Science Friday - Investigating Cat Behavior Through Genetics

Episode Date: April 24, 2025

With the help of cat owners, a new project investigates cats’ biology and aims to link some of their behaviors to their genes.Calling all cat people: This one’s for you. Despite humans’ long history of welcoming felines into their homes and delis, research on cats lags far behind research on dogs. Now, scientists behind the project Darwin’s Ark are working to close the cat gap by enlisting cat caretakers from across the country to submit a tuft of fur and answer a few questions about their feline’s appearance, personality, and behaviors.Host Flora Lichtman talks about the project, as well as what we do and don’t know about cat genetics, with Dr. Elinor Karlsson, chief scientific officer at Darwin’s Ark, and director of the Vertebrate Genomics Group at the Broad Institute of MIT and Harvard Universities.Transcript for this segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Flora Lickman. Today in the podcast, the underdogs of pet research. People didn't think that cats had as much to study, which I think anybody who lives with a cat will know that they're nothing, if not full of questions. Despite humans' long history of welcoming felines into our homes and our bodegas, cat research lags far behind that of dogs. Now scientists are working to close the cat. gap by enlisting cat caretakers from across the country to submit a tuft of fur and answer a few questions about their feline's appearance, personality, and behaviors. Here to tell us all about this new project, and what we do and don't know about cat genetics is my guest. Dr. Eleanor Carlson,

chief scientific officer at Darwin's Ark, a professor at UMass Chan Medical School, and director of the vertebrate genomics group at the Broad Institute of MIT and Harvard University. Eleanor, welcome back to Science Friday. Thank you very much for having me. Why is there more research about dogs than cats? That's a really good question. I could come up with a lot of reasons why scientifically we focused more on dog genetics early on. There are a lot of advantages to the breeds that we have in dogs, especially when genomics was very difficult in the beginning. But I think also people didn't think for some reason that cats had as much to study, which I think, anybody who lives with a cat will know that they're nothing, if not full of questions.

The cat people are pounding their fists right now against their tables, you know? I mean, I'm like, are cats like the women of scientific research, you know, like, ignored, basically. It feels a little bit like that. I got to say, it's like, you know, there's a bunch of diseases that cats get that would be fantastic models for human diseases. And so this is often why we study other species, is that there's something we can learn from them that will also help people. And yet, despite the fact that we know that, for some reason, those studies just haven't been done. I mean, are cats actually better models for human disease than dogs in some cases? They're very complementary in the sense that there are diseases that cats get that dogs don't get. One of the most sort of common diseases that cats get that people also get is type 2 diabetes.

dogs get something that's more like type 1 diabetes, but they don't get type 2 diabetes. And yet it's this huge disease in humans as well. And so by studying cats and how this disease happens in cats, we might be able to learn something about its causes in people as well. What are some of the big questions you're hoping to answer with this project? I think right now the question might be what isn't a question. You know, the more we dig into it, the more we're surprised. by how little we know about this animal that lives with so many of us. You know, we're not even really sure exactly what a cat breed is.

What do you mean? What? I know. Doesn't that seem so, it's like, everybody's like, well, it's just a breed. And you're like, well, in dogs, you know, a breed is this population of dogs where all the dogs in the breed are super closely related to each other. And it dates back to Victorian England and they were selected for what they look like, etc., etc. And some cat breeds might be like that, but other cat breeds like Siamese, you might have some cats that are in the breed, but also cats where people just sort of say, well, they look Siamese, and so we're going to call them a Siamese. And do different cat breeds or cats that people think are in different breeds come from different parts of the world? You know, we've got some small studies that have suggested there's some really interesting genetics out there that we could look at to just kind of see how cats have moved around the world. And we just need a lot more cats enrolled in studies to be able to do that work. So, I mean, a lot of people have domestic short hair cats. That's like the breed listed on their vet records. Is that a breed? You know, well, you know, it depends on how you define a breed. I would say, no, I have, I live with

three absolutely wonderful domestic short hares, which means that I adopted them at the MSPCA, and it said on their form that they were domestic short hairs because they had short hair. And so it's more a, I guess, a phenotypic definition, we would call it. That's interesting. You know, I think also some quote breeds, some types of cats have different reputations. And, you know, we put out this cat or wall to our listeners for their questions about cat behaviors and traits. And we got, you know, for once, many welcomed cat calls. And I want to play you, a call from Joni in Maryland who bristled at the stereotype that orange cats are menaces.

Are you kidding? Orange cats, destructive neney. No way. My cat used to greet all the children coming into the house, any kind of neighbor. The only people he was a menace to was one really witch of an attorney. And I'll tell you what, this gentle, beautiful cat spit at her. And I told her to bring a bribe next time and take off the noisy shoes. She brought a bribe, and he, hissed and he went out to try to bite her. I could not believe it. So, uh, nini, uh, only if you're a witchy. I'll tell you what? Orange cats are outgoing behavior and they're fun and I love them. Any response for Joni? Well, I am with Joni on this one. The first two cats that I ever had, their names are Laif and Darwin were both orange and they're both the best cats ever. So, yes, I do not think there's anything to the stereotypes. And one of the things that really surprised me when we started doing this project was how many stories there are out there. How many people have told me that particular colors of fur are connected to particular personalities and behaviors.

And to me, it feels very similar to something that we've been also looking at in dogs, where people assign different dog breeds different behavioral characteristics. We call them breed stereotypes. And we looked at it in dogs very deeply using all of the survey data that people gave us about their dogs. And very few of them could we find a lot of support for. And so we're going to do the same thing in cats now. We're going to try to get a whole lot of cats signed up. We're going to ask their owners lots and lots of questions about their cats.

And then we'll look at whether the personality characteristics reported by people who have orange cats are any different than the personality characteristics reported by people who have other. colors of cats. I mean, that seems like, is there a chance there would be personality traits that would be linked somehow to fur color? You know, I can't as a geneticist see any real reason why that would be true. You know, color is controlled largely by changes in a few genes and behavioral traits are usually what we call complex, meaning that they're influenced by many, many different genes and also by environment. So the lead scientist on our project, who's an amazing scientist, Kasha Brick, has actually taken a quick look at this with the number of cats that we have signed up right now, which is about 5 or 10,000. And we're not seeing anything in that

data set right now, but we're going to keep looking at it because this is something, as I said, that people keep telling me. Well, look out for orange cats and their attention and attunement to witches, witchy people. Yeah, I can't say that we ask that survey question. I'm trying to figure out a way we would phrase that, and it's not really immediately coming to mind. Okay, while we're on breeding, we got this very intriguing listener question. This is Chuck of McMill, Oregon, and my question for you is, why are there no miniature cats? There's miniature, almost everything else, miniature pigs, miniature horses, miniature goats, miniature dogs. And it'd be so great if there were small cats for apartments and things like that.

that if we had adult cats, the size of kittens, that would be fabulous. And I just don't understand why they've never successfully miniaturized cat. Eleanor? You know, I find this to be a really interesting question as well. And I actually looked into this a number of years ago when the same question occurred to me when I was sitting on my couch in the middle of the night. And, you know, are you serious? Yeah, no, totally.

I was like, why are they not miniature cats? you would think somebody would have done this by now. I was working on dogs and there were these teacup chihuahuas and I was very confused by why there were not miniature cats. And the best I can come up with is that, you know, the interesting thing about dogs is not just that genetically we can breed them to be very different sizes, but that for some reason the dog physiology, their shape,

sort of works okay at all those different sizes. I think what might be happening in cats is that people, People can try to breed them really small, but then they might have issues like maintaining their body temperature as kittens and things like that. And so it may not be a size that really works for them physiologically. Don't go away. After the break, the evolutionary history of house cats and how they're different from their wild ancestors.

I think anybody that's tried to live with a wild cat would probably say absolutely, definitely, definitely in terms of their behavior, but possibly not as much as much. in terms of their shape. Animal was the pet cat descended from? Like, who was my cat's ancestor? That's a great question. So there was actually just a couple weeks ago, some new papers came out that sort of confirmed

that the most likely origin of cats was in Egypt. And it was actually surprisingly recent. It might have been as recently as about 3,000 years ago that domestic cats sort of became part of our world. How does that compare to dogs? Dogs are actually really old. Everything we've looked at in dogs suggest that they're probably one of the first, if not the first domestic species. And our best guess is probably somewhere between 15 and 20,000 years ago.

Okay. Okay. And so they're in Egypt. And what is what animal, what's the animal, the wild version of? Yeah, there's an African wild cat that was the ancestor of all house cats. with a small caveat, which is that some cats actually have what we call admixture, which means ancestry from other species of cats. I think the most famous is probably Bengal cats, which many people own,

so they have some ancestry from a different species of cats. But we're kind of curious to find out in pet cats how often this happens. And so that's actually one of the things we're going to be looking at as we build up our genetic data set. Okay, I'm looking at pictures of an African wildcat right now, and they look like just a legier, long-legged version of a cat, of a house cat. Like, they look very similar. There's also amazing amount of consistency across cats, though, too. I bet if you Google like Scottish wildcat, which was another contender for the ancestor of pet cats, it also looks strikingly similar to what cats look like today. It looks like they're very.

shape works pretty well for them. Yeah. I mean, dogs, you know, my sense, you tell me, are quite different from wolves. Have cats changed much from their wild form? I think anybody that's tried to live with a wild cat would probably say absolutely definitely in terms of their behavior, but possibly not as much in terms of their shape. Basically, the process of dog domestication was that wolves somewhere started eating human garbage as a food resource. And so dogs actually switched from being hunters, which is what wolves are, to scavengers. They basically have evolved to eat our garbage. They have all these changes in

genes related to carbohydrate processing and things like that in order to be able to survive on our garbage. Cats chose a different evolutionary strategy, which is that they're still hunters. They still hunt mice. They hunt the mice that live in our grain and the the rodents that live on our garbage, that the dogs are busy eating, but they never made that switch from being hunters to being solely scavengers the way that dogs did. And so we might not actually expect that in terms of their hunting behavior, we've had as many changes as what we see in dogs. That's fascinating. Is that, I mean, is that a genetics thing? Oh, totally. So in dogs, wolves have something called the predatory sequence, which is a series of behaviors that they implement

in order to be able to hunt. And in dogs, that sort of all got mixed up. And the result of that was actually a lot of the different behaviors that you see in dogs today, like retrieving and herding and livestock guarding are sort of all different versions of what was originally the wolf sequence that they used to hunt. In cats, you still see that hunting predatory motor pattern, as they call it. I remember Catherine Lord, who's the scientist of my group that knows the most about behavior, was over at my house one day. I was playing with my cats with one of these very string toys with a bird thing at the end of it, feathers at the end of it. And my cat jumped up to grab the bird and she said, and now she's going to put one paw on it.

And then my cat put one paw on it. And I was like, oh my God, how did you know that was going to happen? She's like, that's just what they do. That's their sequence. And I was like, I had no idea until that point how encoded in our DNA some of these behaviors are. But it makes sense if you think about it because the one thing that an animal needs to be able to do is feed itself. And so it can't really leave that up to chance. Well, speaking of behavior sequences, here's a strange one from another listener. Hello. My name is Rye. I'm calling from Louisville,

Kentucky. My calico does not like it whenever I practice any of my instruments. I first started noticing this whenever I was a floutist in my marching band, anytime I would take out my flute and try to practice, she would come up to me, she would take her paw, and she would put it on the end of my flute and bring it gently down, telling me that she did not like that I was practicing. Since then, I've taken a banjo, and she does the exact same thing, where she will, like, physically stop me from practicing. Why does she not like my artistic endeavors? thoughts? I have absolutely no idea what's going on there, but I will say that one of the things that I found interesting about trying to figure out how to study behavior is how important it is to

separate our observation of what the cat is doing from our sort of emotional interpretation of it. So it's possible that the sound of the instruments, especially if it's more high-pitched, the cat hears really well and it sounds really exciting like birds or something, or maybe she really doesn't like it because it's a really distracting noise. I have absolutely no idea. But, you know, it's kind of an interesting question. You know, could we ask people, does it bother your cat when you play music? I don't know what the answers would be, but I'm kind of curious now. Okay. If folks want to contribute to your cat genetics project, what do they do? How can they sign up? It's very easy. You can go to our website. It's called darwinsark.org and sign up

there. It's free to sign up your pet and answer all of our survey questions. We love people who answer our survey questions. We also have the option on there to send us a fur sample to do DNA sequencing. We need a donation to do that because there's a cost associated with that. But the whole thing is an open data project, meaning that any information that we collect is going into a big data set that we're building to share with other scientists on the theory that that's the way to increase the amount of science that's being done on cats very quickly. Yeah, we've got to build up the data set. I feel like we can, how much people do you want to get? What's your goal? You know, for things like diabetes or kidney disease,

we're going to need much larger sample sizes for that. And so the more pets that we can get enrolled, the more complex the questions are that we're going to be able to answer. One million cats, a hundred thousand. I'm just like, I feel like our audience can do this. I feel like we can solve this problem today. This would be like my total dream. So, okay, so if I have to give a number, I would love to have like a million cats enrolled. A million cats. It's okay. Where do we go? What's the website? Darwin'sark.org. Darwin'sark.org.

Eleanor, thanks so much for giving us the whole kitty and caboodle on this. Appreciate it. No problem at all. Thank you. Dr. Eleanor Carlson, Chief Scientific Officer at Darwin's Ark, professor at UMass Chan Medical School, and director of the vertebrate genomics group at the Broad Institute of MIT and Harvard. And that is about all we have time for. Lots of folks helped make the show happen, including John Denkoski.

Annie Niro. Jason Rosenberg. Rasha Reedy. I'm Flora Lichtman. Thanks for listening.