Almost Cannibals

What’s the line between cannibalism and mere predation? In this episode of Stuff to Blow Your Mind, Robert and Joe consider some thought-provoking cases of predation and cannibalism in the animal world. 

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Episode Transcript

Speaker 1 (00:03):
Welcome Stuff to Blow your Mind, a production of I
Heart Radios How Stuff Works. Hey, are you welcome to
Stuff to Blow your Mind? My name is Robert Lamb
and I'm Joe McCormick. And no, you're beating around the bush.
It looks like cannibalism is on the roster for today.
That's right, And I just want to remind everybody that

(00:23):
we're not going to be talking about a hannibal lecter.
This is not a show about like modern cannibalism among humans.
This is not the Dahmer cast exactly. This is mostly
going to deal with animals, and towards the end of
the episode, we are going to discuss some some of
the questions surrounding cannibalism among ancient humans. But again, if

(00:46):
it don't worry, We're not going to be talking about
like like true crime cannibalism here. That's your thing. There's
plenty of that out there, you know where to find it,
that's right. So we we've frequently discussed predation on the show,
and we've of course discussed cannibalism as well. You know,
we've talked about how it factors into any given organism, organisms, life,
whether it's predator or prey, as well as its role

(01:08):
in human evolution. And I think we've also tried. I mean,
obviously it can be fun to talk about, especially grizzly
predatory practices in the wild, especially among like invertebrates, But
I feel like we tried to do our best to
dispel predator hatred, right. We We did a whole episode
a while back about why predators are so beneficial for

(01:29):
ecology and even for for human civilization. Absolutely, and you
can't look at predators just as the villain of any
given peace, no matter how dramatic the music and a
given nature documentary might be. That's something I found watching
just so many nature documentaries with my son, is that
earlier on he would get a little wigged out by

(01:50):
scenes of predation or pending predation because they just have
such overly dramatic music and they're really playing into the
idea that the predator is the villain. Yeah, but I'm
I'm happy to say that he is. He's really gotten
out of that. It's very rare now that at age
he just turned seven. Uh, it's very rare that he'll
be wigged out by predation scene. In fact, there will

(02:12):
be scenes where say, like some young lions or ripping
apart of water buffalo or something, and I'll be a
little wigged out. I'm like, this is getting kind of bloody,
and I'm like, you sure you wanna finish watching this scene.
He's like, oh, yeah, it's cool that they're hungry. No, no,
he's not. He's not bloodthirsty for it. But he he
has he's already has his appreciation that. Yeah, those those

(02:32):
animals are hungry. They need to eat. This is how
they eat. This is part of the natural order of things. Yeah,
that's really cool. I mean it's it's a hard thing
to appreciate because of course, within a human context, if
you see like one human chasing after another human trying
to hurt him, we know that's morally bad. That's something
to to oppose. When you see a predator chasing prey, Yeah,
the prey is fighting for its life, but the predators

(02:53):
also fighting for its life. It's just obeying its instinct.
That's part of what it does. And if if the
predator doesn't get some prey, it too will die. Yeah,
a wrong move on the on the part of a
predator giving chase could lead to its death as well.
Via via starvation, if it were to say, in draw leg.
But of course, one of the strangest forms of predation

(03:14):
and one that often seems to even when you see
it among animals, even when you know better. One that
I think still strikes many people as a kind of
taboo or a kind of violation is when predation is
turned inward on one's own kind, when it turns into cannibalism. Yeah,
and we've and we've again we've discussed cannibalism on the
show before, especially sexual cannibalism, I think more recently, Yeah,

(03:38):
we did a whole episode on sexual cannibalism, especially as
it appears like among arachnids, in which there are some
fascinating behaviors. It's far more complex and interesting than just
like well, male spider mates with a female spider and
then the female eats the male. They're all kinds of
economic energy dynamics going on different behavioral adaptations to that,
to that kind of world. It's a really truly complex

(04:01):
and interesting subject. Yeah, And I think economics is the
way I always try and and and focus on it,
you know, just thinking of just the the economy of uh,
turning sunlight into flesh, which is basically what happens with
the food chain. And so you're going to reach a
point where even another member of your own species is energy.

(04:22):
And what are you to do if you are, say
a scorpion or something. I mean, especially with the with
the scorpion, which is you know, UM tends to be
a solitary organism. Uh, you know you're not going to
let that energy just go to waste because you have
some sort of you know, heightened scorpion morality or you know,
our ethical system in play. No, you're gonna you're gonna
show down on some cannibal meat. Well, no, again, animals

(04:45):
are not humans. We with human brains can appreciate reasons
that one should not eat one's own kind. Yeah, but
if in the rest of the animal animal world cannibalism
is widespread. So I today's episode, you know a lot
of what we're gonna deal with this this idea of
almost cannibals, which is something I started thinking about while
I was vacationing in Belize. I was out there with

(05:07):
the family, snorkeling, and I was slipping through a guide
book for Caribbean organisms um aquatic organisms, and I came
across a couple of entries for the head shield slug. Okay,
this is kind of like a it looks sort of
like a hammerhead slug. Yeah, it looks like a hammer
head sea slug. They're also known as bubble snails um
and and these are members of the clade um Cephalospidia,

(05:30):
and the these names head shield slugs bubble snails. The
name refers to their common head shield, as is a
broad head that's used for burrowing in the sand and
it helps to keep the sand out of their mantle cavities.
And most have have shells, but some species have have
to have a reduced shell and some have what's known

(05:50):
as a like a bubble shell. Now I never got
to actually see one while snorkeling, but the two entries
in the book, I got my my mind working because
there was leech head shield slug, which was this beautiful
dark blue indigo creature with bright yellow stripes. This is
one of the counterintuitive things about nature, is that clearly
one of the most beautiful types of animal in the

(06:13):
entire world or sea slugs. Yeah, yeah, absolutely, uh. But
then there was another one. There was the mysterious head
shield slug. That's what it's called that was in in
this in this book, and this may have been an
older book. There may be updated names for some of
these now, but this one looked had the color of
just rotting vegetation swearing camo. And as for their diets,

(06:35):
the book listed that the mysterious head shield slug feeds
on other sea slugs, especially the the lettuce sea slug. Okay,
fair enough, right, there are a lot of sea slugs
out there, and there's a lot of competition in aquatic environments. Um,
you know, we're dealing with a very large subclass of
the gastropod of family here. But the leech head shield

(06:56):
slug its diet was listed as other head shields, So
it's getting even closer to home, right, Yeah, so it's
not cannibalism. You know, they're not the same species. Uh,
they're in the same family, but I suppose, you know,
it's it's the name that that gives me pause. The
fact that they're both classified as headshield slugs. Well, that
is a kind of interesting question to say, Like, Okay,

(07:18):
we know cannibalism happens pretty often in the wild, and
we'll discuss the conditions and just a minute here, there
are some limitations that are imposed by genetics, by the
energy economy, and by epidemiology on on how far you
can go with practicing cannibalism as a lifestyle as an animal.
Uh So they these limitations are in place. Some of

(07:38):
those limitations might not be in place if you're preying
on something that's a lot like you, but is not
exactly you. Right, So, yeah, that's something we're going to
talk about here. You know, what are some examples of
um near cannibalism, Like what are some of the more
closely related prey predator relationships out there in the animal world?
And then what does that say about us? What does

(07:59):
that say about the way that humans think about cannibalism?
In a weird way, this episode topic even got me
thinking about some of the strange economic dynamics of digital media.
I promise that's not as boring as it sounds. We'll
come back to that later. I don't know, digital media cannibalism.
That sounds pretty exciting and probably just like spot on
and just a fact of life. So let's refresh a

(08:23):
little bit about cannibalism. So, to eat one's own species
is to commit an act of cannibalism. Now, sometimes especially
we'll get into a few cases later on. Sometimes this
word we the word cannibalism is used for things that
are not quite cannibalism. But that's where we get into
that gray area of near cannibalism. Yeah, and it's sometimes
said with the derogatory context, but I mean again, it's

(08:45):
something that like, obviously, if you kill and eat your
next door neighbor, that's a bad thing. But animals this
is just sometimes an adaptation that animals have, that's right.
And there are many different varieties and classifications we've discussed.
Somebody's done the show before. Sexual anibalism for instance, which
like you said, can be can be, you know, rather complex.
It's not just a situation of well I made it

(09:06):
with him, I guess now I'll consume his flesh. A
lot of times it depends on, for example, what the
male brings to the table in the sexual encounter. There
are some species of spider where if a male shows
up with a food gift for the female, for example,
he can he can be more likely to avoid being
cannibalized after mating, whereas if he shows up and just

(09:27):
wants to mate and doesn't bring her anything to snack on.
He's more likely to be cannibalized. And this sort of
makes sense, right, like or is he is he contributing
additional food resources to the development of the offspring? Right?
And then there are other examples like matrophagi where babies uh,
where the offspring consume the mother um. You know, they're
they're examples where um of a mother organism will consume

(09:50):
the young. And a lot of these cases of cannibalism
in the while, they're they're going to be influenced by uh,
you know, economic um uh resource uh deprivation issues like
are those offspring going to survive? Is something threatening them?
Should then the energy of those uh of the offering
be uh brought back into the host or into the

(10:11):
mother organism. Yeah, Now, I detect among the literature in
in zoology and behavioral ecology and all that that there
there's been a shift in consciousness about cannibalism over the
previous decades where I think it used to be more
common for scientists to believe that cannibalism would was something
animals would only do under extreme scenarios, like if they

(10:32):
were in a starvation scenario, you know, just like the
absolute limits of survival, and that has increasingly it's increasingly
become clear that that's not the case. Though animals don't,
you know, they're not usually going to practice cannibalism as
some kind of primary mode of living. There are actually
a pretty wide range of scenarios in which cannibalism occurs,

(10:55):
and we're we're documenting more and more of those scenarios
all the time. It's not always just star ovation at
the very edge of survival and the peaks of stress. Yeah.
So it's one of these things that is, you know,
we're learning as ubiquitous in the natural world. It it
offers some really key advantages, though there are some downsides.
It remains highly popular without ever becoming like the thing

(11:17):
right like you made your species might engage in cannibalism
for a number of different reasons, but you were not
going to become an obligate cannibal like that is where
the system would collapse. Yeah, and I think there are
some reasons that that's sort of impossible. I'll talk about
that in just a minute. It reminds me a lot

(11:37):
of some things I've heard about the band Primus. I've
heard stuff, but okay, well I'm going with you. I'm
not saying that the members of Primus are cannibals, but
rather um, I think it was less Claypool himself, who
at one point pointed out that like they were in
a good place popularity wise, like they like they never
completely went out of fashion, but at the same time,
like they never just really blew up. Like I feel

(12:00):
like most people, Uh, if you asked them, they might say, oh, yeah,
Primus is cool. I did Primus. I myself have enjoyed
a prime Primus in concert before, but I would I
would never say Primus is necessarily my favorite band. Uh. Likewise, cannibalism,
It's okay, I'm with you. I see what you're saying. Yeah,
I mean, yeah, they're Primus has long been By the way,

(12:22):
my candidate for what I joke about is like the
least sexy or least romantic possible music. So if you're
trying to like figure out what to put on for
a Valentine's Day dinner or something like that, so you
could go with like your Marvin Gay or you know,
your classic romantic options, and at the other end of
the spectrum you've got Primus. Yeah. For me, Primus is

(12:43):
more like driving around music, you know it nothing will
scribe if you if you were thirsting for primus, nothing
else will do. But then there are plenty of other
cases where it probably is not going to be the
ideal soundtrack for life. But anyway back back to canalism,
So yes, there it can be especially useful in certain

(13:03):
ecological situations. Uh and and there are a lot of
key benefits to the individual. On the other hand, it
can impact community dynamics. But the exact shape and scope
of a species cannibalism it varies greatly. Yeah, exactly. Um So,
so there are these obvious, like you're talking about, economic
and evolutionary limits on what forms cannibalism can take, even

(13:25):
though it can to each individual animal that practices that
give all kinds of benefits. One example would be that
you know, when one species regularly eats another species, it
is common that the prey species is in some way
more vulnerable, it's smaller or weaker, definitely more numerous than
the predator species. You can't make a diet out of

(13:46):
eating mostly or entirely animals that are say as good
at killing you in self defense as you are at
killing them in predation or the economics of acquisition. Just
don't work out, right, You're not gonna go chasing down
something that's got all the same muscles and teeth and
claws and all that as you. Right, you have to
have some sort of an advantage, either a direct biological
advantage or some sort of behavioral advantage such as pack

(14:09):
hunting or something like that. But but even in those
cases it can be exceedingly risky. And and think again,
how I mean, I think we sometimes because we have
medical care, we uh downplay the risks to an animal
in the wild of a mirror like you know, leg
injury or something like that, which can be fatal to
an animal in the wild, while you know, you can
just go to the hospital and get fixed up. So

(14:31):
if adults of a species focus on other similarly sized
adults of the same species, hunting probably becomes too dangerous
to sustain as a regular practice. Also, a species cannot
make a diet out of eating mostly or entirely animals
that are less numerous than itself, because it's going to
run out of food and starve, or it's gonna have
to switch to a different food source. If an animal

(14:53):
were to eat primarily or entirely members of its own species, Uh,
there would immediately be a couple of problems. And number one,
you would have to think, if it's a sexually reproducing species,
this behavior is probably going to interfere with mating and
lead to depletion of mates. Probably more importantly, the species
couldn't survive. It would sort of eat itself to extinction.
Like if every member of the species needed to eat

(15:15):
one other member of the species every month in order
to not starve to death. Your best case scenario is
having the number of individuals every month. Now, maybe you
think you could replace those through rapid reproduction, but where
does the energy to create and grow those new bodies
come from unless you're eating even more of your own kind.
So it seems kind of I was trying to find

(15:37):
an example of something that comes close, but it seems
to me you can't really have something like an obligate
cannibal species, something that only eats its own kind. That
seems like an an absurdity. So you have that fact,
but then you also have the fact that we do
observe lots of in species cannibalistic behavior in the wild
in the wild, and we know that this can only

(15:58):
take place in sort of limb did conditions and scenarios,
and we're discovering more and more of those types of
scenarios all the time. Here's a common one we know.
You can't just eat members of your own species for
your entire diet and have every member of your species
do this for your entire life, for the species would
cease to exist. But within certain phases of life, cannibalism

(16:20):
can be a primary strategy. Consider the larval stage of
many amphibians. Uh you have like cannibal morph larvae of
tiger salamanders. We talked about those in our episode on
salamanders with Mark Mandica. Or think about the cannibalistic tadpoles
of toad species like the spadefoot toad. And this is
where the biggest tadpoles in a small body of water

(16:40):
will eat the smaller ones to survive and grow even bigger.
It's sort of like a letting letting the strongest of
the of the litter absorb the energy of all the others. Now,
obviously this kind of strategy can't be continued for the
amphibians entire life cycle, but it can work in a
phase of the life cycle because the other energy inputs

(17:01):
into that phase. Another great example from another episode we
had with a with a guest was thinking about intra
uterine cannibalism in some sharks species, like we talked about
with Mara Hart, where some unborn sharks will swim over
and eat their siblings or half siblings before they even
leave their mother's uterus. Do we talk about cannibalism with

(17:22):
all of our guests? I don't know. It does seem
to come up a good fit, but maybe we do.
I don't think we brought either of these up, did we.
I mean, I guess they were just an innate part
of the cut, the conversation and the expertise of the guests.
Maybe we just invite creepy guests. They're not creepy. Maybe
we're creepy. We're talking about cannibalism right now. We're definitely creepy.

(17:43):
So while cannibalism can't be the entire diet of a species,
it can be an important supplemental part of a diet,
especially in scenarios of environmental stress, and it can even
reduce competition when times are tough. One example here is
that cannibalism, according to what I've read, it's much more
common if you live life in the water. Oh, yes, definitely. Yeah,

(18:04):
if you're wet, you're probably involved in cannibalism in some way.
It just happens a lot more in aquatic environments. For example,
when fish are foraging for food, one type of energy
source they will often come across is little sphere ules
of lipids and energetic materials floating in the water. Other
fish eggs. Uh. These fill the waters of the ocean

(18:25):
by the bazillions, and this will include some eggs of
their own species, which they basically just eat discriminately along
with the other eggs. We recently did the episode on
the Christmas Island crabs. Oh, yeah, where they just stuff
the crabble are right into their mouths. Yeah, I mean,
how do you know if it's your own offspring. Chances
are it's not. There's so many out there, it's probably

(18:45):
somebody else's. Also, I think I accidentally said that they
will eat them discriminately. Obviously they eat them indiscriminately, is
what I mean. Fish don't discriminate. But yeah, it works
out because fish produce a lot of eggs. Under the
evolutionary assumption that most of the eggs, many of the
eggs at least, will not survive and the eggs of
one's own species are only a supplemental part of the

(19:05):
adult fishes diet, not the whole thing for the whole species,
which again would be a problem. But the phenomenon of
adults eating young of their own species actually happens in
many scenarios outside the water too. Obviously, it would make
no sense for animals to have instincts to kill and
eat all of their own young, but there is some
selective strategic snacking of this kind. Like often rodent mothers

(19:28):
will eat some of their own litters, especially those that
are sickly or don't seem like they're gonna thrive. Male
carnivores like lions, will sometimes eat the cubs sired by
another male, and this tends to increase the female lions
receptivity to mating and the pride. Yeah, this is seen
in bears as well, for sure. Oh yeah, definitely. And
then there are some really strange cases that were observing

(19:50):
again more and more all the time, even with animals
once thought to be herbivores engaging in occasional cannibalism. Here's
when I came across hip pose what hundred percent herbivores right, Well,
that this one one I always assumed. I mean you
hear to hear about like the vast amount of vegetation
that a given hippo needs to consume, and that is
their primary diet. They mostly are herbivores, but occasionally they'll

(20:13):
just be versatile. So we used to think there are
a hundred percent herbivores. They're mostly herbivores, except now it's
been observed that sometimes they'll kill and eat an impula,
or even sometimes they will eat a fellow hippopotamus. Well,
they are ferocious. I mean, we can't take that away
from them. So there are just more and more examples
all the time that science is documenting about ways that

(20:34):
animals will occasionally or opportunistically or even in some controlled ways,
regularly engage in direct in species cannibalism. Yeah. I was
reading the amazingly titled two thousand tin paper Cannibals in Space,
the Coevolution of Cannibalism and Dispersal in spatially structured Populations

(20:55):
and U. And in this the authors point out that
the propensity for cannibalism, you know, it's going to vary
considerably among even closely related species. And then a lot
of questions remain concerning exactly what drives variation and the
evolution of cannibalism across and even within a species, and
the can and the same can be said for the

(21:15):
evolutionary consequences of cannibalism. Yeah, a lot about cannibalism remains
an open question. There's still a ton we don't know.
But I think one thing that is emerging is what
we're getting some good ideas of what the major downsides
to cannibalism are, like, what are the limitations that are
imposed on it as a practice, And so I want
to mention I think three major ones that there may

(21:36):
be other ones, but these are three major ones. One is,
if you're practicing cannibalism, you could end up eating animals
closely related to you. And given the self preserving tendencies
of genes and evolution, there's going to be a selection
pressure against this. Genes will tend to come about and
become prevalent within the species that say don't eat each
other if you have this gene. Also, as we mentioned

(21:59):
are here, it's a risky to try to kill and
need an animal that has ald the same equipment you do,
the teeth, the muscles, the fighting abilities, it's easier to
go after weaker prey, and there's usually some kind of
weaker prey out there. But there are ways around both
of these. I mean, for one thing, you can try
to avoid eating animals you're closely related to, even if
you're eating your own species, by evolving ways of detecting relatedness.

(22:22):
So maybe you know there's some gene that allows you
to recognize who is your from your immediate family and
not eat them. I actually have an example of this.
We'll come back to that later. Okay. Another thing you
can get around is that animals with cannibalistic tendencies can
get around the problem of fighting uh something, fighting something
just as big and dangerous as as you are by

(22:42):
eating smaller, weaker con specifics. And this can take the
form of sexual cannibalism, like in some spiders like the
red back spider, where there's a huge difference in size
between the males and females and it works out just
fine for the females to eat the males after mating,
or this can happen with adults preying on larvae or
smaller juveniles of their own species. But finally, one last

(23:03):
big problem with cannibalism, and we'll come back to this.
When you eat your own kind, you put yourself at
risk of catching diseases and parasites. You're more likely to
consume or otherwise expose yourself to something bad that can
infect your species. If you're eating animals that are already
of your own same species, Yeah, you're basically diving into

(23:26):
a swimming pool of this other individual's potential viruses and illnesses.
You're you're diving into a swimming pool marked bio hazard. Yeah.
So there's always a cost benefit calculation going on. And
I'm not saying obviously that the animals are doing this
calculation consciously in their heads, but somehow this calculation is
being worked out. There benefits to cannibalism, there's an obvious

(23:48):
energy advantage, and there are all these downsides, And so
the circumstances and and the specific traits of each individual
species are going to interact to determine when cannibal is
m is actually appropriate. Alright, Well, on that note, we're
going to take a quick break, but when we come back,
we're gonna continue exploring this topic. And we're going to
kick off by discussing this idea of near cannibalism a

(24:11):
little bit more than thank you. All right, we're back.
So we were just talking about the limitations, Uh, well,
all of the examples we see of cannibalism in the
natural world, true cannibalism where members of one animal species
are eating members of the same animal species. Uh. And
then limitations on wind cannibalism can be practiced, and what

(24:31):
what might hold it hold it at bay from becoming
too prevalent. But there are probably examples of animals doing
something that is not quite cannibalism, but where they're eating
something that's kind of close to them. Yeah, And so
I started looking around for answers on this, and one
thing that that did come up when I was looking
for near cannibalism and um and you know, scholars, scholarly

(24:55):
works and academic papers, I ended up running across it
in some myth papers on myth and medieval histories. And
I found this rather telling, not so much about like
what's going on in the animal kingdom, but about like
why I'm fascinated with it, Why this idea of near
cannibalism is perhaps even a little more interesting than interesting

(25:18):
to me compared to apps absolute cannibalism. So For instance,
there are medieval accounts of the Danes roasting animal flesh
to eat alongside, like right next to heaped the heaped
human dead from a battle, so like feasting on the
battle grounds with their slain enemies around them, almost sort
of suggesting a mental connection. Uh yeah, And of course,

(25:41):
again these are accounts of the Danes probably you know,
with it with the idea of portraying them as being
in the state of of near cannibalism, Like look at that,
they're just cooking their meat right next to the bodies
of the dead. They're just there's just one misstep away
from going full cannibals. Romans would never do anything like that.
Another thing that come up came up with was the

(26:02):
myth of like Cayan, which we recently discussed, and there's
an act of near cannibalism cannibalism there as well, where
the flesh of a human is offered up to the
god Zeus to say, like, hey, Zeus, do you want
to eat some human flesh? Like they're trying to trick Zeus. Uh. Now,
granted Zeus humans a god, but sort of yeah, I

(26:23):
mean it seems like species enough, like if if if
the gods of Greek mythology can mate with humans. It
seems like that they should be like biologically close enough
that eating us would be a cannibalism, right right. And
of course you know the gods, especially the Greek gods,
they were down for any number of horrible acts. They
would turn into an animal to mate with a human,

(26:44):
that sort of thing. But I guess the thing is
that they probably are not going to look kindly on
being tricked into doing anything vile that they didn't want
to do. No, And of course when Zeus was almost
tricked into eating human flesh, he retaliated. By their different
tellings of the story, sometimes he retaliates by just like
killing a bunch of people. Sometimes he retaliates by turning
the king who tried to trick him into a were wolf,

(27:07):
has pointed out by seed down him in the Good,
the Bad, and the Ugly portrayals of Vikings in the
Fragmentary Animals of Ireland, near cannibalism and near paganism were
considered the apotheosis of the evil. Yeah, you see this
in many ancient sources. It's like cannibalism is sort of
held out as it's it's the archetype of barbarism. You know,

(27:29):
it's like the ultimate act that in itself in an
iconic way shows that somebody is not civilized and not good.
And there's something as he's pointing out her, there's something
tantalizing about like that that that moment before cannibalism, that
or that moment before paganism, like that slip that decline
into this barbarous nature. Uh, the idea that, oh, they're

(27:52):
not cannibals now, but I bet they'll be cannibals tomorrow
because look what they're doing right now. And of course, uh,
in the animal king um, all these species we're you know,
we're looking at cannibalism is already in the blueprint, like
it's already part of the of the of the act.
But there is there's something about about about that to

(28:14):
the the human mind, I think, you know, because we
can't help to think of of of all of these
changes taking place not against the the in in the
time scale of evolutionary history, but we think about it
within the terms of lifespan and the choices that we make.
But anyway back back to just like purely the the
animal world here I did can run across a study

(28:36):
that points at a possible case of cannibal fueled speciation,
because I think that's something to interest to think of,
because it's like if I'm if if one if within
a species, members of that species are deciding to just
go full cannibal like they're like, oh, I can just
eat my own species all the time. If that were
to happen, could that conceivably lead to a speciation event

(29:00):
where the cannibals become their own species. Oh yeah, that's
an interesting question. And so this this study I found
in two thousand seventeen study, and I should stress that
this is an unrefereed preprint in bio archive, so caveats
on not going through peer review, right. But in it,
the author's point to cannibalism in South American um annual

(29:21):
killie fish that's austro lebias as a possible speciation event.
So they're they're they're presenting what they refer to as
an alternate hypothesis for giant dwarf speciation where where some
of these uh we're basically the chilly fish here have
evolved in sympathy without geographic separation by character displacement and

(29:44):
cannibalism but in this day, the authors are discussing cannibalism
in South American annual killie fish, and the idea here
is that it could it could be a speciation event
going on here, that that accounts for giant dwarf speciation,
So basically bigger, bigger killy fish versus a smaller chilly fish,

(30:04):
and cannibalism could play a role in that right right there,
That that could be what's what's pushing this species into
two species based on the size of the individuals. Yeah,
that's interesting if I am understanding their argument correctly. Okay, Now,
there's one thing that I had been thinking about as
a potential case of near cannibalism, which we've already sort

(30:25):
of discussed in a previous episode called Strange Milk. So
I won't linger on it too long. This has come
up before, but I just wanted to remind us of
one form of feeding that could be seen as analogous
to cannibalism, but without the element of lethal predation, and
that is found in various systems where an adult animal
feeds its offspring with some part of its own body. Ah. Yes,

(30:50):
so this is not predation. The offspring does not necessarily
kill and eat the adult, but it could be considered
a form of alternative cannibalism, as if I could like
off one of my arms and feed it to my kids. Interesting,
and the great example here is the type of amphibian
known as Sicilians. Now it's not spelled like from Sicily.

(31:12):
It's c A E C I L I A N.
Sicilians are amphibians. They're kind of like frogs and salamanders,
but they've got no legs. They look like a cross
between a snake and a worm, like a like a
wet earth snake. They tend to live underground, so we
rarely see them, and if you do see one, you
might mistake it for some kind of gigantic worm. Yes,

(31:32):
I remember we we talked about about the about the
Sicilians with Mark Pendina. Oh yeah. And one of the
things we talked about with the Sicilians and the strange
Mailk episode was that after the mother of a Sicilian
species called a boo Langarula titan us gives birth, she
turns her outer skin into a nutrient rich secretion for

(31:53):
her offspring, and then the young gross special teeth. I've
seen these referred to as shaped a slotted spoon so
that they grow special teeth, uh quote, which they used
to peel and eat the outer layer of their mother's
modified skin. And that's a quote from a two thousand
six paper in Nature. So basically, the mother turns her

(32:15):
skin into like this cheese like substance, and then the
juvenile worm like creatures chew off their mother's skin. They
peel her like a like a vegetable. This is interesting.
This is it's very it's consensual. It's it's not just
a situation where the young eat the mother, but the
mother is mother said is essentially saying, here, take of
this specially prepared skin and eat it in remembrance of me. Yes,

(32:38):
take of my body and take of my skin. I mean.
It seems to combine multiple elements of the Texas Chainsaw
Massacre together at once, but somehow without the massacre. So
there's the peeling of skin, peeling the skin off, and
a form of near cannibalism, but without the elements of predation.
The the the willing adults says, try my skin. It's good,
and they do. That's what we aid for the the

(33:01):
to to reboot the Texas Chainsaw Massacre franchise is we
need to we need to take the mascre at mascre
at just have everything else happening consentually, and ultimately that's
going to be more terrifying. I think it's just about
a consensual human barbecue cook from from Texas. Yeah, you know,
I've had that thought with a few different horror films

(33:21):
that have come out where you know, they're there, you know,
people behind them are sometimes pushing the boundaries and they're like,
and it's all about like horrible things being done to people.
And I'm and I'm thinking, you know, the creators here
obviously they think that this is that this is horrible,
and this is a terrifying vision of of life. But

(33:43):
but what if what if it what if everyone was
engaging in it willingly, like you know, then it would
put an entirely different spin, and arguably a more thought
provoking and even terrifying spin. I feel like that's often
what black mirror is. Black mirror is often like a
what would otherwise be like a horror movie or a
horror show, except most of the time the people who

(34:05):
are the victims of whatever is happening in the episode
get involved consensually. Yeah, because it's technology because the technology exactly. Like,
for instance, if you had a Friday the Thirteenth film
where all of the young people went off to camp
and the thing that they all really hoped for, that
the thing they desired most of all, was to be
massacred by the mass killer that runs the woods. You

(34:28):
know that that would fulfill some sort of deep desire
in them, some desire for I don't know, like teenage
martyrdom or something like that. Ultimately, like that that that
gets me thinking a lot more. There's a sort of
almost element of that in Hell Raiser. I guess people
are looking for trouble messing around with a puzzle box.
They should know better than Yeah, And of course that

(34:48):
would make sense. Clive Barker, especially in the younger Clive Barker,
I think he did engage in a lot of a
lot more subversive treatment of these things. Well, speaking of
Clive Barker, okay, on that. You know, I thought of
Clive Barker already earlier in this episode when there were
a couple of times where you just said flesh and
I was like, you kind of can't do that without

(35:09):
saying it in the Doug Bradley voice. Yeah, obviously, we're
big fans of some of the hell Raizor films, and
and uh, and I definitely hold up some of Barker's work,
especially his books of blood short stories. There's some some
really good short stories in those collections. Yeah, I've always
meant to read them, might never have yet. But we
should get back to near cannibalism. Well, let's bring things

(35:33):
around to the human realm, or at least the you know,
the the ancient human realm. So let's talk about humans
and Neanderthals. So evidence has been presented and sometimes dismissed
regarding regarding cannibalism among both ancient humans. Though it gets
kind of complicated because we're talking about ancient humans, but

(35:53):
technically you call these modern humans. They're they're ancient from
our standpoint, but they are evolutionarily modern humans. So uh,
at anyway that there's there's their arguments and evidence for
both these ancient modern humans and the indertal is engaging
in cannibalism. And as we've discussed on the show before,

(36:14):
the evidence that scientists look for when they're talking about that,
they're looking for signs of processing on the bones. In
other words, it's not enough that a human or a
neandertal skull was caved in by heavy object, But are
there signs of the bodies having been systematically or ritually
stripped of meat or marrow for the purposes of consumption?

(36:36):
And uh so, so that's one of the things they
look for. And as Bill Shoot points out in his
his excellent book Cannibalism, archaeologists generally want to match this
sort of evidence up with similar damage on the bones
of game animals from the same site, so that way
they can say, look, this is what these people were
doing to the bones of animals that were clearly praise

(36:58):
a prey species, and here's what was done to the
bones of other members of the species. And then you
have more of a direct comparison to make here, so
that you can say, this looks like this was cannibalism.
That all makes sense. There's some pretty convincing there's some
pretty convincing evidence that Neanderthals engaged in cannibalism, at least
survival cannibalism. And Shoot points out in his book that

(37:20):
the near Neanderthal species Homo antecessor quote, may have simply
considered others of their kind to be food, and he
pointed out. You know that again, this is hardly out
of step with the rest of the animal kingdom. Cannibalism
is ubiquitous, so it's not surprising that Neanderthals or Neanderthal ancestor,
or that Homo sapiens engaged in this practice. But what

(37:42):
what's interesting us the most for this episode is the
question of near cannibalism. Right, whether ancient modern humans considered
Neanderthal's prey or vice versa, how much uh consumption of this,
of this this other man like creature was going on, this,
how much near cannibalism was happening. So for starters, we

(38:05):
have some competing theories, but for the most part, we
don't know exactly what happened to the Neanderthal. They obviously
they went extinct, and we know that they likely transition
from Homo antecessor to Homo Neanderthal plenis about about a
hundred and fifty thousand years ago, and then they went
extinct thirty thousand years ago, So that's kind of the
the period of their existence as far as we understand it.

(38:27):
One hypothesis is that that's out there is that humans
in the Neanderthals interbred and that they simply became us,
or at least they became those of us with some
portion of Neanderthal DNA and uh, and there is there
is DNA evidence to support this, and then there but
there's some that to take issue with leaning too heavily
on this idea. Apparently, paleo anthropologist Ian Tattersall, who Shoot

(38:52):
interviews in the Cannibalism book Um this guy, is a
critic of the idea, and he argues that quote structurally, anatomically,
and presumably behaviorally too, Neanderthals and modern humans were very,
very different, and he says that while a certain amount
of genetic exchange definitely took place, he doesn't think that
they were absorbed into our population through inter breeding alone. Now, interestingly,

(39:18):
Tattersall points out that modern humans and Neandertals managed to
share the Near East for a long time, but this
was before we became creatures of symbolism, as Shoot puts it, quote,
an advanced symbolism driven species. These new humans at least
outcompeted the Neanderthals for resources, and it's reasonable to expect

(39:40):
that they did a bit more than that. Right when
you look at at certainly the way humans have have
treated other groups of humans, um, you know throughout history. Now,
some researchers have argued in support of of of predation
and cannibalism that that Homo sapiens uh hunted and consumed

(40:02):
Neanderthal meat. But there's currently no clear fossil evidence that
this occurred. So it might seem uh like something that
they would have done. We can, we can point to
aspects of human nature and and uh in humanity's historical
treatment of others, but when it comes down to the
hard fossil evidence of it, when it comes down to
looking at bones and looking for signs of processing, uh,

(40:25):
it's just not there. Again, we have clear evidence of
cannibalism in either group of Homo sapiens eating Homo sapiens
and neandertals eating the ander dolls, but uh, if it occurred,
we don't have any evidence of actual intragenous cannibalism between
the inder dolls and Homo sapiens. That's interesting. That being said,

(40:46):
I think if if you were to present me with
the time machine and make me place money on the
on on the the chances that humans in Neanderdals, I
would personally um want to place my back on humans
eating neander DoLS. Well, i'd say it's probably because humans
will eat anything. That's true. If something existed, humans probably aided.

(41:08):
I bet generally a safe bet. Now, let's back up
out of the human realm here, and I want to
come back to something you said earlier about how a
particular cannibalizing species might make sure that it's not cannibalizing
its own young Oh yeah, or or members of its
own near family. Because then you the closer relative within

(41:28):
your own species is the more genes you probably share
with them, which makes it more likely that some of
those genes would would discourage you from eating other carriers.
And so I found a recent article that deals with this.
Max Plank Society article titled a Peptide against Cannibalism from
April of twenty nineteen. The researchers noted that nematodes in

(41:52):
the genus pristianchas we're all all about some cannibalism because
their favorite food is worm lark. So how do you
keep from consuming your own offspring? Well, the answer, they
said is that they carry a quote small highly variable
protein on their surfaces. So what they do is they
experimented by offering adult worms of different uh of different

(42:16):
species again within this genus. Uh, they gave them their
own larva to potentially eat larva of a closely related
species or larva of a related line within their own species.
And in all cases they avoided their own larva but
tore into everything else, so they were they were totally

(42:37):
fine for eating another species. It's closely related to them
that near cannibalism. They were also readily engaging in an
absolute cannibalism. But uh, this peptide was at least aiding
in their identification of their own offspring and preventing them
from eating uh those uh those larva. They identified this

(42:58):
particular gene, which they called self one, as playing a
key role in distinguishing self from non self. However, it
doesn't seem like it's the only factor in the decision
to attack or not. And this is ultimately one of
those areas where more research is going to be needed.
But it does give us some idea of the kinds
of of mechanisms that are in place, that kind of

(43:21):
fail safes that are in place to keep cannibalism from
just decimating a species. Yeah, and it's really interesting trying
to work out exactly when and how those could controls
fall into place. All Right, we need to take a
quick break, but we'll be right back. Alright, we're back now.
I want to talk about something related to what you

(43:41):
were just saying, especially when it comes to praying on
the larva of your own species or related species. Uh,
this is a case of true cannibalism, but with interesting features.
I want to talk about the cane toad or Ranilla marina.
So the cane toad has an almost beaut to fully
horribly ironic history in Australia. I'm sure, I'm sure all

(44:04):
of our Australian listeners are pulling their hair out right
now because if you if you read Australian writers talk
about the cane toad, they there's I don't want to
over generalize, but there is very often utter revulsion just
the idea that they want to beat all these things
to death with a sock full of quarters. Now, we

(44:24):
we don't encourage wanton violence against wild animals, but there's
a reason behind this. So in the nineteen thirties, Australia
had a problem protecting sugar cane crops from populations of
a pest known as the cane beetle, and in order
to control beetle populations in sugarcane agriculture, they introduced a

(44:45):
South American toad. I think this was a nive. It
was the cane toad. They brought it to Australia because
it was believed that this toad would eat up the
beetles that were getting to their crops. And this turned
out to be a horrible idea. Uh. The cane toad
became a kind of breakout character, right, It's like the
fawns circle, you know. It's like it took on a

(45:07):
life of its own for the continent of Australia. It
did eat some cane beetles, but it also became extremely
numerous and ate all kinds of other insects, and its
populations in Australia just exploded. So it's another case of
an already unbalanced environmental situation due to agricultural activities and
then they intentionally introduce an invasive species and things go

(45:31):
out of whack. Very bad idea. And what's worse, the
native marsupial and reptile predators of Australia, like crocodiles and
like coals that might have been expected to control and
exploding toad population by eating the toads were totally unprepared
because the cane toad produces toxins that kill the predators

(45:52):
that eat them, So since the cane toad was out
of its native range, the predators had no resistance to
these toxins and no one stinctual avoidance of the cane toads.
So simply introducing these like poison candy toads into the
ecosystem was devastating to some predator populations. But this threat

(46:12):
to predators doesn't apply only to the marsupials and the
reptiles like crocodiles that might eat the adult cane toads.
It would also apply to perhaps smaller predators that tried
to eat the cane toads also poisonous eggs. The eggs
have similar poisons. So I was reading a New York
Times article from two thousand eleven about research on cane toads.

(46:33):
The articles by Natalie Angier, but the the article tells
the story of a scientist named Dr Richard Shine, a
biologist at the University of Sydney in Australia, who began
to notice years back that cane toad eggs were being
depleted by something, and at first he assumed that some
predator was at risk of mass poisoning by eating these

(46:54):
killer toad eggs uh to quote from the article. Follow up,
field Stead soon revealed the identity of the caviar thieves
to the researchers astonishment. Dr Shine said it was cane
toads themselves, or rather their tadpoles, which would swim over
to each fresh batch of vanilla eggs and quote desperately

(47:15):
consume every slick black sphere that they could find. And
then a two thousand eleven study in the journal Animal
Behavior found that not only do cane toads cannibalize eggs
from their own species, they strongly prefer them. When given
the option to eat cane toad eggs or other food
sources like similar eggs from another amphibian species, the cane

(47:37):
toads went right for the delicious cane toad eggs. And
this was just the cane toads that did this, It
wasn't other uh frogs amphibian species. Now, remember that while
lots of species practice cannibalism under some circumstances, no species
is exclusively obligately cannibalistic like that would make no sense.
But what if you're kind of edging in that direction

(47:59):
by at least in one stage of life, preferring to
eat your own kind over other forms of prey. Yeah,
we're definitely in that near well, we're definitely in that
that zone where it's cannibalism. But is it potentially becoming
something else? Now? You would think since this is tadpoles
eating eggs of the same species, you think maybe once
you metamorphos into an adult cane toad, you'd get past this,

(48:22):
uh this problem? Right? The answer is no. Studies have
also shown that that like midsize adult cane toads like
to eat smaller, younger cane toads. They even have like
deceptive lure tactics where they will wiggle the toes of
their back feet in water to attract smaller conspecifics and
then just literally swallow them whole. So I've, as we've discussed,

(48:45):
there's lots of occasional opportunistic cannibalism in the animal world.
But what causes the cane toads to go so hard
after their own species? Why do cane toads prey on
other cane toads so aggressively, and the researchers here in
this paper i mentioned hypothesize several answers with regard to
the campbalization of eggs by by cane tode tadpoles. Number One,

(49:07):
it eliminates rivals who you're probably not related to, and
this has to do with the specifics of the timing
of ovipositing and mating by cane toads. Obviously, it doesn't
make evolutionary sense to eat your own brothers and sisters,
but due to the timing of cane toade reproduction, if
you're a cane toad tadpole and there are eggs in

(49:29):
the pond with you, you can be pretty sure they
belong to some other family of cane toad's. Number two,
eating the eggs speeds up the maturation of tadpoles. Obviously
it's free energy. And three, the resource is abundant since
it's poisonous and other potential predators can't eat it, but
you can, since cane toads are immune to their own poison,

(49:50):
so they're kind of like the de facto specialized predator
of their own young. It's it's like when you know
somebody orders something for lunch, and there's one thing out
on the buffet that you're the only person in the
office that likes. So it's all for you. Enjoy this
braised red cabbage robbers. And there's a quote from from
Dr Shine in that Times article where he says, quote,

(50:12):
we're talking about a tropical animal that was relocated to
one of the driest places on Earth. Cannibalism is one
of those clever tricks that makes it such a superb
colonizer and a survival machine. Talking about the cane toad um. Now,
of course this does come with some of the regular
downsides of cannibalism, like it came across the two thousand
eleven paper with a pretty great title. Also, Richard Chin

(50:35):
was one of the authors on this quote. You are
what you eat parasite transferring cannibalistic cane tod So you know,
do cane toad's risk infection and paras parasitization by eating
their own The answer is, oh yes. When a cane
toad eats another cane toad and infected with, for example,
nematode lung worms. This study found that the cannibal toad

(50:55):
can end up with viable lung worms in its own body,
so they are paying this cost for their cannibalism behaviors.
And nevertheless, I was reading in another context that cane
toads are so aggressively cannibalistic that that cane toad juice
from the poison glands of an adult cane toad is
one of the best imaginable baits for a trap for

(51:17):
catching cane tone tadpoles. Okay, I think it's a cane
tone cane toad tadpoles. That's a tongue twister. Uh So
it smells like eggs, right, because they have these same
chemicals and poisons, And it's an ingenious method for removing
the tadpoles of this invasive species from a water source
without harming other creatures. Like the cannibalistic tadpoles are attracted

(51:40):
to it in swarms because of course they want to
eat the eggs of their own kind, and other animals
are not really attracted to it at all. So you
can put traps out with this and catch thousands of
cane toad tadpoles and almost nothing else. But I think
it seems like this species in Australia in particular favors cannibalisms.
Aggressively because it's a tough physical environment, like they need

(52:04):
to reproduce in water, and yet it's a relatively dry landscape.
And yet at the same time, there's an abundance of
their own species due to a lack of adapted predators. Interesting,
So I feel like one of the crazy things about
this is that a lot of what they're observing here
it's it's it's nothing you would observe, at least on
this scale in their natural habitat, Like they're the cane

(52:27):
todes of Australia have this kind of bloated and and
an natural space in the ecosystem that has yet to
be uh, you know, sort of recalibrated by other factors. Yeah.
Now I don't know what they're what they're cannibalistic tendencies
are like within their native range, it might be something equivalent,

(52:48):
but but this seemed to be focused on the ones
that are in Australia, So I'm not sure how prevalent
this would be in the species as they live in
South America. It's like, if you know, if cannibals took
over a date care, like and you observed it on
like the first day of activities, you know, it's like
everything is going to be crazy that first day. Hopefully
by day three or four things would have have settled

(53:11):
down and or the police had shown up, etcetera. Uh.
And of course before that, before the cannibals took over
the daycare, you would not have this um, this out
of balance scenario in which to observe how things would
take place. That's a beautiful analogy. Wrout. Before we wrap up,
I wanted to mention just one more type of predation
that we might consider a kind of close analogy to cannibalism,

(53:34):
and that is when you kill and eat an animal
that is not the same species as you, So it's
not cannibalism, but which makes a living the same way
you do, maybe does the same job as you. And
this brings us to a biological concept and as intra
guild predation, in the words of entomologists j Rosenheim and
Jason Harmon into intra guild predation occurs quote when two

(53:58):
consumers that share a resource and which therefore are potential competitors,
also engage in predator prey interactions with each other. So
you've got two different species competing for the same resource.
Like how at different times. Maybe Elmer Fudd and Yosemite
Sam are both trying to go hunting for bugs Bunny.

(54:18):
But what if instead Elmer Fudd kills and eats Yosemite Sam. See,
this solves two survival problems at the same time. It
provides an immediate meal. You get to eat Yosemite Sam,
and there's energy in that. But it also reduces future
competition for the webbit. Right, all right, it's a it's

(54:38):
a basic Freddy versus Jason scenario. Right, Yeah, that's pretty good.
So the benefits of this kind of thing are obvious,
and there are a couple of versions here. There is
asymmetrical inter guild predation, and this occurs when two species
compete for the same prey resources and one of those
two species also kills and eats the other. And then
there's what you might guess, the other half of that,

(55:01):
the other side of that coin, symmetrical intriguild predation. It's
when two species are in competition and they also both
kill and eat one another. If one predator is regularly
bigger than the other or something. This kind of two
way mutual predation can often cross the lines of life phases,
where say one predator adults of one predator prey on
the juveniles of the other predator. Okay, So with asymmetrical

(55:25):
um intriguild predation, there's always going to be probably a
clear winner, yeah, Like the the larger of the two
competing species is going to be the one that eats
the smaller. But in symmetrical interguild predation, it could go
either way depending on body size, phase of life, or
other factors of superiority exactly. And so this type of

(55:45):
stuff often happens in insects and arthropods that share the
same prey, like in some centipedes, but it also occurs
in large mammalian carnivores like canids and fields. They often
prey on one another when they're competing for the same
food resources, for example lions and wolves, or coyotes and
foxes or bobcats. According to a n paper in the

(56:07):
American Naturalists by by Palomari's and Caro uh quote, interspecific
killing among mammalian carnivores is common in nature and accounts
for up to sixty eight percent of known mortalities in
some species. So there's some carnivorous predatory mammals for which
more than two thirds of their deaths are caused by

(56:28):
other predatory mammals. And because inter guild predation accomplishes two
different goals at the same time, inter guild predation can
be extremely useful as the survival adaptation. It's a very
efficient way to do things. Of course, since members of
the same species are often in competition for the same resources,
the same advantages that apply to inter guild predation often

(56:49):
apply to straight up cannibalism. Right because you know you,
you and the other one of your species you're you're
probably also in competition. But straight up cannibalism is more
likely to come with the other downs sides, such as
reducing the gene pool of your own species, making making
more difficult, exposing you to more parasites and diseases, and
so forth. Now you said you were going to bring
all this back to social media. No that I was.

(57:11):
I was thinking about this and I started to think
that I see parallels between the strategy of intra guild
predation and some types of business strategies, especially like in
digital media where we work. So why don't you think
about this example? What did Facebook due to the rest
of the web? Like digital media companies are in competition

(57:34):
for audience. You can almost think about audience as their
prey in a way. They make money when more people
spend more time on their side or their platform. Facebook
was a digital media company in competition for users attention
and time, and their competitors were the other places where
people might spend their time on digital devices, other websites,

(57:56):
other apps, other platforms. So it seems to me Facebook said,
you know, instead of just competing with these other media platforms,
I will eat them. And that's sort of what it did.
Right So now instead of just going to your blog
or homepage or whatever, people would go to your Facebook
page or just follow you on Facebook or rely on

(58:18):
Facebook to keep people updated on what you're doing, whether
you're a person or a business or a content provider.
And I think the analogy holds that Facebook functions like
an asymmetrical intriguild predator. Here it gets double benefits both
by getting a direct meal off of you, like it
gets the traffic that you would be getting elsewhere that
gets just subsumed into its diet of traffic, and it

(58:41):
reduces competition in the future by training people evermore to
just go directly to Facebook instead of to other sites.
And apps, And it makes me wonder if there are
other examples in the business world where there is something
like intriguild predation going on, where where one business gets
double benefits out of assuming or subsuming another one. Yeah,

(59:03):
I think you may have something. You may have a
point there. I mean, also, it's very easy to imagine
any of these large media companies as kind of a
bloated cannibal king feasting and blood soaked on a on
a pyramid of bones of its competitors. Uh, and the
attentions of its clients. I couldn't put it any better
than that, Robert, But but I feel like we're kind

(59:26):
of given normal predators, a normal cannibals a bad name
by associating them with with that kind of ghastly you know,
very uh, you know, human centric image. That's true. Normal animals,
even the ones that sometimes practice cannibalism, are not. Corporations
don't decide that hippos are bad now just because occasionally
hippos will eat another hippo, They're still they're hippos. They're animals,

(59:49):
they're they're living within an ecology, and they're doing what
they have to do to survive. Yeah, I mean, it's
like with mice and hamsters and so forth. You know,
it's like you can if you get one as a
pet and you in your you end up tricking yourself
or falling into this idea of thinking them it's like
tiny furry people and you're a little furry friend that
lives in this box and scurries around. And then but
then if you're going to become horrified when they engage

(01:00:12):
in something in humans such as cannibalizing their young, uh,
And that's I mean, you should take that as a
learning lesson. You know that this is ah, these are
the perils of of anthropomorphizing, uh, the animal world and
then then the wild world and the natural order of things.
But really, cannibalism is simply ubiquitous and it is going

(01:00:33):
to be practiced by um, you know, most of these
organisms at one point or another. Totally exactly right. Though
I want to make clear also I'm not implying that
the inverse excuse supplies where you can you can take
that logic and apply it back to human institutions like
people and like corporations and all that, because come on,
they got people in them. People out oft know better.

(01:00:53):
And also we are not condoning human cannibalism, right, that's
what I mean. Yeah, I think you're just talking about
the digital media, but neither one neither actually eat killing
and eating other humans, nor doing stuff that's akin to
cannibalism in metaphorical way right now, Survival cannibalism, that's that's
a different scenario. If somebody's already dead and you've got

(01:01:13):
nothing else to live on. Maybe maybe, But then again,
like that's that's a decision you're going to have to
make in those dire situations. We can't make it for you.
It would be you know, it would just be rude
of me to rule on that. I do not know
the particulars of your survival cannibalism. So if you are
in a survival cannibalism situation right now while listening to

(01:01:35):
this podcast, I cast no judgment. Eat your earbuds. If
that that's what you should do, well, maybe if you
chew on the earbuds a little, it can distract you. Right,
It's kind of like sucking on a button if you're thirsty, right,
the I don't know if that actually works, but that's
the old wives tale, right. This has been a lot
of fun, Robert, Yeah, another page in the book of Cannibalism. Uh. Likewise,

(01:01:57):
with a lot of these topics, there's so much more
we could discuss, and cannibalism will probably come back around
to cannibalism again, either generally or you know, regarding a
specific organism at some point in the future. Uh. Also,
I want to stress again that Bill shoot book Cannibalism
is excellent. Do pick it up. You wrote another one
on vampires dealing with vampiric organisms, and that too is

(01:02:22):
an excellent read. So either of those books are wonderful
if you want to, like I guess you know, slightly
uh slightly ghastly um biological read, They're they're great books.
In the meantime, if you want to check out more
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to Blow Your Mind subscribe to Invention as well. Uh,
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is an invention by invention, look at human techno history. Recently,
we've been spending a lot of time talking about photography

(01:03:03):
and now we're getting into the realm of motion pictures,
but in exactly the opposite direction. I've just had in
mind a very ancient invention that I want to go
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as a tease ancient superweapons. Yeah, absolutely huge, Thanks as
always to our excellent audio producers Alex Williams and Tory Harrison.

(01:03:24):
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