Listener Q's: A Giant Voltron of Babies

So let's take a moment to dive into a think hoole and answer some questions. Hi, Katie, I was recently re listening to the lemon and grapefruit episodes of Secretly Incredibly Fascinating, and in those episodes, Alex springs up that citrus can cross breed and mutate easily with each other. I would like to know if there are any other genuses of organisms that can cross breed and mutate as well or better than citrus. Also, are there any specific

genes or structures in organisms that facilitate mutations? Overall? I was thinking and wondering if an organism's ability to more easily mutate would be an evolutionary advantage. Thank you for the great podcast, Daniel. Thank you so much, Daniel. This is really a fantastic question. Also, thanks for the secretly incredibly fascinating shout out. That is a show that I do with Alex Schmidt where he teaches me about wild stuff every week. So let's tackle this question one part

at a time. So can animals cross breed and facilitate evolution? So can there be a hybrid animal that progresses evolution? Yes, this can happen as long as the animals are closely related. So this is called hybrid speciation when you have two different species who create a hybrid, and then that hybrid goes on to propagate and create its own species. So in plants it is far more common than in animals, likely because hybridization is less likely to make them infertile.

You also have more rapid reproductive cycles in a lot of plants. In animals, the reason hybridization often causes the offspring to be sterile is when the number of chromosomes

don't line up. Say one animal has twenty chromosomes and the other has twenty one, and then when you add those together, the hybrid is going to have an uneven number of chromosomes, say forty one, and when it tries to split that in half and create its own gameats, this odd number of chromosomes means that it doesn't have pairs that can recombine properly, like not missing the other half of a zipper, so that when it goes through myosis in the creation of its gam meats, it can't

create viable gameats even though it was able to be created by its parents. Sometimes hybrids can be created have an even number of chromosomes because the two species ended up having matching sets of chromosomes the matching numbers, and then they can reproduce and then so this hybrid, which is viable and not sterile, could become a new species. Doesn't always, so this is the case for Koi wolves.

So coyotes hybridized with red wolves, who are becoming very quickly more common in eastern North America, potentially displacing red wolves, and so this could be a case of hybrid speciation. But in order to become a new species, the hybrid has a pretty difficult task. It has to both be fertile and more fit in order to become its own viable species, particularly one that takes over the evolutionary niche

left thereby its predecessors. So, in terms of what kinds of animals are really good at creating hybrid speciation, insects seem to be the best at it in terms of creating new hybrid species that then becomes their own species. So this is probably due to just the sheer quantity and diversity of insects, making viable and successful combinations much more likely. So one example is fruitflies. Fruitflies are a

family that seems to hybridize and specie pretty well. So onto the next part of your question, So are there specific genes or structures in organisms that facilitate mutations? And would an organism's ability to more easily mutate be an evolutionary advantage? So let's talk about the second part of the question. First, is more easily mutating a good thing for a species because it makes you more likely to

evolve faster. So mutation is a bit like genetic gambling or maybe an investment portfolio, where there's, you know, the bigger the risk, perhaps the bigger the reward, but also the bigger the downfall that you might have. So most mutations that occur are actually either neutral or actively harmful to an animal. Only rarely is a mutation actually beneficial. So the more dramatic the mutation, say a mutation that makes you just not have a head right, the more

dramatic the problem. So if you're if you have a mutation, like there's a very low chance that it's going to be helpful, there's some chance that it's going to be neutral, and it could get passed on, and then there's a pretty good chance that that mutation is actually going to negatively impact your survival. So it's very very rare that like a dramatic mutation would be beneficial and then lead to a sudden jump in evolution. It can happen, but

it's very very rare. So if you're an animal, do you want there to be a higher chance of genetic errors? And I would say probably not. So, in addition to many mutations being harmful to offspring, greater risks for genetic errors would potentially increase the risk of cancer because cancer is a result of genetic mishaps genetic errors that causes the cells to reproduce uncontrollably and not go through cell death, which is called apoptosis, So having a genetic error that

creates these like bad immortal cells is not good. And so yeah, it would not necessarily be advantageous to have a greater rate of mutations in order to facilitate evolution. You want some chance of mutation without it being too much of a risk, like having a you know, kind of diversified investment portfolio instead of something that's very very you know, wild and chaotic and volatile. I don't actually

know much about investment. I can't give you advice, probably both legally and also just I'm not good at it, so don't listen to me. So there are some ways to increase your chance of positive genetic mutations. One is a greater genetic library. So the more genes and the more diverse genes that a species has had, the more it has to kind of randomly pull upon in response to environmental pressures, and more stuff to kind of play with, like more legos in a giant bin that could be

used to create new mutations or new characteristics. So like kind of think of your genetic code as an archive full of like blueprints, only some of which are actually used and copied over to build things. Actually a lot of it is not generally used. But say like there's like an earthquake or something and a blueprint falls next to another blueprint and changes the design. The more blueprints you have, the more chances you have to find something

that might actually address a certain issue. Like, say an earthquake happened, all your bridges got damaged, and this blueprint that kind of fell off the shelves next to this other one gives you an idea for more flexible bridge, which maybe it's a little weaker, but in this situation, in this type of environment, with a lot of earthquakes,

having the more flexible bridge is actually better. So so for an animal, what this means, right, is if you have a large sort of genome, a large genetic lot of genetic diversity, a big genetic library, and then also other members of your species who have their own sort of large genetic library, there's a good chance that, say there's an environmental pressure, right, some change in your environment, maybe a disease or a new predator, there's a greater

chance that you're going to randomly Again, none of this can be planned, right, It's all a random mutation that happens to be able to address some environmental pressure. Even though most mutations are either neutral or bad, once in a while you might happen upon a mutation that's actually good. And it's those rare cases that advanced evolution. And that's

why evolution is so so so slow. Millions and millions of years to get to where we are at the very least, you know, like like a thousand years on the evolutionary timescale is very short, so hundreds of thousands of years. It might take like hundreds of thousands of years to address a certain evolutionary problem, right, So it's very very very slow. It's hard to have really rapid evolution.

It can happen, like there are cases in which animals adapt to situations quite quickly, it's just that's not super common, right, Especially the more dramatic the change has to be, the less likely it is to be happening really rapid, because the more dramatic the change, the more likely it's going to mess up that organism in a way it can't survive. So like, hey, if there's a lot of flooding around us, why can't we evolve gills in a few generations, Well,

you mess with our ability to breathe. The most likely outcome is our offspring is just gonna die and not be able to function. So going from something really dramatic whereas like say having more of a say more say the sun gets really bright, right, and then we end up having more brown eyed people because they end up being a lot more well suited to a lot of harsh light or something. This is just an example. I

have nothing against blue eyed people. I have blue eyes myself, but in that case, perhaps brown eyes might become more common, right Like if somehow having really in a situation. Now we live in a society right where we have sunglasses, so this would not happen. I want to be clear, but say, you know, we're an antle that really relies on our site, and then say, if you have blue eyes,

you're a lot more sensitive to light. Then maybe blue eyes might start to phase out a little bit more quickly, right because eye color is something is a trait that could say mutate or change really quickly without it being devastating to the whole body. Right Like, like certain there's certain sort of more superficial or minor changes to the body that could be could happen more rapidly, like hair loss, right, hair gain, or hair loss that's not necessarily going to

doom an animal. Right, So you might have changes in coat, changes in coat color changes, you know, slight changes in size, things like that can happen much more quickly over an evolutionary timeline than say, whether you have lungs or gills, whether you have legs or tentacles. Right. So, yeah, so evolution just happens really really slow because mutations are definitely not something you typically want. You typically don't want a mutation typically that would be bad news or at the

very least neutral. It's super super rare for there to be a mutation that's actually beneficial, that's actually going to make the offspring more viable than its parents. But it does happen, and that's the whole reason that evolution works. So that's why it's really slow. Now onto the next part of the question. Are there certain genes and structures more prone to mutations? Absolutely, there's structures and genes more prone to mutations, both in bad ways and potentially very

rarely in good ways. So these are genetic hotspots that are more prone to mutation. Usually well, especially this happens in DNA strands with many repeating sequences which can cause that little enzyme that runs along your DNA to copy it called a polymerase, to kind of like when it like decouples from the DNA and then reattaches and it can actually sort of like lose its spot more easily

if you have repetitions of certain sequences. So it's kind of like if you're trying to memorize a really long sequence of numbers or letters, say, like you know, you're memorizing a pin or a telephone number, and then like there's like a bunch of fives, and it's like, I can't remember how many fives there were? Were there four fives or five fives? That's sort of not on an

intellectual level, right, a polimeraise can't think. But on a physical level, the reattachment is more likely to happen erroneously in slip when you have repeating sequences, So this is more likely to result in a mutation. This is actually something that could be you know, like in terms of practicality, right, like you may have DNA hotspots that are prone to mutation, and that can be a bad thing, like be more

likely to result in say certain types of cancers. But you know you also have say like if you have cells that are certain characteristics of somatic cells, that means like cells that are not involved in creating offspring. Somatic cells in generally are more likely to mutate, right, because they only affect really that cell and then that cells offspring. It doesn't affect an entire like new organism and new offspring.

So like you know, skin cells or muscle cells, right, are much more likely to have some kind of like mutation than germline cells. So germline cells meaning cells involved in creating gam meets, and those gam meats are what then create offspring, right, sperm and eggs. So it's much more likely you have mutations in cells that are happening like happening in your body, then you are to have

mutations that affect your offspring. And in general that's a good thing because if you have a mutation of of something important for your offspring, most likely that's going to result in say like a spontaneous abortion, right, a miscarriage, which is very natural, happens very often, and or you know, in some some severe cases, right, the offspring has some severe issue that makes it harder for it to survive. So you know, it's it's a really it's a really

interesting thing. Evolution has to be really slow. If it were too fast, basically, our cells would be mutating at such a rate that we would have so many potential problems, cancer, debilitating mutations that say, like, you know, like I said, the example is like a mutation that like lops your whole head off, right, Like you're born without a head. You can't really do much. So mutations have to be

countered counterbalanced by, you know, some some slowness. Otherwise, things that mutate too quickly are not going to last very long because they're taking too many genetic risks. But like I said, you know, having a lot of genetic diversity, a huge genetical library is one way that animals can instead of going for speed of mutations, going for a higher probability of different types of diverse mutations and then increasing the chance that one of those mutations might end

up being something good. All right, on to the next listener question. Hi, Katie, our three year old German shepherd Betty. Sometimes we'll kick up the grass behind her after going to the bathroom, both number one and number two. The last time we saw this. My daughters Eleanor and Penelope seven and ten almost tune and I try to figure out why dogs do this. Their guesses were to either

spread the smell or conversely cover the smell. I suggested maybe it is like doggy toilet paper, kicking up grass and leaves and such to knock shake loose any hangers on. I further suggested, maybe Betty evolved to have a higher likelihood of kicking dirt at me while I bent over to pick up her poop. Any actual research on this topic, what are your thoughts? Thank you? Patrick? Hi? Patrick, Yes, there is actually some research on this topic. It is

a very common behavior among dogs. My dog does it too, which is especially funny when she poops on cobblestone and she tries to scratch at that nothing really happens. Also, don't worry, I pick up every single dog turn she leaves on the cobblestones because I am not a filthy degenerate. I very much believe in picking up dog doodoes, to the point where my dog probably thinks I'm obsessed with

collecting her poop. Okay, so you may notice that your dog is more likely to do it when another dog is around, right like after she's pooped or peed and she sees another dog, maybe she's more likely to scratch at the ground, or even when you stoop down to pick up the poop, that's when your dog suddenly decides it's scratch and time, tend to kick up some turf and possibly peepee or poopoo in your face. So this

seems to be an instinctive territory marking response. So rather than covering up the smell, which is a very good theory, they seem to actually be trying to enhance it. So they're likely using scent glands on their paws to make some smell markings. There might be visual cues like scratch marks, and given that it's more likely to be done actively in the presence of other dogs, according to studies, it might be a form of visual communication too, so like hey,

look at me, I'm marking my territory. I'm doing it in front of you, just so you know what's going on. So my theory is that dogs feel pretty vulnerable when they poop and pee, so I suspect that scratching, even growling after they use the toilet may be a way

of defensively marking their territory. But also not just in terms of saying like, this is my spot, but a warning to other dogs who any dogs that might have an idea about messing with them while they're in such a vulnerable potty position, just like, hey, I'm alert and

I'm aware and I see you and back off. This is my toilet, like don't mess with me, essentially while I'm doing my potties, which I can totally you know, but I get it, like when someone's pounding on the door when I'm trying to do my potties, I get very upset. So an anecdotal example is that my dog primarily does the ground scratching behavior after she goes to

the bathroom when she notices another dog approaching. So I think that for her, she's feeling sort of insecure, and so it's not necessarily that she really wants this to be part of her territory as much as it's saying like, hey, I see you there, this is my toilet. Don't bother me while I'm doing my potties and don't try to take advantage of me when I'm in this vulnerable position like I'm on it and I want you to know.

And other dogs that might pass by here know that like, I'm aware, I'm on it, and I'm not going to tolerate anyone messing with me when I do my potties. So yeah, I think that if a dog is feeling territorial defensive, insecure, or simply wants to communicate this is my toilet, the kicking behavior helps them spread their scent and visually communicate that they're not going to tolerate interlopers

or look at loose. So interestingly, there was a study that found that older shelter dogs were more likely to do the ground scratching behavior, which does lend a bit of credence to my theory that dogs who are more insecure, perhaps feeling that they don't have a stable established territory or that they're in an area that may be frequented by other dogs, that they might be more likely to do the ground scratching behavior in general. Now, I don't want anyone to like freak out and think, oh, no,

I have an insecure dog. That's not necessarily what I'm saying, Like this might be more of a general rule, like if your dog may have no problems or not be insecure at all, they may like have the sort of instinct to do it and then just kind of really enjoy the feeling of it, like the feeling of scratching, the feeling of security of like kind of securing their toilet.

For instance, my dog really enjoys doing sort of scratching, digging and real behavior in her bed and on the couch when she's really relaxed, So that is not a stress behavior. That's her relaxing and kind of settling and sort of like tucking herself in and feeling secure. So I don't think it's always a stress response, but for a lot of dogs it might be like when they

are feeling a little vulnerable or a little insecure. It's not a problem though, Like it's it's not a problem behavior unless for some reason they it seems to really stress them out. Like it's very very common, So I wouldn't worry about it other than the fact that your dog it does seem to be kicking turf into your face, which you know is a little disrespectful, but hey, what

are you gonna do about it? I think that she's made her point, which is you should, you know, give her maybe some reading materials while she's going to the bathroom. My newspaper think about it all right, onto the next listener question. Hi Katie. Every day in my seventh grade Life Science Clubs clssroom, I highlight some organism. Sometimes they're just living things I find cool or interesting. Other times

the creatures related to the day's topic. Tomorrow we begin that middle school rite of passage, the cell model project. I remember that tomorrow's creature is going to be the Portuguese man o war. I'm highlighting this creature because it is a complex colonial organism with several zooids, which are multicellular little things that are specialized in work together. But wait,

doesn't that mean the whole organism is multi cellular? Some internet person wrote it is colonial from the morphological, developmental, and evolutionary points of view. I have an idea of what that means, but don't have time right now to research the details of it. This is what made me think of you, because that's literally your job as the host of my favorite podcast. I would love to hear a show about this distinction and other examples of organisms

that blur the lines between unicellular, colonial and multicellular. As always, I love the show and wish you the best. And this is from Amanda m Hi Amanda, this is a fantastic question, and I love the Portuguese Man of War. They are beautiful, They're amazing. They look like aliens, sort of like a cross between a jellyfish and a discarded shopping bag floating in the ocean. Definitely not something you

said should touch, given their venomous stingers. And that's a great idea for a whole episode to do a show about colonial and multicellular organisms. I will probably do that, but for now let me answer your questions. So the difference between a unicellular and multicellular organism is straightforward, right, A single cell like a protozoan versus multiple cells. But what is a colonial organism and how does it distinguish

itself from a multi cellular organism? So why is a man of war considered a colonial organism whereas a jellyfish is considered multicellular. So technically, a colonial organism is one made up of individual organisms that could, in theory, be separated from the collective organism and survive. And these are called zooids. So a human skin cell can't survive on its own, whereas like a zooid such as a part of a piece of coral like a coral polyp could

in theory or in general, survive on its own. The reason the man o war is confusing is that it has progressed so far into being a colonial organism that the individual zooids now act more like little organelles, and it couldn't really survive on their own. So the distinction between a man of war and a multicellular organism is partially semantic, but also it's in terms of how it

develops and its evolutionary history. So I think the best way, perhaps most horrifying way, but the best way to imagine it is it's as if a human embryo, like a human fetus, cloned itself in utero, differentiated a bunch of other fetuses that were good at different jobs, and formed a giant monster made out of hundreds of babies, and then evolved to the point where all these babies were connected by tissue and there were helpless and would die on their own if you separated them from the giant,

horrifying megatron baby. So one could argue that functionally this is the same as a multicellular organism, or maybe it's on its way to being a multicellular organism, but the way it evolved right in the way that it developed, right as like basically making a bunch of clones of itself and then each like sort of clone organism, differentiating sort of starting out as a collection of zoids and

then becoming more of a cohesive, interdependent organism. The way things are classified now, this would be considered a colonial organism. But it's a really good question because there is it's there's a lot of gray areas in evolutionary biology, and

this is one of them. At one point, does something that's like a colonial organism just become a multicellular organism and a lot of it's a lot of it's a semantic difference, but it's it's a semantic difference that's based on its evolutionary history and the way that it develops, right, the reproductive cycle, the way it develops. So that is the answer to your question, I hope, and definitely stay

tuned in the future because I will. It's a great idea for an episode to do one on colonial organisms and why they're so weird, what's going on with those guys? Well, thank you guys again so much for your questions. If you have a question, please write to me at Creature featurepod at gmail dot com. I do love doing these listener questions episodes. Let me know so if you enjoy hearing them, if you want me to do less more

of them, but I am definitely. I have a really great lineup of guests coming up on the show, so I'm gonna have some fowlength episodes with a guest so that I'm not just staring at my dog talking to her as I'm podcasting, right, Cookie, Is that better? Yep? Yep, She's leaving. She doesn't want me to do this anymore anyways, Thank you guys so much for listening, and thanks to the Space Classics for their super awesome song Exo Lumina.

Creature features a production of iHeartRadio. For more podcasts like the one you just heard, visit the iHeartRadio app Apple podcast, or Hey guess what where you listen to your favorite shows. I can't judge you, and I'm not your mother, so I can't tell you what to do. But don't touch a man o war. It's outchi kaboobers. It'll hurt you, even though it does look kind of like a pretty grocery bag floating in the ocean. See you next Wednesday. M