Speaker 1: I was interested in animal behavior, and for my master's degree,
Speaker 1: I was studying juvenile smallmouth pass So I went out
Speaker 1: in the wild and after getting all of the permits
Speaker 1: I needed, I brought a bunch of them back into
Speaker 1: the lab and they were like these little guys. And
Speaker 1: as they were growing up, I noticed that the number
Speaker 1: of fish in the tanks was going down, and I
Speaker 1: was totally stuffed. The water quality was great. I wasn't
Speaker 1: finding any dead bodies in the tank. They weren't like
Speaker 1: getting sucked into the filters. I was crawling around on
Speaker 1: the ground trying to see if they were somehow getting
Speaker 1: out of the tanks despite there being a lid on
Speaker 1: all of the tanks. And then one morning I walked
Speaker 1: into the environmental chamber and I was shocked. One of
Speaker 1: the fish had a giant tail sticking out of its mouth.
Speaker 1: It had not occurred to me that they were eating
Speaker 1: each other like one. It hadn't occurred to me because
Speaker 1: the fish in the tank were pretty similarly sized, and
Speaker 1: this was not the first time in my life. I
Speaker 1: was going to be amazed at how big prey items
Speaker 1: are for these basts, like how much food they can
Speaker 1: fit into their gigantic mounds, so they were apparently able
Speaker 1: to eat each other even when they were like pretty
Speaker 1: close to the same size. But also I was totally
Speaker 1: naive to how common cannibalism apparently is in the animal Kingdom.
Speaker 1: I was like, you can't eat your brothers and sisters,
Speaker 1: but no, absolutely, they were totally fine with that. And
Speaker 1: that's what we're going to be talking about today is
Speaker 1: cannibalism in the animal Kingdom. We're gonna mostly be talking
Speaker 1: about non human animals and it's going to be quite
Speaker 1: a ride. We're interviewing Folka Rudolph and he'll tell us
Speaker 1: all about his research in this field. Welcome to Daniel
Speaker 1: and Kelly's Extraordinary Universe.
Speaker 2: Lone epetite.
Speaker 3: Do Daniel and Kelly's Extraordinary Universe. I'm Daniel, I'm a
Speaker 3: particle physicist and I've never eaten a human being.
Speaker 1: I'm Kelly Waider Smith. I also have never eaten a
Speaker 1: human being, no desire to do so, but as an ecologist,
Speaker 1: I have seen lots of animals eating other members of
Speaker 1: the same species.
Speaker 3: Well, let's dig into that a little bit more. Kelly,
Speaker 3: my question for you today is what is the most
Speaker 3: intelligent animal you have ever eaten.
Speaker 1: Oh, geez, probably pigs because they're super intelligent. I eat
Speaker 1: meat less these days because ever since I got on
Speaker 1: a farm and I've started interacting with like cows and
Speaker 1: pigs and goats and sheep, I'm like, oh my gosh,
Speaker 1: you all like you have personalities if some of you
Speaker 1: are very smart. But I gotta be honest, I feel
Speaker 1: way better about eating chicken because our chickens are so stupid,
Speaker 1: and I don't feel too bad about eating chicken.
Speaker 2: So anyway, what about you?
Speaker 3: Where are you saying the dumb deserved to be eaten?
Speaker 3: Is that what's happening here?
Speaker 1: That is not what's happening here. You don't need to
Speaker 1: extrapolate to the forbidden meal. But I do think chickens,
Speaker 1: you know, they're delicious and silly.
Speaker 2: What about you?
Speaker 3: I'm not going to answer your question yet, I'm gonna
Speaker 3: keep pushing you. Would you eat a champanzee or a
Speaker 3: buonovo if somebody puts a chimp of skull in front
Speaker 3: of you and flips it open and says, here's a
Speaker 3: brain delicacy. Is Kelly saying no, thank you? Or are
Speaker 3: you digging in?
Speaker 2: Hm? I am saying no thank you. Yeah, why am
Speaker 2: I saying no, thank you?
Speaker 4: Oh?
Speaker 1: So much introspection happening right now? Are there not loads
Speaker 1: of bonobos in the wild. I don't know their status, so,
Speaker 1: like one, I don't want to eat anything that's like
Speaker 1: endangered or threatens or anything like that. But also, I
Speaker 1: guess I do feel uncomfortable the closer they are to me.
Speaker 1: And partly that's because, like, there's a lot of zonotic diseases,
Speaker 1: so a lot of diseases that jump from wild animals
Speaker 1: to humans, and I guess I would worry that the
Speaker 1: more closely related you are to those organisms, the more
Speaker 1: likely something is to jump.
Speaker 2: But I wouldn't have that excuse if it was like.
Speaker 1: A labraze chimpanzee. I still don't think i'd want to
Speaker 1: eat it. Yeah, nope, I don't know that I have
Speaker 1: a good logical reason, but my tummy is saying no.
Speaker 3: Well, I'm an una bashed speciesist. I feel like being
Speaker 3: human is different from being a puppy or a chicken
Speaker 3: or a pig. And I used to feel like that
Speaker 3: wasn't fair that you couldn't just say, hey, members of
Speaker 3: the human species have certain rights that pigs and dogs
Speaker 3: and whatever, don't. But these days I've come to accept
Speaker 3: that that's just kind of how I feel, even if
Speaker 3: it is wrong. And so, for example, I'm happy to
Speaker 3: eat an intelligent pig, but I wouldn't eat a very
Speaker 3: stupid person. Okay, you're cool with that.
Speaker 1: Well, trying to figure out what is the logical framework behind?
Speaker 1: Is it just anything that's not humans as good?
Speaker 5: Like?
Speaker 1: So you still haven't answered. Would you eat the chimpanzee
Speaker 1: and the bonobo?
Speaker 3: I probably would eat the champanzee and the bonobo. Yeah, exactly,
Speaker 3: nice clean libraries. Chimpanzee, Yeah why not? I mean I
Speaker 3: eat pigs, and so let's go all in. They're probably delicious.
Speaker 2: At least you're consistent.
Speaker 1: I recognize I'm not very consistent, which is part of
Speaker 1: why I shy away from meat all together, because I
Speaker 1: feel like I haven't quite formulated the framework for what
Speaker 1: I feel comfortable with and what I don't feel comfortable with.
Speaker 1: Props to you for being consistent.
Speaker 3: Well, I think it's interesting that a lot of people
Speaker 3: probably haven't really thought through what they would eat and
Speaker 3: what they wouldn't eat and why. I remember reading an
Speaker 3: article about speciesism like twenty something years ago that actually
Speaker 3: inspired me to become a vegetarian. Made me realize that
Speaker 3: I was being unfair to really smart pigs because I
Speaker 3: was giving them fewer rights then I was giving to,
Speaker 3: you know, not smart humans that I would refuse to eat.
Speaker 3: It made me feel like, hmm, maybe I just shouldn't
Speaker 3: be eating any creatures at all. And you know that
Speaker 3: lasted for like ten years. I was a militant vegetarian
Speaker 3: for like ten years until I had a son and
Speaker 3: he was very obviously a carnivore, and we lived in France,
Speaker 3: where if you ask for vegetarian lunch they give you
Speaker 3: like chicken or fish. So it didn't last that long.
Speaker 3: And these days I just feel like, yes, there is
Speaker 3: something special about being human.
Speaker 1: For a while, I was some special kind of vegetarian
Speaker 1: where I like mostly wouldn't eat meat, but if I
Speaker 1: knew that the animal had been treated mainly its whole
Speaker 1: life and was euthanized humanely, so it was a cow
Speaker 1: that lived on this beautiful farm and had free range
Speaker 1: and had buddies.
Speaker 3: It could paint twice a week and do arts and
Speaker 3: crafts and.
Speaker 1: Stuff yoga class on Wednesdays. I would make exceptions for that.
Speaker 1: And since I was in grad school at the time.
Speaker 1: I couldn't afford to do that very often. So it
Speaker 1: was like I'd have, you know, one meat dish a
Speaker 1: month where I would go and pay for that. And Zach,
Speaker 1: my husband, likes to laugh because the thing that ended
Speaker 1: up breaking my like vegetarian streak was I just couldn't
Speaker 1: stop craving Arby's beef and cheddars.
Speaker 2: Can't witches, which is just the lowest quality food ever.
Speaker 1: But like my grand student heart just had to have one,
Speaker 1: and that was the thing. Like I had one, and
Speaker 1: then I was like, well, I've broken it, and then
Speaker 1: for a while I just ate what I could afford,
Speaker 1: which was Arby's because I was a grand student. Anyway,
Speaker 1: I've always had a complicated relationship with meat, I guess.
Speaker 3: And all of these behaviors are not rational, right, These
Speaker 3: are people's emotional feelings about what's right and what's wrong.
Speaker 3: What you grew up with, you know, I grew up
Speaker 3: not eating the shellfish at all, and so like I
Speaker 3: think shellfish are gross, and you cannot catch me eating shrimp.
Speaker 3: I'll eat a chimpanzee. But like shellfish, if it's icky,
Speaker 3: it's like insects of the ocean. I'm as likely to
Speaker 3: eat a cricket as I am to eat a shrimp.
Speaker 2: I am more likely to eat a cricket than a shrimp.
Speaker 1: I mean, so you kind of like deep poop the
Speaker 1: shrimp before you eat them, Like, I know that's just gross.
Speaker 3: Are gross? Exactly? And so on today's episode, I'm looking
Speaker 3: forward to exploring that line, like who eats who? And
Speaker 3: why do they do it? Why don't we eat our
Speaker 3: neighbors kids or should we?
Speaker 1: You know, I think law probably plays into why we
Speaker 1: don't eat our children's kids.
Speaker 3: Why is the law that way? And should it be
Speaker 3: that way?
Speaker 6: Right?
Speaker 3: Should we have a reform movement that says cannibalism is
Speaker 3: actually okay?
Speaker 2: You are asking all the big questions, Daniel.
Speaker 3: This is not my field, and so I feel totally
Speaker 3: comfortable just like asking the big dumb questions.
Speaker 2: Well that's great, I love that, all right.
Speaker 1: So, speaking of big dumb questions, I asked, how common
Speaker 1: is cannibal and non human animals? And have you ever
Speaker 1: seen it in nature? So I asked this to some
Speaker 1: of my friends. And the big dumb thing that I
Speaker 1: did was I accidentally mistyped my friend's number in because
Speaker 1: like it was somebody I hadn't messaged for a while,
Speaker 1: and I said some questions about cannibalism to like random
Speaker 1: person who's probably very confused.
Speaker 2: They never responded by like said the questions, and I
Speaker 2: was like.
Speaker 1: Oh gosh, I'm sorry, prom number, I'm a scientist. This
Speaker 1: is for like a science thing, and uh, like I
Speaker 1: got all awkward and I was like, I need to
Speaker 1: just stop texting this person. Let the more texts I send,
Speaker 1: the more crazy they think.
Speaker 2: I am.
Speaker 3: Well, at least you gave them a funny story that
Speaker 3: they can tell at their next dinner party, which I
Speaker 3: hope is not a cannibalistic one. And if you would
Speaker 3: like to give answers to random questions, maybe about cannibalism,
Speaker 3: maybe about particle physics for future episodes of the podcast,
Speaker 3: please write to us to questions at Daniel and Kelly
Speaker 3: dot org.
Speaker 2: And now let's hear from Kelly's friends.
Speaker 7: I have definitely heard of animals being cannibalistic. I remember
Speaker 7: being in the fifth grade and I had gotten like
Speaker 7: a tink of fish as a birthday peasant, and I
Speaker 7: had one fish that attacked all the other fish and
Speaker 7: ate them, and it.
Speaker 5: Was a little traumatic I am really not sure. I
Speaker 5: don't think that it's terribly common in the vertebrate world,
Speaker 5: but maybe more common in some invertebrates for some reason.
Speaker 5: I'm thinking among the insects possibly. I do think I
Speaker 5: have seen, especially some insects cannibalizing other insects that I
Speaker 5: believe would be the same species.
Speaker 4: I think it is pretty widely you know, out there,
Speaker 4: So I think like insects and even like some amphibians
Speaker 4: and things like that do it because it's one of
Speaker 4: those things where you want to eat no matter what
Speaker 4: and survive. I've also heard about bears, so bears will
Speaker 4: do it to other young cubs from from breeding mothers
Speaker 4: because that will then induce them into like a breeding
Speaker 4: cycle so that they can then become the father, et cetera
Speaker 4: and pass on their genes.
Speaker 8: I think this is probably pretty common in the animal kingdom,
Speaker 8: but I mostly associated with parenting. My understanding is that
Speaker 8: it in my brain anyway, is that it comes up
Speaker 8: most often in situations where like a cat or a
Speaker 8: rabbit or a dog like is really kind of distressed,
Speaker 8: maybe like whatever. The dog equivalent of postpartum depression is,
Speaker 8: I don't know, and they eat their offspring.
Speaker 9: I would guess that cannibalism is kind of common among
Speaker 9: fogs and snakes and insects, possibly fish. I do remember
Speaker 9: that I had signed these fighting fish that gave birth
Speaker 9: to babies, and you had to quickly separate the babies
Speaker 9: otherwise mom and dad would eat them.
Speaker 6: Yeah.
Speaker 9: I guess if the bud dies in a colony, they're
Speaker 9: not just gonna.
Speaker 4: Give it a burial.
Speaker 9: They'll probably just repurpose all it's nutrients or something. I'm
Speaker 9: just guessing.
Speaker 3: How do you feel about these answers, Kelly?
Speaker 1: I thought that my friends gave great answers about cannibalism.
Speaker 1: I also felt like they were really great sports.
Speaker 6: One of the.
Speaker 1: People, like, I texted in the question and they texted back,
Speaker 1: I didn't know what to expect, but this is so
Speaker 1: totally on brand for you.
Speaker 2: I was like, what does that mean?
Speaker 1: But then also, yes, you're right, totally on brand. So no,
Speaker 1: I thought they were great. It seems like there's this
Speaker 1: like hypothesis building based on the answers that invertebrates maybe
Speaker 1: do cannibalism more than vertebrates, because I thought that was
Speaker 1: like a pretty common theme. I don't actually know if
Speaker 1: like insects are more likely to eat each other than
Speaker 1: fish or frogs. I've seen lots of fish eating the
Speaker 1: same species. But yeah, I thought there were great answers.
Speaker 1: What did you think? And how are you going to
Speaker 1: try to connect it to humans?
Speaker 2: This time?
Speaker 3: I thought it was interesting how widespread the answers were.
Speaker 3: Some people thought it almost never happens, and some people
Speaker 3: think it's pretty common. I'm pretty curious to know how
Speaker 3: often does this happen out there in the animal kingdom?
Speaker 3: Is just humans that awkwardly joke about cannibalism on podcasts?
Speaker 3: Or is that also something that happens in the fish world.
Speaker 1: Let's learn more about the forbidden meal on today's show,
Speaker 1: We Have Folk Are Rudolph. He's a full professor of
Speaker 1: ecology and evolutionary biology at RICE. He's editor in chief
Speaker 1: at The American Naturalist, which in my field, that is
Speaker 1: a huge stinking deal. He is self diagnosed with scientific
Speaker 1: add He studies stuff like a penology, which is like
Speaker 1: the timing of when stuff happens in nature, like when
Speaker 1: are the flowers blooming, when are the tadpoles turning into frogs?
Speaker 2: And how does that change over time?
Speaker 1: He also studies like temporal dynamics, you know how that
Speaker 1: stuff is changing across the United States, for example, and
Speaker 1: climate change. But we're not talking about any of that
Speaker 1: today because a few years ago he was studying cannibalism
Speaker 1: and I've never forgotten how awesome that is. So we're
Speaker 1: going to talk to him today about cannibalism.
Speaker 2: So what got you into cannibalism.
Speaker 3: And what do your parents think about that?
Speaker 10: So I got interested in doing grad school. I was
Speaker 10: looking for a thesis topic, and I did some reading.
Speaker 10: I was generally interested like in the role of size
Speaker 10: and like mediating interactions, and at some point it came
Speaker 10: across some work in cannibalism and fish, and they were
Speaker 10: really curious about kind of like the role of cannibalism
Speaker 10: and regulating the populations. And then this had bigger consequences
Speaker 10: for the entire ecosystem because this was like a top
Speaker 10: predator and they got this interesting dynamics that were all
Speaker 10: driven by cannibalism, and so like look more into it
Speaker 10: and realize that there is not much known about cannibalism,
Speaker 10: especially ecological consequences of it, and most have been tweeted
Speaker 10: this kind of like weird thing that happens, but we
Speaker 10: don't want to talk about it kind of like, but
Speaker 10: it was really interesting to me, and so like I focused,
Speaker 10: I wanted to know more about the ecology of it,
Speaker 10: kind of.
Speaker 6: Like what's driving it.
Speaker 10: We've now been looking more into like the evolution of
Speaker 10: it as well, so it's been more like a slow
Speaker 10: organic process.
Speaker 1: So as a parasitologist, people always want to tell me
Speaker 1: about the time they thought they were infected by a parasite.
Speaker 1: Sometimes they want to show me photos of their feces.
Speaker 1: As someone who studies cannibalism, do people try to tell
Speaker 1: you stories about like, oh, my fish, ate my other fish?
Speaker 1: Have you acquired many weird stories?
Speaker 10: If I talk about my research, then you should people
Speaker 10: get stuck on the cannibalism stuff because the most interesting
Speaker 10: dinner conversation topic.
Speaker 3: People wanted to talk about cannibalism over dinner.
Speaker 10: Yeah, but it's like once we start publishing some more
Speaker 10: and then especially and then we're going to talk about
Speaker 10: later this stuff we did on the interaction between comes
Speaker 10: from disease. I started getting a lot of you know,
Speaker 10: like media stuff from like in radio shows and other
Speaker 10: podcasts thing, and nine of those all had to do
Speaker 10: with some weird human anecdote thing, which is like nothing
Speaker 10: I do at all or right, but it's like so
Speaker 10: I got a little frustrating. They're like, okays, like this
Speaker 10: is not really what I do, but sure, yeah.
Speaker 3: Well, how widespread is any knowledge of cannibalism, Like do
Speaker 3: people have mostly a misunderstanding of what cannibalism is and
Speaker 3: how it works? Or is the concept in the minds
Speaker 3: of the general public pretty much accurate.
Speaker 10: I would say there's a pretty big misconception overall. And
Speaker 10: most of that so really comes from like our take
Speaker 10: on like entreprenmdvising the whole thing when we think about
Speaker 10: cannibalism it so it goes back to the idea that
Speaker 10: this is something that only happens on the extreme weird circumstances.
Speaker 6: It's not normal.
Speaker 10: I think that's kind of like how most people think, like, oh,
Speaker 10: there's this week antidote about the shark doing some freaky thing,
Speaker 10: and like.
Speaker 6: That's not normal.
Speaker 10: And in reality, and when cannibalism is completely normal, it's
Speaker 10: super widespread. It's everywhere in animal kingdom, And there's why
Speaker 10: do we take the morals away from it? It makes
Speaker 10: sense because it's some normal ecological interactions just to predator
Speaker 10: prey interactions.
Speaker 6: This happens to be like the same species.
Speaker 2: And how widespread is it?
Speaker 1: So I tell a story at the beginning of the
Speaker 1: episode where my small mouth bass we're eating each other
Speaker 1: during my master's project, and I was like totally surprised
Speaker 1: by you know, where all the fish and my experiment
Speaker 1: were going.
Speaker 2: What other organisms do it?
Speaker 10: I mean, I would say, like, if it's predatory, there's
Speaker 10: really high chance it's cannibalistic. So most species and other
Speaker 10: predators are probably to some extent cannibalistic, and then there's
Speaker 10: some variation and nuanced. But I would say for me
Speaker 10: that it's like the default. There are exceptions to that
Speaker 10: that are not cannibalistic, and there various reasons for that.
Speaker 10: But I'd say the default is kind of like predatory.
Speaker 10: It's cannibalistic, and there are a bunch of other species
Speaker 10: that are not even predatory. There's still cannibalistic, right because
Speaker 10: it can help, but like nutrient deficiencies, the components or
Speaker 10: just removing competitors from the field, right, So it's all
Speaker 10: over the place. It's probably one of the most underreported
Speaker 10: interactions in the animal kingdom.
Speaker 3: I think a lot of people might wonder why cannibalism
Speaker 3: is so widespread. I think like a naive understanding of evolution,
Speaker 3: like the one that I have, for example, would suggest
Speaker 3: that it might be detrimental to the population as a whole. Right,
Speaker 3: But is it as simple as yeah, but it helps
Speaker 3: you and your genes or all you care about pretty much.
Speaker 10: Yeah, it's from a in real perspective, it's just another
Speaker 10: way of getting resources, and you're not doing it to
Speaker 10: the benefit of the population. You're just trying to increase
Speaker 10: your own personal fitness. And in many scenarios that's a
Speaker 10: good option. Right, So you can think of it, for instance,
Speaker 10: if you're cannibalistic, you can remove competitors from the environment.
Speaker 6: Right, that's like a direct goal.
Speaker 10: Not only do you remove them from the environment, you
Speaker 10: actually get energy from them on top of it. Right,
Speaker 10: So it's a double wind situation and the costs are something.
Speaker 10: Then that's like under which conditions is it not beneficial?
Speaker 10: And then you come back on like inclusive fitness and
Speaker 10: kind of like what does it do to your offspring
Speaker 10: and what's the risk of eating those.
Speaker 3: It's like Google acquiring other companies, right, competitors off the field.
Speaker 6: Yeah, pretty much.
Speaker 3: All right, Well, then I have a question for you
Speaker 3: about cannibalism that I'm pretty sure you've never gotten before.
Speaker 6: Okay, So I've.
Speaker 3: Heard the argument that on other planets, if life evolves,
Speaker 3: it's very likely that there will be predators there because
Speaker 3: beings will chomp on other beings because, as you say,
Speaker 3: it's a rich source of nutrients. So then my question
Speaker 3: to you is are you suggesting that aliens are very
Speaker 3: likely also cannibals.
Speaker 6: That's a pretty good chance.
Speaker 3: Yeah, all right, and I think we have our spinoff
Speaker 3: movie Alien Cannibals. We'll wait for the first drafter the
Speaker 3: script from you looking forward to that.
Speaker 6: It's the question I heard before.
Speaker 2: So Daniel.
Speaker 3: And I got the work in Aliens double bonus.
Speaker 1: Okay, So is there a difference between cannibalism if you're
Speaker 1: the one killing the conspecific you plan on eating, or
Speaker 1: if you like come across it and it's dead, both
Speaker 1: of those are cannibalism or does the definition of cannibalism
Speaker 1: imply that you had to like kill the organism before
Speaker 1: you eat it or is it all the same?
Speaker 10: So the definition were kind of stuck in bin was
Speaker 10: like killing in at least partial consumption of a conspecific,
Speaker 10: So if it's already dead, we would call it necrophagi.
Speaker 10: As I comment, so we talked about this, so like
Speaker 10: in the disease perspective, that's like a different dynamic. But
Speaker 10: I guess so I would usually we can talk about
Speaker 10: cannibalism and most of the literature in the walls the
Speaker 10: killing part. But of course, like most terms, there's various
Speaker 10: definitions of it floating around.
Speaker 1: Okay, all right, so I know that all of us
Speaker 1: on this call are parents, So what are some benefits
Speaker 1: of eating your children?
Speaker 10: Interesting choice? I mean, so when you see parents consuming
Speaker 10: their offspring, right, But for many ways, that's like the
Speaker 10: thing that usually selects against cannibalism. But there are reports
Speaker 10: of this and various instances where you have parents eating
Speaker 10: their offspring. And the example for instance, like in fish,
Speaker 10: there's an interesting study that came out a while ago
Speaker 10: where they showed that males that was regarding the eggs
Speaker 10: for the females, we're more likely to cannibalize the eggs
Speaker 10: if they thought that they weren't actually the deads, right,
Speaker 10: so the other dad would swoop in doing like the
Speaker 10: fertilization process, and if they thought someone else actually fertilized
Speaker 10: the eggs that would just eat it and do it
Speaker 10: over again. There's another one where you have scenarios where
Speaker 10: like parents will consume their offspring, for instance, in case
Speaker 10: of a disturbance for instance, or like the risk of predation.
Speaker 10: I think in those cases it's kind of like the
Speaker 10: idea behind it is the evaluating is, Okay, if some
Speaker 10: preter comes in, they're going to eat all my eggs,
Speaker 10: I get nothing. If I eat the eggs, I at
Speaker 10: least get part of the energy back that invested in it,
Speaker 10: all right, So it's kind of like a very risky
Speaker 10: kind of like to lose it all or do it
Speaker 10: keep some of it? So like scenario which it does
Speaker 10: happen in some scenarios that's cold, yeah.
Speaker 3: Rather cannibal dilemma, huh yeah.
Speaker 10: But there very few instances where eating your offspring is beneficial.
Speaker 6: I mean, I can not really think of a whole lot.
Speaker 10: Like I said, in most cases, that's what selects against it.
Speaker 6: Don't eat your kids.
Speaker 1: Follow up on that one, we do like a random
Speaker 1: survey of people before we do an interview to ask
Speaker 1: what their opinions are on the topic, and one of
Speaker 1: the people we interviewed said that they thought mostly cannibalism
Speaker 1: was about eating their young because they had heard so
Speaker 1: many store worries and I guess they had a lot
Speaker 1: of like hamsters, and the hamsters would get stressed out
Speaker 1: and they'd eat their young, so it was like a
Speaker 1: stress thing. But you're saying that, like, it definitely happens sometimes,
Speaker 1: but it's probably not the most common example of cannibalism.
Speaker 10: So, I mean, the most part is like the eating
Speaker 10: you're on is kind of like a byproduct of just
Speaker 10: eating your conspecifics, right, So it does happen.
Speaker 3: Sorry, what's a conspecific for those of us who are
Speaker 3: not biologists.
Speaker 10: Sorry, conspecific means like a member of your own species.
Speaker 10: I see, Okay, because sometimes cannibalism gets so confused with
Speaker 10: like predation, but it has to be the same species or.
Speaker 6: It's not cannibalism.
Speaker 10: So in most scenarios where you have cannibalism, you get
Speaker 10: the accidental or occasional eating of your own offspring, right,
Speaker 10: and so incentce Like, we did a study in flower beetles,
Speaker 10: so we kind of tried to figure out whether these
Speaker 10: guys recognize their eggs their own eggs and whether they
Speaker 10: would eat them less, because these are really cannibalistic. And
Speaker 10: so what we figured out is that, yes, they do
Speaker 10: seem to recognize it, but that just means they eat
Speaker 10: them some what less, not that don't eat it.
Speaker 6: Right.
Speaker 10: And so I feel like many examples, it's kind of
Speaker 10: like when the risk of encountering your own like babies
Speaker 10: is relatively there's no real selection for like recognizing or
Speaker 10: worrying about it, and you just eat whoever's like it
Speaker 10: fits in your mouth sort of perspective.
Speaker 6: And sometimes those may be your offspring and sometimes they're not.
Speaker 10: And I think in the case of the hamsters and
Speaker 10: the others, it's like they would probably eat other babies too.
Speaker 10: In there, it's not that they specifically want to eat
Speaker 10: their own babies. They're just like stressed at they're trying
Speaker 10: to remove competitors the territorial and there's just not enough
Speaker 10: of a bear to like select against not eating your
Speaker 10: own in that scenario.
Speaker 3: But yeah, I'm still trying to understand the fact that
Speaker 3: there's no selection pressure against eating your neighbor's kids. I mean,
Speaker 3: don't a lot of creatures survive because of communities, You know,
Speaker 3: A bunch of penguins held together to survive the wind,
Speaker 3: or a pride of lions help each other out or whatever.
Speaker 3: Don't we all get along better if we stop eating
Speaker 3: our kids and worry about our kids being eaten every
Speaker 3: time we leave the house. Isn't there some benefit to that?
Speaker 10: I just brought up the pride of line because lines
Speaker 10: are also pretty cannibalistic, so i'llout that helping now. In fact,
Speaker 10: you often have so like the meals go in and
Speaker 10: like when the takeover, probably to especially like kill all
Speaker 10: the offsprings of the female and eat them because they
Speaker 10: want to be like the dad's of the kids and
Speaker 10: not like raise somebody else's kid. At least that's how
Speaker 10: the theory goes. I mean, that's a very sort of
Speaker 10: group selecting perspective, which is an interesting discussion. I'm sure
Speaker 10: Kelly has some ideas about it too.
Speaker 3: Is that a controversial topic or something partial because we
Speaker 3: don't understand whether it happens or some people believe it
Speaker 3: does and some people who believe it doesn't. Or as
Speaker 3: a non biologist, I don't know what sort of the
Speaker 3: third rail to discuss in terms of.
Speaker 10: Evolution, because it's a hard scenario to really make work
Speaker 10: to like care and like help the unrelated individuals. It's
Speaker 10: a complicated strategy to get working because it's just so
Speaker 10: prone to cheating. And so usually when you see this
Speaker 10: or like helping behavior, that's kind of like more something
Speaker 10: where it's like your offspring or your siblings or something
Speaker 10: like that. In that case, is it comes back to
Speaker 10: like kind selection and inclusive fitness, which is also something
Speaker 10: that influences cannibalism. In fact, for the helping, I often
Speaker 10: like to think of this altruistic behavior, and cannibalism is
Speaker 10: like the flip side of a coin. Right, then both
Speaker 10: extreme there's the helping and being mutualistic and beneficial, and
Speaker 10: then there's the other extreme of like just being as
Speaker 10: selfish as you possibly can. And so cannibalism is like
Speaker 10: the selfish as possibly can because you're literally killing someone
Speaker 10: on for your own benefit, right, it's hard to be
Speaker 10: more selfish and understanding at what point you know, like
Speaker 10: selection favors one strategy over the other.
Speaker 6: That's kind of like I think one of the interesting questions.
Speaker 1: Yeah, I feel like my take on it is that
Speaker 1: for a while, you know this idea that animals were
Speaker 1: doing things for the benefit of the species was kind
Speaker 1: of a popular idea. It was a long time ago,
Speaker 1: and then pretty quickly when we started digging in, it just.
Speaker 2: Wasn't making sense.
Speaker 1: And doing things for the benefit of the species at
Speaker 1: the expense of yourself just sort of doesn't really work evolutionarily.
Speaker 1: And now the big question is when organisms are helping
Speaker 1: each other, why the heck are they doing that.
Speaker 2: So we've almost swung to the opposite direction.
Speaker 1: Now we're trying to explain why animals help each other out,
Speaker 1: and often it turns out that they're related in some way,
Speaker 1: or maybe they're like reciprocally sharing resources, and it's like,
Speaker 1: all right, you helped.
Speaker 2: Me out, so I'll help you out.
Speaker 1: But like if someone doesn't help out, then you know,
Speaker 1: maybe you eat them instead. That's sort of my take
Speaker 1: on how we've sort of swung from one direction to another.
Speaker 3: Is that how biologists all look at each other. They're like, look,
Speaker 3: we'll collaborate on this paper, but if you stop pulling
Speaker 3: your weight, I might just eat you.
Speaker 2: Academia is tough, exactly, but not that tough.
Speaker 3: I guess. Well, you know, something that's forefront in my
Speaker 3: mind during this conversation is the obvious counter example which
Speaker 3: is humans right, as humans, we do help each other out.
Speaker 3: Young men go off and die in wars to protect
Speaker 3: other people. It's also one of the examples of a
Speaker 3: species that maybe has less cannibalism than other species. Is
Speaker 3: it because we've succeeded to help each other out so
Speaker 3: much and work together as a society. Is that why
Speaker 3: we have a stigma against cannibalism? Or are you going
Speaker 3: to tell me that people eat each other just as
Speaker 3: much as other species.
Speaker 10: So I'm not an althropologist, but it's like when we
Speaker 10: so I looked into some of this, we kind of
Speaker 10: got into the anthropology literature, and I will say, like,
Speaker 10: for most of the human history there's been an element
Speaker 10: of cannibalism, and they're linked back to Neanderthal it's different cultures.
Speaker 10: The point at which all societies, as far as we know,
Speaker 10: stop cannibalism is actually pretty recent, like and some of
Speaker 10: Papua New Guinea you still have cannibalism, and they're like
Speaker 10: the nineteen fifties to nineteen seventies somewhere around that. So
Speaker 10: for modern humans, right, twenty first century humans, that's definitely true.
Speaker 10: But in the past cannibalism has been pretty much part
Speaker 10: off like many different cultures, like across all the different continents,
Speaker 10: and that ranged between you know, like some ancestral ritual.
Speaker 10: It's about now ensuring that you ants live on to
Speaker 10: like getting the powers of your enemies and these sort
Speaker 10: of different commonents. So humans have definitely engaged in cannibalist
Speaker 10: activities in path societies for sure.
Speaker 1: You mentioned that in the nineteen fifties cannibalism was still
Speaker 1: happening in Papua New Guinea and that group became fairly
Speaker 1: famous because of a disease that they got through that practice.
Speaker 1: And when we come back from the break, we're gonna
Speaker 1: go ahead and talk about that.
Speaker 3: So everybody finished cooking up your dinner and get ready
Speaker 3: to hear about it. Kelly, do you have a snack
Speaker 3: in front of you? Are you ready to talk about cannibalism?
Speaker 2: Somemore, Oh, you know, I always have snacks.
Speaker 1: I've got my cheese and crackers in salami, and I'm
Speaker 1: just not thinking too hard about it. And you know,
Speaker 1: as a person who studies parasites, I never think too
Speaker 1: hard about what are meeting or maybe I.
Speaker 2: Should, but anyway, it would be a good diet strategy.
Speaker 1: We talked about the folks in Papua New Guinea who
Speaker 1: were engaging in cannibalism up until the nineteen fifties. And
Speaker 1: another area of research that you focused on is disease
Speaker 1: and how it maybe makes cannibalism less beneficial. So can
Speaker 1: you tell us a little bit more about Kuru and
Speaker 1: then about disease transmission from cannibalism in the non human animals.
Speaker 10: So Van Koura got famous because it's like it's a
Speaker 10: prime disease that's in some way you can think of
Speaker 10: it like creterrali arc up disease, another prime disease that's
Speaker 10: like an alternative disease.
Speaker 6: And it's interesting about it that it.
Speaker 10: Often can take a long time for it to come up,
Speaker 10: like in a several years.
Speaker 1: Can you tell us real quick what are prion diseases?
Speaker 1: Because I think a lot of people don't know.
Speaker 6: About this, right, it's a prime disease.
Speaker 10: Is diseases that are called by infectious proteins, which actual
Speaker 10: proteins the normally in your body, but they're being inspired
Speaker 10: to change their shape and that shape then.
Speaker 6: Is not as functional, can cause various diseases.
Speaker 8: Right.
Speaker 10: There's like I mentioned critrial yaka disease, which is like
Speaker 10: a new generative disease. There are several equivalents that we
Speaker 10: know of, like an animal disease is like make out disease,
Speaker 10: a few other ones.
Speaker 3: So if prions are proteins, it means they're not alive, right,
Speaker 3: there's like little bits of stuff. They are little molecular machines.
Speaker 3: What makes it a disease and not like a poison?
Speaker 3: Is it because it replicates itself somehow.
Speaker 10: Or it replicates itself in the body Because it's basically
Speaker 10: so like a dynamic reaction where it's like you can
Speaker 10: think of one protein that's like changed in the shape,
Speaker 10: bumping into the normal shape one and like changing it
Speaker 10: to that shape like with chain reaction.
Speaker 3: That's crazy. Proteins are amazing.
Speaker 10: It was a long controversy to prove that they're actually
Speaker 10: the cause of a disease because they're like normal parts
Speaker 10: of your body and there's no like external infectious agent
Speaker 10: that was initially identified. So they it's a really interesting
Speaker 10: history about like how long it took them to figure
Speaker 10: out what prime diseases are and what causes them.
Speaker 1: Yeah, they're crazy, but so as you noted for the
Speaker 1: folks who were suffering from this neurodegenerative disease. It was
Speaker 1: really hard to figure out a cause because there was
Speaker 1: this long delay between the activity and then the onset
Speaker 1: of symptoms.
Speaker 2: Can you tell us some more about that before I
Speaker 2: derailed you.
Speaker 10: The idea was that they found these diseases in certain
Speaker 10: cultural groups and Papua New Guinea, and ultimately it was
Speaker 10: tracked to some of their like burying rituals, which involved
Speaker 10: actually so consuming part of the dead ancestor right so
Speaker 10: like it handsome diseased, and they figured that this was
Speaker 10: like the main source and how these things were actually
Speaker 10: being transmitted. And that's kind of like the history of
Speaker 10: how curu was linked to the cannibalistic practices in humans.
Speaker 3: Wait, so they would bury the ancestors and then eat
Speaker 3: them or eat them and then bury them or eat
Speaker 3: them and bury them. I lost track.
Speaker 6: That's a good question. I've hard to remember how.
Speaker 3: Or maybe it's like that Swedish dish where you bury them,
Speaker 3: you let them rode for six months and you dig
Speaker 3: them up and eat them.
Speaker 10: No, I think was before I remember the details. I
Speaker 10: would have to look that up again. Listening about prime
Speaker 10: diseases too, the extra very stable so sometimes even cooking
Speaker 10: can kill them, right, which is another sort of thing
Speaker 10: that mixed firing disease is weird.
Speaker 3: And so the connection to cannibalism is that if this
Speaker 3: exists in the person you're eating, you eat the thing,
Speaker 3: now you have the protein in you, and so now
Speaker 3: you have the disease.
Speaker 6: Yes, So that's how it was like traced back.
Speaker 10: It was tricky, but I mean they used to like
Speaker 10: in the records of like previous infections or like weird
Speaker 10: behaviors of people and other sort of stuff and trying
Speaker 10: to trace it back to like where they came from.
Speaker 10: But of course it's hard to trace a disease back.
Speaker 10: That sometimes takes twenty plus us to establish and figure
Speaker 10: out where's coming from.
Speaker 1: Yeah, so how common is this in non human animals?
Speaker 1: Not necessarily pryons jumping back and forth during cannibalism, but
Speaker 1: just like any disease, and what kind of diseases are
Speaker 1: most commonly transmitted.
Speaker 10: It's an interesting question because the things like in one way,
Speaker 10: you can just think of like cannibalism being so like
Speaker 10: a way of acting with members of your own species,
Speaker 10: which can always increase the risk of infection.
Speaker 6: Right, So if you.
Speaker 10: Consume an individual that's infected just by like getting in
Speaker 10: contact with infacted individual as a good chance that you
Speaker 10: pick it up.
Speaker 3: What are you saying you're more likely to get a
Speaker 3: disease if you eat somebody from your own species, then
Speaker 3: if you eat somebody not from your species. Is that
Speaker 3: because you're more likely to be susceptible to the same diseases, it's.
Speaker 6: More likely to go to susceptible to the same diseases.
Speaker 10: In fact, there spends like some theories and experiments like
Speaker 10: Dave Finnick who was like testing that and so that
Speaker 10: I was like, are you more likely to get infected
Speaker 10: by your own species?
Speaker 6: They did that actually in tadpoles.
Speaker 10: Believe it or not, they also cannibalistic, some of them
Speaker 10: spayed for tadpoles actually, and they found that like when
Speaker 10: they consumed the conspecific that was infacted, they get more
Speaker 10: likely to be in facted and if they ate another species,
Speaker 10: And so they used that as like an idea of
Speaker 10: selecting against cannibalism. And they did find that they were
Speaker 10: more likely to discriminate against their own species than any
Speaker 10: other unless likely to eat them. And so there was
Speaker 10: the idea that disease could select against cannibalism because there's
Speaker 10: a higher risk of infection.
Speaker 1: Does it depend on the kind of diseases? So, like,
Speaker 1: you know, if someone's not sneezing anymore because they're dead,
Speaker 1: they're probably not going to give me the cold or
Speaker 1: the flu. If I eat their brains, I might get
Speaker 1: a pry on disease. So is there certain kinds of
Speaker 1: diseases you're more likely to get or is it not
Speaker 1: that easy because it's ecology.
Speaker 10: I think ultimately there is not a lot of research
Speaker 10: on this specific topic. You might be surprising, but them,
Speaker 10: I was like there, for instance, I have like an
Speaker 10: insects and others, Like it's pretty common there. When the
Speaker 10: individuals become infected, then the jest can lead to another infection.
Speaker 10: But there's also this scenario where like if it's a
Speaker 10: disease that for instance, needs to be inhaled to get
Speaker 10: any respiratory tract or like go a certain route and
Speaker 10: you eat it and they're just go in your stomach
Speaker 10: and get digested, They're not going to actually become infected, right,
Speaker 10: So if you consume the individuals before it's an infectious state,
Speaker 10: especially then you know, like you could actually remove sick
Speaker 10: individuals from the population. So it really so depends on
Speaker 10: how much the infection relies on you actually come in
Speaker 10: contact with it, or whether it relies on you being.
Speaker 6: Ingested by the individual.
Speaker 10: I think there are no hard facts on it, but
Speaker 10: I think it comes down to the transmission mode of
Speaker 10: the disease.
Speaker 3: And in general, most of these diseases are killed by cooking, right,
Speaker 3: So if you cook the creature, you're most likely going
Speaker 3: to kill the disease, except for preons, which is why
Speaker 3: they're so terrifying. Right, Yeah, I guess in the natural world,
Speaker 3: temples don't usually like grill each other before eating.
Speaker 6: There's not a lot of cooking going on in the
Speaker 6: natural world.
Speaker 3: But is there zero, like I mean, is there really
Speaker 3: zero use of fire by any other creature other humans?
Speaker 3: Excuse my completely naive question.
Speaker 1: I don't think chimpanzees are Bonobo's cook over fire. They've
Speaker 1: got other ways of trying to remove parasites that folks
Speaker 1: have postulated, but they're not cooking their meat beforehand.
Speaker 3: And so are there other species where cannibalism seems to
Speaker 3: be sort of disinclined or suppressed the way it is
Speaker 3: in modern humans or is it really everywhere in the
Speaker 3: animal kingdom?
Speaker 6: I would say it's almost everywhere. It's like I always
Speaker 6: call it ubiquitous.
Speaker 10: I'm not saying everybody is cannibalistic, but a lot of
Speaker 10: them are.
Speaker 6: And there's of course a gradi end, right.
Speaker 10: It's like some species are highly cannibalistic and some species
Speaker 10: may not be cannibalistic.
Speaker 6: Yeah, it's a full spectrum, I would say.
Speaker 3: And is there any organization to that spectrum. Is it
Speaker 3: like the more you're fish, like the more cannibalistic you are,
Speaker 3: or you know, the larger your number of offspring or something.
Speaker 3: One of the.
Speaker 6: Patterns, well, Kelly is like list digress.
Speaker 10: So I always thought about it, and it's like I
Speaker 10: don't think there is a general Somatan land list that
Speaker 10: I can pull that out. I think part of that
Speaker 10: is because I don't think cannibalism is sufficiently reported in
Speaker 10: most organisms.
Speaker 6: Sometimes I remember reading like papers.
Speaker 10: About food webs where it's like, oh, like in this
Speaker 10: food web, there's like, you know that no cannibalistic link
Speaker 10: in it, And like I looked at it and like
Speaker 10: pulled out ten spieces that are known to be cannibalistic.
Speaker 6: There's a strong under reporting.
Speaker 10: That makes it difficult to go out there and say, okay,
Speaker 10: are the general patterns are like certain taxa or certain
Speaker 10: functional groups and more cannibalistic than others.
Speaker 6: I don't think we even have the data to test
Speaker 6: that right now.
Speaker 10: That's why I say, like, I do think like most
Speaker 10: prosit cannibalistic, But then after that it's very hard to
Speaker 10: make more generalization about which ones are more likely. I
Speaker 10: think there's certain like if your species with parental care
Speaker 10: or certain social structure, it's a lot less likely or
Speaker 10: even selected against it. So there should be some patterns,
Speaker 10: but I'm not aware of any analysis it'll look to that.
Speaker 3: And when you say underreported, that makes it sound like
Speaker 3: it's you know, stigmatized or something people who don't want
Speaker 3: to talk about it. Is it just that we don't
Speaker 3: have the data because there isn't enough funding, or because
Speaker 3: it's difficult to gather for some reason, or.
Speaker 10: I think it's because for like decades people stigmatized it.
Speaker 6: Right So if you think if.
Speaker 10: You go back to like Bibil apples Felt was a
Speaker 10: famous behavior psycologist, and he was the one that I
Speaker 10: was talked about like they're good for the species, whereas like, oh,
Speaker 10: we don't do that, and cannibalism was immediately linked into.
Speaker 6: This where it's kind of like, oh, that's just a
Speaker 6: freak of nature.
Speaker 10: It only happens, you know, like maroond On and Alan
Speaker 10: and have nothing else to eat over the airplane crashes
Speaker 10: in the Arctic or something. Right, I was definitely considered
Speaker 10: as non normal interactions, and I still think to this
Speaker 10: day it's like it's lester in other interactions.
Speaker 6: Also, it's a lot more than it was let's.
Speaker 10: Say, like in the nineties or the early two thousands,
Speaker 10: So I was like, so it's getting a little bit
Speaker 10: more attention. But because of the stigmatization, there was very
Speaker 10: little research for law, and I felt every time I
Speaker 10: publish it on my paper at first to argue and saying, actually,
Speaker 10: this is everywhere, we just don't talk about it, right,
Speaker 10: So I was like I had to justify why we've
Speaker 10: been doing this, and then it's not weird and and
Speaker 10: just you know, like an unnatural behavior, but it's like
Speaker 10: pretty common.
Speaker 3: So if I had to summarize your entire academic career
Speaker 3: in one sentence, would it be fair to say cannibalism
Speaker 3: is everywhere? And actually it's usually good.
Speaker 2: He does a lot of other stuff too.
Speaker 6: But yes, I think it's.
Speaker 10: Fair to say that it's really a part of the
Speaker 10: natural ecosystem, and in many ways it can be good.
Speaker 6: Right.
Speaker 10: For instance, cannibalism in predatory species can really stabilize predative
Speaker 10: predynamics and in fact help natural ecosystem do not cyclis much, right,
Speaker 10: or it can promote coexistence, so it actually plays an
Speaker 10: important role in natural ecosystems.
Speaker 6: Test we haven't appreciated.
Speaker 3: I didn't expect we were going to end up being
Speaker 3: pro cannibalism, but here we are.
Speaker 1: We jumped around, which is totally great. But we were
Speaker 1: talking about parents eating their kids. I feel like it's
Speaker 1: much worse for kids to eat their parents because like,
Speaker 1: how can you not appreciate all the effort your parents
Speaker 1: have put in there?
Speaker 2: But does that happen? Yes, what could you give us.
Speaker 6: Some exp.
Speaker 10: I mean in those cases, well, as if you think
Speaker 10: about it's like there's subspecies out there, they are pretty
Speaker 10: much just reproducing once in their lifetime, right. It's like
Speaker 10: we often think about like these repeated reprodactive events where
Speaker 10: during a lifetime you have multiple babies and so on.
Speaker 10: But for many species it's a one time thing. Right,
Speaker 10: It's like they put all their eggs in the basket
Speaker 10: that reproduced and in those instances actually is like there
Speaker 10: are some species. I'm trying to think of it. I
Speaker 10: think there's at least like a spider species. As essentially,
Speaker 10: the idea there is that the parents would die anyway,
Speaker 10: and it's kind of like parent nourishment position.
Speaker 6: Right, It's like they give their kids.
Speaker 10: More food and in this case it's just their last
Speaker 10: donation and it's them man.
Speaker 6: Right, it's like all in investment, the ultimate parenting.
Speaker 2: Kids, they're always taking taking.
Speaker 3: All right, Well, I feel like I have to connect
Speaker 3: the obvious dots here. You're telling us that cannibalism is
Speaker 3: actually pretty widespread. It even existed in human society for
Speaker 3: a long time. It's often beneficial, and it's probably a
Speaker 3: good idea to eat your parents. So would you advise cannibalism?
Speaker 3: Were you saying, like, hey, you're putting your parents to rest,
Speaker 3: your options or like cremation, burial or sate. Is that
Speaker 3: something we should have?
Speaker 2: And I'm really shocked you're going there, Daniel, But.
Speaker 10: Okay, yeah, yeah, I feel like I should be answered
Speaker 10: that question at all.
Speaker 3: Look, when the aliens come, they're going to ask us
Speaker 3: this question, and we need to have an answer. You know, you.
Speaker 2: Complete the fifth.
Speaker 10: I always go back to like what Kelly says, like
Speaker 10: with parasites and all items, like that's just an iffy thing.
Speaker 1: God, yeah, we're not going to think too hard about that.
Speaker 1: So I'm trained as an ecologist. I love hearing about,
Speaker 1: you know, ecological systems. And I was going through the
Speaker 1: like titles of papers that you've published, and I got
Speaker 1: really excited about the bulgie frogs and so tell us
Speaker 1: about why salamander cannibalism results in bulgie frogs.
Speaker 10: So the frogs is the tadpoles that are bulgey, right,
Speaker 10: So now that people think of like giant blobby frogs,
Speaker 10: so they're actually tadpoles and they like get bulger by
Speaker 10: getting these like out of jelly layers that really make him.
Speaker 6: Way bigger than they normally would be.
Speaker 10: And so that's a species in Japan and like one
Speaker 10: of our collaboratives that came across and it's a defense mechanism,
Speaker 10: but being bigger, they can't get eaten by salamanders potentially
Speaker 10: because they don't fit in their mouth right, So it's
Speaker 10: like blow yourself up like the popper fish, so you
Speaker 10: don't fit in somebody else's mouth.
Speaker 6: Which means you survive too big to fail, and so and.
Speaker 10: So these researchers found is like so cannibalism in these salamandos,
Speaker 10: which actually cannibalism in salamandes is really common. I've seen
Speaker 10: one species so far that it's not cannibalistic, but everybody
Speaker 10: else have worked with all the other species.
Speaker 6: We're all cannibalistic to some extent.
Speaker 2: But they're so cute.
Speaker 6: They are very cute. I agree.
Speaker 10: Salamanos will leave whatever fits in their mouth, right, It's
Speaker 10: kind of like if it moves, they'll try to shove
Speaker 10: it in.
Speaker 3: Their mouth like toddlers. I'm convinced if your parents would
Speaker 3: fit in your mouth.
Speaker 10: They probably would just shove it out there. It's like,
Speaker 10: if you don't think about it, right, it's just like food,
Speaker 10: exactly more food and so in salomon is. Sometimes you
Speaker 10: get so like different courts betweens, Like some parents lay
Speaker 10: their eggs earlier and then maybe like a few weeks later,
Speaker 10: another egg laying events, right, and these guys hatch and
Speaker 10: they're smaller than the earlier ones. And for those early
Speaker 10: ones they often get eaten by the older salamon the larvae,
Speaker 10: and because of that, they actually grow a lot faster
Speaker 10: and get bigger, like way bigger than they would without cannibalism. Right,
Speaker 10: So there's the clear beneficial roll of like you now
Speaker 10: eating it con specific to get bigger and stronger, and
Speaker 10: that's like accelerates growth for a few individuals, as like
Speaker 10: the cannibolts in the system, and they are the ones
Speaker 10: that then also pose the biggest risk for the tadpolts
Speaker 10: in the system because that's the other main food source.
Speaker 10: And so when you have those giant cannibals in the system,
Speaker 10: that select for balgy tadpoles. And so that's kind of
Speaker 10: how to get the feedback.
Speaker 1: So why aren't the tadpoles all is bulgi? Is it
Speaker 1: just like hard to move around if you're always bulgy,
Speaker 1: So you only do it if you have to be bulgie.
Speaker 10: I think there's a big investment cost in doing that,
Speaker 10: and they don't have to they don't do it. So
Speaker 10: it's kind of like an antipredator response, like once the
Speaker 10: predation is clearly happening, they're like, oh crap, like I
Speaker 10: better get boldry fast.
Speaker 3: So it's expensive, but it saves your life. Yes, but
Speaker 3: you don't do it unless you have to exactly excellent.
Speaker 3: So this is something at the cutting edge of understanding cannibalism.
Speaker 3: Can we zoom out and understand like what are the
Speaker 3: big questions remain? Like you're a researcher, your professor, you're
Speaker 3: doing research right now in a cannibalism What is like
Speaker 3: a big question you would love to know the answer
Speaker 3: to about cannibalism, or what are we going to know
Speaker 3: about cannibalism in twenty years that we don't know today?
Speaker 6: Thanks, I get for me.
Speaker 10: What's something we're working on and we currently actually have
Speaker 10: a grant they'd just like submitted to look at this more.
Speaker 10: It's trying to understand kind of like what limits cannibalism because,
Speaker 10: like what I've seen work with a bunch of different spieces,
Speaker 10: there a range of cannibalistic behavior, like I said, that
Speaker 10: goes from like the super cannibalistic, right, it's like they
Speaker 10: see another conspasy, they will eat them.
Speaker 6: I merely was one where like it's prutty uncommon.
Speaker 10: Even within the same species, you can find populations where
Speaker 10: some or more cannibalistic than others, and it has a
Speaker 10: genetic component to it, so it's not just like some
Speaker 10: environmental media one. It's like it's an inherited trade, where
Speaker 10: like some are more cannibalistic, some or less, and we
Speaker 10: don't really understand why. And I always like to think
Speaker 10: of this, whereas I said before, catalysm is a form
Speaker 10: or the ultimate selfish behavior. And kel I mentioned before
Speaker 10: that for like decades people were really interested in kind
Speaker 10: of like, Okay, when should selfish behavior move to altruistic behavior?
Speaker 10: And we spend on like decades on like figuring out
Speaker 10: when vidualism antalism should happen.
Speaker 6: But we don't really have a rule.
Speaker 10: It tasts like what should stop being extremely selfish?
Speaker 8: Right?
Speaker 10: Why isn't everybody as cannibalistic as they can possibly be?
Speaker 6: Right? There has to be something that's limited.
Speaker 10: And so what we're trying to understand is like, what
Speaker 10: are the environmental conditions that can do this? Is this
Speaker 10: something that really can go in different ways? And they
Speaker 10: are like multiple behaviors that can mitigate the cost of cannibalism.
Speaker 10: We talked about like one big of the cost of
Speaker 10: cannibalism is eating your own offspring, right, your own children,
Speaker 10: because that's a big loss of fitness. You can mitigate
Speaker 10: this by recognizing your own offspring, and you can still
Speaker 10: be as cannibalistic as you want, right, because then you's
Speaker 10: like set off the cost of fitness loss, but you
Speaker 10: can still remove your competitors.
Speaker 6: You can still get extra meals and all that stuff.
Speaker 3: And your kids competitors. Right, if you eat your neighbor's kids,
Speaker 3: then your kids are like top of the class.
Speaker 2: Right, So many lessons here.
Speaker 10: So there are many different ways of like mitigating the
Speaker 10: cost of cannibalism. And it's more like so like a
Speaker 10: behavioral multidimensional space where you can like just recognize them,
Speaker 10: or could be that your kids just get the genes
Speaker 10: to get the hell out of here, right, leave your
Speaker 10: parents as fast as possible and walk.
Speaker 6: Away from them.
Speaker 10: And then also like the parents can just continue to
Speaker 10: be cannibalistic. Right, So the different behaviors that can play
Speaker 10: a role with it, and understanding how they're all interact
Speaker 10: with the jail that to really drive the evolution of cannibalism,
Speaker 10: and then see how that can like explain a lot
Speaker 10: of the variation that we see within and across PCs.
Speaker 6: I think that's a big question for us.
Speaker 1: So you said, you've been like beating the drum that
Speaker 1: like cannibalism is common, this happens all the time. We
Speaker 1: need to understand it more. Has that message gotten out?
Speaker 1: Are ecologists over the stigma? Are more people studying this now?
Speaker 10: I think there are more people studying it now. It's
Speaker 10: like I'm not sure that this is because of me
Speaker 10: or whether that's just well, actually, I'm pretty sure it's
Speaker 10: not because of me.
Speaker 6: I'm sure there's nothing to do with it.
Speaker 10: I think that the stigma is like seeded in is
Speaker 10: just by having more and more studies over the time
Speaker 10: to like look at this. I know that there's been
Speaker 10: like a popular book on cannibalism that came out a
Speaker 10: few years ago that it was just on like talking
Speaker 10: about the misconception behind and how that's pretty common. I
Speaker 10: don't think it was actually a scientist necessarily who works
Speaker 10: on it that wrote it, but they just thought it
Speaker 10: was a cool topic or something that probably helped too
Speaker 10: to like get it more out and then like public's mind.
Speaker 6: But I think for researchers it's funny.
Speaker 10: Whenever I gave this talk and then talked about cannibalisms
Speaker 10: and other things, and people would.
Speaker 6: Always come up and say, yeah, I see this all
Speaker 6: the time and just never thought about it, or like
Speaker 6: what are the consequences?
Speaker 10: And so right post people that work in natural system,
Speaker 10: unless they're work on plans, probably have seen cannibalism at
Speaker 10: some point, Like you said, like or at home, I
Speaker 10: do you see you fish getting eatings and you're like, oh,
Speaker 10: how Colm, I'll never get you know, more guppies.
Speaker 6: And it's like they're eating ill got eaten up. Yeah.
Speaker 1: One books that cannibalism have the best titles I've got
Speaker 1: is Eating People Wrong, which I found on my husband's
Speaker 1: table the other day and I got fairly nervous. So
Speaker 1: the children and I you know, went on a vacation.
Speaker 1: But it turned out it was not about us, just
Speaker 1: for research, just for research.
Speaker 3: Well, what about portrayals in popular media? You know when
Speaker 3: I watch a show and they talk about particle physics
Speaker 3: and often cringing because they get all the details wrong.
Speaker 3: If you watch Silence of the Lambs or you know
Speaker 3: that TV show Hannibal was very popular, are you cringing
Speaker 3: because you're like, oh my god, that would never happen
Speaker 3: that way, or are you just glad to hear people
Speaker 3: talking about cannibalism since it's your position that more people
Speaker 3: should do it.
Speaker 10: They both of this is nolla, right because like all
Speaker 10: the human cannibalism is nothing that I do.
Speaker 6: It's all really like a psychological, mostly weird behavior that it's.
Speaker 10: Not in line with like the natural cannaalistic behavior that
Speaker 10: we see like in these ecosystems. So no, it's like,
Speaker 10: I don't think they get it wrong because to me,
Speaker 10: it has nothing to do with what I see out
Speaker 10: in nature.
Speaker 1: All right, So Folka is not saying that any of
Speaker 1: us should engage in cannibalism. No, And I think that's
Speaker 1: where we need to end this conversation.
Speaker 10: I feel like we pushed you to like brace it
Speaker 10: and adorse it, but like, no, we should study it more,
Speaker 10: not actually do it.
Speaker 3: That's right, right, all right, the lawyers have gotten to
Speaker 3: you both. You're so afraid to say the truth, all.
Speaker 2: Right, all right, Well, thank you so much for being
Speaker 2: on the show.
Speaker 1: You might have noticed I've avoided saying your name the
Speaker 1: whole time because now I'm convinced that I'm doing it
Speaker 1: wrong and I'm super.
Speaker 2: Embarrassed about it.
Speaker 1: But anyway, this has been a ton of fun. Thanks
Speaker 1: for being a good sport about all of the jokes
Speaker 1: that we made and the weird human references that we
Speaker 1: insisted on shoehorning in. And we look forward to having
Speaker 1: you back on the show in like a decade to
Speaker 1: tell us about what you've discovered.
Speaker 6: All right, it sounds good.
Speaker 3: Thanks for having me, Thanks for the delicious conversations.
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