they look like ants but finally their eggs look like seeds and they're hard like seeds too. They're made out of the stuff that kidney stones are made out of. This is the thing though. This is the big thing. You should have stuck with one fact, Sam. They're hard like that.
Starting point is 00:16:54 So parasite wasps can't put their parasite babies inside of the stick bug's eggs. But they found out that if a stick bug's eaten while pregnant by a bird, it is possible for that bird to not digest the eggs and then fly away and poop their eggs out somewhere far away and they can still hatch. Seed dispersal. Even like they're eating a whole stick insect and the eggs are still inside the stick insect. Yes. And they can't be digested because of what they're made out of. That's cool.
Starting point is 00:17:19 That's really weird. So you said something about like the material from kidney stones? Yes. So this is like a hard mineral substance of some kind protecting these. Calcium oxalate. That's a good hard mineral. Yeah. Does the bird poop like help the babies grow at all?
Starting point is 00:17:36 Kind of like seeds and actual fertilization? They said that they already had pretty bad survival rate for their eggs. already had pretty bad survival rate for their eggs so they fed a bird 70 eggs
Starting point is 00:17:47 and 14 of them emerged capable of hatching and 2 of those did hatch into babies and from what I
Starting point is 00:17:56 could tell that wasn't too much worse than in nature so it doesn't help them and I guess like
Starting point is 00:18:02 when you got that many babies and I don't know how often stick insects make the next generation like when you got that many babies and I don't know how often stick insects make the next generation but when you got that many babies
Starting point is 00:18:08 and that kind of mortality rate that is like a recipe for like good evolution happening you know like the ones that are gonna do good
Starting point is 00:18:16 they're on every continent except for Antarctica is that the one? yeah what's the one on the bottom? is that Antarctica?
Starting point is 00:18:25 you got it right. Honestly, I like that it has this mineralization going on because that's very weird and that's like that's hardcore insect stuff right there. But I like better
Starting point is 00:18:34 that they have this like fatty thing that the ants are like I'm going to take that and eat it and it feeds the ants and then they wake up and they're like
Starting point is 00:18:40 I'm a good old stick insect. I look like an ant so don't eat me. They live in their old ant dump. Yeah, get born in an ant dump. I was raised in this here ant dump. All right, Sari, go. And when doctors are analyzing semen, they look at qualities like motility, which is like how many moving sperm there are, the volume of it, so how many sperm per milliliter
Starting point is 00:19:01 usually, concentration, and the morphology. Are the sperm normal looking? Can they fertilize an egg properly? And normal sperm densities can vary, and it's really, really hard to predict fertility even with all these different variables because there are a lot of biochemical factors that go into a sperm fertilizing an egg. You have to have the right enzymes and antigens, and it has to be able to actually penetrate inside. So you can run lots of different tests to figure out whether something is fertile besides just straight up in vitro fertilization, which is like taking a human sperm and an inhuman egg and seeing whether it works. There's a lot of like ethical mumbo jumbo around that. So instead, scientists have come up with a
Starting point is 00:19:41 different method for testing for infertility, seeing whether human sperm can penetrate and fertilize hamster eggs. And it's called the hamster test. Don't do it. Don't put them in the hamster. Because it's not going to fertilize the egg. It goes inside the egg. It goes inside, but it's not going to make a baby. One of these days it will.
Starting point is 00:20:05 Don't make a hamster. It's called a humster. H-U-M-S-T-E-R. No, don't make a humester. So they make like little zygote. Yeah. Human hybrids. Yes. And that's more ethical? It's not viable, but it can
Starting point is 00:20:23 become a zygote, from my understanding, but it's non-viable. Of course. And they've never tried implanting it into a human or a hamster. They don't want to go there. Of course. But wait. But what if they did? What would happen?
Starting point is 00:20:38 Scientists don't think it would work. They think that the hamster genome and the human genome are too incompatible. That's why it's a hamster test, not a chimpanzee test. Because that's way scarier. Also, there's a lot more hamster eggs around than chimpanzee eggs. We could have been doing this the whole time. We could have
Starting point is 00:20:56 animal people. No, we can't have animal people. No, it's horrible. We could have animal people. We just shouldn't. Sorry, did I miss this? So hamster eggs are similar to human eggs? Yes. And that's why they're not just like... They're more similar than like mouse eggs or...
Starting point is 00:21:12 So the test involves... It's called the hamster zona free ovum test. So they modify the hamster eggs to make the test possible. The zona pellucida is the outer membrane on eggs. And usually that's necessary to initiate the sperm fusing with the egg reaction. Like that's where the antigens bind. Some sort of chemical reaction goes and then it like gives the sperm permission. I don't know.
Starting point is 00:21:40 I hate using language like that when describing biology. But essentially that to merge and bind to the cell membrane and fuse. And so these hamster eggs have the zona pellucida removed. So it doesn't have this outer protective layer on the egg. So it is easier for the sperm to penetrate the egg. A lot of the chemical barriers are gone, but it's still a test of whether the sperm can actually get into an egg cell, which is often times
Starting point is 00:22:06 a very hard part of fertilization yeah I gotta give a hank buck for humpsters I know humpsters who knew
Starting point is 00:22:14 who knew but like Sarah's already got two hank bucks I know give me that hank buck that's how it goes the rich get richer
Starting point is 00:22:21 yeah the poor get the picture that's me it would be like that car commercial with the dancing hamsters remember that one The rich get richer. Yeah. The poor get the picture. That's me. It would be like that car commercial with the dancing hamsters. Remember that one? The big hamster men. And they're like,
Starting point is 00:22:33 Nope. Remember that? Nope. For the box-shaped cars. Scions. Scions? Oh, yeah. And they have pulls up and the hamsters and their track jackets jump out and they do a dance. Well, now I have to give Sam a Hank Buck just so we'll have one to spend on that.
Starting point is 00:22:46 Terrible. These are the things I learned instead of science. Somebody's got to watch the hamster commercials. And now it's time to ask the science couch, where we ask listener questions to our science couch of finely honed scientific minds. Me and Sari over here. Hopefully, Sari can back me up because my finely honed scientific mind has been dulled on corn dogs. At Valerie2776 asks, are there any eggs not shaped like eggs?
Starting point is 00:23:20 So we talked about shark eggs being like the little mermaid's pouches, but also the weird screw-shaped ones. So those are definitely not egg-shaped at all. So, wait, I have a quick question. Sharks, do sharks have their babies live inside of them? Some of them. And then put them in a thing? No. Or just some of them give life?
Starting point is 00:23:37 Some of them give life. Okay, okay. Yeah, they put the embryos straight into the pouches. And sometimes the pouches just stay inside. The pouch is always involved. So like whale sharks, they have the egg cases. They have the mermaides just stay inside there the pouch is always involved so like whale sharks they have the egg cases they have the mermaid's purses inside them but they just hatch inside them and so they still have big old egg cases made of this collagen tough but is it
Starting point is 00:23:57 more like an evolutionary holdover i think so yeah interesting and so like whale sharks have the biggest eggs of any organism but we don't always consider them eggs because they're on the only inside. Yeah, they don't lay them. Yeah. Which is like a very weird thing. Our definition of egg is where it is, not only what. Mollusks have weird egg shapes, too. Oh, yeah.
Starting point is 00:24:19 Yeah. So gastropods fall under mollusks, but even I think clams and oysters and things like that lay eggs. Yes, they do. Yeah. So if you look up whelk, W-H-E-L-K, egg case, it's also called a mermaid's necklace, which I thought was really like beautiful to go along with the mermaid pouch. All the accessories for the mermaid. So they are like a snail, a sea snail. Whelks are.
Starting point is 00:24:43 And aren't they like conch shell looking things? Yeah, they're like what snail, a sea snail. Welks are. And aren't they like conch shell looking things? Yeah, they're like what lives inside conch shells. And their egg pouches are like these long stringy accordion shaped things, which are very weird. So there are all these different packages for eggs or packages for embryos that organisms can have. But the eggs themselves are just little spheres. I think so. I think so. Yeah.
Starting point is 00:25:07 And this is like almost all marine organisms and things that make a bunch of eggs do have those little individual spheres because it's the easiest shape to make. Yeah. You know, if you're going to fill a package with liquid, the natural shape it will take is a sphere. I think that's probably why they're that shape.
Starting point is 00:25:25 Probably, yeah. Just physics. So why are eggs egg-shaped? Like a chicken egg, bird eggs. Because bird eggs do tend to mostly be egg-shaped. Bird eggs mostly tend to be egg-shaped. And we thought that they had a lot of theories for it. Like, you won't want your egg to be completely round,
Starting point is 00:25:40 otherwise it might roll off a cliff. Or they need to fit together in the nest in a nice way to cluster and stay warm and like all fit under a chicken butt. But according to a 2017 study, it's more complicated. New information. Yeah.
Starting point is 00:25:53 New information. Fresh info. That fresh research. They looked at nearly 50,000 eggs of 1,400 bird species. So it's a pretty comprehensive study and correlated bird egg size and shape with what they eat,
Starting point is 00:26:10 where they make their nests, how big they are, and how good they are at flying. And that last one seems like a weird wild card thing, but it ended up being the most important factor because the way the egg fits in the oviduct determines the egg shaped.
Starting point is 00:26:24 And that is just based on how streamlined their body is. the way the egg fits in the oviduct determines the egg shape and that is just based on how streamlined their body is. So if they're more aerodynamically shaped, then their eggs end up being pointier. Okay. We have our Hank Buck winner for the day. It's not
Starting point is 00:26:39 Stefan with zero. It's not Sam with zero. It's not me with one. It's Sari with two. Unless there's me with one. It's Sari with two. Unless there's some tangent you went on that I didn't notice. I don't think so. I don't think so. I think you were very good. I was so focused on real egg facts.
Starting point is 00:26:53 I didn't have any. There's too many good real egg facts. Yeah, that's the problem. If you like this show and you want to help us out, there's a bunch of easy ways to do that. First, you can leave us a review on iTunes. We're just trying to make this thing. It's just getting started. The more support we can get. It's a little egg. It's a little egg.
Starting point is 00:27:09 You got to sit on it, everybody. Warm it up. Second, we would love it if you tweet out your favorite moment from this episode. Thank you to Emily Cody, Cyborg organizer, Quell Edwards, and everyone else who tweeted your questions to us. And finally, if you want to show your love for Tangents, you could just tell people about our show. All the people who you think might think, wow, that was fun and I learned things. Those guys seem pretty nice and cool. Thank you for joining us.
Starting point is 00:27:35 I have been Hank Green. I've been Stefan Chin. I've been Sam Schultz. I've been Sari Reilly. SciShow Tangents is a co-production with WNYC Studios. Our art and music are by Hiroko Matsushima and Joseph Tunamedish. Our social media organizer is Victoria Bongiorno. And we couldn't make any of this stuff without our patrons on Patreon.
Starting point is 00:27:53 And remember, the mind is not a vessel to be filled, but a fire to be ignited. But one more thing. Female snakes can store sperm in their butts until they're ready to have their eggs fertilized by it, and it can be there for months. Boo!

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