Speaker 1: Hey, are you welcome to stuff to blow your mind?
Speaker 1: My name is Robert Lamb and I'm Joe McCormick, and
Speaker 1: it's Saturday. Time to venture into the vault, this time
Speaker 1: with an episode about youth and aging. This is Eternal Youth,
Speaker 1: Part one, originally published January four. This is one of
Speaker 1: the episodes. I think we did a pair here where
Speaker 1: we were sort of asking the question why animals age? Why?
Speaker 1: Why why not just stay young? Forever? Yeah? Youth like
Speaker 1: diamonds in the sun, right, um, forever young Alphaville. Hopefully
Speaker 1: I don't remember if I referenced that track uh in
Speaker 1: these episodes, but I hope I did. I think you
Speaker 1: referenced it more recently when pointing out how creepy the
Speaker 1: lyrics are that they they sound like a serial killer. Note, yeah,
Speaker 1: they're they're they're super creepy. That track is the reason
Speaker 1: I didn't share my You know a lot of people
Speaker 1: are sharing, uh, these curated lists of what tracks they
Speaker 1: listened to the most in the previous year. That was
Speaker 1: your number one? It was, it was, it was, it
Speaker 1: was up there way too much, and I have to
Speaker 1: I can only share that with people if I can
Speaker 1: also explain to them that I have a very creepy
Speaker 1: interpretation of the song and therefore me listening to Forever
Speaker 1: Young is like most people listening to death metal. I'm
Speaker 1: gonna see you and raise you there because the other
Speaker 1: Forever Young also has creepy lyrics if you listen to them.
Speaker 1: Oh yeah, this is the Bob Dylan r. Yeah yeah yeah,
Speaker 1: just go listen, you'll you'll see. All right, Well, let's
Speaker 1: jump right into it. Welcome to Stuff to Blow your
Speaker 1: Mind from how stuff dot com. Hey you, welcome to
Speaker 1: Stuff to Blow your Mind. My name is Robert Lamb
Speaker 1: and I'm Joe McCormick and Robert, I want to ask
Speaker 1: you about a Greek commit go for it. You know,
Speaker 1: the myth of tiffan Us. This is not one that
Speaker 1: I am am readily familiar with off stuff of my head. Well,
Speaker 1: it's one of those great ones with doomed lovers. Are
Speaker 1: doomed lovers? Just fantastic? Yea? Is there? Does a god
Speaker 1: show up the act particularly crappy towards mortals? Uh not.
Speaker 1: I don't know if it's on purpose. You do get
Speaker 1: Zeus being a jerk, but he might be like he's
Speaker 1: a jerk by accident. Or maybe he's a jerk on purpose.
Speaker 1: It's kind of hard to tell, because being a jerk
Speaker 1: is kind of Zeus is default thing in general. Yeah,
Speaker 1: Zeus in this myth acts kind of like the Monkeys
Speaker 1: Paul and the classic short story, where you get the
Speaker 1: wish but not quite in the way you wanted it.
Speaker 1: So here's how it goes. And this is the version
Speaker 1: that's in the Homeric Hymn to Aphrodite. So the myth
Speaker 1: involves the goddess aos Aus is the goddess of Dawn,
Speaker 1: and she falls in love with a mortal man from
Speaker 1: Troy named tiffan Us. And this is horrible, right, It's
Speaker 1: horrible for a goddess to fall in love with a
Speaker 1: mortal because while the gods may live eternally, dining on
Speaker 1: the ambrosia and just going on into the future, of course,
Speaker 1: mortal people, as the name implies, will die. And she
Speaker 1: hates this idea. She hates the idea that the man
Speaker 1: she's fallen in love with will someday die while she
Speaker 1: gets to go on living forever. She can't bear the
Speaker 1: thought of it. So she goes to Zeus and she
Speaker 1: makes a request, Well, you grant my lover Tiffanus eternal life,
Speaker 1: and Zeus does it. Usually, you know, usually Zeus is
Speaker 1: a jerk, but here he's like, yes, yes, I will
Speaker 1: do that for you. Aos. Well, maybe he was busy
Speaker 1: and he's just like, okay, yeah, I'm just go ahead
Speaker 1: check this off the list because I've I've got this, uh,
Speaker 1: this other torment in mind for another mortal. Right, don't
Speaker 1: have time to be a jerk. Just bam, eternal life.
Speaker 1: You will not perish and die like the other mortals.
Speaker 1: But then it takes a dark turn. So let me
Speaker 1: read from the translation of the Home Eric him to Aphrodite,
Speaker 1: and this is translated by Hugh Evelyn White. Quote. So
Speaker 1: also golden throned Aos wrapped away Tiffanus, who was of
Speaker 1: your race and like the deathless gods. And she went
Speaker 1: to ask the dark clouded son of ChRI On knows
Speaker 1: that he should be deathless and live eternally. And Zeus
Speaker 1: bowed his head to her prayer and fulfilled her desire. Okay,
Speaker 1: so he's granning the wish. Too simple, was queenly Aos.
Speaker 1: She thought not in her heart to ask youth for
Speaker 1: him and to strip him of the slough of deadly age.
Speaker 1: So while he enjoyed the sweet flower of life, he
Speaker 1: lived rapturously with golden throned Aos, the early born by
Speaker 1: the streams of ocean at the ends of the earth.
Speaker 1: But when the first gray hairs began to ripple from
Speaker 1: his comely head and noble chin, queenly Aos kept away
Speaker 1: from his bed, though she cherished him in her house,
Speaker 1: and nourished him with food and ambrosia, and gave him
Speaker 1: rich clothing. But when loathsome old age pressed full upon him,
Speaker 1: and he could not move nor lift his limbs. This
Speaker 1: seemed to her in her heart the best counsel. She
Speaker 1: laid him in a room and put to the shining doors.
Speaker 1: There he babbles endlessly, and no more has strength at all,
Speaker 1: such as once he had in his supple limbs. M Okay, well,
Speaker 1: this makes me think Zeus probably just agreed to her request,
Speaker 1: because all the gods know that mortals are going to
Speaker 1: ask for immortality at some point or the other, and
Speaker 1: they're probably not going to phrase the question properly, and
Speaker 1: you should let them have it because it will teach
Speaker 1: them a lesson. Well, yeah, he'll learn when he's old
Speaker 1: and babbling and decrepit. But cannot die. Yeah, because global
Speaker 1: myth cycles are filled with stories of of immortality gone wrong.
Speaker 1: You know, it's either a wandering immortal who's doomed or
Speaker 1: or lovers who you know, obtain a portion of immortality
Speaker 1: and it's mishandled. There's a there's a wonderful example of
Speaker 1: this in in Chinese myth with the the Elixir of
Speaker 1: Immortality and the and the Woman of the Moon. Oh
Speaker 1: does it come back to bite her? Or come back
Speaker 1: to bite the person who wants it? Um it gets
Speaker 1: There are a few different versions of the tale, but essentially,
Speaker 1: you know, one person is immortal and the other is not.
Speaker 1: That sort of thing, this this this mismatch that we
Speaker 1: see president in the Greek tale as well. Man, why
Speaker 1: are there so many myths and folk tales where people
Speaker 1: get punished for wanting better than their lot in life? Well,
Speaker 1: because you can't have it, I mean, especially when it
Speaker 1: comes to things like avoiding death and avoiding aging. You're
Speaker 1: not gonna get it. So there's something refreshing about stories
Speaker 1: in which people do get it and it backfires because
Speaker 1: that way we think, oh, well, this this thing that
Speaker 1: I cannot have is actually not that great. So thank goodness,
Speaker 1: I'm going to grow old and die. Yeah. I wonder
Speaker 1: if it makes you feel like you're not so bad off.
Speaker 1: It's like, well, I'm gonna die one day, but I
Speaker 1: could be like Tiffanous, and that's even worse. Exactly, So,
Speaker 1: I think the myth is sort of an embodiment of
Speaker 1: this cruel fact about human nature. It's not just that,
Speaker 1: as they say in Bravos, all men must die, but
Speaker 1: that all people must decline. I think warrensy On put
Speaker 1: it best. He said time treats everybody like a fool.
Speaker 1: And I think that's the case. And no amount of lawyers, guns,
Speaker 1: or money will get you out of this, that's right.
Speaker 1: So on one hand, you've got the idea of death.
Speaker 1: And death is a sort of unavoidable fact about biology
Speaker 1: because living organisms are these finely tuned factories of chemical reactions,
Speaker 1: and if you make substantial changes to the factory, say
Speaker 1: by jamming a rock through part of it, or biting
Speaker 1: part of it off, or filling it up with parasites
Speaker 1: that gum up all the gears, the factory isn't going
Speaker 1: to work the same anymore. It might not work at all.
Speaker 1: Were physical creatures were subject to physical disruption. So the
Speaker 1: potential for death is unavoidable. It's sort of part of
Speaker 1: what it means to be alive. But aging not quite
Speaker 1: so much. This steady time correlated decline in our biological fitness.
Speaker 1: Why does that have to happen? That's not physically inevitable
Speaker 1: in same way that death is. Yes, and this is
Speaker 1: going to be the question we're gonna be discussing in
Speaker 1: this pair of episodes. Now, we do want to drive home.
Speaker 1: We're not going to get as much into some of
Speaker 1: the mechanics of aging, like we're not going to get
Speaker 1: into telomeres and telomerase and all and all of that,
Speaker 1: although that's a wonderfully insightful topic onto itself. We're gonna
Speaker 1: be talking more about the these this sort of evolutionary
Speaker 1: function of aging, if it has one, right, aging is
Speaker 1: something that has such a cost for the organisms that
Speaker 1: undergo it, like tiffanus. What pays for it biologically? Why
Speaker 1: does it exist? Now, to underscore the fact that aging
Speaker 1: is not necessarily something that is inevitable, and especially not
Speaker 1: aging as early as we do, we should maybe look
Speaker 1: at some organisms that do not age in the same
Speaker 1: way we do. Yeah, they're there are a number of organisms.
Speaker 1: I'm sure a number of them come to to everyone's
Speaker 1: mind here. You think of ancient hoary tortoise is stumbling
Speaker 1: across the the ground, right, or perhaps your mind turns
Speaker 1: with the greenland shark. Will come back to that one
Speaker 1: in a second. But really one of the more insightful
Speaker 1: examples here is the hydra, or at least individuals in
Speaker 1: the Hydra genus. So you're talking about the monster that
Speaker 1: gets its head cut off and grows two more. No,
Speaker 1: as much as I do love the mythical hydra, now
Speaker 1: these are the natural world. Hydra's tiny tentacled creatures that
Speaker 1: need to continue to wow scientists because they have a
Speaker 1: number of just wonderfully bizarre and monstrous capability. So they
Speaker 1: can reproduce through a sexual butting. They have these mouths
Speaker 1: that open up kind of like wounds in their body
Speaker 1: and then close. There's some fabulous videos of them doing that.
Speaker 1: It looks like you're staring into the mouth of hell.
Speaker 1: And they have this seemingly natural inability to grow, grow old,
Speaker 1: and die of natural causes. They boast low mortality rates
Speaker 1: throughout their lives, and apparently this is according to when
Speaker 1: Dr Owen Jones from the University of Southern Denmark. He
Speaker 1: has claimed that it would take four hundred years for
Speaker 1: of a hydro population to die of natural causes in
Speaker 1: the lab. Wow, well, well that's a hardy species. Yeah,
Speaker 1: So let me let me back some of that up
Speaker 1: here with with some more the facts about the life
Speaker 1: of the hydra, so their fertility rates remain constant their
Speaker 1: entire lives, which, as will discuss is is pretty unique.
Speaker 1: And according to Pomono College biology researcher Professor Daniel Martinez,
Speaker 1: he has repeatedly found no evidence of sinescence in laboratory
Speaker 1: caddled hydra. Yeah, and even goes so far as to
Speaker 1: state that an individual hydra can live forever under the
Speaker 1: right laboratory circumstances. Now, of course, that's the catch, right.
Speaker 1: The hydro's natural environment offers sufficient hostilities to make natural
Speaker 1: death by old age and impossibility. You got disease, predators,
Speaker 1: water contamination. These are the things that usually all a
Speaker 1: hydra off in due time, and likewise, scientists have yet
Speaker 1: to create a hydra utopia that can sustain them indefinitely. Now,
Speaker 1: this is a good point in the use of the
Speaker 1: word immortality, which sometimes comes up when people are covering
Speaker 1: organisms like these. There are a couple of different ways
Speaker 1: you could look at immortality. One would be the Highlander
Speaker 1: version or something like that, where there's just like nothing
Speaker 1: that can kill you except maybe one or two little things,
Speaker 1: but that you are generally invulnerable to death. And then
Speaker 1: there'd be a different version of immortality that says, yeah,
Speaker 1: you're vulnerable to death by injury or disease, you just
Speaker 1: don't naturally grow old and die. You don't have a
Speaker 1: cap on your life span. That would be more like
Speaker 1: what are the elves of Middle Earth? Kind of like that,
Speaker 1: Like they can be killed in battle, but they don't
Speaker 1: grow old and die. Yeah. Well, I mean I would
Speaker 1: argue that the immortals of Highlander are much the same,
Speaker 1: Like there's a there's a very specific thing you can
Speaker 1: do to kill them, uh, and technically anyone can do it.
Speaker 1: It's just you've got to get the drop on a right.
Speaker 1: We should mention that we're popping in little references to
Speaker 1: Highlander to get you ready for the fact that one
Speaker 1: day soon we're going to do a Science of Highlander
Speaker 1: two episode and I'm not kidding. Yeah, you have advanced
Speaker 1: warning so you can all go review at least the
Speaker 1: first two films. Well, I would say just the first
Speaker 1: two films actually, okay, but back to the hydra and
Speaker 1: biological immortality in the real world. Yeah, so this is
Speaker 1: a major point really for all organisms. The natural world
Speaker 1: is generally sufficient to ensure mortality. It's dangerous, It's filled
Speaker 1: with competitors, predators, pathogens, accidents, and all manner of additional hazards. Now,
Speaker 1: humans and their captives tend to live in a very
Speaker 1: privileged space, largely removed from the threat of predation. At least,
Speaker 1: you'll find other creatures with no natural predators as well.
Speaker 1: Typically these are apex predators, but that doesn't mean they
Speaker 1: don't have to deal with all these other dangers. Well. No,
Speaker 1: when you think about an apex predator, just because there's
Speaker 1: nothing that tackles it and tears it apart and eats it,
Speaker 1: that doesn't mean that it's not subject to attacks from
Speaker 1: its environment, right. I mean, it of course is subject
Speaker 1: to disease. But one of the other things to think
Speaker 1: about with an apex predator is these creatures are very
Speaker 1: often constantly at the edge of starvation. And so when
Speaker 1: you see the antelope running from the cheetah or something.
Speaker 1: Of course, the cheetahs trying to kill the antelope, but
Speaker 1: by escaping, the antelope is sort of also trying to
Speaker 1: kill the cheetah. It is starving the cheetah to death
Speaker 1: by escaping. The cheat is a great example too, because
Speaker 1: either cheetah injures itself in the pursuit of a prey,
Speaker 1: especially if it tackles prey that is a little beyond
Speaker 1: its ability or or is potentially beyond its ability, it
Speaker 1: can sustain an injury that results in death, not because
Speaker 1: it becomes infected or what have you, but because say,
Speaker 1: a wounded limb on a cheetah can mean it cannot
Speaker 1: pursue prey and it starves. Right. This is another thing
Speaker 1: we often fail to appreciate in the natural world is
Speaker 1: how how absolutely damning a small injury can be to
Speaker 1: an organism that has to hunt or escape hunters to survive.
Speaker 1: You also, of course, have read about large cats that
Speaker 1: have turned man killer, and uh in some of these
Speaker 1: cases I remember correctly, Sometimes it has to do with
Speaker 1: the decline of dental health, like their their inability to
Speaker 1: depend on their their teeth for their traditional prey, and
Speaker 1: it leads to sort of a desperate switch in their
Speaker 1: their selection of prey. So anyway, most most individuals are
Speaker 1: going to die or be killed before they can grow old,
Speaker 1: so there's already a low probability of being alive and
Speaker 1: reproductive at an advanced age. Still, hyders are are really
Speaker 1: interesting because it give us a real world of world
Speaker 1: example of how how undying creatures would work on a
Speaker 1: biological level. They're hardy, their regenerative they have they have
Speaker 1: evolved to thrive in harsh environments, and it actually reminds
Speaker 1: me of an alien species that shows up in Ian
Speaker 1: m banks. The Culture series, of course, go into the
Speaker 1: Culture Yeah, I mean he he always managed to work
Speaker 1: so many wonderful scientific topics into his his books, and
Speaker 1: one of these topics is biological immortality. Alright, So we
Speaker 1: meet in the really the very first Culture book, we
Speaker 1: meet the Adherens. And here's just a quick quote. The
Speaker 1: Adherens themselves had evolved on their planet a deer as
Speaker 1: the top monster from a whole planet full of monsters.
Speaker 1: The frenetic and savage ecology of a deer in its
Speaker 1: early days had long since disappeared, and so had all
Speaker 1: the other homeworld monsters. Except those in zoos. But the
Speaker 1: Adherens had retained the intelligence that made them winners, as
Speaker 1: well as the biological immortality, which, due to the viciousness
Speaker 1: of the fight for survival back then, not to mention
Speaker 1: a deer's high radiation levels, had been an evolutionary advantage
Speaker 1: rather than a recipe for stagnation. Now, I think that
Speaker 1: might be something interesting to come back to, maybe in
Speaker 1: the second episode, and consider whether it would actually work
Speaker 1: that way and what the effect of high mortality at
Speaker 1: different stages of life would have on the life span
Speaker 1: of an organism. Alright, Well, on that note, let's take
Speaker 1: a quick break, and when we come back, we're gonna
Speaker 1: roll through just a few other long living organisms, uh
Speaker 1: that are not a hydra or an endearing thank alright,
Speaker 1: we're back. So I mentioned the greenland shark earlier. This
Speaker 1: one is pretty impressive because greenland sharks live where we
Speaker 1: understand now about four hundred years uh. And this is
Speaker 1: an exclusively wild species as well. This is not something
Speaker 1: you're gonna find growing old and fat and an aquarium.
Speaker 1: These are sharks generally don't do very well in aquariums. Correct. Yeah,
Speaker 1: it's and no one has a greenland shark that I
Speaker 1: am aware of as of this recording. At two thousand sixteen,
Speaker 1: University of Copenhagen study estimated that one female greenland shark
Speaker 1: UH had it was, it was at least four hundred
Speaker 1: years old, and that the species doesn't even reach sexual
Speaker 1: mature until one fifty. So think of that, not until
Speaker 1: they've reached an age that exceeds every human being who
Speaker 1: has ever lived, and that's counting unverified but not mythic
Speaker 1: individual humans, right, not the Highlanders or you know, like
Speaker 1: you know, biblical days. Right. Yeah. Now, of course that's
Speaker 1: still not the oldest animal, because there was a clam
Speaker 1: named Ming. This is the first line of a children's book.
Speaker 1: I know it should be. Well, I would be. I
Speaker 1: would actually be surprised if there's not a children's book
Speaker 1: about Ming. There was a clam named Ming. Yeah, and
Speaker 1: Ming did love to sing. Yeah, it's this here writes itself.
Speaker 1: So technically Ming was a qua hog clam. This is
Speaker 1: uh an Arctic variety of clam, and it was discovered
Speaker 1: off the coast of Iceland in two thousand six Now
Speaker 1: at the time they thought it was around four hundred
Speaker 1: and five years old, so they named it after the
Speaker 1: Ming dynasty that would have ruled China at this time.
Speaker 1: Later estimates, and this is supported by urban dating, would
Speaker 1: boost that age to five hundred and seven years half
Speaker 1: a millennium. So this means that the creature was born
Speaker 1: in fourteen and that's still within the Mean dynasty which
Speaker 1: went four And to throw another point of context in there,
Speaker 1: this was around the time that Leonardo da Vinci completed
Speaker 1: the Last Supper. It's the year Portuguese explorer Vasco da
Speaker 1: Gama reached India. That's when this this thing was was
Speaker 1: born and then it died in two thousand and six,
Speaker 1: there was a clam named Ming, and Ming remembered everything.
Speaker 1: There you go now the plant where world, of course
Speaker 1: has all of this beat uh. There's the great basin
Speaker 1: bristle cone Pine or Pinus along Gava and it can
Speaker 1: only lived to over five thousand years of age, and
Speaker 1: that takes us back to the very end of the
Speaker 1: Neolithic period. Work on Stonehenge had begun. This was the
Speaker 1: age of the Pharaoh, so it lived through the rise
Speaker 1: and the fall of the Roman Empire. Now, of course
Speaker 1: this highlights that different kinds of organisms have massively different
Speaker 1: potential when it comes to lifespan. Yeah, and of course
Speaker 1: plants are very different from animals. This reminds me that
Speaker 1: one of the ideas that was brought up recently. I
Speaker 1: believe on our discussion module on on Facebook or Facebook group,
Speaker 1: that we should do something just on plants, like what
Speaker 1: is a plant? To sort of strip it down to
Speaker 1: its basics. I kind of like that idea, it's a
Speaker 1: really lazy animal. Well, I've got a really lazy one.
Speaker 1: Then for you here, Uh, there's at least one step
Speaker 1: beyond the great basin bristle Cone pine. And this is
Speaker 1: something you'll find in fish Lake National Park in Utah
Speaker 1: here in the United States, Uh, the quaking aspen tree,
Speaker 1: which is also the state tree by the way, also
Speaker 1: known as the trembling Giant or pando, which means I spread.
Speaker 1: So what we have here and this is this is
Speaker 1: one where not everybody necessarily agrees with that this might
Speaker 1: be sort of bending the definition a little bit of
Speaker 1: what is a long living organism. But what we have
Speaker 1: here is a single clone of quaking asp been connected
Speaker 1: by a single extensive roots system that's roughly the size
Speaker 1: of Vatican City, a hundred and six acres thirteen million
Speaker 1: pounds and it's all eighty thousand years old. So what
Speaker 1: you're talking about is a forest that is all sort
Speaker 1: of in some way the same organism. Right, you can.
Speaker 1: It's it's not as simple as the clam was born
Speaker 1: in the century and it died in this one. But
Speaker 1: if you if you've been the definition enough and you
Speaker 1: accept this as an example, we're talking about a thing
Speaker 1: that has lived since humans first left Africa to colonized
Speaker 1: the world. Wow. Yeah, Now, Robert, here's something I've always
Speaker 1: wondered about. Okay, dinosaurs. You got to wonder how long
Speaker 1: they lived, especially because this gets warped by our sense
Speaker 1: of history. I think because they lived so long ago,
Speaker 1: you just naturally go to this completely illogical place where
Speaker 1: they must have lived a long time. Like, Okay, tyrannosaurs
Speaker 1: rex lived maybe three hundred years. I mean they they
Speaker 1: they've got very big, so you have to imagine it
Speaker 1: took them a while to grow as big as they did.
Speaker 1: This would take a lot of years of eating and
Speaker 1: cell division and all that. So so surely they had
Speaker 1: very long lifespans. Well, this used to be the main theory,
Speaker 1: and this was in part because of ai their size
Speaker 1: or at least the size of many of the specimens
Speaker 1: and the fact that we thought, well, they were essentially
Speaker 1: giant reptiles, and so based on slow reptile growth rates
Speaker 1: and their size, they said, well, big dinos probably lived
Speaker 1: several hundred years. But today paleonto just believed they grew
Speaker 1: more like birds and mammals, and this cuts back on
Speaker 1: their lifespans somewhat. So, for instance, the Field Museum of
Speaker 1: Chicago they have this, uh, this these t rex remains
Speaker 1: that they named Sue. Sue. Sue is great. Yeah, she's
Speaker 1: a wonderful specimen. You get to look right up at
Speaker 1: her and get a sense of the true size of
Speaker 1: this this amazing species. Can I say something embarrassing, go
Speaker 1: for it. I cried a little bit at Sue. Yeah,
Speaker 1: I'm not kidding. When we were in Chicago and I'm
Speaker 1: just sitting there looking at Sue for a while, I
Speaker 1: did something to me a little misty. That's that's beautiful.
Speaker 1: I I can understand it because it is like looking
Speaker 1: back in time to encounter, you know, a fossil like that.
Speaker 1: So Sue is a rather big specimen, or at least
Speaker 1: the fossil remains are rather large and speak to a
Speaker 1: large specimen. They we think now that she probably achieved
Speaker 1: adult size at age twenty and lived to a ripe
Speaker 1: old age of twenty nine. So I am now older
Speaker 1: than than this Tyrannosaurus rex was when it dies exactly. Yeah,
Speaker 1: and uh, and you just underlines that what you had
Speaker 1: with the dinosaurs was likely rapid growth but short lives.
Speaker 1: Now one sort of side question that we won't fully explore.
Speaker 1: But this this may raise the question, well, dinosaurs have
Speaker 1: cancer because you're thinking about rapid growth, right of course. Well,
Speaker 1: basically this is the question we have to come back to.
Speaker 1: But based on the research I was looking at, we
Speaker 1: only have evidence of the haddress sores the duck build
Speaker 1: dinosaurs developing any form of cancer. Now that's the caveat
Speaker 1: that's the only the only ones we have evidence of
Speaker 1: that that occurring in. But it is interesting to think
Speaker 1: of like the late model dinosaur as being the place
Speaker 1: where we see the cancer showing up. We got to
Speaker 1: come back and do an episode on dinosaur cancer in
Speaker 1: the future. Yeah, by all means, well, I want to
Speaker 1: do something that we often end up having to do,
Speaker 1: which is that after we've explored a concept for a while,
Speaker 1: it becomes more and more complicated, and our lay definition
Speaker 1: starts to get a little less useful. So I think
Speaker 1: maybe we should ask the question what actually is aging? Now?
Speaker 1: We have a pretty uh intuitive, gut level understanding of
Speaker 1: what aging is. We know when we see it, But
Speaker 1: how would you define it? I mean, it's it is
Speaker 1: something different from death, and it is something different from
Speaker 1: just like, I don't know, your skin getting wrinkles or
Speaker 1: something like that. What what is the actual scientific thing
Speaker 1: that all of the stuff we call aging has in common. Well,
Speaker 1: this is a great question. I mean, on one hand,
Speaker 1: it is closely tied to death, and I think one
Speaker 1: of the stumbling blocks is that will will alreadily admit
Speaker 1: that aging is something that our body does, but we
Speaker 1: tend there's tends to it tends to be a cultural
Speaker 1: bearer in place to saying that death is something our
Speaker 1: body does. We like to push that off onto some
Speaker 1: sort of external force of of fade or anthropomorphized dread,
Speaker 1: you know, or some sort of limit imposed on us
Speaker 1: by the gods. Well, yeah, yeah, death is something that
Speaker 1: we more often characterize as happening to us. Death happens
Speaker 1: to you. It's not something you do, though, there you
Speaker 1: can kind of see that the division between the death
Speaker 1: and the aging death I was talking about at the
Speaker 1: beginning of this episode comes into focus, because of course
Speaker 1: death can happen to you if you get a rock
Speaker 1: jammed through your you know, through your body or something
Speaker 1: like that. But the body does seem to naturally progress
Speaker 1: toward death of time, and that's kind of a weird question,
Speaker 1: like why would it do that. We will definitely explore
Speaker 1: the science behind that question in the second episode that
Speaker 1: we will look at some archaic ancers to it in
Speaker 1: this one, because when especially with the human, with the
Speaker 1: human experience of aging and death, it seems completely illogical
Speaker 1: that in many cases a human being would spend the
Speaker 1: majority of its life progressing towards death, Like the majority
Speaker 1: of your life is declined. Uh, that just feels either
Speaker 1: gross or cruel or just like a horrible design flaw
Speaker 1: or yeah, or nonsensical. Where's my eternal youth? Doesn't make
Speaker 1: any sense? Um? So. In his book The Evolutionary Biology
Speaker 1: of Aging published by Oxford University Press, the biologist Michael R.
Speaker 1: Rose defined aging in the following way quote a persistent
Speaker 1: decline in the age specific fitness components of an organism
Speaker 1: due to internal physic eological deterioration. Now Rose actually has
Speaker 1: offered has said that in some ways we might need
Speaker 1: to update that understanding a little bit to accommodate for
Speaker 1: some new discoveries. But I think this is a good
Speaker 1: place to start. So let's look at the parts of
Speaker 1: that definition. Number one, it's persistent decline, which means aging
Speaker 1: only goes one way. It's not characterized by say decline
Speaker 1: and rebound. And some organisms do have patterns like this
Speaker 1: is not quite aging, like you can think about the
Speaker 1: jellyfish that have regenerative capabilities where they can revert to
Speaker 1: a younger stage of life. But then so it's persistent decline.
Speaker 1: And then in the quote age specific fitness components biological
Speaker 1: fitness meaning the ability to survive and reproduce. So these
Speaker 1: are the things that are persistently in decline. You become
Speaker 1: less able to survive and less able to reproduce. And
Speaker 1: then it's due to internal physiological deterioration. So it's saying
Speaker 1: that this persistent decline in the ability to survive and
Speaker 1: reproduce is not due to disease or injury, but to
Speaker 1: something deteriorating within the body. Tissues themselves, yeah, this is
Speaker 1: this makes me think, of course, of the phrase cradle
Speaker 1: to the grave and with the with the hydra. The
Speaker 1: cradle to the grave is kind of a straight line
Speaker 1: with reproduction taking place at all levels until something happens
Speaker 1: to kill it. Whereas most of the models that that
Speaker 1: we look at, most of the models we looked at
Speaker 1: in researching this episode, it's more of a of a
Speaker 1: rise rising and lowering. There's a rise towards like peak
Speaker 1: sexual maturity, peak reproductive maturity, and then a decline. Yeah. Yeah,
Speaker 1: and then it gets even stickier, right because we we've
Speaker 1: just tried to be very careful and how we're defining this.
Speaker 1: But then I realized that I said the it's a
Speaker 1: decline in the ability to survive and reproduce, not due
Speaker 1: to disease or injury. But a lot of the things
Speaker 1: that are the characteristic signals of aging are sometimes thought
Speaker 1: of as diseases, even though maybe they're not caused by
Speaker 1: say a germ or something. Uh. There are all kinds
Speaker 1: of things like diabetes melitas, or like rheumatoid arthritis that
Speaker 1: are totally characteristic signs of aging and human beings, and
Speaker 1: they're thought of as diseases. But they're not so much
Speaker 1: something that gets done to the body by external forces.
Speaker 1: There are a thing that happens when the body is
Speaker 1: around for a long time under certain conditions. It makes
Speaker 1: me think back to our episode on Chinese immortality and
Speaker 1: about the the idea of the the older body being
Speaker 1: kind of an alien body, Like it's a different biology.
Speaker 1: We're changing into a different being with different physical characteristics,
Speaker 1: generally characteristics that that lean towards towards weakness. Absolutely, But
Speaker 1: then again, you can also look at aging through the microscope,
Speaker 1: look at it on the cellular level, and this is
Speaker 1: where you'll often see people using words like senescence. Defined
Speaker 1: by by Nature's scientific glossory quote, senescence is the process
Speaker 1: by which cells irreversibly stop dividing and inter a state
Speaker 1: of permanent growth arrest without undergoing cell death. Senescence can
Speaker 1: be induced by unrepaired DNA damage or other cellular stresses.
Speaker 1: So this is looking at it on the microscopic level
Speaker 1: and saying senescence, often used as as a synonym for aging,
Speaker 1: happens when the cells stop making new rejuvenated cells. This
Speaker 1: is kind of the lack of upkeep keep model. It's
Speaker 1: the idea that well, the house is falling apart because
Speaker 1: nobody's working on it, nobody's maintaining, or at least the
Speaker 1: maintenance has really been scaled back or it's all. It's
Speaker 1: been my experience thus far with aging that you find
Speaker 1: the maintenance requests are are kind of rolled out in
Speaker 1: an a logical way where you you may think yourself, well,
Speaker 1: why am I still sore from this injury I sustained
Speaker 1: last month? But my my, what my body is really
Speaker 1: trying to do is like grow a bunch of nose hair.
Speaker 1: You know, it's like, why why is that the the
Speaker 1: main operative that's been passed down to my body? You know,
Speaker 1: everything is beginning to get out of whack. It's as
Speaker 1: if it's as if there's nobody in charge anymore. Uh,
Speaker 1: and they're just letting the house fall apart. Yeah, if
Speaker 1: you were the superintendent of an apartment building, it would
Speaker 1: be like, there's a water leak in the basement that
Speaker 1: has not been fixed for months, and your repair person
Speaker 1: is busy building hundreds of kitchen cabinets on the roof.
Speaker 1: Yeah yeah, and you think, well, in the old days,
Speaker 1: we we didn't have all these kitchen cabinets on the
Speaker 1: roof and things got fixed. Why do things not got
Speaker 1: to get fixed anymore? That is a great question, and
Speaker 1: I guess we should try to look at some answers
Speaker 1: to that when we come back from this next break.
Speaker 1: Than alright, we're back, all right, So let's look at
Speaker 1: some historical and lay answers to the question, and why
Speaker 1: do we age? What's the point? Why does it happen?
Speaker 1: One common example that seems to make sense to people
Speaker 1: is the idea that our body is over time quote
Speaker 1: get worn out. Uh So. In his nine paper Pleotropy,
Speaker 1: Natural Selection and the Evolution of Senescence, which we will
Speaker 1: definitely come back to in the second episode here, the
Speaker 1: American biologist George C. Williams pointed out that one problem
Speaker 1: explaining the true biological reason behind aging is that many
Speaker 1: people think they already understand what aging is and why
Speaker 1: it happens. And they're wrong. They're wrong. But if you
Speaker 1: think you've already got the answer, you'll never go asking
Speaker 1: the question and writing of these kind of folk explanations
Speaker 1: for aging. He says, quote the most injurious of these
Speaker 1: is the identification of senescence with the quote wearing out
Speaker 1: That is shown by human artifacts, And doesn't this seem
Speaker 1: very sensical? Right? Our tools get worn out over time.
Speaker 1: If you use a knife a whole lot, eventually it'll
Speaker 1: lose the sharpness of its blade. Uh, any tool you
Speaker 1: use too much. I'm thinking about a broom that we
Speaker 1: used to have for years around our house that eventually
Speaker 1: got worn down to nubs. There were just really no
Speaker 1: bristles on it anymore. Shouldn't our bodies be the same.
Speaker 1: This reminds me I've had to explain this to my
Speaker 1: my son recently, where he'll get some sort of cheap toy,
Speaker 1: you know, as a prize or something, and uh, and
Speaker 1: he'll be really into it, and I'll have to explain
Speaker 1: to him that this is not the sort of toy
Speaker 1: that lasts very long. You know, toys like this may
Speaker 1: last a week or so. And He's like, no, some
Speaker 1: some toys last forever. And I'm like, well, they don't.
Speaker 1: They don't. Really, you have to try to explain how
Speaker 1: pretty much everything that is made by man is going
Speaker 1: to fall apart. Okay, after I finished my children's book
Speaker 1: about ming the clam, I'm writing a second children's book
Speaker 1: called Toys Die. What it reminds me of the short
Speaker 1: story that that A I was was based on. Oh yeah,
Speaker 1: I forget the exact title, but to believe it was
Speaker 1: Super Toys Last All Summer, which I always thought was
Speaker 1: a rather fun title. That is great, But knowing knowing that,
Speaker 1: we also know that they won't last forever, like you,
Speaker 1: like you say so. Going back to what Williams wrote, quote,
Speaker 1: A moment of serious consideration should convince a biologist of
Speaker 1: the fundamental dissimilarity between these two processes, meaning the body
Speaker 1: wearing out and tools wearing out. The breakdown of human
Speaker 1: artifacts is strictly mechanical and is readily cured by mechanical repairs.
Speaker 1: The system is a static one, since the same material
Speaker 1: is continuously present and there is no endogenous change with
Speaker 1: the passage of time. An organism, on the other hand,
Speaker 1: is an open system in a state of material flux.
Speaker 1: Even such structures as bones maintain constant exchanges with the environment. Moreover,
Speaker 1: an organism produces itself by a morphogen netic process. It
Speaker 1: is indeed remarkable that after a seemingly miraculous feat of
Speaker 1: morphogenesis and that means like growing into the adult shape,
Speaker 1: a metazoan should be unable to perform the much simpler
Speaker 1: task of merely maintaining what is already formed. I think
Speaker 1: this is a fantastic point. I mean, it doesn't make
Speaker 1: sense to say we get old because over time our
Speaker 1: bodies just get worn out. Because our bodies have the
Speaker 1: ability to rejuvenate tissues. They built the tissues in the
Speaker 1: first place, they could just keep building them as long
Speaker 1: as they wanted. Yeah, I mean, I think part of
Speaker 1: this is the I mean part of it is just
Speaker 1: that we are so close to the aging process. We
Speaker 1: experience it and we see it in others. Uh, we're
Speaker 1: almost too close to it to have an objective view
Speaker 1: of it. And then to your point, we're informed by
Speaker 1: what happens to our tools. And then I also they're
Speaker 1: tying into the experience as well, and the wearing out
Speaker 1: of things. I think dental health has a has a
Speaker 1: huge impact on it because we observe this happening with
Speaker 1: our very teeth. Teeth of others that you get that
Speaker 1: those adult teeth in and those are the ones you're
Speaker 1: going to have for the rest of your life as
Speaker 1: long as you can keep them. You know they are
Speaker 1: going to wear out, and unlike other organisms, there's not
Speaker 1: going to be an additional set there that are going
Speaker 1: to lock into place. Third children's book for when children
Speaker 1: get their baby teeth knocked out, it's called this is
Speaker 1: your Last Chance. Yeah, I've actually heard parents, I think
Speaker 1: half joking, we talk about not worrying with brushing that
Speaker 1: much for young children because now they're gonna go they're
Speaker 1: gonna get that second pit. You know they're gonna be
Speaker 1: These are not even these are just the baby teeth.
Speaker 1: Wait till the adult teeth come in and then start
Speaker 1: worrying about Yeah. Now, beyond these simple folk explanations, we
Speaker 1: know that there have been lots of thinkers throughout history
Speaker 1: who must have tried to explain why aging happens before
Speaker 1: we had modern modern genetics to really understand the true mechanisms. Right, Yeah,
Speaker 1: this is you know, aging is part of the human experience,
Speaker 1: and so some of the great thinkers and human history
Speaker 1: have pondered it. We have a few examples here to
Speaker 1: run through. For instance, Lucretius B. C. E uh he
Speaker 1: wrote about it in his text on the Nature of Things,
Speaker 1: and he argued that aging and death are beneficial because
Speaker 1: they make room for the next generation. This is probably
Speaker 1: another folk explanation. A lot of people would employ. Right,
Speaker 1: It totally seems to make sense. You can't just keep
Speaker 1: living forever because you've got to make room for the
Speaker 1: next generation. Yeah. It especially makes a sort of sense,
Speaker 1: I think for human populations when you have, say, individuals
Speaker 1: who have over the course of their lifetime, accumulated certain
Speaker 1: benefits and powers and possessions. And then the idea as well,
Speaker 1: when they fall away, those resources spread to someone else,
Speaker 1: you know, I mean we we we have always lived
Speaker 1: in a world of of finite resources. And I want
Speaker 1: to be clear, it is good that that happens. The
Speaker 1: next generations actually do benefit from the fact that older
Speaker 1: generations grow old and die. Uh, but there are some
Speaker 1: serious problems with thinking about this as the reason biologically
Speaker 1: that they grow old and die. Yeah. Though this this
Speaker 1: observation persisted well up into the twentieth century. For instance,
Speaker 1: nineteenth century German biologist August Weismann also believe that the
Speaker 1: death mechanism created room for the next generation of young
Speaker 1: to thrive at And you know, I have to men
Speaker 1: as well that I always it always, I always kind
Speaker 1: of felt this was the case, you know, at a
Speaker 1: gut level, without putting a lot of serious thought behind it.
Speaker 1: Oh yeah. Before I investigated this, I assumed something along
Speaker 1: these lines. But then I started to doubt myself because
Speaker 1: I was like, oh, wait a minute, that's group selection
Speaker 1: and I always feel iffy about that. The problem here
Speaker 1: is pointed out by Daniel Fabian of the Institute of
Speaker 1: Population Genetics in in the publication Nature is that quote
Speaker 1: the cost of death to individuals likely exceeds the benefit
Speaker 1: to the group or species. And because long lived individuals
Speaker 1: leave more off ring been short lived individuals given equivalent
Speaker 1: reproductive output, selection would not favor such a death mechanism. Yeah.
Speaker 1: This is one of the classic arguments against any kind
Speaker 1: of group level selection influence. And we can revisit this
Speaker 1: in more detail in the second episode. Now, of course,
Speaker 1: another great thinker is Aristotle, right yeah, and he of
Speaker 1: course wrote about this as well in on Longevity and
Speaker 1: Shortness of Life. Aristotle tell us how it is? All right? Well,
Speaker 1: before I got going here, I do want to point
Speaker 1: out I I am going to be the last person
Speaker 1: to to criticize Aristotle. Uh. I feel like he uh
Speaker 1: he did did a lot with the wisdom of the day, obviously,
Speaker 1: and that's an understatement. Uh, but he was not able
Speaker 1: if We're not going to take the opinion that Aristotle
Speaker 1: was dumb though I was talking. I was actually talking
Speaker 1: about this with my my wife last night when I
Speaker 1: was running through the material I'm about to to relate here,
Speaker 1: and she said, well, that would actually make a wonderful
Speaker 1: like BuzzFeed style article like six things that dummy Aristotle
Speaker 1: got wrong. I mean, he got a lot of stuff wrong,
Speaker 1: but I mean everybody in the ancient world did. I
Speaker 1: mean he people just didn't know what we knew today, right,
Speaker 1: and he was attempting and attempting to figure it out.
Speaker 1: He threw out a number of hypotheses that were not
Speaker 1: that did not shake out. So here are just a
Speaker 1: few quotes from the work that will give you an
Speaker 1: idea of where he was going. The reasons for some
Speaker 1: animals being long lived and other short lived and in
Speaker 1: a word, causes of the length and brevity of life
Speaker 1: call for investigation. Fair enough, Yeah, same question, we're asking
Speaker 1: why does it happen? And then he goes on to
Speaker 1: say race is inhabiting warm countries have longer life, those
Speaker 1: living in cold climates have a shorter time. Likewise, there
Speaker 1: are similar differences among individuals occupying the same locality. I
Speaker 1: don't know if that's true. I mean, we already touched
Speaker 1: on the greenland shark, and I think we've gone more
Speaker 1: in depth in the greenland shark in the past on
Speaker 1: this show. But a part of it is its environment,
Speaker 1: which is quite cold. Okay uh. He also commented on
Speaker 1: the connection between the soul and the body. The soul
Speaker 1: must stand in a different case in respect of its
Speaker 1: union with the body. And then this at least rings true,
Speaker 1: hints to all things are at all times in a
Speaker 1: state of transition and are coming into being and passing away. Okay,
Speaker 1: So this could be interpreted to mean something kind of
Speaker 1: like the fact that we're constantly undergoing cell division and
Speaker 1: our bodies maintain them I mean, obviously Aristotle didn't know this,
Speaker 1: but that our bodies maintain themselves through cell division and
Speaker 1: repair of tissues. Yes. And then there's this quote speaking generally,
Speaker 1: the longest lived things occur among the plants, example of
Speaker 1: the date palm. Next, in order we find them among
Speaker 1: the sanguineous animals rather than among the bloodless, and among
Speaker 1: those with feet rather than among the denizens of the water. Hints.
Speaker 1: Taking these two characters together, the longest lived animals fall
Speaker 1: amongst sanguineous animals which have feet. Uh, men and elephants. Well,
Speaker 1: clearly we've learned how to make your aquarium fish live longer.
Speaker 1: You transplant some feet onto them. Uh, this at least
Speaker 1: as good quote. As a matter of fact, also, it
Speaker 1: is a general rule that the larger live longer than
Speaker 1: the smaller. For the other long lived animals to happen
Speaker 1: to be of a large size are also those I
Speaker 1: have mentioned. Now, I'm sure this is not a hard
Speaker 1: and fast rule, though I think there are probably some
Speaker 1: weak correlations along these lines. So, I mean, we already
Speaker 1: touched on the dinosaur thing. But but certainly there are
Speaker 1: some examples of rather large animals that have longer lifespans
Speaker 1: within typical longevity. Now Aristotle's working theory, though, is that
Speaker 1: all of it revolves around moisture in an organism. Yes, quote,
Speaker 1: we must remember that an animal is by nature human
Speaker 1: and warm, and to live is to be of such
Speaker 1: a constitution, while old age is dry and cold, and
Speaker 1: so is a corpse. I think Aristotle also tried to
Speaker 1: explain earthquakes by way of moisture, maybe misremembering that. And
Speaker 1: he also said that aquatic animals don't count here because
Speaker 1: they're not humid. Their watery and quote watery moisture is
Speaker 1: easily destroyed since it is cold and readily congealed. And finally,
Speaker 1: he also throws in four in animals, the males are
Speaker 1: in general the longer lived. I don't think that's true either. Yeah,
Speaker 1: I believe in in in in many cases it is
Speaker 1: the It is the female that lives longer, certainly in humans,
Speaker 1: though that may be more pronounced in cases where we
Speaker 1: have been removed from the like when we've got modern
Speaker 1: medical care, because, for example, there is a lot of
Speaker 1: natural mortality during childbearing. Correct. So I don't know, you
Speaker 1: can maybe a point for Aristotle. There maybe a point
Speaker 1: for modern science. We'll see, um. But anyway, that's that's
Speaker 1: that's what Aristotle had to say in the matter. And uh,
Speaker 1: and I like, I say, it's it's it's fascinating to
Speaker 1: look back on his writings and see how he's working
Speaker 1: this all out totally. So in the end, I think
Speaker 1: we're still left with this biological paradox of aging. Once
Speaker 1: we think about aging in a biological context, it's sort
Speaker 1: of fails to make sense. Evolution selects for genes that
Speaker 1: increase biological fitness, meaning that increase the chances of survival
Speaker 1: and reproduction. Aging is characterized by an organism level decline
Speaker 1: in the chances of survival and reproduction. So why would
Speaker 1: organisms that have been evolving for billions of years still age, deteriorate,
Speaker 1: lose the ability to reproduce, and eventually die. Shouldn't we
Speaker 1: have evolved to maximize survival and reproduction as long as possible.
Speaker 1: Shouldn't we survive and keep making babies until a leopard
Speaker 1: bites our head off? But obviously this is not how
Speaker 1: things are. So what's the answer to this mystery? Will
Speaker 1: explore that in the next episode. As right, we have
Speaker 1: a cliffhanger. Will it be cruel twist of fate? Accident? Uh,
Speaker 1: biological mechanism that serves a purpose? I don't know. We'll
Speaker 1: find out maybe our genome has been evolving to feed
Speaker 1: leopards all right. Well, in the meantime, while you're waiting
Speaker 1: for that next episode, head on over to Stuff to
Speaker 1: Blow your Mind dot com. That's the mothership. That's where
Speaker 1: you'll find all the podcast episodes. You'll find videos, blog
Speaker 1: post links out to our various social media accounts such
Speaker 1: as Facebook, Twitter, Instagram. Big thanks, of course to our
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