Dog Ears to Deep Sea Shrimp: Listener Q's!

let's get right into it. First off, I have a couple of really good questions from Eva H, so I'm going to answer both of them, all right. In multiple episodes, you talked about how when we domesticated dogs, their ears got floppy and coats got spotted because of the genetic link. But when these traits and a more calm demeanor. When I shared that fun fact at the dinner table, my father immediately shot me down, saying, what about German shepherds

and other similar breeds that have upright ears? I couldn't answer the question or find a good answer on Google. Could you help me out and finding the answer? Thank you so much. In advance, Eva H from Slovenia, So great question, Eva Um also, I will always back you up in a fight against your dad. So the answer, well, the short answer is we can selectively breed back traits that were lost in dogs, such as stronger ear cartilage or even aggression. So German shepherds and other breeds can

have ears that stick up um. But here's the longer answer. So floppy ears and spotted coats aren't necessarily intrinsically tied to calm behavior, but they are linked to neural crest cells, namely the amount of neural crest cells. So neural crest cells are a group of cells that arise early in embryonic development and these will generate a number of different cell types. So in terms of the domestication of dogs and other animals, the domestication process has actually resulted in

less proliferation of the neural crest cells. And because these cells mediate a wide range of characteristics, the theory is that by reducing the proliferation of neural crust cells, all

sorts of traits are affected. It lowers things like hormone levels that mediate aggression and causes the animal to be less aggressive, but also coincidentally, the lowered proliferation of these neural crest cells also affects the development of the animals cartilage production and melanine distribution, which can result in floppy ears spotted coats. So this is called domestication syndrome. Now, you can selectively breed back in the stronger ear cartilage,

you can breed back in different kinds of coats. But the question is, by breeding back the upright ears, are you also breeding back more aggression in the dog? And if not, how is it possible to separate the ear cartilage strength from the aggression? And you know, disappointingly, I actually don't know, and I haven't found a lot of good research about it. Um. I suspect that if we find an answer to those questions, will have a much

better understanding of how domestication syndrome works. I would suspect that things like ear cartilage and aggression are not inevitably linked. So I think you could probably breed back stronger ear cartilage without causing a dog to be um, you know,

just sort of innately aggressive. Because I mean that's rather evident because we do have dogs that we've bred uh to have that stiffer ear cartilage, like huskies and German shepherds and while German shepherds may be known for being easily trained to be more aggressive, Um, I think that it is clear that they are not wolf like, so

they are not as nearly as aggressive as wolves. You know, I don't even know too much about research on whether German shepherds without training are like inherently aggressive or anything like that. So I think that you can basically fiddle around with the dogs such that you're able to uh, kind of bring back some of the genes that would code for stiffer ear cartilage. But at the same time, it isn't completely undoing all those MANI any years of

selecting for lower digression. Now, how does this work in terms of the neural crest cells. Whether it means there's a few more neural crest cells, but uh, that doesn't mean the dog goes back to being as aggressive as a wolf. I really don't know, and I was unable to find research about it. So I think that is a super interesting question, and I'm really hopeful that I'll be able to find some new research in the future, and I'll share it with you guys if I ever do.

And here's the second question from Eva. H. Hello, it's me again. After some more binge. Listening to your wonderful podcast, I have gotten an idea. I'm from Slovenia and one of our symbols kind of is the Clovesca rubica, which the literal translation is human fish. The Latin name is Proteus anguinus. Despite it being very famous for being only found in our region, I know surprisingly little fun facts

about them, and I would love to change that. They're also endangered, so I want to raise awareness for their conservation. I find them beautiful and maybe some of your listeners might also take an interest in them. Maybe you could do an episode about all the weird humanoid animals or something like that. Thank you so much in advance. So Eva, thank you so much for your questions. I agree that

the Proteus anguinus deserves more love. It's also known as the ulm, and it's a cave dwelling salamander that is pink, long and basically eyeless. I have actually talked about these guys in detail in the episode called Yum Troglobites, which aired on February three, But here's a little bit of info on them right now, including some things I didn't cover last time I spoke about them. So they're called human fish because of that fleshy, pink coloration that is

similar to some human skin. They're not fish, but they are aquatic. They're actually similar to axilotels and that they are a permanent what a juvenile form of a salamander. So this is called neontony when an animal retains the traits of a juvenile for its entire life. By the way,

we were just talking about the domestication of dogs. Dogs can actually be considered to be examples of neontany, as they retain the puppy like traits of their wolf ancestors, like playfulness, floppy ears, large foreheads, shorter muzzles, smaller size, and so on. So back to the human fish a k A ohm uh. They can grow to be quite long, about a foot or thirty centimeters long. They have these tiny cute legs on their front and their back, and

to me they look like little water dragons. They kind of just swim like we imagine a serpentine dragon might fly undulating around. So even though their eyes are basically useless, they have extremely sensitive taste, smell, and hearing, allowing them to locate praise such as insect shrimps, and snails. Even though they can't really see distinctly with their sunken eyes, both their eyes and their skin is photosensitive, so they can quote unquote see light with their skin, which is

really ridiculously amazing. In addition to all these strange things, their lives are very weird and mystical. They can live to be over sixty years old, with some studies estimating that they could live to be up to a hundred years old. They only breed every twelve years, and males seduce females by exerting an attractive pheromony uh then circling the female while fanning her with his tail, which sounds very alluring. Incredibly, they can survive for years without feeding

by slowing down they're already pretty slow metabolism. That slow metabolic rate may also be the key to their longevity, outliving all of the world's known amphibians. They're also kind of introverts and home bodies. They don't like to move around much. One home that was tracked by researchers stayed in the exact same spot for seven years without moving.

Because they lack natural predators, they can afford to be very chill and just kind of hang out, and I guess you kind of have to take it slow when you live in a cave where food and change is very scarce. But yeah, I love the idea of talking about animals with human traits. Maybe I will do a whole episode on it. In the meantime. Here's a quick sample. There's the Kintacanthus incarnatus, otherwise known as the man faced

stink bug. It's an orange, red, or yellow or cream colored stink bug found in India and Southeas East Asia, with black markings that can look like a face or a decorative mask. It's possible that the mask are eye spots, a form of defense, tricking predators into thinking there's a

large pair of eyes looking at them. In the stink bugs case, if that doesn't work, they've got something hidden up their sleeve, or at least stink glance hidden under their abdomen that they can deploy as a defensive measure chemical warfare against anything that would want to eat it, or anyone that pokes at it and is unlucky enough to learn that. Hey, stink bugs are named that way for a reason. So I'm gonna take just a real quick break and then when I get back, I'm going

to answer another listener question. So I am back, and here is another listener question. Thank Katie. I'm in a mammalogy class this semester and it made me want to find an episode. I don't think I completely hallucinated. I seem to recall you talking about mammals that coexisted with dinosaurs for an episode, and you even had a book recommendation to go with it. Maybe it wasn't a whole episode, And if you hadn't done this, then I'd love to

hear you talk about mammals that coexisted with dinosaurs. Thanks Hannah. Hi Hannah. So yes, I have to be honest with you. I'm not sure I remember if I did an episode about mammals that coexisted with dinosaurs. But if I didn't yet, which I don't think I have, that is a great idea. The two dinosaur focused episodes that I remember are Jurassic Paul Blart from January and Go Home, Nature You're Drunk

from July, which must be a pretty old episode. I don't remember how good I was back then, probably a little bit rough, but hey, you know what, we all start somewhere. So in that episode, the one from nineteen. I checked my notes and I did make a book recommendation. I recommended All Yesterday's Unique and Speculative Views of Dinosaurs and Other Prehistoric Animals, which is by John Conway see Him Closeman and Darren Nish and illustrated by Scott Hartman,

and it is a lovely book. It shows pictures of how contemporary animals might be depicted if we only had their fossil records and tried to guess what they looked like. Uh. It's like it's this thing that we actually call shrink rapping, where when you depict a dinosaur, you're basing it off of fossil records. And while fossil records can preserve quite a bit of things such as bones, even sometimes tissues or imprints, it doesn't contain the totality of the information

about the animal. And so, especially back before we had ways to detect less visible things in these fossil records, things like you know, we found uh prints of like mites and things that would be found in feathers and so on. Uh, we had this view of dinosaurs as being you know, mostly brown or green, kind of like

you know, reptiles. I suppose although there are a lot of very colorful reptiles um, but we also viewed them as being quite lean, so very muscular, but kind of skeletal, so that that lean look where you are sort of guessing that they have the least amount of muscle mass are not covered by anything like feathers or ornamentation, is called shrink wrapping because of what shrink wrapping is, so we have probably done this to dinosaurs, where we uh

kind of underestimate how much stuff they have, either fat or ornamentation or feathers, and so in this book they illustrate what this is like by using contemporary animals that we know what they look like, and then treating giving them the sharing grapping treatment, imagining if they were a paleo artist with only the fossil records of say like a swan to work from, and then they draw this swan that's this featherless, gaunt, kind of frightening monster whose

wing tips are these like spears that they used to impale fish, or a baboon which looks absolutely demonic when you remove its fur and a lot of its flesh. So it's meant to show how we may have been

making similar errors when depicting dinosaurs. Um. It also offers speculative depictions of dinosaurs as being more colorful and ornamented than we typically imagine them with feathers, and also maybe showing behaviors we wouldn't think that dinosaurs have, like maybe small dinosaurs going up in a tree and climbing it and trying to eat the leaves there. So yes, uh,

this I think is a really good book. Um. And yeah, So mammals did coexist with dinosaurs, and while many of them died out due to the same asteroid disaster that resulted in this you know, massive heat wave masses climate disaster that killed off so much vegetation and then famine. Um this uh yeah, this killed the dinosaurs except for birds, who are dinosaurs and still alive. Uh. And it also killed off a lot of mammals. But because many mammals were small and able to survive the heat wave by

being in their little burrows. Uh. And then when they emerged, they were able to adapt to that shortage of food more easily given their size. The same adaptability is found in things like you know, birds who were ancestors of the smaller feathery dinosaurs that survived. Also like all of the reptiles, amphibians, uh, fish, these other animals that all survived the asteroid impact. You know, they were tended to be smaller, um, tended to be more adaptable to and

in terms of finding new food sources, finding shelter. So then we ended up with, of course, this diversification of this small number of mammals that survived the asteroid UH. And they were able to become bigger and more dominant given the absence of the dinosaurs. But during the reign of the dinosaurs, mammals were somewhat relegated to the margins of the I was gonna say society, dino society. I don't really know if you can call it a society.

But they were small, nocturnal and had to constantly be on edge during the presence of fierce dinosaur predators. Mammals did not evolve from dinosaurs, but diverged from a common ancestor in a clade known as synapsid. So mammals evolved from a mammal like reptile about a hundred e d two two hundred million years ago. Uh. The largest mammals that co existed with the dinosaurs were about the size of a badger, and the smallest were like these tiny

wool like creatures, and I yes, it is fascinating. I think I will do a full episode on the mammals that coexisted with the dinosaurs, and then the consequences of the asteroid impact and then the diversification of mammals after that. I think that's a great suggestion. So thanks so much for the idea, Hannah Um. But now I'm going to take a quick break and then we'll come back and do the final listener question. All right, we are back, and it's just one more listener question to you answer.

So have you done a podcast about undersea event creatures? I don't suppose they would taste very good, but who knows what a genius Italian chef could come up with. I have a slightly more serious question. Articles about these events tell out shrimps, lobsters, and other living things around the vents. I would like some clarification about that. Are these creatures who aren't related to shrimps who only look like shrimps? I thought only micro organisms used chemosynthesis? Do

the creatures living around these events use chemosynthesis? Thanks sincerely, Stephen. So this is a great question, Steven, So, I did do an episode on the undersea vent shrimp. It's called the Shrimp Episode and it aired March thirty one. It was all about shrimps, not just the deep sea variety of shrimps, but a bunch of different shrimps. Um. But yes, now, onto what is going on with those deep sea events? How can life survive down there? Are they shrimp? Are

they giant bacteria? So to answer your question, yes, shrimp. These things that you have heard of are indeed shrimp, and they don't use chemosynthesis, but they do feed on

the micro organisms who do use chemosynthesis. So, one you have microbes who can survive near these deep see events, you open up things for animals that are bigger and then slightly bigger than that, and so like there's a whole food chain based on these small microbes who are able to utilize the chemistry of the hydrothermal vents that

animals cannot really use. So here's how it works. There are these chimneys at the bottom of the sea, called the hydrothermal vents that spew hot, hot, hot hot water filled with a variety of chemical compounds such as hydrogen, hydrogen, sulfide, ammonia, and other things that we can't really eat and life cannot really survive in the hottest part of the vent, But radiating out from the hottest part are zones that

are inhabitable by different living organisms. Microbes, including both archaa and bacteria, can survive in very high temperatures and can convert the inorganic compounds being spewed out by the vent into energy. This process is called chemosynthesis, and it involves the conversion of inorganic matter into organic matter. The microbes capable of chemosynthesis are the foundation of the chain of

life near these hydrothermal vents. So next you have the animals that eat the microbes themselves or the byproducts the microbes produce. Deep sea limpets, which are a type of aquatic snail, feed on the microbial mats like these thick carpets of microbes giant tube worms. Meanwhile, these things that look like organic pipe organs almost feed on the byproducts of the microbes. They allow bacteria to live inside them

and then they feed on the bacteria's byproducts. So this is a symbiotic relationship between the two worm and the bacteria, and the bacteria gets a nice place to live. Whereas the two warm gets food produced by the bacteria, and the tube warm actually has no other way of eating. It does not have a gut. It just feeds on the byproduct of the bacteria entirely, so onto the shrimp in the room. Yes, shrimp do live near these hydrothermal vents.

In particular, there is a really interesting case. The Biba hydrothermal vent, which is the deepest hydrothermal vents in the world, are found in the Caribbean near the Cayman Islands and are a host to the species of pale white eyeless shrimp called Rima carris hibisa. These shrimp can either eat bacteria or become carnivores and eat those tiny snails, crustaceans,

or even each other. Areas where the shrimp populations are dense are typically areas where these shrimp eat bacteria, and in the areas where the shrimp population is more sparse, they actually typically hunt. So let's think about this for

a minute. Does this mean that when the shrimp are in these dense clusters, they're more likely to eat bacteria because they're in these clusters um and then when they are more sparse they're more likely to hunt for some reason because they are in more sparsely populated areas well, that's not clear, so this is not necessarily causal. Perhaps the reason that they mostly eat bacteria rather than hunt in the areas where they're dense is simply because there's

more bacteria there, so they don't have to hunt. So they're like in a bacteria hotspot and they can afford to just eat the bacteria and they don't have to worry about hunting. But maybe in areas where bacteria is less abundant they have to resort to hunting and cannibalism.

I don't know what this is true. This is a relatively newly discovered species of shrimps, so uh, you know, it's just an interesting example of like you have to when you see some kind of connection between like um a behavior and the environment, you have to figure out, like which way is the causality going in terms of these like chains where you have like this sort of this species that establishes itself in this place that doesn't seem like anything could live there, and then from that

from that organism, like the bacteria that lives near the hydrothermal events all sorts of other life that can even get bigger and bigger can live there. Uh. You don't actually have to travel to the bottom of the ocean to see examples of this kind of chain um of animals being able to colonize a space. You can go to the woods. You could even go somewhere in your city if there's anywhere that has like some old brick or old stone structures, because you can observe plant succession.

So a big rock or just like a stone wall is not a great place for something like a plant or a flower to live in. But lichens are hardier and they can actually establish themselves. All they really need is sun and water, and not that much water, even just a little bit. Lichens, by the way, are really incredible and super deeper weird. They're not plants. They're not even one species, but a mutualistic relationship between fungi and

algae or sometimes cyanobacteria. It's a composite organism made up of combined species, which is totally wild. I probably need to talk about them more, but first I have to learn more about them, because they confuse me. Anyways, Once the lichen has established itself, it actually breaks down the rock with acids, which makes the rock easier for moss to establish roots. So then moss can move in and

mosque is a non vascular plant. If the moss is successful, the decom the decomposition of the moss actually allows vascular plants to take roots because now they are is nutrients for the vascular plants. Vascular plants are plants that transfer water and nutrients through their conducting tissues. And that includes most of the plants that you know as plants like trees, flowers, et cetera. So you have a bare rock, you have

to start with lichen. If that's successful, then you can get moss, and then if that's successful, you can get more vascular plants. Uh. And so this can be the cycle of an area becoming full of vegetation and it's really fascinating. So that's it for the questions. UM. I know that I said I would answer the mystery animal sound this week, but I do want to save it for when I have a guest on, so I will answer it next week. Um and in case you want to hear it again to try to guess before next week.

Here's the sound and the hint. They sound like drunks on land and alien spaceships in the sea, but they're always chill. M hm m m m h m hm. Yeah. Alrighty, that'll do it for us today. Um, if you're aching for more Katie content, I just actually recorded an episode with Alex Schmidt the Secretly Incredibly Fascinating podcast on Eels, which is a lot of fun. I love Eels, so check that out. And uh, hey, you know what, thank you so much for listening. I really enjoy doing these

listener questions episodes. It gives me a chance to feel like I'm kind of directly talking to you, and I really love your questions, you guys. I'm thinking about doing another one of these pretty soon actually, so please please please, if you have questions, send them to me at Creature feature pot at gmail dot com and I always try to answer them either on the show or I will try to email you back. So yes, send me your questions,

even it's silly. I like silly questions too. And thanks so much to the Space Classics for their super awesome song Exo Lumina. Creature features a production of I Heart Radio. For more podcasts like the one you just heard, visit the I Heart radio app Apple podcasts or hey, guess what. However, you listen to your favorite shows just you and me, like you don't have to. You don't have to, like pretend that you do any of you know, any specific podcast provider, Like I won't tell on you. I'm not.

I'm not gonna tattle on you. See you next Wednesday,