Speaker 1: Welcome to Stuff to Blow your Mind from how Stuff
Speaker 1: Works dot com. Hey, welcome to Stuff to Blow your Mind.
Speaker 1: My name is Robert Lamb and I'm Joe McCormick. So, Robert,
Speaker 1: I've got a question for you. Okay, shoot, I know
Speaker 1: you've heard the old would you rather be able to
Speaker 1: fly or be able to turn invisible question? What's your
Speaker 1: answer to that? But it's always been invisible? Yeah, that's
Speaker 1: the creep's answer. Well, it's the creepy it's you know,
Speaker 1: it's the observer's answer. It's this, it's the student of
Speaker 1: human behavior's answer. Because if I'm flying around looking at stuff,
Speaker 1: I'm going to be scaring wildlife. You know, people are
Speaker 1: gonna be staring up at me, and tripped traffic accidents
Speaker 1: are gonna occur. But if I've invisible, and if I'm
Speaker 1: invisible and I play it safe and I you know,
Speaker 1: and ethnically, then you know, I get to observe the
Speaker 1: world as it goes about its business. You know. Another
Speaker 1: advantage there is that flight can easily be achieved with technology,
Speaker 1: but there's no way to become invisible technologically, So that's
Speaker 1: the really more magical power. But what I was gonna
Speaker 1: ask you is would you rather have wings or a
Speaker 1: prehensile tail. This is interesting because I was I was
Speaker 1: actually blogging about this a little bit yesterday. I was
Speaker 1: looking into because there's a particular plastic surgeon, Joseph Rosen,
Speaker 1: who's a real real trends that are real, real, just
Speaker 1: amazing intellect in the world of plastic surgery, does a
Speaker 1: lot of actual real life work with facial reconstruction and
Speaker 1: wounded warriors. But he's also a trans humanist, so he's
Speaker 1: he's written a lot about the not only can we
Speaker 1: do all these things, we should do them. We will
Speaker 1: get to the point where we add tails and wings. Well,
Speaker 1: I was coming at this from a somewhat magical perspective
Speaker 1: because I don't think humans would necessarily be able to
Speaker 1: fly even if they had wings, because we're just too dense, right,
Speaker 1: you would, They're like, our beings are much more dense
Speaker 1: than birds. Yes, now, there are theoretical ways to transform
Speaker 1: the human arm into a bird's wing, and it's would
Speaker 1: be a lengthy surgical process, and then they still wouldn't
Speaker 1: be able to support you and fly. You would have
Speaker 1: to have additional uh tissue, perhaps clone tissue or vat
Speaker 1: grown tissue that would be used to to graft on
Speaker 1: and create the size of wings necessary to fly. And
Speaker 1: then of course you still wouldn't have any arms. You
Speaker 1: would just have like the large bat wings. So I mean,
Speaker 1: along those lines, I would probably go with the tail
Speaker 1: because it would it would change my life less dramatically.
Speaker 1: Now would it be more horrifying to not have hands
Speaker 1: at all and just have wings like a bird, or
Speaker 1: to be like a bat and basically have gigantic hands
Speaker 1: that you can't really use as hands but you can
Speaker 1: still see some finger bones in there. Um, well, they're both.
Speaker 1: They're both fine choices. But wait a minute. This episode
Speaker 1: isn't about wings. It's about tails. That's right. We're talking
Speaker 1: about tails specifically in this episode, about animal tails, and
Speaker 1: then there's gonna be a second episode when we talk
Speaker 1: about the absence of tails for the most part in
Speaker 1: human beings. Okay, so did you come down one way
Speaker 1: or another? Wings or tails? Definitely tails. You'd rather have
Speaker 1: a prehensile tail than wings, yes, I mean especially it
Speaker 1: was a nice functional tale that, you know, the prehensile
Speaker 1: tale that I could utilize in my daily environment. It
Speaker 1: wouldn't just be about you know, keeping flies away from me.
Speaker 1: I've always thought a prehensile tail would be most useful
Speaker 1: to a musician. Yeah, you know, playing a musical instrument,
Speaker 1: that's when you really wish you had more hands. Yeah,
Speaker 1: if you're a one man band, you could you could
Speaker 1: really use that extra appendage, right that that's for your
Speaker 1: double bass drum pedal. Yeah, so before we got one
Speaker 1: man death metal band? Not but what would it be?
Speaker 1: Speed metal, thrash metal? Who uses the double bass pedal?
Speaker 1: It's two technical question for me. But you know, when
Speaker 1: when it comes to tales, and you know we're already
Speaker 1: talking about semi fictional accounts. But but I say a
Speaker 1: few examples that come to my mind that make me
Speaker 1: also I want to want to go into the prints
Speaker 1: off to the prehensile tail direction versus the wing direction. Um.
Speaker 1: I think of Minos from Dante's Inferno, who has this
Speaker 1: enormous serpentine tail, and when you have a new arrival
Speaker 1: in Hell, he wraps this tail around you and he
Speaker 1: is able to determine which level of the Inferno you're
Speaker 1: bound for based on how many coils wrap around your body.
Speaker 1: Now I can't remember. Does this also go into sorting
Speaker 1: the virtuous Pagans or is this only once you're definitely
Speaker 1: in the hell part. I think this is more about
Speaker 1: like definite hell as opposed to the the the limobile
Speaker 1: page Pagans and limbo on the outside. Yeah, this is
Speaker 1: your inhale. Help now we need to get you where
Speaker 1: you go. And Minos is in charge of sorting it. Well,
Speaker 1: that's a smart tale. Another one that comes to mind
Speaker 1: is u Calabos from Clash of the Titans, the old
Speaker 1: Clash of the Titans Harry Hamlin duking it out version.
Speaker 1: I assume you've seen this classic film, you know, I
Speaker 1: have to admit I actually have not said this is
Speaker 1: this is some ray he Housing claimation. Yeah, fabulous, fabulous claimation.
Speaker 1: I love that stuff. And I've never seen this movie.
Speaker 1: I think I've seen the scene where the where the
Speaker 1: Titan comes to life is a huge statue of that
Speaker 1: from Clash of the Titan. Well, there's the kracking. This
Speaker 1: one has the Kraken, it has Medusa Pegasus, that little
Speaker 1: mechanical owl. Of course, Calibus, who's this um, this character
Speaker 1: who's twisted by the gods into this sort of caliban
Speaker 1: esque creature with horns and a demonic face. And then
Speaker 1: a long swinging tale. That's great. We'll have to watch it.
Speaker 1: I love the Harry Housing sin Bad movies. Great creatures,
Speaker 1: those are wonderful. Yeah, there's one that has um what's
Speaker 1: his name? That went imp be doctor who or the
Speaker 1: the doctor and Doctor who? Rather um the class. Oh
Speaker 1: I don't know, yeah, Tom Baker, Tom Baker? Yeah, which
Speaker 1: one is it? I don't know. I saw it a
Speaker 1: like a drive in event once and it was It's
Speaker 1: fabulous because you get to see him as a dark sorcerer.
Speaker 1: Oh that's great. Um. One other fictional tale creature that
Speaker 1: I want to mention because it's it's played a role
Speaker 1: in my life a lot recently is the Chippendale mup
Speaker 1: from Dr Seus's Sleep Book. I don't know what you're
Speaker 1: talking about. Oh, well, this is This is a fabulous
Speaker 1: Dr Seuss book in that it just takes the soon
Speaker 1: hopefully to be a sleep child through this dreamland. Um
Speaker 1: or so I guess this awaking dreamland and all these
Speaker 1: creatures are going to sleep. And the the overall argument is, hey,
Speaker 1: look at all these things that are going to sleep.
Speaker 1: You should join this crew in slumber. And the Chippendale
Speaker 1: um up is this character who quote, his tail is
Speaker 1: so long, he won't feel any pain till the nip
Speaker 1: makes the trip and gets round to his brain. So
Speaker 1: what happens is this, Um, this creature bites it's exceedingly
Speaker 1: long tail right before it goes to sleep, so that
Speaker 1: the pain will travel all the way through the tail
Speaker 1: and travel eight hours all the way around and back
Speaker 1: up the spinal column hit his brain, and then he'll
Speaker 1: feel the pain and wake up. And I recently crunch
Speaker 1: the numbers on this, and if I'm correct, for this
Speaker 1: to work, based on the speed at which pain travels
Speaker 1: through a nervous system, uh, the tail would need to
Speaker 1: be about a thousand and eight kilometers or six six
Speaker 1: miles long. So that's enough. That's so if the thing
Speaker 1: we're laying out straight in the Western United States, it
Speaker 1: could lay with its nose in Seattle, Washington into tail
Speaker 1: in Sacramento, California. Wow. Yeah, I have absolutely nothing to
Speaker 1: add to that horrifying children's story. Yeah. Um, beyond that,
Speaker 1: I mean, the only other fictional tail that that instantly
Speaker 1: comes to mind is, of course the xenomorph tail uh
Speaker 1: from Alien and Aliens creature that every every part of
Speaker 1: the creature is a is a weapon, and of course
Speaker 1: its tail is a rather cinematic weapon as well. Yeah,
Speaker 1: it's a it's a barbed spear. If you look at
Speaker 1: it, it it looks like it was designed to get stuck
Speaker 1: in you. And one thing I have to notice about
Speaker 1: that tail. It never seems like you see the tail coming.
Speaker 1: It's always suddenly poking out of your torso and you're
Speaker 1: looking down at it. And why did this happen? Yeah,
Speaker 1: it had whips it around and then right through you.
Speaker 1: But those are fictional tales. We should, uh, we we
Speaker 1: should start by just talking about the very basics here,
Speaker 1: the basics of tales. Yeah, for example, what is a tail?
Speaker 1: What is the essence of a tail? It's uh, it's
Speaker 1: a harder question than then you then you, you know,
Speaker 1: because when you first think of it, especially from a
Speaker 1: vertebrate standpoint, you think, well, that's just the other end
Speaker 1: of of the vertebrae, right, that's the the tail end
Speaker 1: of the verb. It's almost indifficult to think about tails
Speaker 1: outside of our language of tales. Yeah. And an interesting
Speaker 1: fact is that even animals that don't have tails as
Speaker 1: an adult often show a tale at some stage of
Speaker 1: their development. So a frog might not have a tail,
Speaker 1: but the tadpole that became that frog had a tail.
Speaker 1: You might not have a tail, but when you were
Speaker 1: in the womb as an embryo, you had a tail.
Speaker 1: That's right. And then it it simply goes away, usually
Speaker 1: before we're born. Usually we'll get to that, I guess
Speaker 1: in the next episode. Yeah, it gets reabsorbed by the body, right, Yeah,
Speaker 1: So tales are a huge deal with vertebrates. We just
Speaker 1: happen to belong to rather exclusive club of creatures that
Speaker 1: do not have tales. Uh. And likewise, you look at
Speaker 1: the invertebrate world and tons of fascinating tales there as well,
Speaker 1: that exist without the necessity of underlying vertebrate. Now, if
Speaker 1: you're an invertebrate and you have whatever we would call
Speaker 1: a tale, is that technically a tale or not? Yeah,
Speaker 1: it's a It's a more difficult question than than you think,
Speaker 1: you know when you start, especially when you look at
Speaker 1: some of the specific examples that we're going to roll through.
Speaker 1: Um uh, you know, particularly with a scorpion, like trying
Speaker 1: to forget where this tail came from and how it
Speaker 1: uh eventually evolved into this rather curious form. Now, when
Speaker 1: in discussing tales, you basically have two types. There's kind
Speaker 1: of and you can sort of think of this as
Speaker 1: non functional or barely functional tales versus functional and highly
Speaker 1: functional tales. So the first thing I've got to ask
Speaker 1: about before we get into these vertebrate tales is what
Speaker 1: is going on with the scorpion? Because I love I
Speaker 1: love aragnids, and I love scorpions. When I was a
Speaker 1: little kid, my dad one time took a trip to
Speaker 1: Arizona and when he came back, he had one of
Speaker 1: those one of those tourists you know, gifts that that
Speaker 1: is a scorpion inside a piece of glass. Oh yeah,
Speaker 1: And he he gave this to me, and I used
Speaker 1: to just stare at it, thinking like, this is the
Speaker 1: coolest thing on planet Earth. Where where does this tail
Speaker 1: come from? Why is it so cool? Well, it's a
Speaker 1: it's interesting because of course what you what you have
Speaker 1: here when you're looking at a scorpion, you have a segmented,
Speaker 1: curved tail that's tipped in a venomous stinger which he
Speaker 1: uses for self defense, but also against prey that's large
Speaker 1: or feisty, like if they're if they're coming up against
Speaker 1: something small, they'll often just use their claws and not
Speaker 1: even employ the stinger um. And about twenty five different
Speaker 1: species of scorpion possessed of venoms capable of killing a human,
Speaker 1: and the rest have venoms that are not that potent.
Speaker 1: But of course, you know, allergies and whatnot can play
Speaker 1: into reactions. Uh. Now, the interesting thing about scorpions is
Speaker 1: that their body is a very old design. It's changed
Speaker 1: little over the past four hundred million years, and they
Speaker 1: probably evolved from the long extinct sea scorpions. Oh, the euryptorids. Yeah,
Speaker 1: the eureptroids. Those are the huge ones, right, Like you
Speaker 1: see the fossils of those, and it's just astounding. The
Speaker 1: biggest people and uh, the sea scorpions. They also featured
Speaker 1: a segmented tale that ended in at least a spike. Now,
Speaker 1: it's difficult, perhaps even impossible, to know if these were
Speaker 1: venomous or non venomous. It's likely that they used to
Speaker 1: use them for propulsion or balance steering swimming, and that
Speaker 1: it just eventually evolved into a venomous weapon over time.
Speaker 1: This is one of the interesting stories about evolution because
Speaker 1: you see this primeval tale emerging in many older forms
Speaker 1: of life. Where they've got some kind of appendage coming
Speaker 1: out the back of their body. But there are so
Speaker 1: many different evolutionary routes this tail could go down in
Speaker 1: in later development. Uh, And I guess that's what we're
Speaker 1: going to be exploring in in this episode of the podcast.
Speaker 1: Today is like eighteen roads diverged in a yellow wood,
Speaker 1: and depending on which one you picked, you might have
Speaker 1: a tail that communicates your emotions, or a tail that
Speaker 1: stabs your prey and injects venom, or a tail that
Speaker 1: helps you climb trees, or who knows what I mean.
Speaker 1: There are tons of things you can do with a
Speaker 1: part of your body that you don't necessarily have to
Speaker 1: use for walking or propulsion, though some animals do continue
Speaker 1: to use it for that. Yeah, so I definitely challenge
Speaker 1: everyone to keep our trans human question in mind as
Speaker 1: we move forward. If you were to to have the
Speaker 1: chance to gain a tail, might some of these examples
Speaker 1: sweeten the deal for you. I think everybody is just
Speaker 1: going to go with the xenomorph tail and yeah, but
Speaker 1: you know, I don't see the xenomorpha doing a lot
Speaker 1: of practical things outside of murder with that tale, right,
Speaker 1: it must not be that fulfilling to be a xenomore. Well,
Speaker 1: you know, fulfillment is a very human classification, right, I'm
Speaker 1: just projecting. I guess well, I think we should first
Speaker 1: talk about prehensible tales in the animal kingdom. If you're
Speaker 1: not familiar with what they are, I guess you might
Speaker 1: have been a little bit lost so far. But a
Speaker 1: prehensible tale is a tale that to some degree can
Speaker 1: be used for manipulation and grasping. They're usually divided into
Speaker 1: fully prehensible or semi prehensible tales, depending on what the
Speaker 1: animal can do with and you you might think it
Speaker 1: would be really great to have a prehensible tail as
Speaker 1: a human because it'd be like having another hand. You know,
Speaker 1: you could just do whatever we were talking about it earlier.
Speaker 1: You could play more musical instruments or something like that.
Speaker 1: But I also want to ask the question of do
Speaker 1: you really need one? Because when you look at all
Speaker 1: the animals that have prehensile or semi prehensile tails, I
Speaker 1: see a common feature. And this might not be the case,
Speaker 1: but at least in my observation, they all tend to
Speaker 1: live in environments that are kind of like a jungle gym,
Speaker 1: where there are branches or sea grass or coral reefs.
Speaker 1: And if you look at pictures of animals using their
Speaker 1: prehensile tails, sometimes they're used for free object manipulation, you know,
Speaker 1: scooping up a bunch of something. But the majority of
Speaker 1: what I see is animals using the prehensile tail is
Speaker 1: an aid in climbing, or an anchor against some force,
Speaker 1: such as hanging from a tree limb, so anchoring against gravity.
Speaker 1: Or how a sea horse uses its tail as a
Speaker 1: grasping oregan the latch onto things like coral and anchor
Speaker 1: itself against the tide so it can just sit there
Speaker 1: and wait and and do its thing with its head.
Speaker 1: I guess the seahorse doesn't really have hands to work with. Yeah,
Speaker 1: the discussion of a jungle gym like environment, it reminds
Speaker 1: me of Dan Simon's Hyperion Cantos, his sci fi series.
Speaker 1: There's a kind of a subspecies of humans or a
Speaker 1: branch of humanity known as the Alsters, and they live
Speaker 1: in uh in in in low gravity or zero gravity environments,
Speaker 1: and so they're their soldiers particularly will often be seen
Speaker 1: with robotic tales added to their suits to to aid
Speaker 1: in this very kind of environment. Because you're in a
Speaker 1: wait list, like you know, shiphole environment. You are essentially
Speaker 1: living in this kind of jungle gym. So we would
Speaker 1: be advantageous in that environment to have a tale. Uh,
Speaker 1: even if it's just a robotic one, a robotic tale,
Speaker 1: you know. I think I've seen people have already created
Speaker 1: robotic tales. Have you read about these? No, I was looking.
Speaker 1: I've looked at a few different studies that have involved
Speaker 1: the biomimicry of say, the sea horse tail. Oh yeah,
Speaker 1: but I haven't. I didn't notice in any studies where
Speaker 1: anyone's actually fixing this thing under the their posterior. Oh,
Speaker 1: not so much studies. There's something I know we've talked
Speaker 1: about in for we're thinking that was it wasn't so
Speaker 1: much functional as it was decorative, but it was a
Speaker 1: tail that would respond to your emotions. Okay, all right,
Speaker 1: so the tail of the communicator. You could, Yeah, you
Speaker 1: could wag your tail like a dog, which we will
Speaker 1: get to in a bit. But of course, I I
Speaker 1: said at the beginning, what you can do with the
Speaker 1: tail if you don't have to use your tail for movement.
Speaker 1: Of course, plenty of animals do still have to use
Speaker 1: their tails for movement. They're they're a crucial part of
Speaker 1: their locomotion method. We birds, for example, Yeah, I mean snakes,
Speaker 1: fish birds in particular, you have a highly specialized tailed,
Speaker 1: the feathered tail. The flighted bird contributes to lift as
Speaker 1: well as stabilization drag reduction, so it's a very fine
Speaker 1: tune part of their anatomy. Yeah, and of course there
Speaker 1: are fish. Animals that live in the water often use
Speaker 1: tails for propulsion, generating a paddling motion that pushes against
Speaker 1: the water in a way that cancels outside to side
Speaker 1: motion but generates net thrust in the forward direct And
Speaker 1: in fact, if you've never seen it, you should look
Speaker 1: up simulations of fish swimming motions and fluent in fluid
Speaker 1: dynamics simulators. There. I found a couple of videos of
Speaker 1: this on YouTube, and it's really interesting seeing the waves
Speaker 1: that are generated by the side to side motion of
Speaker 1: a fish's body and tail. As the waves sort of
Speaker 1: starts at the head and then gets bigger and bigger
Speaker 1: as it goes back towards the tail, and it generates
Speaker 1: this upside down y shape of of directional motion. Oh yeah,
Speaker 1: it's like a full body movement as opposed to just
Speaker 1: you know, a mechanical fish with the tail that goes
Speaker 1: back and forth from their your bathtub, right, that'd be
Speaker 1: more like a I don't know, a side to side propeller.
Speaker 1: I guess that's kind of like sculling in a in
Speaker 1: a boat, right, if you just wag the rudder back
Speaker 1: and forth. Another interesting fact, if you've never noticed, is
Speaker 1: that fish tend to sweep side to side and there swimming,
Speaker 1: and marine mammals like dolphins and whales sweep up and down. Uh.
Speaker 1: There may be a septions to this, I'm not aware
Speaker 1: of them if there are, but it's an interesting artifact
Speaker 1: of the divergent and then subsequently re convergent evolutionary pathways
Speaker 1: of fish and marine mammals, so that like the whale tail,
Speaker 1: the horizontal whale tail versus the vertical shark tail. Yeah.
Speaker 1: Or I guess the more apt of comparison would be
Speaker 1: dolphins and sharks, as that is the distinction one is
Speaker 1: often trying to make at the beach in the water. Yeah.
Speaker 1: I don't know why it took me so long in
Speaker 1: my life to notice this, but I just never noticed
Speaker 1: that difference until I think I was at an aquarium
Speaker 1: one time and I was looking at the belugas that
Speaker 1: we're swimming through the aquarium, and I was like, what's
Speaker 1: wrong with that thing's tail? Oh, it's just not like
Speaker 1: fish tails, it goes the other way. Yeah. Of course
Speaker 1: we already mentioned that communication is a big deal with
Speaker 1: tales and a number of species, and of course what
Speaker 1: what manner of communication is more important than than that
Speaker 1: involved in courtship? Exactly right, And here we're going to
Speaker 1: get to one of the most interesting things I've come
Speaker 1: across in in our research about tales, which is the
Speaker 1: courtship tail feathers of the p cock. Actually, another pop quiz.
Speaker 1: Do you know the generic non gendered term for peacocks
Speaker 1: and p hens? No? I don't. It is p foul
Speaker 1: foul Okay, that's that's that seems brother neutral. Yeah, I
Speaker 1: just thought that was a great word. Fo Yeah, nobody
Speaker 1: ever says, let's go look at the p foul though
Speaker 1: the peacocks. It's true. Well, it's an unfortunate fact that
Speaker 1: nobody cares about seeing the p hens because they do
Speaker 1: not have these gigantic, interesting tails. Uh. I'm sure phns
Speaker 1: are wonderful. No, no offense to them, but that they
Speaker 1: don't put on a display like this, and that's what
Speaker 1: we're gonna talk about here. Another interesting fact, did you
Speaker 1: know that what we call the peacocks tail is usually
Speaker 1: not actually it's tail really yeah, most of the time
Speaker 1: this thing you see when you think of a peacock,
Speaker 1: what we're talking about is it's covert feathers, which your
Speaker 1: feathers that cover the tail feathers. It's also referred to
Speaker 1: as a peacock's train. And as you've surely seen before,
Speaker 1: when a when a peacock props up and spreads out
Speaker 1: its covert feathers, they formed this gigantic, shimmering, iridescent display
Speaker 1: of plumage full of spots that look like eyes, and
Speaker 1: if you want to use a cool word, those eye
Speaker 1: spots are called ocelli. I had always read that the
Speaker 1: peacocks train was known to be used for mate selection purposes,
Speaker 1: though in reading up on this for today's episode, I
Speaker 1: found out that there have been some really interesting questions
Speaker 1: and doubts recently thrown into the mix here. But this
Speaker 1: is a really interesting story about the complexities of evolutionary
Speaker 1: biology and and questioning what we thought we knew. So
Speaker 1: there's this mate selection theory of the peacocks train. The
Speaker 1: ideas of the most prominent one, this is the one
Speaker 1: we've all heard growing up. Yeah, and and Charles Darwin
Speaker 1: thought about this. Charles Darwin. If you're Charles Darwin and
Speaker 1: you look at a peacock's train, this huge, huge, shimmering,
Speaker 1: eyespot covered extravagance, you think, what on earth is this for?
Speaker 1: You're you're coming up with this theory of natural selection,
Speaker 1: where organisms that are the most adapted to survive and
Speaker 1: reproduce in their environment are the ones that survive. How
Speaker 1: do you encourage a trait that's so wasteful and pointless.
Speaker 1: I mean, it doesn't it takes energy or resources to
Speaker 1: develop a train like this. It doesn't seem to provide
Speaker 1: any sort of mechanical survival advantage, So it doesn't help
Speaker 1: the peacock fly higher, or you know, kick with its
Speaker 1: spurs harder or something. In fact, it would actually seem
Speaker 1: that feathers like this make the peacocks more vulnerable to predators.
Speaker 1: So what's the deal. Why would you have something like
Speaker 1: this in an animal? So I've actually read several hypotheses
Speaker 1: over the years to explain the the extravagance of the
Speaker 1: peacock's train display and the I guess we should start
Speaker 1: with the sexual selection effect. This is what's sometimes called
Speaker 1: runaway sex sual selection. And the point is that at
Speaker 1: some point, way way back in the p fowl's ancestral lineage,
Speaker 1: the p hens, the female p foul preferred slightly longer,
Speaker 1: more elaborate trains for some reason related to fitness. Maybe
Speaker 1: it made the males stronger, more powerful in flight. And
Speaker 1: this choosiness kept being magnified more and more over the generations,
Speaker 1: until the peacocks were no longer displaying fitness, but they
Speaker 1: were just being bred by the females to have longer
Speaker 1: and more elaborate trains. In the same way we would
Speaker 1: breed a dog to encourage a certain trait to to
Speaker 1: intensify over generations, we just end up with a ridiculous
Speaker 1: breed of dog that has no clear function anymore other
Speaker 1: than to look funny. Yeah, And that's what the p
Speaker 1: hens are doing to the pea cocks. Over the generations.
Speaker 1: They develop a preference for a certain type of trait
Speaker 1: in males, and the males that have that trade get
Speaker 1: more mating opportunities, and this gets magnified over the generations,
Speaker 1: and if there's not enough of a selection pressure to
Speaker 1: counteract the sexual selection, like if there's not a strong
Speaker 1: enough force saying okay, males with these big train displays
Speaker 1: really are going to get killed all the time, then
Speaker 1: they'll just keep getting bigger and bigger. Another evolutionary explanation
Speaker 1: that I've read about is that the large extravagant displays
Speaker 1: function as a sort of calculated, conspicuous handicap to show
Speaker 1: off the fitness of the mail. And it's kind of like,
Speaker 1: in human terms, a guy showing off how much money
Speaker 1: he has to waste by wearing lots of pointless expensive jewelry,
Speaker 1: or like a swordsman demonstrating his superiority by dueling with
Speaker 1: one hand tied behind his back. The point is like
Speaker 1: I am so fit, I am such a good mate
Speaker 1: that I can have this enormous handicap, this pointless waste
Speaker 1: of resources, and still be the best that made that
Speaker 1: that makes sense. It's like I have the time and
Speaker 1: energy to put into this ridiculous, uh cumbersome uh addition
Speaker 1: to my body. Another hypothesis that's been developed over the
Speaker 1: years is that the ability to produce large, elaborate trains
Speaker 1: is an advertisement that the peacock is relatively free of
Speaker 1: parasites which would impair his ability to produce and maintain
Speaker 1: a large, beautiful train like this. But I want to
Speaker 1: talk about some specific studies because, like I said, the
Speaker 1: research now seems to have gone back and forth about
Speaker 1: the role that the peacock's tail plays in the mating rituals.
Speaker 1: So in the early nineteen nineties, the behavioral ecologist Marian
Speaker 1: Petrie of Newcastle University carried out some really often cited
Speaker 1: research and this is one of the big studies in
Speaker 1: this field. One paper and Animal Behavior in nine was
Speaker 1: called p Hen's prefer Peacocks with elaborate trains. So what
Speaker 1: do what do peacocks do when they want to mate? Well,
Speaker 1: they aggregate into something called a leck. I believe I'm
Speaker 1: pronouncing that right. It's l e K and that so
Speaker 1: the males gathered together and in this case, uh Petrie
Speaker 1: and her her team observed one leck that was consisting
Speaker 1: of ten males, and they found that there was a
Speaker 1: big difference in how much the different males in the
Speaker 1: leck got opportunities for mating. So the top male, according
Speaker 1: to them, copulated twelve times, while the least successful males
Speaker 1: in the leck got no sex whatsoever, and Petrie's team
Speaker 1: concluded that quote over fifty percent of the variants in
Speaker 1: mating success could be attributed to train morphology. There was
Speaker 1: a significant positive correlation between the number of eye spots
Speaker 1: a male had in his train and the number of
Speaker 1: females he made it with. So they found that the
Speaker 1: females didn't mate with the first male they met, but
Speaker 1: they would visit several different males and in ten out
Speaker 1: of a in cases in their study that ended with
Speaker 1: successful copulation. In their terms, I'm trying to imagine what
Speaker 1: unsuccessful copulation is, the male that the female chose was
Speaker 1: the one with the greatest number of eye spots. So
Speaker 1: this seems pretty straightforward. More eye spots on your train
Speaker 1: means you get more mating opportunities. Okay, that's pretty straightforward.
Speaker 1: It's kind of like more the more jewelry, the more
Speaker 1: the fancier the clothes, the more the more money that
Speaker 1: the that the individual has to spend on drinks and
Speaker 1: nights out translates to the the economics of the development
Speaker 1: of these eye feathers. Yeah. Yeah, So this seemed to
Speaker 1: be accepted for a while. Until now. That paper was
Speaker 1: called p Hen's prefer peacocks with elaborate trains. In two
Speaker 1: thousand eight, in the same journal Animal Behavior, there was
Speaker 1: a paper called p Hen's do not prefer peacocks with
Speaker 1: more elaborate trains. This was carried out by a team
Speaker 1: led by Mariko Takahashi, and they were trying to replicate
Speaker 1: the original results in a feral population of Indian pe
Speaker 1: foul in Japan. Over the course of seven years of observation,
Speaker 1: and Takahashi and her co authors claimed to have found
Speaker 1: no evidence at all that the phn's expressed any preference
Speaker 1: for peacocks with more elaborate trains. That's what they said.
Speaker 1: This means the females did not show any noticeable preference
Speaker 1: for males with longer trains, more symmetrical trains, or more
Speaker 1: eye spots. And those are the three things that are
Speaker 1: often cited as as being the you know, the things
Speaker 1: you want your train to have. So what does that?
Speaker 1: What does that mean? Where does that leave us? Well?
Speaker 1: According to them, they concluded that the peacock train display
Speaker 1: is it might be a necessary part of successful mating.
Speaker 1: So a male that can't show a train display is
Speaker 1: not going to get to mate. But they came up
Speaker 1: with three concluding points. They said, the train is not
Speaker 1: the universal target of female choice. Uh, the trains don't
Speaker 1: vary a whole lot across male populations. And then they
Speaker 1: also said, quote, based on current physiological knowledge, it does
Speaker 1: not appear to reliably reflect the male conditions. So they
Speaker 1: don't think that the train is all that much of
Speaker 1: an indicator of fitness. And what they ended up concluding
Speaker 1: is that it's just an obsolete signal that maybe it
Speaker 1: used to correlate to female preference, but it just doesn't anymore.
Speaker 1: It's it's tempting to take that and try to apply
Speaker 1: it to the human world and and various mating practices
Speaker 1: and you know, romance practices that are really kind of
Speaker 1: becoming pointless than our modern age. But it's it's part
Speaker 1: of traditions, so you kind of have to do it.
Speaker 1: I mean, you don't really do it, but every you
Speaker 1: don't I mean you don't really have to do it,
Speaker 1: but everyone feels a little weird if you don't write. Yeah,
Speaker 1: how many common I don't know, dating or courtship practices
Speaker 1: are still somehow based on the idea that in a relationship,
Speaker 1: a man will be the person who's earning the money
Speaker 1: for the couple, when in you know, many or most
Speaker 1: cases in the Western world, that's not the case anymore. Yeah,
Speaker 1: Or there's so many different little you know, superstitions and
Speaker 1: traditions and the wedding ceremony itself. My my wife shoots
Speaker 1: a lot of weddings, so I get to hear I
Speaker 1: always hear, you know, how did they do a first
Speaker 1: look or did they do the whole you know, the
Speaker 1: straight up deal where no, the bride in the room
Speaker 1: do not see each other till the ceremony, Like that's
Speaker 1: something that really had there's no bearing on anything whatsoever.
Speaker 1: But when it comes time to put the wedding together,
Speaker 1: there's often you know, enough tradition, uh, you know, bouncing
Speaker 1: around in your head that you say, I know, we're
Speaker 1: gonna we're gonna stick to the old I don't see
Speaker 1: you and you don't see me until the moment of
Speaker 1: of our of our our actual ceremony, our weddings. The
Speaker 1: human version of investing tons of resources in an elaborate
Speaker 1: train display. Yeah, I think there's a strong case for that.
Speaker 1: So that was what they concluded. But there's still more
Speaker 1: to the story because yet another animal behavior study was
Speaker 1: published in two thousand eleven that seemed to strike a
Speaker 1: note somewhere in between the two that came before, and
Speaker 1: said p ns prefer peacocks displaying more eye spots, but rarely.
Speaker 1: I can see this study perhaps not getting as much
Speaker 1: play and the media. Yeah there, I did read a
Speaker 1: good Nature News article about it, but the main takeaway
Speaker 1: was and I want to read a quote here to
Speaker 1: get it exactly right. They said, p foul mate choice
Speaker 1: is clearly more complex than previously thought. Females may reject
Speaker 1: a few mails with substantially reduced I spot number while
Speaker 1: using some other queue to choose among males with typical trains.
Speaker 1: In other words, if you have way fewer eyespots the normal,
Speaker 1: if you were obviously I spot deficient, you will not
Speaker 1: get sex as a peacock. But there's no real difference
Speaker 1: between an average number of eye spots and a much
Speaker 1: greater than average number of eye spots. The main takeaway
Speaker 1: I got from this is that p foul mate choice
Speaker 1: seems to be more complicated than we originally thought. And
Speaker 1: actually the main author of the original study from nine,
Speaker 1: Marjorie Petrie, said as as quoted in a two thousand
Speaker 1: eleven article in Nature News quote, at the end of
Speaker 1: the day, we will never know what p hens are
Speaker 1: looking at and how they select their mates. You can't
Speaker 1: ask them. Now at this point in our discussion of
Speaker 1: peacocks and p hen's um, you know, I have to say,
Speaker 1: there's got to be a way to spice it up
Speaker 1: a little bit. I feel like some some listeners out
Speaker 1: there might be saying, all right, I'm I'm ready to
Speaker 1: extract from the whole peacock discussion. But wait, right, what
Speaker 1: if we throw cyborgs in there? Right? Because you can
Speaker 1: answer Marjorie Petriots question in a way you can ask them.
Speaker 1: I mean, you can't ask them, but you can take
Speaker 1: a look at what p hens are looking at by
Speaker 1: making a cyborg p hen with eye tracking devices. In
Speaker 1: the Journal of Experimental Biology in April, there was a
Speaker 1: paper called Through Their Eyes Selective Attention in p hen's
Speaker 1: during Courtship, and the researchers behind the study wanted to
Speaker 1: see if they could find out exactly what phn's were
Speaker 1: looking at when they were presented with a male doing
Speaker 1: his courtship display. So they rigged up what looks like
Speaker 1: a cyborg PHN. She's got eye tracking hardware on, and
Speaker 1: she looks like something out of those you know, those
Speaker 1: Terminator rip off movies that started coming out in the
Speaker 1: late eighties where everybody was a cyborg or had had
Speaker 1: some kind of like cyborg upgrades for a while. Though
Speaker 1: there were so many of them, they were all shot
Speaker 1: on the same pseudo industrial setting back lot where everybody
Speaker 1: just seemed to wander around factories and alleyways all the time. Anyway,
Speaker 1: what did the PHN look at? Curiously? In the video
Speaker 1: I saw of this, she spent almost all her time
Speaker 1: looking across the bottom of the Peacock's train display, and
Speaker 1: the scientist in the video suggests that that means she's
Speaker 1: evaluating the width and symmetry of the train. So I
Speaker 1: don't know, we're kind of back to the beginning. Yeah, Anyway,
Speaker 1: I thought this was very interesting that something that we
Speaker 1: originally thought was a pretty settled matter of evolutionary adaptation
Speaker 1: turns out as very complicated and we don't fully understand it.
Speaker 1: And just one more hypothesis I came across. I don't
Speaker 1: know where to fit this into everything else, but this
Speaker 1: was that the Peacock's train display makes infrasound as it vibrates,
Speaker 1: and this infrasound might play some sort of role in mating. Wow,
Speaker 1: so it could be even more nuanced than originally suspected. Yeah.
Speaker 1: Now I want to talk just briefly about the hippo tale. Um,
Speaker 1: because this is a tale that is easy to miss,
Speaker 1: is easy to you to forget to draw. When you're
Speaker 1: drawing hippo's for a child, as I often do, I'm
Speaker 1: picturing a hippo tail. It's not very big. No, it
Speaker 1: doesn't make a courtship display. No, it doesn't seem to
Speaker 1: communicate a whole lot. Maybe it communicates a little. So
Speaker 1: what's the point. It's just a little dangly tiny thing. Yeah,
Speaker 1: like barely covers the hippo anus really. Um, Well, here's
Speaker 1: the here's the thing. If you see, if you see
Speaker 1: a hippo in a while, if you see a hippo
Speaker 1: at the zoo, uh. The what the tail does is
Speaker 1: that as the hippo releases its bowels, uh, the tail
Speaker 1: flips back and forth in order to fling poop like
Speaker 1: some sort of fecal sprinkler system. And it's suspected that
Speaker 1: this is how male hippos wou mates and territory, So
Speaker 1: it could be a form of communication, a fecal communication system. Uh.
Speaker 1: Though there's another theory out there then. This theory is
Speaker 1: that it's a means of flinging parasites away from the
Speaker 1: hippo's body, such as the place of dell Odeo's Dieger
Speaker 1: Skio Delhi leech a special leech that feeds exclusively on
Speaker 1: the rectal tissue of a hippopotamus. So what's it like
Speaker 1: to be that leech. It's a very specific lifestyle. I mean,
Speaker 1: there's so many different types of leech leeches out there
Speaker 1: with the very specific hosts in some cases, uh, and
Speaker 1: some actually eat worms as opposed to the on blood.
Speaker 1: But this leech knows what it wants it and it's
Speaker 1: hippo rectum. So it's possible that the hippo tail is
Speaker 1: as much about just flinging those away from its body
Speaker 1: as possible, and certainly in other large herbivores, we see
Speaker 1: the use of the tail as a means of keeping
Speaker 1: flies away from the rectum as well, and ultimately about
Speaker 1: you know, keeping parasites away from that delicate area of
Speaker 1: the anatomy that is otherwise difficult to reach. Now. I
Speaker 1: want to get back to monkeys for a second, because
Speaker 1: when I talked about monkeys and their prehensile tails, obviously
Speaker 1: not all monkeys have preensile tails, but the New World
Speaker 1: monkeys that have them, I talked about them using them
Speaker 1: in climbing. And there are multiple ways actually that a
Speaker 1: tail could come into climbing behaviors. It wouldn't necessarily just
Speaker 1: have to be for gripping branches or for bracing against
Speaker 1: trunks and limbs, right, yeah. It can be used as
Speaker 1: a as a balance, as a counterweight. Ah there you yeah,
Speaker 1: and and certainly you can imagine this, but I just
Speaker 1: imagine yourself balancing on a beam and the various things
Speaker 1: you use your arm for, you know, spreading your arms
Speaker 1: out and all that. If you had a tail, that
Speaker 1: would just be another part of your body that you
Speaker 1: could utilize in such a fashion. Even something like your
Speaker 1: modern house cat will utilize it's its tail for balance. Yeah.
Speaker 1: But another animal that uses it not only uses its
Speaker 1: tail for balance, but also for propulsion and uses it
Speaker 1: for pulp for propulsion on land is of course the kangaroo.
Speaker 1: You know, they have that large tail, uh, sticking out
Speaker 1: behind a huge muscular tail, and according to a two
Speaker 1: fourteen study published in the journal Biology Letters, the kangaroo
Speaker 1: utilizes its tail as a true fifth leg. The researchers
Speaker 1: found that the tail of a walking kangaroo works as
Speaker 1: hard as the leg of a comparably sized human moving
Speaker 1: at the same speed. Wait, so the tail makes contact
Speaker 1: with the ground. Yes, it does, and I'll get to it.
Speaker 1: To to that part in a second. For the most part, though,
Speaker 1: as it hops, the tail lashes up and down, helping
Speaker 1: the creature stabilize while also serving as a motor to
Speaker 1: lift and help accelerate the kangaroo's body. So it's almost
Speaker 1: it's almost like a ficio's tail, except it's uh, it's
Speaker 1: just it's moving in the air, and it's about, you know,
Speaker 1: thrusting the body as opposed to actually making contact with anything. However, However,
Speaker 1: to your point, though, the that that fifth lag, that
Speaker 1: giant tail can support the kangaroo's full body, and you'll
Speaker 1: you'll often see this occur when when male kangaroos are
Speaker 1: kicking at each other, they'll kick up, you know, they
Speaker 1: do that kangaroo kick and uh, and in doing so,
Speaker 1: they actually come up on the tail. Now, of course,
Speaker 1: a lot of the rest of the time, the creatures
Speaker 1: are not doing high speed hops and they're not kicking
Speaker 1: each other. They're just you know, gently browsing um for
Speaker 1: stuff to eat. And in those those situations, the tail
Speaker 1: just kind of, uh, you know, faces into the background
Speaker 1: for a little bit. But it's a really really remarkable
Speaker 1: tale when you when you look at at at its
Speaker 1: high speed hopping behavior and its ability to just rear
Speaker 1: up on that tail and kick with its feet. When
Speaker 1: I was a kid, I remember I thought kangaroos were
Speaker 1: one of the coolest animals, and I think that simply
Speaker 1: had to do with the obvious athleticism you see in
Speaker 1: in a kangaroo bounding, and I never really thought about
Speaker 1: the role it's tail played. Yeah, it's easy because they have,
Speaker 1: you know, pretty remarkable physiologies. Otherwise that nothing really looks
Speaker 1: like a kangaroo um. But yeah, when they're that challenge
Speaker 1: anyone to next time you're watching a kangaroo run, either
Speaker 1: at at a zoo or or just looking up you
Speaker 1: know videos on YouTube, observe the tail. I mean, what
Speaker 1: the kangaroo is doing. It's a full body movement obviously,
Speaker 1: and the tail plays an enormous role in that movement,
Speaker 1: even if it's not making contact with the ground. Um.
Speaker 1: I have to admit the kangaroo is a creature I
Speaker 1: kind of took for granted because because you would see
Speaker 1: cartoons where they get in boxing matches, you'd see footage
Speaker 1: of them running. But then you go to the zoo
Speaker 1: and you see captive kangaroos and they're just all, you know,
Speaker 1: lying on the ground and kind of splayed, and they
Speaker 1: kind of look like old men, like naked, furry old
Speaker 1: men laying around. I can think of it as a
Speaker 1: kanger danger. You know, you just want to look around,
Speaker 1: look away, and tell the children not to make eye
Speaker 1: contact with the creepy kangaroo. Yeah, there is something kind
Speaker 1: of sad about seeing bounding animals in captivity, and yeah,
Speaker 1: well it's it's almost the equivalent, though not quite the same,
Speaker 1: of hunting animals in captivity. I'm sure you've seen those
Speaker 1: YouTube videos where a tiger will see a child at
Speaker 1: the zoo and come up and through the glass and
Speaker 1: try to eat the baby. Yeah. Yeah, it's far more,
Speaker 1: far more depressing with the with a large carnivores for sure,
Speaker 1: and and certainly any animal that depends on you know
Speaker 1: a large territory in which to range about. Now I'm
Speaker 1: gonna also and throw the fox in here. There's not
Speaker 1: a lot to this one, but with the fox, you
Speaker 1: do see them using their big bushy tails as a
Speaker 1: warming wrap. So there's another use right there. Of course,
Speaker 1: the tail can play a role in some kind of
Speaker 1: energy conservation. Another way it could play a role in
Speaker 1: energy conservation is storage of fat, like you might see
Speaker 1: this in an alligator that stores fat at the base
Speaker 1: of its tail. I was trying to find information about this,
Speaker 1: and when I googled alligator tail, almost all of the
Speaker 1: results were about meat. I thought that was interesting. For example,
Speaker 1: a grocery item on Amazon called alligator tail meat five
Speaker 1: pounds and have very good reviews. Uh. But apparently alligators
Speaker 1: aren't the only ones who will put some fat in
Speaker 1: their tail store it for later. Yeah. For instance, sheep
Speaker 1: also keep a fat reserve in their tail. And really,
Speaker 1: if there's if there's room for fat in an animal's tail,
Speaker 1: it's essentially serving that purpose. And that's one of the
Speaker 1: things when you start looking at tails um with various creatures,
Speaker 1: there's often like a very predominant talking point purpose for
Speaker 1: the tail. But then there are various other uses as well,
Speaker 1: like you could be a prehensile tail, but if there
Speaker 1: is room for any fat storage in there, well, then
Speaker 1: it's it's also achieving that go as well. Another way
Speaker 1: that a tail can be fat without necessarily being fatty
Speaker 1: or having fat cells in it is tail volume. Yeah.
Speaker 1: I was interested in the question of what creature in
Speaker 1: the world has the biggest tail, But then I realized
Speaker 1: that's actually not very interesting because and I can't find
Speaker 1: any documentation to confirm this. I have to assume that
Speaker 1: it's probably just the blue whale, since the blue whale
Speaker 1: has the biggest of everything it has. That would I
Speaker 1: think that would be a very sick that But if
Speaker 1: you know otherwise, please email us that blow the mind
Speaker 1: at how stuff works dot com and let us know.
Speaker 1: But I did think of the question of what land
Speaker 1: mammal has the largest tail in relation to its body,
Speaker 1: So the largest tail to body ratio, and if you
Speaker 1: count the volume of fluff rather than mass, the trophy
Speaker 1: seems to go to the tufted ground squirrel of Borneo
Speaker 1: or Rathroscurus macrotis. I found a great feature in Science
Speaker 1: from June about this bizarre animal and what they said,
Speaker 1: is that it First of all, it's about twice the
Speaker 1: size of most tree squirrels, and they say it reputedly
Speaker 1: has a taste for blood. But like for real or
Speaker 1: just in like folklore. I think it's folklore. But we'll
Speaker 1: get to that in a second. So the size of it,
Speaker 1: it's about like thirty five cis long. It has the
Speaker 1: bushiest tail to body size ratio of any mammal, with
Speaker 1: the tail being thirty percent greater by volume than the
Speaker 1: rest of the squirrel's body. Wow, that's a big tail.
Speaker 1: Is a big tail, So why is the tail so bushy?
Speaker 1: One of the scientists referenced in that in that science
Speaker 1: article hypothesized that this giant puff ball of a tail
Speaker 1: could confuse or distract predators like leopards, or it could
Speaker 1: simply prevent the predator from getting a good grip on
Speaker 1: the squirrel if I'm just trying to catch it. Also, apparently,
Speaker 1: like I said, squirrel has this messed up reputation. In
Speaker 1: local legend, hunters claim that it attacks much larger animal
Speaker 1: like deer, it slashes them to death and then tears
Speaker 1: their guts out. Well, I certainly want to believe that story.
Speaker 1: Like the blood crazed killer squirrels. He reminds me of
Speaker 1: a certain rabbit from Monty Pyth. Right, Yeah, it's the
Speaker 1: only squirrel you know of that might harvest your organs.
Speaker 1: But it looks like the scientists are skeptical that this
Speaker 1: is true. All Right, we're gonna go and cut the
Speaker 1: tail off here, Okay, But next time, in in part
Speaker 1: two of our two parter about tales, we're going to
Speaker 1: talk about using tales in communication. We're going to talk
Speaker 1: about the strange world of autotomy. Am I pronouncing that right? Autotomy? Tommy?
Speaker 1: But yeah, and the scorpion will come back up again
Speaker 1: as promised. Um. And then of course humans human, why
Speaker 1: don't we have tales? Where's our tail? We will discuss
Speaker 1: in the meantime. If you want to check out more
Speaker 1: content from Stuff to Blow your Mind, hadn't over to
Speaker 1: stuff to Blow your Mind dot com. That's the mothership.
Speaker 1: That's where we'll find all the podcast episodes, all the
Speaker 1: blog posts, various videos. This one links out to our
Speaker 1: social media accounts that we we keep all our eyes on.
Speaker 1: And if you want to follow up on any of
Speaker 1: the rabbit trails we went down about tales today, or
Speaker 1: if you just have an interesting tale fact you'd like
Speaker 1: to share with us. You can email us at blow
Speaker 1: the Mind at how stuff works dot com. For more
Speaker 1: on this and thousands of other topics. Is it how
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