The Weirdest Thing I Learned This Week - Thank Your Local Horse, OG Canners, Busting Bird Gender Norms

Episode Date: August 27, 2025

Nathan H. Lents joins the show to discuss why some birds are extra loud in bed, along with his new book: The Sexual Evolution: How 500 Million Years of Sex, Gender and Mating Shape Modern Relationships. Plus, Sara Kiley explains how horses are used to create snake anti-venom, and Rachel talks about how Napoleon played a part in instigating the art of canning food. The Weirdest Thing I Learned This Week is a podcast by Popular Science. Share your weirdest facts and stories with us in our ⁠⁠⁠⁠⁠⁠⁠⁠Facebook group⁠⁠⁠⁠⁠⁠⁠⁠ or ⁠⁠⁠⁠⁠⁠⁠⁠tweet at us⁠⁠⁠⁠⁠⁠⁠⁠! ⁠⁠⁠⁠⁠⁠⁠⁠Click here to learn more about all of our stories! ⁠⁠⁠⁠⁠⁠⁠⁠ Go check out Mary Roach's new book, ⁠Replaceable You: Adventures in Human Anatomy!⁠ ⁠https://maryroach.net/replaceable.html⁠ Links to Rachel's TikTok, Newsletter, Merch Store and More: ⁠⁠⁠⁠⁠⁠⁠⁠https://linktr.ee/RachelFeltman⁠⁠⁠⁠⁠⁠⁠⁠  Rachel now has a Patreon, too! Follow her for exclusive bonus content: ⁠⁠⁠⁠⁠⁠⁠⁠https://www.patreon.com/RachelFeltman⁠⁠⁠⁠⁠⁠⁠⁠ Link to Jess' Twitch: ⁠⁠⁠⁠⁠⁠⁠⁠https://www.twitch.tv/jesscapricorn⁠⁠⁠⁠⁠⁠⁠⁠ -- Follow our team on Twitter Rachel Feltman: ⁠⁠⁠⁠⁠⁠⁠⁠www.twitter.com/RachelFeltman⁠⁠⁠⁠⁠⁠⁠⁠ Produced by Jess Boddy: ⁠⁠⁠⁠⁠⁠⁠⁠www.twitter.com/JessicaBoddy⁠⁠⁠⁠⁠⁠⁠⁠ Popular Science: ⁠⁠⁠⁠⁠⁠⁠⁠www.twitter.com/PopSci⁠⁠⁠⁠⁠⁠⁠⁠ Theme music by Billy Cadden: ⁠⁠⁠⁠⁠⁠⁠⁠https://open.spotify.com/artist/6LqT4DCuAXlBzX8XlNy4Wq?si=5VF2r2XiQoGepRsMTBsDAQ⁠⁠⁠⁠⁠ Learn more about your ad choices. Visit podcastchoices.com/adchoices

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And while most of the stuff we stumble across makes it into our articles, we also find plenty of weird facts that we just keep around the office. So we figured, why not share those with you? Welcome to the weirdest thing I learned this week from the editors of Popular Science. I'm Rachel Feldman. I'm Sarah Kylie Watson. And I'm Nathan Litts. Nathan, welcome to the show. It's so great to have you. It's a pleasure to be here and a pleasure to be with you again, Rachel. Would you tell our listeners a little bit about your, well, a little bit about who you are and what you do and also about your wonderful new book, which I've really been enjoying talking about on as many of my podcasts as possible. Well, thanks very much for that. I appreciate it. I'm a professor of biology at John Jay College, and that's in New York City. It's the City University of New York, one of the probably the largest urban university.

in the world. And, you know, I study, I'm a geneticist by training. I study mostly genes and cells. And I study them primarily in the human evolutionary context. So I'm very curious at how humans got this way. You know, we talk a lot about, yeah, why are we like this? We talk a lot about human evolution in terms of, you know, behavior, anatomy, and, you know, morphology, kind of the typical stuff. And people don't, one thing that people don't realize is that we have almost no understanding. of the genetics of all of that, you know, about really what makes us different from, say, for example, chimpanzees or, you know, other apes or even just Neanderthals, we know some of those differences, but connecting those differences to actually our experience of it, whether it's anatomy, behavior, or whatever, that work is really just getting started. So that's what we do. But I also

am a science writer sort of as a side gig in a sense. But the reason I do it, it is still part of my scholarly work. I write a lot about comparative human and animal behavior and physiology and things like this, because while I study human uniqueness in my lab, I really study human continuity with other animals in my writing. And the reason why is I think you need both perspectives to really understand humans, human beings. The fact that we are animals with this long history is half of the story. And then the other half of the story is the uniquely human aspects of our existence. I put them both together, one in my writing and one in my laboratory research in the hopes of one day, I'll have it all figured out of why humans are the weirdest primate on the planet. Yeah.

Well, tell us about the sexual evolution, your latest book. Right. So my latest book is about sex and gender diversity in animals, including and especially humans. I concentrate mostly on animals. And this came out of my teaching. So I've been teaching about the biology of sex and gender and sexuality for about 15. years, actually probably more than that now. And, you know, I kept, I kept observing the same sort of patterns with a lot of the research that we would cover in my class. So I would always have students

go find articles on their favorite animal or whatever, you know, behaviors, things. And they would bring it in. And one thing I notice is that very frequently, the scientists themselves seem to ignore gender diversity and sexual diversity in other animals. They really, biology has this, especially field biology, like animal behavior. biology has this tendency to want to collapse behaviors into like an example, like a type that everything else is measured against. So there's an ideal way to be a male, for example, and an ideal way to be a female, and they all kind of want to do the same thing.

And the variety of sex and gender, so the way that one can succeed as a male in reproduction or even other aspects of their social life, it was really ignored by the same. scientists themselves. So there's just a lot of diversity out there in the animal world that is only very recently being appreciated because of this tendency that biologists have to like consider what is the ideal or you know, what is the alpha male mythology, for example. That's one of the more famous and obvious examples of this idea that there's an alpha male and every other male is is trying to be in that position and their job, you know, and we now know that that that model doesn't work in very many speeches at all actually.

And there's a whole rich variety of animal approach to sex, including sexed bodies, but also in reproductive behaviors and strategies. And the more I look at this diversity in animals, the more the diversity that we see in humans makes sense. You know, when you consider that there's a whole variety of males in birds and reptiles and primates and gorillas, even you come up our closest relatives, it would be unusual if humans didn't also have diversity in our approach to sexed behaviors and sexed bodies. So I think that there is a political message in this book in the sense that diversity is

never something to scoff at, something to fear or something to loathe. Diversity is a normal part of the experience of being an animal, including in behaviors. And this is what I try to do in the book is the diversity is good for the species, you know, for the individuals, but also for the species as a whole. The species is better and more resilient, more ecologically. resilient, socially resilient by having different kinds of males and females. And not everybody does the same thing the same way. That makes a population more robust. So I would say that's the theme of my book is diversity creates robust populations, including and especially with sex.

So yeah, that's the punchline. It's a great book. And I hope our listeners will check it out. But today we're really excited to have you on to talk about, you know, some of the weird and wonderful stuff in the animal kingdom you've been exploring. So let's dive right in. On the weirdest thing I learned this week, we start by each offering up a tease about some kind of fact or story that we found in the course of reading, writing, reporting, et cetera. Decide which one we just absolutely have to hear more about first. Then once we've all had time to spin our little science yarns, we reconvene and decide what

the weirdest thing we learned this week actually was, except there's not a winner anymore. And I'll never rewrite the intro. It's fine. Now it's a bit, and I love a bit. Sarah Kylie, what's your tease? All right. So if you've ever survived a cobra bite, you should thank a horse. What shouldn't you thank a horse for?

I mean, on the list of things to thank a horse for, this one's pretty good, but there's lots of things to be thankful, grateful to horses about. Nathan, what's your teeth? My tease would be that many birds are loud in bed. I'm surprising to anyone who's walked around on a spring day. Oh, man. Population calls are very common in birds, and they do it for a variety of very interesting reasons. Oh, I love it. This is so exciting.

My tea is very different, not an animal story. I'm going to talk about how canning was used to pursue. or food before anyone knew why it worked and long before anyone thought to invent a can opener. Oh, my goodness. Okay. Love that. Well, Sarah Kylie, why don't you start us off so we can go animal can animal?

Okay. I love this. Okay. Wonderful. Yay. So, yeah, today I'm here to talk about surviving a venomous snake bite and the science and animals that we have to thank for that even being a. a possibility. So before we get into the thick of it, I think we should just talk a little bit

about venomous snakes. And so out of the about like 4,000-ish snake species that we know about that are slithering around on earth, about 600-ish of them are venomous. And some of the most dangerous of these guys are in the Ellipid family, which include the terrors like King Cobra, coral snakes, black mamba, you know, all the big baddies. And these guys are mostly found in tropical and subtropical regions in Asia, Australia, Africa, and the Americas, and there's even marine versions of them that are like lurking around in the Pacific and Indian oceans. And while not all elipids are venomous, most of them do use a neurotoxin, which they like channel into their prey with these nasty bites and these hollow fangs. It's all very scary.

And yeah, when a small creature or like really any creature goes up against one of these, or you get bit by a cobra or another venomous member of the Ellipid family, it's like guaranteed death, pretty much. Cobra venom is a neurotoxin that hacks into your nervous system, which like scrambles all these electrical impulses that tell your nerves and muscles what to do. And just one bite can kind of paralyze an animal skeletal muscles in diaphragm, which inhibits their ability to run away or even breathe. Very dangerous stuff we're talking about.

But there are several species of animals that can fight them off, Instead of having like a horror movie-esque death, they can, you know, survive one of these really scary snake bites. And this is kind of where my rabbit hole journey to the horse of it all began. So I was working on a story about a new study for Nautilus magazine. And it's in the International Journal of Molecular Sciences. And it's all about how skinks, which are these little Australian lizards, have developed an evolutionary, like basically, plot armor from being killed by cobras all the time. And so this Australian toxicologist named Brian Fry and his team, they basically described in this new study how across 25 different

occasions, 13 out of 45 studied skink species have built up molecular, you know, zh, to keep the cobra venom from immediately killing them. So we'll get into that first and then we'll keep going. But so these little lizards called skinks, they faced a serious conundrum when about 30 million years ago, the first elipid snakes arrived in Australia from Asia and basically presented them with an evolve or die situation. And some of, I mean, we still have them. So they were successful. Some of them did evolve, which is why they still exist,

and they're not, like, just decomposing in the stomachs of, like, thousands of generations of poisonous snakes. And cobra venom normally targets, yeah, these muscle receptors, but a mutation in the surviving skinks created this mechanism to deploy a sugar that basically, like, physically blocks the toxins. And this just happens to be the same way that cobras resist their own venoms and how cobra-eating creatures like mongooses protect themselves when they eat the cobra. Because, yeah, you can't eat something venomous without having a little backup plan going on.

And so the team went even deeper and used skink tissue from museum tissue banks to kind of recreate the receptors of the major skink, which is a type of this lizard. and they recreated what happens when the Pilbara death adder takes like a little nibble out of them. And this team had previously uncovered the like single amino acid change that honey badgers actually evolved to avoid death by cobra. And the skinks had convergently evolved the same little switch, which is very cool. We see that happen all the time, especially when there's scary stuff that creatures need to like avoid. But yeah, this is all super fascinating and nifty. but the really weird bit that I uncovered during this, well, talking to Dr. Fry was actually how we make anti-venom for people

who get bit by a cobra now. And if you're like me and you live somewhere where venomous snake bites are like pretty much a non-issue, I was doing some digging. And in the Netherlands, which is where I live, there's only one venomous snake species. And it's like a shy one. Like it's like a one that doesn't want to bite you. The same situation in New Jersey. Like there is a venomous snake, but it's like just one.

and it's like you kind of need to be trying to mess around with it for it to go after you. Though I grew up running around swamps and woods in South Jersey, blissfully unaware that there was even the one. So I'm glad that didn't backfire. Yeah. And I was looking at pictures of the, what is it called? It's like, I don't even really remember. This poor little snake that happens to be venomous. And it's like just like a plain black snake.

Like I'm like, maybe I have seen this in my. various frolicing through South Holland. You respect their distance. Yeah, I'm like, that's, that is none of my business, frankly, what the venomous snake like singular of the Netherlands is up to. But yeah, they don't want to bite you. They only bite you of provoked. But around the world, like in places that are more tropical than here, um, venomous snake bites

are like a real problem. 5.4 million people apparently are bitten by snakes every year. And between 83,000 and 138,000 people die because of this. So it's a serious thing. And the making of anti-venom, which is the medicine we use to quickly counteract the situation if you do get bit by a venomous steak, it makes me very, very queasy. So this whole endeavor was a wild ride. But to be fair, like getting blood drawn, like I have to take like three to five business days

to recover from that. So maybe the listeners will be stronger than me. But this one was a challenge, just looking at pictures of blood. Because the process in which we create antivenom dates all the way back to the 1890s, which for context is when we were like using heroin as cough syrup. So like a eon of medical discoveries ago and a very different time. But basically it works like this and it still kind of works the same way, which is you have to have the venomous thing and then a kind of like test bank lab in the form of an animal. So I'll explain that. So step one, it's kind of like a two-step process.

Step one is you milk the venom from the snakes. And I fell down a rabbit hole. This is the best explanation I could find was a story from Euro News last year, which is about a group in Costa Rica that does this. And so the natural resource manager, Jasmine Arias, explained it as such. Basically, you take the head and the rest of the snake or whatever, and you bring it into a glass container,

and it's cold in there and you expose the fangs and then you kind of massage those glands where the venom where it basically says like insert venom here and when the venom is released you kind of just gather up the venom and then you disinfect the snake and you put it back so the snake is fine

it got a little tooth massage and now we have the venom from insert snake here the next part is where things get even weirder which is that stuff the venom is injected into horses over a series of months in small but increasing doses. And then the horses, because horses are pretty darn tough animals,

they have an immunological response to this and create the antibodies. And then after they've been working on it, scientists take that blood. And there's this study in National Geographic from 2022 about a group in Mexico that does this, which I saw a lot of pictures of blood. Oh, man, and it goes really in depth. So if you're really into this, I have some stuff. But apparently you can get five liters of horse blood in about 10 minutes. And so basically you get like this bag of blood.

The plasma collects at the top. And then you basically get rid of the plasma and you take the plasma-free blood to the lab where you turn it into antivenom. And how much anti-venom you can get from this blood. Like there's a big variety because, again, you can do this with snakes and you can also do this with like scorpions. So apparently one horse's output can make 2,000 vials of scorpion antivenom and 200 vials of African snake anti-venom. So yeah, and if you're feeling stressed about the horses, you're definitely not the only one. And like the scientists in Mexico that were interviewed for this Nat Geos like story, they basically are like, these horses are spoiled, they get a weekly shower, they get organic food, they're having a great time. But there's still impairment to the horse's health over time.

And there's been studies on this. And also, like, the resulting anti-venom from this process is not perfect. It doesn't always work. It causes a severe allergic response in some patients. And there's some countries where it's like half of the time that that happens. There's a reaction. But it's so essential to global health because this is a huge deal that right now it's kind of like, okay, well, there's not another, like, way to do this.

So we're going to keep chugging along with this horse situation. But basically advocates and scientists are both like, hey, like maybe we want to find another way to do this. And so there's been a couple of interesting situations in the let's figure out how to do something differently here. One was, I mean, the story got published earlier this year, the study. And it's this man named Tim Frida, who is a self-described auto-diadact herpetologist and venom expert. and he deliberately immunized himself with increasing doses of a number of snake venoms over an 18-year period, which, like, do not do this at home. Like, even if you're a horse, if you're a horse listening to this, don't do that.

Like, like, I mean, he, like, almost died a couple of times, apparently. And, like, sometimes this, like, immune response, like, only lasted, like, a couple weeks. So, like, there was, like, varying success in how Tim was doing. But scientists earlier this year, I think it was like May that the study came out, but they were able to extract DNA from his immune cells to make these super antibodies that fully neutralized neurotoxins from 13 of the 19 species that make up the World Health Organization's category one and two deadliest snakes. And so they use this like magical super antibody to protect lab mice from these really scary poisons. So, I mean, we know that this thing works, that using, you know, whether it's Tim's body or a horse's body to kind of like develop these antibodies. It is a way to make it work. But at the end of the day, we really want to be able to make these anti-venoms without having a living creature basically incubate them, which is why like these like venom resistant skink, honey badger or mongoose studies are so important.

even though it kind of is, it kind of sounds just like a little silly off the bat that we have like, okay, well, we've got like some like big Australian random creatures that are resistant to cobras because, of course. But the skink researchers were able to do all of their research without actually like catching or hurting anything. So that's kind of like a great and an interesting way to possibly make this very important medicine and update this like hundred and something old method of doing it. Yeah, obviously it works. Like, and it's what we're doing. But, but yeah.

So if you've ever been bitten by a snake or if your dog has or something, like you owe your local horse, like an entire bushel of apples. And I recommend that you find a way to say thank you because they are really out here putting in the work for us. But yeah, that's that. So people that like blood and horses, this one's for you. Well, I'm wondering, so do you know why they haven't just made a monoclonal antibody in the lab? Because, you know, that's what we've done with a lot of immune therapy. We don't grow these antibodies and animals anymore, right? We make monoclonals, you know, from mouse cells in the lab.

So I wonder why they haven't done that with this one. If it's definitely an ant, I assume it's an antibody that they're... Honestly, I couldn't tell you. And I think it's probably because there's still so much mystery in how any of it works that it's kind of like insert body to figure it out. You know what I mean? But you know what? As soon as there is another way, I'm going to be all over it because this is fascinating stuff.

I love that. All right. We're going to take a quick break and then we'll be back with some more facts. Did you know that there's an online cannabis company that ships federally legal THC right to your door? And talking about mood.com, they have an incredible line of cannabis gummies and a lot more. you can get 20% off your first order at mood.com with promo code weirdest. I'm not a smoker myself, but I do love the occasional weed gummy to, you know, help me go off to Dreamland.

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And in general, like wars and big armies have been responsible for most of our leaps in sort of food preservation and production in the modern world. And this is one of those cases. And apparently Napoleon also, like, he generally liked having sort of innovation contests where he was like, I'll give you a bunch of money if you figure out how to do this thing that I want someone to do. Which, you know, it's a pretty good strategy. So he offered a reward of 12,000 francs to anyone who could come up with a new and efficient method of preserving food. And I saw one source that said that's about $35,000 today. I couldn't really corroborate that because, believe it or not, most of those historical inflation calculators don't include francs in 1795 as an option. But it was a sizable sum, you know.

nothing to sneeze at. So this guy, Nicholas Apeer, he was a French confectioner, he spent nine years working on the challenge before he ultimately opened up the world's first food bottling factory, which was really like proto canning as we know it. For listeners who like don't do canning, I understand it seems pretty scary and potentially terrifying. And it is, you must respect the canning process. You must have a healthy fear of it to begin to can food because if you are somebody

who can look at directions and follow them, you really can preserve food in your home in a way that is safe. If you do not follow even one of those instructions correctly, you can die

horribly. So it's really it really depends on just sort of your approach to following a recipe, measuring things exactly, you know. But I finally, a few years ago, like, took the leap and started canning food. And I still don't do a ton of it because I live in an apartment. So it's like I don't have a place to store a whole winter's worth of canned vegetables or anything. But I am now at least like I no longer actively fear that I am putting my life in my hands

every time I eat food that I can't. Though I will say I stick to acidic foods like pickled vegetables, which are much more straightforward to can safely. If you want to can things like soup or something or like meat, you know, anything that doesn't have like a healthy serving of vinegar in there, it takes a lot more work and equipment and you are much more likely to die horribly as a result. So everything I'm saying about how you really should give it a try, it's not that big of a deal. Consider that, you know, only for like making pickles, et cetera. But anyway, canning, it's great. And this guy named Nicholas, he started it all really with the idea of bottling food. His technique was basically water canning.

So you put food in a vessel, in his case, glass jars. He would put a cork in them. He would seal them with wax, then he would place them in boiling water, and cook them. He would like cook them for as long as he felt that food should be cooked. Again, no one knew why this would work, so it was all sort of haphazard. But in doing so, he was, you know, creating a vacuum seal. He was introducing enough heat that it would kill off bacteria and, you know, sealing the vessel. so that oxygen wouldn't get in, and that prevents spoiling.

And apparently his father had been an innkeeper and a brewery owner, and Nicholas was probably inspired by methods for preserving wine. So, yeah, initially he was essentially just sort of bottling up food the way you bottle up wine. In fact, apparently when he first started trying this out, he used champagne bottles, which he sealed with just sort of like random mixtures. I saw one source saying cheese and like mineral lime. So I don't know why he thought cheese was a good, I guess, maybe hard cheese. I don't know.

But he moved to wider mouth bottles and using cork and wax. He also eventually upgraded his like boiling pots to auto claims, which used pressure along with steam. So a much more actually safe process. So these days, canning involving sort of like wax seals where you like dip them in wax, it's not considered actually safe because the wax is just so, you know, there are so many points of failure on a wax seal. But for the time, it was great. But apparently Nicholas was not a great businessman.

And also the process was very time consuming and expensive. Plus, glass jars are fragile. And, you know, the sort of point of this was making food that would last a long time as you, like, carried it through various military campaigns. So not actually super practical. So he declared bankruptcy in 1806, which was also the year that he first presented his bottled products at a French exposition. And he received none of the award money. But then in 1810, the Ministry of the Interior finally agreed to give him the 12,000 francs, but only if he would make. the details of his process public, which he did. And then also in 1810, some folks invented and patented

the actual canning process involving metal cans, which was exciting because they were much less likely to break in transit. I will say that apparently the Dutch Navy had independently started tining food in like 1772. They would cook beef or fish and put it in a tin canister while was still hot. They would cover it with hot fat, and they would, like, solder the lid right on. Nice. And apparently, yeah, they use this mostly for the Army, but then apparently there are some records of, like, people elsewhere in Europe buying a bunch of tinned fish.

But for whatever reason, this process did not, like, take off outside the Netherlands, was not really heard of. So it was kind of separate, you know, convergent evolution from the larger history of canning. So these initial cans, it was very slow and labor intensive to make them and to use them. And so canned food was like really not a thing for ordinary people. In fact, during the mid-1800s, canned food became kind of a status symbol among middle class European households because it was just sort of like this very frivolous novelty. And so all through this, people did not actually know how this was working.

Nicholas, that original canon guy, he thought at first it was the presence of air itself that led to spoilage. So a lot of his early experiments were really all about getting that air out. And it was sort of just incidental that he was also sterilizing it and creating this seal. And then he did eventually seem to realize that heat was really important, but it still was like, who knows why? And, you know, it's a great reminder that you can brute force a problem and get really innovative without actually knowing what's going on. It's just history is full of that kind of stuff. The entire field of pharmacology is so true. So true.

It works and then we figure out how. Yeah. It's great when your curiosity journey can lead you to understand how something works and then that solves the problem. But it's true. Very often we got to. reverse engineer it. We just got to try stuff until it works. Speaking of the horses and the venom and all of that.

Yes, exactly. Who tried that first? Somebody looked at a horse and was like, that's a great idea. I think he can handle a bite. So yeah, it wasn't until like half a century after

Nicholas took on Napoleon's Food Challenge that Louis Pester actually demonstrated that my organisms cause food to spoil. Before that, people were like, I don't know, it works. And in the late 19th century, a couple of guys in the U.S., they, like, got scientific about canning, and they were like, okay, this is the temperature you need to get to for sterilizing canned foods.

And that's when canning became, like, actually safe and not just, like, safer than having food that could go bad at any moment. And of course it's gotten steadily safer ever since as we've learned more. Also, fun fact, in 1858, John Landis Mason invented threaded glass jars and lids in my hometown of Vineland, New Jersey, which made the process a lot less error prone for home canners because they didn't have to worry about creating a wax seal and failing to like make a good seal. You know, you could screw the lids on and get the seal going that way. And then the Ball Corporation took off after Mason's patent expired. And from there, especially with like World War I and then even more in World War II,

home canning really took off because it became part of the like patriotic victory garden vibe where people were like, you gotta be able to take care of your own family using your ration cards and your garden. And so obviously you gotta learn how to can. But also, meanwhile, as canning was becoming this, ubiquitous food preservation method, can openers weren't invented until 50 years after cans were invented. And of course, the threaded lid jars are great.

We know how those open. You open the lid. But cans, how did people open cans for that half a century? The answer is that generally it was a hammer and a chisel. Oh, okay. The interesting thing here is that it's not exactly that nobody looked at a can and thought, wouldn't it be great if we had a tool for opening that? It's that the first cans were like these really thick metal containers, they often weighed

more than the food they contained. They were made of wrought iron a lot of the time, and they were lined with tin. They could be really thick, like more than an eighth of an inch thick. And so when we think of a modern can opener, it's not like if somebody, came out of a time machine and presented that, people would be like, oh, my God, this is perfect for opening cans. It wouldn't have done it. So literally manufacturers would say, like, the instructions on early cans were like, cut around the top with a chisel and a hammer. And there are definitely stories about soldiers like using bayonets, just pounding them with rocks, like maybe

shooting them open. Yeah, they were great for preserving food in relative to what else was available at the time, terrible for opening up and eating the food. And then in 1855, this guy Robert Yates, he made cutlery and surgical instruments in England. He patented the first can opener. And it was basically this like straight handle with like a short curved blade and a level bar. And then in 1858, a guy in Connecticut patented the first can opener in the U.S., kind of similar, like long blade, curved handle. Basically, they were designed for you to sort of saw your way into a can and leave a jagged rim around the edge. So they weren't super popular with the public because it's like, ultimately, was it that much better than a hammer and chisel?

not really, but it was maybe slightly more efficient. But they were like pretty dangerous to use. And basically they were really helpful for the army where it was like the choices between this and like smacking it with your bayonet until it opens. And then also apparently in grocery stores because clerks would learn how to use them and then they would open cans for customers to take home.

So it was like the point of the can was preserving the food until it got to the store, and then you would have it opened up for you and have to eat it pretty quickly, probably. Then in 1866, there started to be these twist key styles, which you can still see sometimes in like fancy tin fish circles where basically this attached twisting key that helps you pull back the lid of the can. And all of this was happening both the blades for sawing through the cans and the twist keys. They were only possible because cans were getting progressively thinner. So it was possible to do it with more of a knife or a twisting motion than with. So it was possible to do it with like a knife or a twisting motion as opposed to just like literally like hacking it open. Yeah. But still like the twistkey thing, it had to be like designed for the specific can.

And so either it came attached to the can or you would have to have multiple twistkeys for your different kinds of cans. Like you might have one for like your bean cans and one for like your meat cans. And the first rotating wheel can opener, as we know it, didn't show up until 1870. And you had to pierce the can first for it to work. So people were not super into it. Because again, it was like whatever, I'll just saw into the can. Like what's the difference? But by the 1900s, people had figured out can openers more like our modern designs and

they got better and better. But that was really the turning point where people were like, oh, we can have a device that makes these cans easy to open. But I just love that, you know, today cans are so ubiquitous and they're so relatively uniform. And like obviously in different countries or for different products, you'll have slight variations on like what a can feels like and looks like. But they're always pretty thin metal. There's always some kind of lip on top. You know, they're all made to be very easy to open with a can opener of some kind.

And the idea that they used to just be these like giant hunks of wrought iron with like margin, like marginally preserved meat inside them is. Really? But it was a huge, huge ingenuity, even when nobody knew why it worked. And so, yeah, I have, we have a couple of can openers at my house because I have an OXO can opener that I think is great. It's like one of those safety ones where it like takes the whole lid off. And my husband finds it like completely perplexing to use. He like can't get, he can't get it to work the way it's supposed to. So we had to go back and get.

a more standard one. And I'm like, wow, we're so spoiled for choice. So we imagine we could just be here with a hammer and chisel. You don't have an electric ones? No, no. I remember they were, I'm a child of the early 90s. And I remember that they were like a very, you know, a very chic thing to have, especially if you had one that was like attached to the cabinet and like hung under the cabinet.

It was great because they worked like almost half the time. Yeah, so true. We love that 50% success rate. Listen, it's better than a bayonet. You know, I bet a bayonet worked 100% of the time. It was just a question of effort. And whether or not the food was in any way edible after that. Yeah.

I feel like every regiment had to have like one guy who was really good at opening cans. It was like the canned guy. And people would be like, you got to bring your cans to Henri. Yes. Did you, this reminds me of, did you read Deborah Blum's book, The Poison Squad? Yes, yeah. About Harvey Wiley. Yeah, the food, the food situation in this country, in the world, was so dire.

Yeah, no. It's amazing that our species, that our species survives the 19th century, honestly. Because they would, you know, when milk started to go bad, they would just pour. formaldehyde in it. That's it. I swirl it around and sell it to people and they're like, oh, this tastes a little funny. A little spicy. Unbelievable. I mean, that's just one example.

I mean, the food safety situation in this country was so bad before Harvey Wiley. And he had a hard time convincing people that, or the government anyway, that they should regulate some of this because people were just doing whatever. They were putting sawdust in the sausages and whatever they swept up off the floor. you know, all ended up with their food. So, yeah, no, food safety is a fascinating topic. All these candy stories you were telling me was reminding me of Deborah Blum's book. Because if you haven't read The Poison Squad, if you're interested in food safety, you have to read it.

It's so good. It's compelling. Even though it's kind of a biography, but it's really, it's a very compelling lead. Yeah, no, it's a great book. And yeah, I feel like that was, I was thinking of that every time I was like, it's so wild that they just did this. and didn't know why it worked. And I'm like, but when you think of how fast and loose they were with food safety, it's like they probably would have kept doing it even if it wasn't working.

Yeah. Good times. We're going to take one more break and then we'll be back with one more fact. Okay, we're back. And Nathan, why don't you tell us what's going on with birds? Well, it turns out, females, female birds are often loud in bed. They call these copulatory calls. So there's mating calls.

There's mating calls, which everyone kind of know what that is. That's trying to get attention, trying to attract attention from a potential sex partner. But copulatory calls are a little different because birds make it while they're having sex, like during the act of having sex. And of course, when you study this in primates, for example, it has a lot to do with trying to basically enhance the sexual experience. But in MERS, it's really fascinating because when scientists were first studying it, they were very steeped in this kind of Victorian ideals about sex. And it really warped the way that, you know, science is one of these fields where people both inside and outside of it think that they are free of bias or free of subjectivity. And they're just describing the natural world in these purely objective terms and there's no place for prejudice or values and that stuff. Of course, that's horrifically wrong.

That's the mythology about science and its objectivity. And copulatory calls are a good example of how they were totally misunderstood because, and Lucy Cook's recent book, which the title is a profanity, so I don't know what your policy is on this show. But as you know, a female dog is called a bitch, right? That's a regular English non-profane word. That's the title of her book is bitch on the female of the species. And as she writes very compellingly, female behavior was just ignored by biologists for generations, really from the beginning of the field, everybody concentrated on male behavior. And females were just kind of hapless, passive. Maybe they were involved in mate selection, but even that was secondary to the real action, which was male-male competition, right?

And so copulatory calls by birds were just seen as for what their effect was on males. and if it was to basically entice male-male-male competition, that kind of thing. Well, this has been studied for decades and decades by scientists. First of all, more females have entered the more women, excuse me, have entered the ranks of animal behavior and accordingly taken female behavior among animals more seriously. And of course, like many other things I write about in my book, the behavior gets more and more and more interesting when you study it that way, when you open your eyes to various possibilities and arrangements, including arrangements regarding diversity.

So I want to tell you about the Dunnock. The Dunnick is a bird, which has always been seen as something of a black sheep among ornithologists because the females are polyandrous. So you have females with males that compete over them, and the female will have sex with lots of males. And this, of course, was scandalous to the scientists who were first describing it. And in fact, it really, as a behavior, polyandry wasn't really taken seriously in this species or in the other until DNA testing was invented in the 1980s. So prior to the 1980s, most people thought of birds as sort of the Victorian ideals of marriage, which is they mate for life. They're sexually exclusive. They basically saw them as mirrors for human marriage, or at least the ideal of human marriage.

Because as we know, human marriage has never been marked by fidelity. Yeah, I was like instead they were more like what Victorians were actually like sexually. Exactly. Exactly. Yeah. If they had used, they could get the right answer with the wrong formula sometimes, you know. But anyway, so when scientists started studying this more seriously because, basically because they had no choice, when DNA testing was first invented, or I should say applied to birds around 1987, you know, in species after species after species, ornithologists came back and were like, okay, so this net. has a lot of fathers. This female clearly made it with a lot of different males because even in the same clutch of eggs, you'll have multiple fathers. You'll actually also have multiple mothers, but that's a topic for another day.

Let's put a pin in that. But anyway, so as the scientists studied the Dunach more carefully, this polyandrous, scandalous kind of species, they noticed that one of the things that made it very different than other birds was this copulatory call. It's not, copulatory calls are not common in birds. But in this species and some others, the females will engage in this. And so they thought, well, that's what it is then. They're enticing male-male competition.

So they're calling when they have sex with the idea that it would arouse the attention of other males and get them sort of in on the action. And these males were all, these females were all mating with lots of males. Turns out the males are also mating with lots of females. So to call this species polyandria, is interesting because we think of the females as sort of the recipient of sexual attention, not the other way around. So it's got even when we kind of appreciate some female diversity in their behavior,

we still think of it in terms of what it does to the males, right? And this is why I do recommend Lucy book, Lucy Cook's book, Lucy's cookbook, Lucy Cook's book, because it does talk about how biased our understanding of animal behavior is because of the male gaze, right? We're always interpreting it in terms of what it does to males. Anyway, so why do these dunnics, why are they loud in bed then if it's not to entice male-male competition? Well, first of all, it probably does do that. I think we can accept that. But the other thing that's interesting is that there's a difference between when a dunak, a female dunnick calls out loud in bed with their primary partner, and they do have primary kind of mated partners and secondary partners or additional.

our side pieces, right? And of course, it was always thought that, okay, well, of course males will try to spread their seed, you know, extra pair copulations. When they were first discovered, you know, the male, the male perspective was sort of obvious to the scientist. Well, of course, it takes almost no investment from him to try to bother offspring all around. But the females, what do they get out of having sex with lots of men?

Because that doesn't make them have more offspring, right? They can only lay so many eggs, whether it's one male or 12 males, their number of offspring isn't any better. And this is going to bring us to the point. And they should want to have as many opportunities as possible with the best male they can find, the best male they can find. And that's the bias. That's the prejudice that is now coming down. There is no such thing as the best male, or a single way to be successful as a done or anything else. variety is important because from year to year, environments change.

And so your best genetic investment is to throw in with lots of different males, right? Of course, quality matters and quality control competitions are always going to be in there. But female dunnics, like every other female in the animal world, does benefit from having a diversified clutch by having offspring with lots of different males, with different strengths and weaknesses. So let's get back to the calls now. So why does she do this? What does she care about the other males what they do? Because a lot of birds don't, right? They tolerate each other's sexual behaviors with other individuals.

It really doesn't bother them. But the ones that elicit copulatory calls, it seems to be in these dunnics, that they will do it with secondary tertiary, you know, beta males, as the incells would call them, much more than they do with their alpha males. And that doesn't fit the model. of well we're just trying to induce male competition and blah blah why would they do it with their other partners their less desirable rank partners than their main one it turns how it seems because the the dunnick the male dunnics when they're going around to various nests they will actually if they have

sex if they have a copulation with with their other side pieces because they all have side pieces that's the thing it's not polyandria yeah it's it's a mixed mating strategy with you know um But there is pair bonding, so that's the thing. So it's not purely promiscuous, as we might say with like chimpanzees, for example. There are parabonds. So it's a mixed-making strategy, you can call it. But these morals, when they go to their side pieces, and if they are granted sexual acts, they copulate with them, they will often go back and feed them.

It is the food provisioning that seems to be the key aspect of the behavior from the female's point of view because she doesn't care if her main partner is out there spreading his seed but she does care if he's feeding those females this is iconic behavior right it's like have as many girlfriends as you want but do not give them my snacks that's right like don't mess with my money yeah right yeah i get that the phrase that comes to mind for me as remember that when you're throwing your genetic future in with someone. It doesn't matter if they're also into somebody else, but it does matter if the resources are then being driven away from you. And that's what she's trying to prevent. So the reason why she has copulatory calls loud, loud in bed, with her side

pieces is because her main partner gets his ass back to the nest and chases out the other males and immediately copulates with her. Yeah. So the copulation calls. Okay. It hits her going. It's her I'm getting such great snacks, all the snacks I need. Yep, exactly. Exactly. So she's like, I'm over. Look what's happening. Look what I'm doing.

So he comes back, chases the other male out, and then he copulates it with her. We assume to try to replace the sperm with his own. And because she doesn't care where he puts his dick, they don't have dicks. But she doesn't care where he mates, but she does care who he beats because that's a direct competition now to her and her genetic. future. So this behavior, like I said, it only really comes into focus when we when we consider females and males as equally interested in both sexual diversity, gender diversity and also genetic diversity. If we consider them agents that will act in their own interest and all this stuff, if you think of females as just passive recipients of male sexual attempts, then you would

never have appreciated all of these interesting things. And so I love this story because it emphasizes a bunch of themes that have been overlooked in biology. One is diversity itself, sexual diversity and strategies and different kinds of males and females and the animal understanding of that. But also that it's an empowered female sexual behavior that males have to react to. So this is not just, this this puts that Darwinian view on its head to say that, you know, they're all agents capable of evolutionary reasoning, if you will, and that they'll, you know, seek out their interest in the way that makes sense. And it's mixed mating strategy.

And so I love the story that Dunnick. It's one of the stories I talk about in the book on monogamy, if you will, because monogamy is one of these concepts that, of course, very fraught right now. But it's also very misunderstood in the way that animals approach it. Because monogamy by the people who study it is about pair bonding, right? It's not really about sex, exactly. It's about the attachment that two individuals have for each other that's mutual and strong and it's a relationship that's kind of above all others and usually focused around

children and homesteading and whatever. But it has really doesn't involve sexual exclusivity. It just doesn't. It's just not part of the sexual attachment bond that other animals have with a few exceptions. And there are a few. And those are interesting too. But we always kind of thought that sexual fidelity goes along with attachment and pair bonding or it should. And these copulation calls were designed to prevent extra pair copulation, you know, cheating, if you will. But it's not really that. It's part of their sort of collective mixed mating strategy. And the species overall, what it creates is this kind of resilient, robust, diverse. You know, it's interesting. You know, you could watch these birds for weeks and months.

You see all kinds of, you know, competition. Female, female, female, male. And then, of course, there's the battle of the sex as always. because none of these relationships are without conflict. So I think that, to bring this to a summary here, I think that studying animal behavior on their own terms, without projecting human biases, reveals these interesting things,

that then you can bring back to the human, to understanding humans. You see what I mean? Like, it's not anthropomorphism. It's reverse anthropomorphism, in a sense. It's by allowing animals to just do what they do, be who they are, and then what you observe is often, and parallel to how humans actually are, rather than these ideals that early animal behaviorists

were really trying to reinforce. I mean, I don't think these people are consciously, you know, hiding data. You know, that's how bias works. It's almost always implicit. It just kind of comes out in the choices you make and how you describe things, how you categorize things, what counts as a mating behavior, and that kind of thing. So anyway, that's my fact for the days. Some birds are loud in bed and the reasons why are fascinating.

Yeah. No, I love that so much because it is ultimately like a pretty straightforward and easy to understand evolutionary motivator, the resource allocation. And it's just that it's only when you try to frame it in this very particular way that you, that it seems like weird and that you would miss that. Right, right. So that's why, you know, biologists, you know, I'm often quoting Franz de Vall on this. you have to understand animals on their own terms. And removing, you know, the human perspective, the human bias on your observations is difficult because the only eyes we have are our own, right? So it is hard. But once you do that, you reveal all kinds of really interesting things about animal behavior. And that's kind of what I'm urging in the book. And in fact, some people have said my book is as much about scientists as it is about science because how we know what we know about the natural world,

you know, is always filtered through that, that human lens and that human filter, if you will, on truth and knowledge. So I think we're in a much better place that we were, you know, 50 years ago, even 25 years ago. But it's important also to recognize that the scientists who were first doing this, like Joan Roughgarden is the one I'm usually referring to, you know, their work was not well received. You know, bias doesn't fall easily. You know, it goes down kicking and screaming. And so scientists who are working against the grain on some of these things have to work so much harder to get their ideas, you know, accepted or even really taken seriously. Yeah. Well, wonderful story. Would you remind listeners what your book is called so that they can read many more fascinating animal behavior stories from you? Sure. My book is called The Sexual Evolution. And my name is Nathan Lentz. But we chose that title because it's obviously a play on the sexual revolution. And I will be honest and up front, and I say this in the introduction, part of what motivated me to write this, besides just what I was learning with my students teaching sex and gender, part of what motivated me was the diversity in the human experience of sex and gender is often, you know, described as as quirky human, aberrant weirdness, even by allies sometimes. They don't really think it's biological. You know, this debate about gender diversity is often framed as you have.

have, you know, hard science on one side and activism on the other, you know, data and evidence against, you know, thoughts and feelings on the other side. And that's just not right. You know, if you, for those who have a really binary, heteronormative, patriarchal view of animal behavior, I'm sorry, the science is not on your side. It was for a century or two, but the new generation of biologists are looking much more deeply into animal behaviors with a much more open mind regarding sex and gender. And wow, the fascinating things are rolling in. I think my book will become obsolete. I'm hoping within five or ten years because there's so much work being done on this. Hell yeah. That's awesome. Well, thanks so much for coming on. This has been great.

My pleasure. You guys are a lot of fun. The weirdest thing I learned this week is produced by all of our hosts, including me, Rachel Fultman, along with Jess Bodey, who also serves as our audio engineer and editor extraordinaire. Our theme music by Billy Cadden. Our logo is by Katie Belloff. If you have questions, suggestions, or weird stories to share, tweet us at Weirdest underscore Thing. Thanks for listening, Weirdos.