SciShow Tangents - Charles Darwin

Episode Date: March 26, 2019

You might know him from his greatest hits: natural selection, Galápagos finches, and eating lots of the animals he studied… it’s Charles Darwin! This week, we’re talking about this famous biologist and some of the weirder science he did. What kind of books did he write after he published On the Origin of Species? Why was he so disgusted by fish spitting out seeds? And was it normal to write a letter to a scientist friend and ask detailed questions about barnacle sex? Sources:[Truth or Fail]https://motherboard.vice.com/en_us/article/4x38gj/darwins-monsters-parasitoid-waspshttps://books.google.com/books?id=lIcoAQAAMAAJ&pg=PA179&lpg=PA179&dq=charles+darwin+eyebrows&source=bl&ots=YrNkw9VczZ&sig=ACfU3U06m2pYFahEfpPveHOyT8auD0ZeXw&hl=en&sa=X&ved=2ahUKEwivsMeU4LvgAhUbJzQIHUaoA5wQ6AEwFXoECAgQAQ#v=onepage&q=charles%20darwin%20eyebrows&f=false[Fact Off]Seeds & fish:http://darwin-online.org.uk/content/frameset?itemID=F1683&viewtype=text&pageseq=1https://www.darwinproject.ac.uk/letter/DCP-LETT-1681.xmlhttp://blogs.discovermagazine.com/d-brief/2017/11/17/darwin-bird-vomit/#.XBlv3c9Khxwhttps://academic.oup.com/botlinnean/article/161/1/20/2418329Barnacles: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3574338/[Ask the Science Couch]Darwin’s understanding vs. ours:http://www.bbc.co.uk/earth/story/20141017-how-flowers-conquered-the-worldhttps://www.smithsonianmag.com/science-nature/what-darwin-didnt-know-45637001/https://www.wired.com/2014/12/fantastically-wrong-thing-evolution-darwin-really-screwed/http://www.esp.org/books/darwin/variation/facsimile/contents/darwin-variation-chap-27-i.pdfhttp://www.blc.arizona.edu/courses/schaffer/449/Soft%20Inhertance/Geison%20-%20Pangenesis.pdf[Butt One More Thing]Darwin bark spider:http://www.bbc.com/earth/story/20151126-the-worlds-biggest-spider-web-can-span-an-entire-riverhttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0011234

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. Joining me as always are Stephan Chibb, producer of SciShow. Yeah, that's what I do. What's your tagline? Loving those strawberry puffs. I don't know what they are, but I like the sound of them. And we've also got Sam Schultz, artist and editor on various SciShow projects.

Sam, what's your tagline? Hey, future Sam. What's up? Because you're going to listen to this episode. You're going to hear that in about a month. We're also joined by Sari Riley, writer of content. How are you? I'm okay. Tired. I think I'm always tired. You should have eaten more than two carrots today.

Yeah, I ate at least four. Sari, what's your tagline? Hitchhiking toast. And I'm Hank. I created SciShow, and I like to hang out with these people and make SciShow tangents. My tagline is, I ate at least four. Every week on SciShow Tangents, we get together, try it up to one-up amaze, and delight each other with science facts. We're playing for glory, but we're also keeping score, awarding Hank Bucks that we can use to do things with, maybe. We do everything we can to stay on topic,

but judging by previous conversations and also the name of the podcast, we may not be able to do that. So if the rest of the team deems a tangent unworthy, we will force you to give up one of your Hank Bucks. So tangent with care. Now, as always, we're going to introduce this week's topic with the traditional science poem. There is grandeur in this view, powers breathed into one or into a few, whilst this planet has gone cycling on according to the fixed law of gravitation.

From so simple a beginning as our planet kept spinning, I proposed this great mystery finally solved. Endless forms, most beautiful, have been and are being evolved. That was my adaptation, my poem adaptation of the last lines of On the Origin of Species by Charles Darwin, the subject of our podcast today. I'm just going to read to you the actual lines. There is grandeur in this view of life with its several powers having been originally breathed into a few forms or into one and that whilst this planet has gone cycling on according to the fixed law of gravity

from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved That book, a little thick in some places but that is a spot on ending. I liked yours better. You did a little punch up to it. Yeah, well, it's been a while.

You know, we talk a little different now. We have new words and stuff. Sari, what's Charles Darwin? He's a man. Was. Was a man. Biologist and best known for his contributions to evolution you might know him for natural selection that's like the big idea i don't know who i'm talking to people in this room or the

podcast audience you might know him for ideas such as natural selection the galapagos finches the process through which all things happen the understanding of biology those are his hits he has some deep cuts too there's some great moments like that there's a really good scene and I think Voyage of the Beagle

where he is trying to learn how to use a slingshot to catch an animal and he just catches himself and falls off a horse oh no he also ate basically every animal

he found he was a big food guy he was part of like a club where they ate all the animals right I think so yeah so he would like

find animals study them and be like I gotta take a snack too just in case but all the barnacles did he eat the barnacles that doesn't sound like food I don't know sounds like a But all the barnacles? Did he eat the barnacles? That doesn't sound like food.

I don't know. Sounds like a lot of work. Crack it open. To eat a barnacle. If I had somebody to do it for him. He was kind of a rich guy. He was rich, right? Yeah.

His wife was very wealthy. He married up. And he got to just traipse around the globe looking at weird animals. That was before the marriage, I think. Yeah, I think so. I think he got onto the HMS Beagle because they needed an extra person, I feel like. And he was just like,

I'm a naturalist. To be a scientist at this time, you had to be some degree of rich. Yeah. What I read was that they needed somebody to be the captain's friend. And they usually liked that person

to be the captain's friend, also have like a skill. So they tried to get other people to come on the boat and nobody wanted to do it. And then eventually they were like, well, you do it. And he have like a skill. So they tried to get other people to come on the boat and nobody wanted to do it. And then eventually they were like, well, you do it.

And he was like, okay. And also he was unpaid, I think, for his thing. Sure. I don't see why you would be paid to do that. Who's going to pay you for that?

Yeah, I guess so. Is that where first mate comes from? Yeah, it must be. That's why they call it first mate. Because captains are so lonely. It's hard.

It's hard to be in charge. Which one of you wants to be my professional friend? I was going to say, do you need a friend? I'm in charge of the company, and I need one of you to just sign up to be on my boat all the time. Yeah, you can also do naturalist stuff if you want. Collect beetles and such. That sounds hard.

Do we have to do that part? Just like help me take care of Oren and play board games with me? That sounds perfect. I would do that. Sam's in. All right, perfect. I'm so happy. I think everybody roughly knows who Charles Darwin is,

but there are lots of things that we don't know about Charles Darwin, which we're going to get to in this podcast. I feel like I know a lot, but I anticipate all of you surprising me today, so don't let me down. So it's time to start that off. Are you guys ready to science fact me? Well, Sam is here for Truth or Fail. He has brought three science facts for the rest of us for our education and enjoyment, but only one of those facts is true. The rest of us have to figure out either by deduction or wild guess which one is the true fact. If we get it right, we get a Hank Buck. If we don't, then Sam gets the Hank Buck. Sam, hit me with your facts.

So Charles Darwin wrote On the Origin of Species, but he also wrote a bunch of other books too, with a bunch of other wacky ideas in it that you don't hear about as much. So which one of these is a book he wrote? One, a book about parasitic insects peppered with musings on the existence of God. A book about why people have eyebrows and blush. Or,

a book about how Robert Fitzroy, the captain of the HMS Beagle, was a giant idiot. Oh, I thought he hired him to be his buddy. Well,

this was after the fact. So those are the three books that Darwin might have written. Mm-hmm. Give me a summarized versions of them all. Parasitic insects and God, Eyebrows and Blushing, or Robert Fitzroy is an idiot. Okay, those are our three. I know that he was into all kinds of weird animal stuff, but in my experience, he doesn't muse a lot about God.

He tends to avoid the topic in fact when the uh the intro that i or the outro like the last lines of on the origin of species that i read to you that was the original edition outro and then the all subsequent editions had extra words in it to say not breathed into existence but breathed by the creator into existence. Who made the change? Darwin did because a lot of people got mad. Too spicy. Because he said just like, it occurred. Whereas people were like, it occurred by God.

Like, we know how it occurred, Darwin. Already the stuff you're saying is not making me super comfortable. But like to not even mention. And then he was like fine by god and then he later expressed regret that he did that um so he doesn't tend to want to talk a lot publicly about god but i could be wrong i definitely don't know as much about darwin as you but it seems weird to me for him to trash Robert Fitzroy in a whole book. Yeah, maybe it was a chat book.

It's just like a blog post, basically. Or like could be his log from being on the ship. And then he trashed the captain throughout it. And I think Sam would distill that down to be that book title. Well, and I do wonder about Eyebrows and Blush. I think Sam would distill that down to be that title. Well, and I do wonder about eyebrows and blush and if that's just the book about human evolution stuff. Darwin also did expression and emotion research, I think.

He maybe shocked people's faces and stretched them in weird angles and directions. Charles Darwin? Maybe, yes. We're going to have to look it up after this because you can't look it up now because then we'll be ruining. We'll know the lie. But I think he made exaggerated expressions on people's faces through some sort of pain and then had people look at them and be like, are they bored? Are they scared? Are they excited?

Maybe I have heard about this. And studied that somehow. So that I don't know if he wrote a whole book about it, though, or if it was just a study that he did. Say the second one again. A book about why people have eyebrows and blush. That seems like a lot of book for those two things. Was that just a part of the book? Because Descent of Man talks a lot of law stuff.

Yeah, answer the question first. Were they blushing while they were electrocuted? All right, somebody go. I don't want to go first. I think it's number two. Yeah, eyebrows and blushing. I'm going to go with parasitic insects and God. I know it's parasitic insects and God.

You know it is? I'm like, oh, this makes me think it's wrong. So in case, maybe I screwed up because it is definitely the blushing and eyebrows. Ah, shoot. No. I was so confident. Never mind then. So the third book that Darwin wrote was The Expression of the Emotions in Man and Animals,

where he studied animal faces and human faces and was like, all humans and animals express certain emotions in very similar ways. And then he came up with the idea that no matter your culture there's certain emotions that every human expresses the same way

which people did not like probably for racism reasons I would imagine sure and then he declared that at the end of the book that blushing was the weirdest thing and the most human thing

and like no other nothing else blushed except people. I don't think he really tried to guess why. It's so weird. This is weird to me that Charles Darwin wrote a book about natural selection and evolution, something that people are still doing active

and complicated and important research on. And he was like, I'm done with that. I'm going to move on to facial shocks and animal faces. Which I guess is also important. But I feel like you stick with what you know. There's lots of work to be done here still. He was really old, so I think he was sitting around his house looking at pictures

of people with shocked faces that he got from some French guy whose name I can't remember. And he was like, I don't think the facial expressions being made by the shock tests are like real because these French researchers had come up with like 60 different

emotions that humans could have and Darwin thought there were less than that and that there was like a set amount of core human emotions so he would show his

friends the pictures and be like what is this one what is this one and any of them where the people were like well that could be

anger or happiness or something then he would throw that one out. Right. And he just narrowed it down. So we were real wrong. Yeah, we, what's wrong about it?

I want to know. So the book about parasitic insects, Pepper with God thing, he didn't write a whole book about it, but he wrote a letter to one of his friends where he had just learned about parasitic wasps, it seemed like, and they had made him think that there was no such thing as a uh kind and benevolent god in a world where there could be bugs that would put their babies into caterpillars

and let them eat their way out that's the thing that convinced you what a sheltered life you leave my friend i guess you don't have c-span yeah that's true it is pretty horrifying it is but like worse things happen yeah it's just a caterpillar it'sAN. Yeah, that's true. It is pretty horrifying. It is, but like, worse things happen. Yeah. It's just a caterpillar. It's just a caterpillar. That's true. I did read about that letter

and the fact that I think cats chasing mice for some reason. Also, he didn't like... He didn't like them playing with them before they ate them. Yeah, he was like,

no, God, because the cats are playing with these mice and torturing them. That's it. I guess everybody has their own path. He seemed like a super emo dude.

I kind of like when I read his stuff I think I kind of like him. He seems cool. And then the last one the Fitzroy thing he seemed to like Fitzroy up until the very end.

He helped him get into the Royal Society which is like the science thing. And then when Fitzroy died he helped his widow pay off some debts that he left.

But Fitzroy came back from the trip pissed off because he felt guilty that he wrote this book about like disproving god stuff and fitzroy was pretty holy so he so fitzroy was mad that darwin wrote the book yeah so he was disappointed and like he felt embarrassed that he helped him like he brought him on this trip where this book came out that disproved a lot of stuff that he believed in and he would give talks and stuff about how darwin was wrong and he was kind of like a science skeptic at the end of his life it seemed like too so it's kind of the other way around yeah fitzroy kind of trashed darwin he thought and then even afterward darwin was like hey

he's gone and i like you widow of fitzroy who trashed my work a lot. Here's, you know, a hundo to deal with those debts. It actually literally was a hundred pounds, I think is all. Which was a lot. Was it? I don't know. Yeah, it's more than a hundred dollars.

I get two. What's the Hank book to pound conversion rate? I don't think that you can trade one for the other because we really need to not be creating currencies. We've seen how that can go.

Okay. No cash value. No cash value. The government gets mad at you. Okay. Sorry. It's a cryptocurrency. Hank books.

Well, coming up, Stephan and Sari will go head-to-head in a fact-off. But first, a message from our sponsors. All right, we are back. Hank Buck, check in, Sari.

You're coming in at a big old nil. I've got one for my poem. Sam's got two for his excellent duplicitous science facts. And Stefan was correct. I got it. And got one. Good guesser. Now it's time for the fact talk,

where Sari's going to go head to head with Stefan, bringing science facts to present to the others in an attempt to blow their minds. The presentees will each have a Hank Buck to award to the fact that they like the most. However, if both facts are a giant snooze, the presentees can choose to not award our Hank Buck, and instead we can throw them in the Hank Buck trash. We're going to decide who goes first by who's been closest in their lives to a dolphin. Because in the show Sequest VSV, the dolphin was named Darwin.

Oh, okay. I've pet a dolphin before. So you touched a dolphin? I've touched a dolphin. Maybe kissed a dolphin. Oh my. I don't remember. I was small.

Okay, Terry's touched a dolphin. I'm not. I'm no dolphin kisser. How close have you been to a dolphin? I may have seen a dolphin show at SeaWorld or something. Yeah, okay. But I wasn't in the splash zone. Okay.

I remember very specifically I did not allow myself to be splashed. I remember very specifically I didn't want to touch the dolphin really. I felt like I wanted to be gentle with it

and they were like lean in close for a kiss so you can take a picture in our family vacation. Yeah, and you were like leave this poor man alone. Yeah. All right. So Sarah, I guess that means you're going first. Okay. Dolphin kisser. Yeah, and you were like, leave this poor man alone. Yeah. All right. So, Sarah, I guess that

means you're going first. Okay. Dolphin kisser. Yeah. That's my new tagline. So, a big part of Darwin's biology research was trying to explain how dispersal happened of animals and plants and everything besides just how evolution happened. So, like, this is a question of can a bean cross an ocean, which sounds silly but was a valid question at the time because creationism was big and people thought a god chose where to put all the rhinos and pine trees and everything. So Darwin started with some basic experiments. He dunked seeds in jars of saltwater for weeks and then planted them. They got goopy and stinky, but a good number of them grew. But then he was like, oh shit, most of these seeds sank in the water, which would not work for an ocean voyage.

So he tried out dried seeds, which floated a little better and then started involving animals. So he tried to feed the seeds to fish, which spat them out, which was super disappointing. And he got mad at them. Did he write down? Sorry, continue. I have a quote from him, which is great. So after that, maybe as revenge, he stuffed seeds into dead fish and then fed the fish to birds who are much less picky eaters. And he searched through the bird poop and vomit for seeds and a few grew, which was really cool and exciting for him. And lastly, in my favorite of his weird experiments, he took dead duck feet.

Don't know why he didn't use a whole duck. He just took their feet, swirled them around in tanks to see if tiny freshwater snails would hitch a ride and could survive an air long enough to be hypothetically flown from pond to pond. And they did. So he did all these weird experiments.

So why did he get mad at the fish? And how do you know that? So the quote is, when lo and behold, the fish ejected vehemently and with disgust equal to my own, all the seeds from their mouths. I love it. People don't write science like that anymore. You're not supposed to have opinions.

It's like, lo and behold, when these little dick turds spat all my seeds out, ending in a result that I do not prefer. I'm not supposed to have preferences, Darwin. Yeah, the paragraph starts with, everything has been going wrong with me lately. He's so sweet. He's such an emo, Darwin. He'd be so good at Twitter now, I feel like. Oh, yeah.

He'd be a weird Twitter scientist. Delightful. People had a lot of free time back then. No. They didn't have internet. You can't. No, he was doing important research. You can't say, they had a lot of free time back then.

Darwin was like finding out amazing shit. If they had Netflix, he wouldn't have done any of it. If only he could have been watching Great British Bake Off. He never would have swirled dead duck feet in snails. I'm glad he didn't have Netflix,

but he would have watched all of Sabrina like the night it came out. As he was swirling dead duck feet and snails. You can multitask. You can do both. Oh yeah, you can do both. Get you a Darwin who can do both. Stefan!

It is now your turn. Darwin, as we sort of mentioned earlier, was fascinated with barnacles and wrote a couple monographs on barnacles, which are just like explorations of a species or group of species. In particular,

he seemed kind of fascinated by like the reproduction and penises of barnacles. Sure. And I have an excerpt of a letter to one of his friends where he asks, was the penis inserted into more than one

individual? For how long? How many times was it inserted? Was it inserted deeply? At which end of the valves? Did it keep its opercula valves widely open for the reception of the organ? I am anxious to know whether this recipient was a willing agent or adulterer.

What's a willing agent and a barnacle? What's a barnacle and adulterer? Oh my God. What's a willing agent in a barnacle? What's a barnacle adulterer? Charles Darwin, answer me questions. That was an amazing set of questions. I just like that he was really concerned about barnacle consent. He had good reason to be fascinated

about barnacle dicks because they are the longest dicks in relation to body size in the animal kingdom. You know, also it's just interesting. Oh, sure. It doesn't have to be. It doesn't ultimately. Well.

Are you saying that Darwin was only interested in barnacle dicks because they're so long? No. There's more to it than just size, Stefan. They like, they flop around randomly looking for neighbors they can poke. They can change length. They can change shape. They can become thicker if there's too many waves and things happening i just did like the excitement that comes across in his like rapid

fire like tell me about the opercula valves who was he asking were these rhetorical questions he was just throwing out there or no he really wanted to know he was like he was like you have not told me enough about this barnacle sex. You have attempted to relay to me useful information, but it is as if you have no idea all of the interesting and necessary pieces of information I need. So he was right into a barnacle expert. He wasn't right into his aunt or something.

Yeah, yeah. Well, he had heard that a friend of his friend had seen this happen, so he wrote a letter to his friend being like, can you get in touch with your friend, ask them these questions, and he wrote a letter to his friend being like can you talk to your friend ask them these questions and send me a letter back these are such relatable problems he has and he's just the whole time he has a tummy ache

oh no we didn't even talk about how sick he was it must have been so annoying to not be able to just text people these questions and have to wait for like a year and be like writing a letter to your friend so that your friend can ask your other friend about like the valves on a barnacle. And your other friend is just like, I don't know. I only watched him do it once. So I don't have a video.

I'm trying to figure out if he ever ate barnacles. There's definitely people who eat barnacles. That's a thing. but i don't have any proof that darwin did it he definitely ate a lot of other stones though he ate those golemphicus tortoises he had a pet one too right yes but he was like very old yeah right went to australia traveled the world died a couple years ago it ended up in steve irwin's zoo oh i didn't know that one wow what. What a collectible. This is getting awfully close to a tangent.

Let us award our Hank bucks. Okay, I think that all Darwin facts are beautiful, but I think I'm going to give it to Sari because the duck feet thing is pretty funny. Okay, I'm also awarding to Sari. I like an underdog. And now Sam and Sari are tied. Oh, the big penis. Isn't that such a good fact? Now give me the bucks.

All right. Now it is time for Ask the Science Couch. This week, we got Sam delivering us a science question. Gabriella asks, assuming he didn't get everything right, how did Darwin's theory of evolution differ from our current understanding of evolution? Okay. So the traditional way that the science question works is that I like fumble my way around and then Sarah answers the question. So here's me fumbling.

Okay. In detail ways, like the overarching thing of like natural selection, like evolution through natural selection, like is still a thing. Pretty accurate. Mm-hmm. natural selection, like, is still a thing. Pretty accurate. And, you know, there were lots of, like, attempts to work out the fine details that were correct and lots that were, you know, missed the mark a little bit and lots that were pretty wrong. So I guess the main principles are mutations occur.

Like, changes just occur naturally and they are random changes. And if they increase fitness, then they will perpetuate through like not dying and having more sex and that those changes can also be more than just fitness like he also talked about that which is something that is a little weird but like selection for things like giant antlers is not about being good at eating and being good at finding food. It's just about like being impressive. So like the antlers aren't there to help you live a better life. They're there to signal that you are successful.

And so like he was right about that stuff too, that like ultimately it was signals of success and actual success that led to better chances for mating and longer lives for the animals. And that allowed these traits to perpetuate through a population. And those traits perpetuating and those changes occurring added up over time to species differentiating themselves from each other. Did I do okay?

Is that true? Yeah, I was like very good. Yeah, and I think the only thing I would add to that is that all those changes adding up also meant that all species were related to each other

which wasn't a given at the time oh no yeah and like even now we're not like hundo on that there is still the possibility

that life evolved more than once on earth that we do not all tie back to one common ancestor. That is a controversial idea. Not a lot of people would be like, yes, we should explore that. But there's some thought that maybe things like phospholipid bilayer may have evolved separately from RNA or something, where you had, you had two organisms that, like, came together and became our one common ancestor.

The idea that instead of one common ancestor, there are, like, a bunch of things experience abiogenesis. Right. And then from that, a tree emerged. Mm-hmm. That doesn't feel like it's that big of a shift from our current understanding.

No, you're right. It doesn't like affect darwin's theory at all the only thing it affects is like how likely it is for life to evolve and also the story of those first organisms which is the story that probably we will never know yeah and that's sad because it's very weird yeah what do you get wrong so i liked the ways that she phrased the question because hank right. Like he got a lot right. He got so much right that he was able to predict evolutionary relationships that we hadn't discovered yet. Like one story that I particularly like is there's an orchid that has a really long nectary.

So in order to get to the nectar part of it, it's like very deep. part of it. It's like very deep. He was like, I don't know what pollinates this, but I predict that there's some sort of moth with extremely long proboscis that no one had discovered. And then 150 years later or something, people found this big ass moth with a very long proboscis. So like his ideas were so solid that he could just throw out a guess like that. And I bet like if Darwin found out about that, if he like like was still alive 150 years later, he'd be like, oh, cool. Like a little bit sad still. But I was wrong about so many other things. And so it seems like most of the things that he was quote unquote wrong about were just things that he didn't have evidence for at his time. So he had really good ideas broadly about speciation and how it happens because of

different environmental pressures, but he didn't predict all of the ones that we know about today. So for example, it's not only species like on the Galapagos Islands, finches competing over the same resources. A lot of times speciation happens because of big events. So maybe a group of beetles ends up on the other side of a mountain range somehow and so it's thrown into a completely different environment split from the original population and those speciate or i don't know various factors like that that he didn't necessarily predict and pinpoint that we now know exist he knew that evolution took time and at the time creationism gave a

span of about like 6 000 years for things to develop after a god put them in places um at the time we thought that 100 million years was an extremely long time that was right fossil records stretched back about that far and even then he was super confused by flowering plants because he was like um the fossils back then don't look like the plants that we have today okay or in his contemporary time so they look like weird lumpy trees all of a sudden we have this diversity of plants and as far as i can tell he thought that that threw off his his theories because he was like i i don't understand how this slow process happened so quickly for so many plants a little did he know that we have billions of years.

We have more time to work with than that. Like hundreds of times more time to work with than that. And the biggest place that he was off base was genetic inheritance. So he had all these really good ideas about how animals evolve and how biology happens. But the mechanism of genetics was happening at the time. mendel was working in the 1850s as like this little gregorian monk who is the person who we think is the like the founder of modern genetics and learned about alleles and bred his pea plants but no one paid attention to him at the time yep he was just hanging out with pea plants by himself so darwin came up with a theory

that he called pangenesis, which is basically the idea that the mode of inheritance is our cells have particles called gemules that get passed down from parents. So he thought all cells just kind of sprayed out these particles, as far as I can tell. So they get passed down. They construct the new cells somehow. And the mixture of these gemules create variations.

And he still believed in blended inheritance at the time, which is the idea that, like, a black cat mating with a white cat would make a gray cat, rather than independent assortment of alleles. And he was not unique in that. Like, everyone believed in blended inheritance. No, it really should have worked that way. It should have?

That's like how video games work. I mean, it certainly makes the most sense. And, like, that's why Mend video games work. I mean, it certainly makes the most sense. And like, that's why Mendel's work was so weird and why it changed things so much when people sort of rediscovered it. That is a testament to this thing that happens sometimes where you're like, you know, Darwin did a great job of like figuring out

like the explanatory power of natural selection. And then it was like, well, this has to happen somehow. And instead of saying like, but I don't know how, he did that thing then it was like, well, this has to happen somehow. And instead of saying like, but I don't know how, he did that thing where he was like, here's a theory, but I guess there's still like explanatory power behind that

and you have to walk down those paths. And if, you know, suddenly like a white cat and a black cat make babies and half of them are white and half of them are black and none of them are gray, then you have to say, gemules aren't explaining things correctly.

Let's go back to the drawing board. But if Darwin had enough free time to be stuffing seeds into dead fish, I think he could have grabbed a black cat and a white cat and had them mate. Yeah, he tested it during his lifetime. I think he took his cousin, who also did a lot of stuff, and they didn't mate rabbits, but they took blood. Well, to be clear, he did mate with his cousin. He married his cousin.

Oh, yeah, different cousin. This was his other cousin, his bad cousin. This is his kind of racist cousin that he took. And so they took rabbits, and I believe they took blood from one rabbit and injected it into another because by Darwin's theory of gemmules, the blood cells have these inheritable particles and are spewing them out and so they tried doing that and then mated that rabbit see if it made babies and like no traits from the original blood rabbit transferred to it

and so they were just like i don't know it doesn't seem to work but we have nothing better and no one was listening to mendel at the time. But science is beautiful. And even Darwin makes mistakes. And yeah, I don't know. That makes me sound like I'm a Darwin fanboy. No, he does. He falls off horses. Are you not a Darwin fanboy? He's all right. Yeah, he's pretty cool.

Oh God, I'm a Darwin fanboy. He seems like a real cutie. If you want to ask the Science Couch, follow us on Twitter at SciShowTangents where we'll tweet out the topics for upcoming episodes every week. All right, so our final Hank Buck scores, Sari came back.

Tying Sam with two Hank Bucks and Stefan and I are tied in second because I denied you. Sorry. I think we all win though because we all learned a little something about Charles Darwin. All right, if you like this show and you want to help us out, it's really easy to do that.

First, leave us a review wherever you listen to podcasts. That's super helpful and helps us know what you like about the show. Second, you can tweet out your favorite moment of this episode. And finally, if you want to show your love for Tangents, just tell people about us. Thanks for joining us. I have been Hank Green. I've been Sari Reilly. I've been Stefan Chin. And I've been

Sam Schultz. SciShow Tangents is a co-production of Complexly and WNYC Studios. It's produced by all of us and Caitlin Hoffmeister. Our art is by Hiroko Matsushima and our sound design is by Joseph Tunamedish. 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. The Darwin Bark Spider is only a couple centimeters big, but its butt can shoot out a lot of silk. Their webs can span a river 25 meters wide, and the silk is one of the toughest biomaterials out there.