Listener Q's: Pee Science & Epigenetics

those questions on the show. And it is a great way for me to delve into topics that maybe I don't talk about so much, or do some new research, or you know, just get to know you the listener and what you are interested in hearing. And so I'm very excited for this week's listener question episode. There were some really interesting questions that made me study. So make

me be a nerd, make me study. If you have a question that you'd like to ask me, you can write to me at Creature featurepot at gmail dot com. Without further ado, let's get right into your questions about evolutionary biology. Is there any evidence of genetic memory and animals, specifically in fish like bluegills. I have access to this little beach on a lake and have swam there every

summer since I was a baby. I am probably the person who swam there the most frequently in the last thirty years or so, and all that time there have always been very curious bluegills who swim with me. I've noticed that when I get in the water, they kind of flocked to me, but are more reserved with guests. I must have swam with generations and generations of these fish, and I was wondering if they could possibly remember me,

or is it more like with dogs? And that I'm totally comfortable with them, so they're pretty comfortable with me. Thanks for reading all this. You're awesome, Phyllis. Thank you, Phillis. And then here is a related question. I think it would be really cool to talk in Layman's terms about epigenetics and evolution, since a lot of folks misunderstand and the degree to which epigenetics drives long term evolutionary change. And this is from Stellachou. So two excellent questions, and

they are very related. We are trying to get to the bottom of two ideas. Could an organism pass a memory or association to its offspring genetically instead of say, teaching the offspring. And what is epigenetics and how does it influence evolution? So a little background first, a bit of history of our understanding of evolutionary biology. In the early eighteen hundreds, a man named Jean Baptist Lamarque came

up with a theory of inherited characteristics. The theory was that acquired traits by the parent could be passed on to the offspring. The famous example is how giraffnecks purportedly would work. An early giraffe would stretch its neck in an attempt to get some tasty leaves, lengthening and strengthening its neck muscles, and then it would pass on a longer neck to its offspring, and so on until we

have giraffes with very long necks. Similarly, Lamarck believed that in humans, physically acquired traits could be passed on to children. If you built up a lot of muscle, you could pass on that strength directly to your child. When Mendelian genetics came along, you know the guy with all the pea plants, and those were more demonstrably proven as well as Darwin's theory of evolution, Lamarchism was abandoned as being

junk science, and it was wrong essentially. But now scientists think that there may be certain ways in which environment can affect gene expression and how that might also impact gamets and the genetic information passed on to offspring. So, in terms of Phyllis's question about bluegill fish making a positive association and passing that onto its offspring, well, I

have no idea about these blue gill fish specifically. It could be that you are just a fish whisperer, like after many years of swimming, you your body language is soothing to these fish. Could be that they learn from their parents, they're the previous generations seeing that they're comfortable with you, and then the younger ones are more comfortable with you. Or there is a small but not zero

chance that this could be a case of epigenetics. So there was a study that found that mice seemed to be able to pass on negative associations of a smell to their offspring without potentially teaching them. So the study, which was published in Nature in twenty thirteen, looked at whether olfactory learning, so that's the learning that has to do with smell, could be passed down in mice genetically.

So in the study, the mice were made to smell a fruity smell called acetophenone and then were given a mild electric shock to their foot because researchers like to bully mice, so the mice learned to be fearful of the smell and would show startle behavior to that specific fruity smell and not to other smells and would startle, whereas control mice who were not trained with this shock method would not have that reaction. A previous study had also found that the learned fear of smell changed the

neural structure of the mouse's nose. So the change in the mouse's behavior in terms of learning to associate this shock with this smell is so far not surprising, and they also found these same structural changes in these mice in terms of their nasal neural networks in their brains. Again not too surprising, right, Like, you have some kind of environmental impact onto you directly, and that can change you, can change your brain structure, can even change the neurons

around your nose. That is sort of that's not too strange, not too unexpected. The surprising result of the twenty thirteen study was after they allowed these mice to mate, their offspring, who had never been exposed to the scary smell, showed a startle reflex to it, just like their parents had.

They also examined the new generation of mice's nose and olfactory bulbs again that part that is the part of the brain that processes smell, and they found that just like the mice's parents, the new generation had more neural structures and their noses and olfactory bulbs dedicated specifically to

detecting that scary fruity smell as compared to controls. So the researchers wanted to make sure that these mice were not somehow learning it from the other mice, so they trained male mice to be fearful of that fruity smell. Then they sent their sperm to an entirely different lab to female mice, and they did in vitro fertilization, and then those mice then gave birth to offspring who also showed the same areas of the brain and nose with

those increased neural structures for that fruity smell. Unfortunately, it seems they didn't also do a behavioral test on these mice to see if they have the same startle reflex, apparently because of some limitations on how that other lab would do behavioral studies. Which I think is really disappointing, especially for such a bizarre and groundbreaking study. I think that I would like to see Judge Katie would like to see this replicated and also see the behavioral reaction

of the mice replicated in the in vitro fertilization. Regardless, though the results are really really interesting, the fact that you still saw these changes in the neural structures of the brain and nose is really really interesting. So does this experiment show that animals can inherit memory. Not really,

It doesn't prove that exactly. So what it shows is that environmental factors that can change the structure of a mouse's olfactory bulb and nasal neural structures seem to be able to pass something on that also changes the structure of their offspring's olfactory bulb and nasal neural structures. So, sort of condensed into more Layman's terms, a change to the parent mouse in terms of its response to a smell seems to be reflected in its offspring structurally, in

its brain and in its nose. And this study, I think is I mean, it is really interesting and I would like to see many more studies along the same lines because I think that is really necessary to see exactly what's going on. You could define this as a sort of memory, right, Like it could be that they inherit some fear of the smell, but it could just be that they inherit a sensitivity to the smell. It may have not too much to do with fear. So it's hard to know exactly what they are cognitively or

instinctively inheriting. But I think it is still really really a surprising and interesting results. So I'm sure a lot of you as I also question how can you pass on a trait you acquired from your environment to your offspring. So this is where we get into epigenetics, which seems really weird and a little bit scary, but it's not so scary, but it is still pretty weird. So epigenetics looks at how cell functions can be changed without a

mutation or change in the DNA sequence itself. So the DNA sequence has not mutated or been altered like in the actual sequence of the amino acids, but there has been a change that creates a difference in cell functions. So how can you have a change in self function without an alteration of the DNA One way is gene expression, which is the way in which DNA gets copied into RNA,

which can either be used directly. That RNA can be used directly or can further be used as instructions to build another protein that will then be used for self function. So you can, without fundamentally changing the DNA structure, change how the DNA is converted to RNA, and how that RNA is converted into proteins, and that will change the function of the cell. So there are three main ways in which this is accomplished. There is DNA methylation, histone modification,

and RNA mediated processes. That sounds really scary and complicated, don't worry. That also sounded really scary and complicated to me when I was studying up on this, But in very simple terms, DNA methylation is when a methyl group molecule attaches itself to sites on the DNA strand and that affects how the DNA is transcribed into RNA. It's like you have a cookbook and you have some instructions in the cookbook of how to bake a cake, and

you don't like tear anything out. You don't change the cookbook itself, but you paste on top of it some kind of new instructions or something that will affect how you read it. Or you put like a little bit of wide out over part of the recipe and now it changes how you read the recipe, even though underneath the white out the recipe remains the same. So the

other method in which genetics works is histone modification. So histones are the spools that DNA winds around, so it's kind of like a spool of thread to keep the DNA sort of from getting knotted and tangled. It is wound around a histone, and if the histone is modified, it can also change how the DNA strand is transcribed. And apparently this is actually a key factor in the

brain when it comes to addiction. Like this, the modification to the histones can affect how your cells function, especially in your neural cells when it comes to addiction. So the last one is RNA mediated processes. In extremely overly simplified terms, this involves modifications or markers on RNA that changes how they create proteins, and when it changes how they create proteins or how the RNA functions, that will

also change how these cell functions. So to pass down an epigenetic change, the epigenetic tag or marker either the methyl group attached to the DNA the histone modification or marker on the RNA, must somehow also be copied and

passed on in reproductive cells. So transgenerational epigenetic inheritance, which is the inheritance of some kind of epigenetic change from parent to offspring to another offspring, so like to grand offspring and great grand offspring, is largely understood to exist, even though it's not well understood exactly how these mechanisms work, and it's still a question as to how influential epigenetics is on behavior and also how it affects long term

evolutionary changes, which gets into listener Stella Chow's question about explaining epigenetics and long term evolutionary changes. So much of evolutionary change is driven by DNA mutations, So these are random alterations to the DNA that happens as reproductive cells are formed and reassembled into offspring, and then you have selective pressures that may mean certain mutation get passed on

and others don't. So the mutations themselves are random, but the process of natural selection is not at all random it is, it's very much driven by selective pressures, and that's how from random mutations you can get very useful structures. So the role that epigenetics has to play in terms of long term evolution is a very debated topic among evolutionary biologists. So many of lutionary biologists are very skeptical as to how long and inherited epigenetic trait could last.

Maybe it sticks around for a few generations and then kind of wears off, But there's still the possibility that epigenetics has some influence on long term evolution, But it doesn't seem like there's been any definitive research proving such

an influence. So until there's a larger body of research on the topic, you know, I don't think that researchers really know whether epigenetics plays much of a role in long term evolutionary changes, you know, And I certainly don't feel like enough of an expert to state my opinion on it. I just think that there hasn't really been evidence that is convincing that epigenetics has played a big role in long term evolution. But I don't think it's impossible that it has. That it has played some role

in evolution. In fact, there is some there worried that epigenetics in general, the ability to have some kind of epigenetic change, is a result of evolution, which is to allow for a brief change in organisms in a response to environment, one that's not necessarily permanent, because like, if the environment is rapidly fluctuating, you know, you want to kind of be able to rapidly change with the environment instead of having, you know, this longer process of getting

having to rely on random mutations in order to adapt to changes. So I know that saying like, we don't know exactly is kind of an annoying cop out of an answer, but I think it's also really important to remember how new a lot of sciences and how many questions about evolutionary biology still exist and need answers, And sometimes researchers are going to get it wrong. Sometimes they're

going to get it right. Sometimes they're going to think that they got it completely wrong, and then later on they're like, actually, part of this may have been sort of right. It's just the whole process. It's a living science. So onto the next listener question. Dear Katie Golden, thanks

always for your superb show. Thank you so much. Being an old I've lived through decades of human recitations about why non human animals aren't as advanced, animate, or worthy as we are, and decades of these distinctions being found do not actually exist tool use being uniquely human for instance, that is not true. My take on that is that humans as a species clearly have hierarchical anxieties, and ere we are at the elusive possessing a theory of mind.

My related query is about the distinction between instinctive and rationally decided behavior. Is this just something people like saying or are there any effect of definitions? And how are habitual learned behaviors taken into account if they are. Thanks in advance for reading and thinking about this from Mary Anne. Also, I got a related question post on Twitter Great minds

think alike you guys. So here's the similar question. How much do we know about the role genetics plays in passing on instincts, especially those instincts with complex urges that had no way of being taught. For example, animals going to a specific place to reproduce. And this is from radia. So these are also summert related to previous questions on epigenetics, but I think that scientists do have a much better

understanding of the genetics of instincts. So I think the main way to define instinct versus rational behavior is that instinct is something you are preprogrammed with and can start using right out of the box, right out of the egg or woomb crying, for instance, is an instinctive response. You don't have to learn how to cry. It just you're ready to go with that preloaded. A startle response to something sudden, or to a snake or spider is potentially an instinct, like you don't have to be trained

necessarily to have a startle reflex to a spider. In baby sea turtles, as soon as they hatch, they can start to crawl towards the light of the moon reflected in the water, and this is an instinct right out of the egg. They haven't been taught anything. They just know they got to go towards the light reflected in the water. Or they get eaten by a bird or something, but they try to get to that water as fast as possible. They start zooming as soon as they can

right out of the egg. That's instinct. Rational behavior is responding to a situation and instead of having a pre prepared response having to come up with one through cognitive ps sesses your instinct maybe to flinch at a snake, and so that may be an instinctive response, but what you actually do in that situation either picking up a rock and bonking the snake on the head, which I do not recommend, be nice to snakes or avoid them if they're venomous, or you could look at the color

of the snake to see if you really should be afraid of it, using reasoning and cognitive processes. So either of these responses, right, like a violent response to the snake or a more thoughtful response, These are actually both quote unquote rational behavior. These are you're using some kind of reasoning about what you should do about the snakes.

So you have an initial instinctive reaction of like, oh, a snake, and then you start to reason like, well, I will I will smash the snake, or I will look at the snake and hey, maybe it's just a harmless snake and I don't have to worry about it. Either of those are behaviors that have arisen from cognitive processes, and this is not a uniquely human behavior. I want to emphasize many animals use cognitive processes to think their

way through a response. In fact, I would say most animals have that ability, have that ability to use some form of cognition to come up with a response that the most animals do not behave purely on instinct, and they can either reason through something or they can learn behaviors from their parents or peers. Sometimes I would say instinct interacts with learning or rational responses in interesting ways.

So songbirds, for instance, are born with a built in song learning structure in their brains and will instinctively pay attention to songs, but they're also dynamically learning how to sing that song. So you have this initial instinct that kind of grows into more complex learned cognitive processes. So

you know, instinct and rationality. While I think that there is a distinctive definition for both, that doesn't mean that they don't kind of interweave with each other when you actually look at how these behaviors happen in real animals. So instincts are passed down genetically, so or as we discussed earlier, perhaps they could be passed down epigenetically, like those mice that have that increased sensitivity to that fruity smell. But in general, something like the sea turtle who like

goes towards the moon, it is passed down genetically. This kind of pre programming that comes in the brain. I know, it's kind of like spooky, this idea that a brain can come preloaded with a set of instructions of how this organism should behave, But that's absolutely the case. It is like the way that babies know to suckle when presented with a nipple. You don't really have to teach

them that. I mean, you can't. I guess that in some cases, like you can kind of like help teach a baby how to like latch on or something, but generally speaking, the baby, once it is given a certain set of stimuli, it will start to do this suckling behavior, just like a baby calf or something knows to suckle

on the utters. Because you can't, you need to have some behaviors that are preprogrammed and ready to go so that newborn baby, that fresh baby can survive and can communicate that it's hungry and that it can actually act on its hunger. And that's important because otherwise, if you have to wait too long to learn or acquire some kind of behavior, then you're not going to survive because you need you need to eat, You need to eat

fresh out of the box. So we are going to take a quick break and then when we get back, we're going to answer some more listen our questions. So here's the listener question about my dog Cookie. Dear Katie, thanks so much for all your work, love both your shows. Thank you. I was wondering if you could address some questions on your next mailbag show. One what is Cookie's greatest fear? Two? What is Cookie's highest aspiration? Three? What

is Cookie's greatest achievement? For what is Cookie's cutest habit? I know these are deeply personal, but the listeners simply need to know. Thanks again, quote unquote Rusty shackle Ford, thank you for the question. Quote Rusty shackle Ford. Here are all the Cookie facts that you need to know. One. Cookie's greatest fear is being ignored. Two Cookie's highest aspiration is to bark at every single pigeon in the entire city.

Three Cookie's greatest achievement is the time she found an entire chicken leg and managed to eat it, bone and all before we could get it from her, And she spent days in smug satisfaction while we worried and sifted through her poop to make sure she passed the bones safely. Four Cookie's cutest it is that she likes to play hide and seek with her toys and will stand up on her hide legs to get a better visual on her surroundings to find her toys. So those are all

the cookie facts that you need to know. Relate a dog question from another listener. I was looking after Hamish. He mishes a dog by the way this weekend. When he smells other dogs pee, what does he know? Can he tell if they're male or female, or how big they are, or if they're sick? Could he even have some idea what they look like? He definitely knows something, and he's not telling gary D. Thanks gary D. So dogs have exquisitely sensitive noses and can smell all sorts

of things that are beyond our human noses. That said, they may not know what they're smelling exactly. So a dog can be trained to detect cancer cells, but it doesn't mean the dog understands that those are cancer cells or even a sign of illness. They have to be trained to kind of use that as a diagnostic material. They have to go to dog medical school. What I'm saying, so,

what do dogs determine by sniffing the peepee of other dogs? Well, they can determine the sex, the maturity, and reproductive status of the other dog, and all those things have been I think pretty much confirmed by research. But they can also potentially understand what their own brand of urine is. And this has been used in studies to try to see if dogs have a sense of self. So often we will use the mirror study to see if an

animal has a sense of self. So you show an animal it's reflections, then you modify something about the animal, like you at a red dot on its face or something. And then if the animal looks in the mirror and scratches at its own face, it seems to be that the animal is making the connection between itself and the image in the mirror, which one could interpret as having a sense of self or at least understanding that itself exists and it can use the mirror to guide itself

to change an aspect about itself. But dogs fail at the mirror test mostly because they have no interest in mirrors, and so we could say, like, well, dogs don't have a sense of self. They fail the mirror test. But I think this is a limited perspective because mirrors make sense for people like humans, because we have we're very

very visual animals. But other animals don't necessarily only rely on their site, or don't primarily rely on their site to experience the world, and dogs really rely on their sense of smell. They love smells. They do have a sense of sight, and they do have a great sense of hearing, but smells to them, it's just like a buffet, like.

They are really really good at detecting smells. And for them, like the variety of smells that they can detect, in the extent to which they can detect them is probably more precise and more colorful than say, just their vision.

And so because they love smells, especially urine smells, researchers wondered, like, hey, maybe instead of trying to get a dog to look in a mirror like it's a little person, maybe we should try to kind of meet the dog halfway and see if the dog can do a version of the mirror test but with its urine with smells instead of sight. So can a dog understand what its own urine smell is and react and surprise if its urine is somehow modified.

So in a study done on dogs smelling urine, the researchers found that the dogs spend more time smelling their own urine when it was modified compared to just their own urine, and they showed more interest in their urine mixed with the modifier smell than just the isolated modifier smell. So it wasn't just that they were responding to novelty. They seemed especially interested in their own urine when it was mixed with this modifier. Oh, do dogs pass the

pe mirror test? Maybe I personally would like to see a comparison of whether dogs react differently to their modified urine versus the urine of another dog and a urine of another dog that's been modified. So what I'm saying is we need more smelly pee tests for dogs, And I think the dogs would also be thrilled with this, because I bet these dogs love these studies. They love smelling peepee, and if they get to go to a study and smell pepe, I'm sure they would enjoy that.

By the way, most dog behavioral studies these days are using pet dogs, so they just go into the lab for a day. It's not generally dogs that are like held captive in the lab for their lives. So that's that's nice. I like it when studies are ethical with respect to animals, especially when we're trying to learn about animal behavior. I think it's it's nice to be respectful

towards the animal. Doesn't always happen, but I think it is happening much more frequently now that we are really taking into account the animal welfare when it comes to behavioral studies. So yeah, more PPE tests for dogs. They love smelling p. I know my dog loves smelling P. I try to litter do it. It's gross, but you know what, that's how she enjoys life. So I'm not going to shamer I'm not gonna judge her. Here we

are another listener question. Hey, Katie, I've always been in us versus then person when it came to parasitic organisms, be it humans or otherwise. That's not to say I don't find them fascinating, and you've covered quite a few. What I've long wondered, though, is what's the scientific opinion on whether or not they're an important part of the ecosystem. Are they part of the balance that keeps some others in check, or could we remove them all and be

better off for it. Of course, I assume it's not all that black and white, and my guests would be that those that have been here for a while evolutionarily speaking, couldn't just be quickly removed without consequences. But then also there might be some newer ones that are more detrimental overall. But these are just guesses. Any thoughts, PK, great question.

You know. I love parasites, and partially it's because they're really fascinating, but they are also an important part of our world, in our ecosystem, even if they are detrimental to a specific host, so obviously everything is a balance. I would say that it's not so much about the newness of a parasite evolutionarily speaking, but it could be like if a parasite is introduced to an ecosystem, right, like an invasive parasite, that could be quite bad for

the ecosystem. But in general, parasites can keep things in balance. They may keep the population of a certain host species in balance, and if that host species were too successful, then they might take too many resources or prey upon too many other species, so they cannot help maintain a balance in an eco system. They may also help drive biodiversity,

forcing adaptations and animals. Another important thing for parasites is that they are a food source for many species, and they can also compel animals to adapt pro social behavior like cooperation cooperative grooming from any animal from fish to apes. So like part of ape cooperation, some of the ways that apes bond, primates bond is through grooming parasites. And who knows this could have shaped like the pro social

nature of primates. Maybe we humans have parasites in part to think for our evolution as being very pro social. So in short, parasites are awesome and important, but maybe not so fun if you individually have a parasite. And just because they're important for the environment doesn't mean you should feel compelled to keep a tape worm inside of you. It's okay to go to a doctor and get rid of a parasite. I'm not saying you personally have to be the host of many parasites, even though I am so.

Before we go, I would like to go over something very important. It's the mystery animal sound game called Guess who Squawking every week I play Mystery Animal Sound in you, the listener, try to guess who is making a sound. It could be any animal in the wild. And if you think you know who is squawking, you can write to me at Creature featurepot at gmail dot com. Again, you also have a question, feel free to write it to me. And by the way, there are no dumb questions.

You may think your questions like, I don't know, this might be too basic, this might be too silly. Nope, I'm gonna say no. Sometimes the most obvious questions are the ones that make me kind of scratch my head and go like, oh, I gotta hit the books. I have to study up on them. So hit me with all those questions. And now, Auntie the mister analysts sound game. Last week's hint was this you wouldn't want this around

your neck? So can you guess who is making that sound? Well, congratulations to the three fastest guess theer's Laura W, Bryce V, and Auntie B who all guessed albatross, and special congratulations to Chris B, who not only guessed albatross, but guessed the correct species, the black footed albatross. So the albatross

is a sea bird with an incredible wingspan. The black footed albatross is a sea bird found in the North Pacific which has an InCred credible wingspan of around six to seven feet or one hundred ninety to two hundred and twenty centimeters. And they are this lovely gray color with sort of white ombre on their face and indeed black feet and the sounds you just heard are probably either fighting over food or kind of courting or both. Honestly,

kind of sounded like both to me. That you got a little bit of squabbles over food and you got a little bit of romance going on. And speaking of romance, they will form long term pair bonds that typically last for their entire life. So these are faithful boyds. And then they both take part in the care of their chick and they will actually take turns incubating the eggs. We love to see it. We love to see see

successful co parenting in birds. Onto this week's mister Ann will sound the hint this foxy little filler loves bananas. Bonus points if you can guess why it's making the sound. The answer it's very cute. Well, thank you guys so much for listening. Thank you so much for your fantastic questions. I love them every time. They often send me on rabbit holes of studying and I truly appreciate the thoughtfulness.

And if you have a question again, write to me at Creature feature Pod at gmail dot com and I will answer them to the best of my abilities. Thank you so much for listening, and thanks to the Space Classics were their super awesome song Exolumina. Creature features a production of iHeartRadio. For more podcasts like the one you just heard, visit the iHeartRadio app, Apple Podcasts, or Hey guess what where have you listened to your favorite shows? Seed x Wednesday