Speaker 1: Welcome to Stuff to Blow Your Mind from how Stuff
Speaker 1: Works dot com. Hey are you welcome to Stuff to
Speaker 1: Blow your Mind? My name is Robert Lamb and I'm
Speaker 1: Joe McCormick and Robert I want to ask you about
Speaker 1: a Greek myth, you know, the myth of tiffan Us.
Speaker 1: This is not one that I am am readily familiar
Speaker 1: with off the tof of my head. Well, it's one
Speaker 1: of those great ones with doomed lovers. Doomed lovers just fantastic. Yeah,
Speaker 1: is there does a god show up and act particularly
Speaker 1: crappy towards mortals? Uh not. I don't know if it's
Speaker 1: on purpose. You do get Zeus being a jerk, but
Speaker 1: it might be like he's a jerk by accident, or
Speaker 1: maybe he's a jerk on purpose. It's kind of hard
Speaker 1: to tell because being a jerk is kind of Zeus
Speaker 1: is default thing in general. Yeah, Zeus in this myth
Speaker 1: acts kind of like the Monkeys Paul and the classic
Speaker 1: short story where you get the wish but not quite
Speaker 1: in the way you wanted it. So here's how it goes.
Speaker 1: And this is the version that's in the Homeric Hymn
Speaker 1: to Aphrodite So the myth involves the goddess aos Aus
Speaker 1: is the goddess of Dawn, and she falls in love
Speaker 1: with a mortal man from Troy named Tiffanus. And this
Speaker 1: is horrible, right, It's horrible for a goddess to fall
Speaker 1: in love with a mortal because while the gods may
Speaker 1: live eternally, dining on the ambrosia and just going on
Speaker 1: into the future, of course, mortal people, as the name implies,
Speaker 1: will die. And she hates this idea. She hates the
Speaker 1: idea that the man she's fallen in love with will
Speaker 1: someday die while she gets to go on living forever.
Speaker 1: She can't bear the thought of it. So she goes
Speaker 1: to Zeus and she makes a request, well you grant
Speaker 1: my lover, Tiffannus, eternal life, and Zeus does it. Usually,
Speaker 1: you know, usually Zeus is a jerk, but here he's like, yes, yes,
Speaker 1: I will do that for you. Aos. Well, maybe he
Speaker 1: was busy and he's just like, okay, yeah, I'll just
Speaker 1: go ahead and check this off the list because I've
Speaker 1: I've got this, uh, this other torment in mind for
Speaker 1: another mortal, right, don't have time to be a jerk.
Speaker 1: Just bam eternal life, you will not perish and die
Speaker 1: like the other mortals. But then it takes a dark turn.
Speaker 1: So let me read from the translation of the home
Speaker 1: Eric him to Aphrodite, And this is translated by Hugh
Speaker 1: Evelyn White quote. So also golden throned Aos wrapped away
Speaker 1: tithan Us, who was of your race and like the
Speaker 1: deathless gods. And she went to ask the dark clouded
Speaker 1: son of Chronos that he should be deathless and live eternally.
Speaker 1: And Zeus bowed his head to her prayer and fulfilled
Speaker 1: her desire. Okay, so he's granting the wish. Too simple,
Speaker 1: was queenly Aos. She thought not in her heart to
Speaker 1: ask youth for him and to strip him of the
Speaker 1: slough of deadly age. So while he enjoyed the sweet
Speaker 1: flower of life, he lived rapturously with golden throned Aos,
Speaker 1: that early born by the streams of ocean at the
Speaker 1: ends of the earth. But when the first gray hairs
Speaker 1: began to ripple from his comely head and noble chin,
Speaker 1: queenly Aos kept away from his bed, though she cherished
Speaker 1: him in her house and nourished him with food and ambrosia,
Speaker 1: and gave him rich clothing, but when loathsome old age
Speaker 1: pressed full upon him, and he could not move nor
Speaker 1: lift his limbs. This seemed to her in her heart
Speaker 1: the best counsel. She laid him in a room and
Speaker 1: put to the shining doors. There he babbles endlessly, and
Speaker 1: no more has strength at all such as once he
Speaker 1: had in his supple limbs. M Okay, well, this makes
Speaker 1: me think Zeus probably just agreed to her request because
Speaker 1: all the gods know that mortals are going to ask
Speaker 1: for immortality at some point or the other, and it's
Speaker 1: probably not going to phrase the question properly, and you
Speaker 1: should let them have it because it will teach them
Speaker 1: a lesson. Well, yeah, he'll learn when he's old and
Speaker 1: babbling and decrepit but cannot die. Because global myth cycles
Speaker 1: are filled with stories of of immortality gone wrong. You know,
Speaker 1: it's either a wandering immortal who's doomed or or lovers
Speaker 1: who you know, obtain a portion of immortality and it's mishandled.
Speaker 1: There's a there's a wonderful example of this in the
Speaker 1: in Chinese myth with the the Elixir of Immortality and
Speaker 1: the and the Woman of the Moon. Oh does it
Speaker 1: come back to bite her or come back to bite
Speaker 1: the person who wants it um it gets. There are
Speaker 1: a few different versions of the tale, but essentially, you know,
Speaker 1: one person is immortal and the other is not. That
Speaker 1: sort of thing this this this mismatch that we see
Speaker 1: president in the Greek tale as well. Man, why are
Speaker 1: there so many myths and folk tales where people get
Speaker 1: 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 Tiffanius 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 Warren Zevon 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 come up all the gears, the factory isn't gonna
Speaker 1: 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 the same way that death is. Yes, and this
Speaker 1: is going to be the question we're gonna be discussing
Speaker 1: in this pair of episodes. Now we do want to
Speaker 1: drive home. We're not going to get as much into
Speaker 1: some of the mechanics of aging, like we're not going
Speaker 1: to get into telomeres and telomerase and all and all
Speaker 1: of that, although that's a wonderfully insightful topic onto itself.
Speaker 1: We're gonna be talking more about the these this sort
Speaker 1: of evolutionary function of aging, if it has one, right,
Speaker 1: aging is something that has such a cost for the
Speaker 1: organisms that undergo it, like tiffanus. What pays for it biologically?
Speaker 1: Why does it exist? Now? To underscore the fact that
Speaker 1: aging is not necessarily something that is inevitable, and especially
Speaker 1: not aging as early as we do, we should maybe
Speaker 1: look at some organisms that do not age in the
Speaker 1: same way we do. Yeah, they're there are a number
Speaker 1: of organisms. I'm sure a number of them come to
Speaker 1: to everyone's mind here. You think of ancient hoary tortoises
Speaker 1: stumbling across the the ground, right, or perhaps your mind
Speaker 1: turns to the greenland shark. Will come back to that
Speaker 1: one in a second. But really one of the more
Speaker 1: insightful examples here is the hydra, or at least individuals
Speaker 1: in the hydra genus. So you're talking about the monster
Speaker 1: that 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 hydras, tiny tentacle creatures that
Speaker 1: need to continue to wow scientists because they they have
Speaker 1: a number of just wonderfully bizarre and monstrous capability. So
Speaker 1: they can reproduce through a sexual butting. They have these
Speaker 1: mouths that open up kind of like wounds in their
Speaker 1: body and then close. There's some fabulous videos of them
Speaker 1: doing that. It looks like you're staring into the mouth
Speaker 1: of hell. And they have this seemingly natural inability to grow,
Speaker 1: grow old, and die of natural causes. They boast low
Speaker 1: mortality rates throughout their lives and apparently this is according
Speaker 1: to one Dr Owen Jones from the University of Southern Denmark.
Speaker 1: He has claimed that it would take four hundred years
Speaker 1: for of a hydro population to die of natural causes
Speaker 1: in 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 facts about the life of
Speaker 1: the hydra. So their fertility rates remain constant their entire lives, which,
Speaker 1: as will discuss, is is pretty unique and according to
Speaker 1: um Pomona College biology researcher Professor Daniel Martinez. He has
Speaker 1: repeatedly found no evidence of sinescence in laboratory caddled hydra. Yeah,
Speaker 1: and he even goes so far as to state that
Speaker 1: an individual hydra can live forever under the right laboratory circumstances. Well, now,
Speaker 1: of course that's the catch, right. The hydra's natural environment
Speaker 1: offers sufficient hostilities to make natural death by old age
Speaker 1: and impossibility. You got disease, predators, water contamination. These are
Speaker 1: the things that usually kill a hydra off in due time,
Speaker 1: and likewise, scientists have yet to create a hydra utopia
Speaker 1: that can sustain them indefinitely. Now, this is a good
Speaker 1: point in the use of the word immortality, which sometimes
Speaker 1: comes up when people are covering organisms like these. There
Speaker 1: are a couple of different ways you could look at immortality.
Speaker 1: One would be the Highlander version or something like that,
Speaker 1: where there's just like nothing that can kill you except
Speaker 1: maybe one or two little things, but that you are
Speaker 1: generally invulnerable to death. And then there'd be a different
Speaker 1: version of immortality that says, yeah, you're vulnerable to death
Speaker 1: by injury or disease. You just don't naturally grow old
Speaker 1: and die. You don't have a cap on your lifespan.
Speaker 1: That would be more like, what are are the elves
Speaker 1: of Middle Earth? Kind of like that, like they can
Speaker 1: be killed in battle, but they don't grow old and die. Yeah. Well,
Speaker 1: I mean I would argue that the immortals of Highlander
Speaker 1: are much the same, Like there's a there's a very
Speaker 1: specific thing you can do to kill them. Uh, and
Speaker 1: technically anyone can do it. It's just you've got to
Speaker 1: get the drop on them. Right. We should mention that
Speaker 1: we're popping in little references to Highlander to get you
Speaker 1: ready for the fact that one day soon we're going
Speaker 1: to do a Science of Highlander two episode and I'm
Speaker 1: not kidding. Yeah, you have advanced warnings so you can
Speaker 1: all go review at least the first two films. Well,
Speaker 1: I would say just the first two films actually, Okay,
Speaker 1: But back to the hydra and biological immortality in the
Speaker 1: real world. Yeah, so this is a major point really
Speaker 1: for all organisms. The natural world is generally sufficient to
Speaker 1: ensure mortality. It's dangerous, it's filled with competitors, predators, pathogens, accidents,
Speaker 1: and all manner of additional hazards. Now, humans and their
Speaker 1: captives tend to live in a very privileged space, largely
Speaker 1: removed from the threat of predation. At least you'll find
Speaker 1: other creatures with no natural predators as well. Typically these
Speaker 1: are apex predators, but that doesn't mean they don't have
Speaker 1: to deal with all these other dangers. Well. No, when
Speaker 1: you think about an apex predator, just because there's nothing
Speaker 1: 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 a escaping. The cheat is a great example too,
Speaker 1: because 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 cases,
Speaker 1: if remember correctly, sometimes it has to do with the
Speaker 1: decline of dental health, like that 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 stage. Still, hyders are are really
Speaker 1: interesting because it give us a real world of the
Speaker 1: world example of how how undying creatures would work on
Speaker 1: a biological level. They're hardy, they're regenerative. They have they
Speaker 1: have evolved to thrive in the harsh environments, and it
Speaker 1: actually reminds me of an alien species that shows up
Speaker 1: in an Ian em banks. The Culture series, of course,
Speaker 1: go into the Culture Yeah, I mean he he always
Speaker 1: managed to work so many wonderful scientific topics into his
Speaker 1: his books, and one of these topics is biological immortality. Alright,
Speaker 1: So we meet in the really the very first Culture book,
Speaker 1: we meet the Dherens. And here's just a quick quote.
Speaker 1: The Adherens themselves had evolved on their planet a deer
Speaker 1: as 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 stag nation. Now, I think
Speaker 1: that might be something interesting to come back to maybe
Speaker 1: in the second episode and consider whether it would actually
Speaker 1: work that way and what the effect of high mortality
Speaker 1: at different stages of life would have on the life
Speaker 1: span of an organism. Alright, well, on that note, let's
Speaker 1: take a quick break, and when we come back, we're
Speaker 1: gonna roll through just a few other long living organisms,
Speaker 1: uh that are not a hydra or an adheran. Thank
Speaker 1: thank Alright, we're back. So I mentioned the greenland shark earlier.
Speaker 1: This one is pretty impressive because greenland sharks live where
Speaker 1: we understand now about four hundred years uh. And this
Speaker 1: is an exclusively wild species as well. This is not
Speaker 1: something you're gonna find growing old and fat in an aquarium.
Speaker 1: These are sharks generally don't do very well in aquariums. Correct, yeahs,
Speaker 1: And no one has a greenland shark that I am
Speaker 1: 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: maturity until one d and fifty. So think of that,
Speaker 1: not until they've reached an age that exceeds every human
Speaker 1: being who has ever lived, and that's counting unverified but
Speaker 1: not mythic individual humans, right, not the Highlanders or you know,
Speaker 1: like you know, biblical days. Right. Yeah. Now, of course
Speaker 1: that's still not the oldest animal because there was a
Speaker 1: clam named me. Was this the first line of a
Speaker 1: children's book? I know it should be, well, I would be.
Speaker 1: I would actually be surprised if there's not a children's
Speaker 1: book about Ming. There was a clam named Ming. Yeah,
Speaker 1: and Ming did love to sing. Yeah. This here it
Speaker 1: rights itself. So technically Ming was a qua hog clam.
Speaker 1: This is um, an Arctic variety of clam, and it
Speaker 1: was discovered off the coast of Iceland in two thousand
Speaker 1: and six. Now, at the time they thought it was
Speaker 1: around four hundred and five years old, so they named
Speaker 1: it after the Ming dynasty that would have ruled China
Speaker 1: at this time. Later estimates, and this is supported by
Speaker 1: carbon dating, would boost that age to five hundred and
Speaker 1: seven years half a millennium. So this means that the
Speaker 1: creature was born in fourteen and that's still within the
Speaker 1: Ming dynasty, which went to four And to throw another
Speaker 1: point of context in there, this was around the time
Speaker 1: that Leonardo da Vinci completed the Last Supper. It's the
Speaker 1: year Portuguese explorer Vasco da Gama reached India. That's when
Speaker 1: this this thing was was born and then it died.
Speaker 1: In two thousand and six, there was a clam named Ming,
Speaker 1: and Ming remembered everything. There you go now the plant
Speaker 1: where the world of course has all of this beat. Uh.
Speaker 1: There's the great Basin bristle cone Pine or Pinus long gava,
Speaker 1: and it can only lived to over five thousand years
Speaker 1: of age, and that takes us back to the very
Speaker 1: end of the Neolithic period. Work on Stonehenge had begun.
Speaker 1: This was the age of the Pharaoh, so it lived
Speaker 1: through the rise and the fall of the Roman Empire. Now,
Speaker 1: of course this highlights that different kinds of organisms have
Speaker 1: massively different potential when it comes to life span. Yeah,
Speaker 1: and of course plants are very different from animals. This
Speaker 1: reminds me that one of the ideas that was brought
Speaker 1: up recently. I believe on our discussion module on Facebook
Speaker 1: or Facebook group, that we should do something just on plants,
Speaker 1: like what is a plant? To sort of strip it
Speaker 1: down to its basics. I kind of like that idea.
Speaker 1: It's a really lazy animal. Well I've got a really
Speaker 1: lazy one then for you here, Uh, there's at least
Speaker 1: one step beyond the great base in Bristle Cone Pine.
Speaker 1: And this is something you'll find in fish Lake National
Speaker 1: Park in Utah here in the United States. Uh, the
Speaker 1: quaking aspen tree, which is also the state tree by
Speaker 1: the way, also known as the trembling Giant or pando,
Speaker 1: which means I spread. So what we have here, and
Speaker 1: this is this is one where not everybody necessarily agrees with.
Speaker 1: This might be sort of bending the definition a little
Speaker 1: bit of what is a long living organism. But what
Speaker 1: we have here is a single clone of quaking aspen
Speaker 1: connected by a single extensive roots system that's roughly the
Speaker 1: size of Vatican City, a hundred and six acres, thirteen
Speaker 1: million pounds, and it's all eighty thousand years old. So
Speaker 1: what you're talking about is a forest that is all
Speaker 1: sort of in some way the same organism, right, you could.
Speaker 1: It's it's not as simple as the clam was born
Speaker 1: in this century and it died in this one. But
Speaker 1: if you if you've been the deaf Issian enough and
Speaker 1: you accept this as an example, we're talking about a
Speaker 1: thing that has lived since humans first left Africa to
Speaker 1: colonized the world. Wow. Yeah, now, Robert, here's something I've
Speaker 1: always wondered about 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 got
Speaker 1: they 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 so surely they
Speaker 1: had very long lifespans. Well, this used to be the
Speaker 1: main theory. And this was in part because of either
Speaker 1: size 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 paleontolo 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 Chicago,
Speaker 1: they have this, uh, this these t rex remains that
Speaker 1: they named Sue. Sue. She is great. Yeah, she's a
Speaker 1: wonderful specimen. You get to look right up at her
Speaker 1: and get a sense of the true size of this,
Speaker 1: this amazing species. Can I say something embarrassing? Go for it.
Speaker 1: I cried a little bit at Sue. Yeah, I'm not kidding.
Speaker 1: When we were in Chicago and I'm just sitting there
Speaker 1: looking at Sue for a while, I did something to me,
Speaker 1: like a little misty. That's that's beautiful. I I can
Speaker 1: understand it because it is like looking back in time
Speaker 1: to encounter, you know, a fossil like that. So Sue
Speaker 1: is a rather big specimen, or at least the fossil
Speaker 1: remains are rather large and speak to a large specimen.
Speaker 1: They We think now that she probably achieved adult size
Speaker 1: at age twenty and lived to a ripe old age
Speaker 1: of twenty. Wow, so I am now older than than
Speaker 1: this Tyrannosaurus rex was when it dies exactly. Yeah, and uh,
Speaker 1: and it just underlines that what you had with the
Speaker 1: dinosaurs was likely rapid growth but short lives. Now, one
Speaker 1: sort of side question that we won't fully explore. But
Speaker 1: this this may raise the question, well, dinosaurs have cancer
Speaker 1: 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 hadrosaurs, the duck build dinosaurs
Speaker 1: developing any form of cancer. Now that's the caveat that's
Speaker 1: the only the only ones we have evidence of that
Speaker 1: that occurring in. But it is interesting to think of
Speaker 1: like the late model dinosaur as being the place where
Speaker 1: we see the cancer showing up. We gotta come back
Speaker 1: and do an episode on dinosaur cancer in the future. Yeah,
Speaker 1: by all means, well, I want to do something that
Speaker 1: we often end up having to do, which is that
Speaker 1: after we've explored a concept for a while, it becomes
Speaker 1: more and more complicated and our lay definition starts to
Speaker 1: get a little less useful. So I think maybe we
Speaker 1: should ask the question what actually is aging? Now? We
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 tend to be a cultural barrier
Speaker 1: in place to saying that death is something our body does.
Speaker 1: We like to push that off onto some sort of
Speaker 1: external force of of fade or anthropomorphy, eyes dread, you know,
Speaker 1: or some sort of limit imposed on us by the gods. Well, yeah, yeah,
Speaker 1: death is something that we more often characterize as happening
Speaker 1: to us. Death happens to you. It's not something you do. Though.
Speaker 1: There you can kind of see that the division between
Speaker 1: the death and the aging death I was talking about
Speaker 1: at the beginning of this episode comes into focus, because
Speaker 1: of course, death can happen to you if you get
Speaker 1: a rock jammed through your you know, through your body
Speaker 1: or something like that. But the body does seem to
Speaker 1: naturally progress toward death over time. And that's kind of
Speaker 1: a weird question, like why would it do that. We
Speaker 1: will definitely explore the science behind that question in the
Speaker 1: second episode that we will look at some archaic answers
Speaker 1: to it in this one, because when especially with the human,
Speaker 1: with the human experience of aging and death, it seems
Speaker 1: completely illogical that in many cases a human being would
Speaker 1: spend the majority of its life progressing towards death, like
Speaker 1: the majority of your life. His decline, Uh, that just
Speaker 1: feels either gross or cruel or just like a horrible
Speaker 1: design flaw, or yeah, or nonsensical. But where's my eternal
Speaker 1: youth doesn't make any sense? Um. So in his nine
Speaker 1: book The Evolutionary Biology of Aging, published by Oxford University Press,
Speaker 1: the biologist Michael R. Rose defined aging in the following
Speaker 1: way quote a persistent decline in the age specific fitness
Speaker 1: components of an organism due to internal physiological deterioration. Now
Speaker 1: Rose actually has offered has said that in some ways
Speaker 1: we might need to update that understanding a little bit
Speaker 1: to accommodate for some new discoveries. But I think this
Speaker 1: is a good place to start. So let's look at
Speaker 1: the parts of that definition. Number one, it's persistent decline,
Speaker 1: which means aging only goes one way. It's not characterized
Speaker 1: by say decline and rebound, and some organisms do have
Speaker 1: patterns like this, it is not quite aging, like you
Speaker 1: can think about the jellyfish that have regenerative capabilities where
Speaker 1: they can revert to a younger stage of life. But
Speaker 1: then so it's persistent decline. And then in the quote
Speaker 1: age specific fitness components biological fitness meaning the ability to
Speaker 1: survive and reproduce. So these are the things that are
Speaker 1: persistently in decline. You become less able to survive and
Speaker 1: less able to reproduce. And then it's due to internal
Speaker 1: physiological deterioration. So it's saying that this persistent decline in
Speaker 1: the ability to survive and reproduce is not due to
Speaker 1: disease or injury, but to something deteriorating within the body
Speaker 1: tissues themselves. Yeah, this is this makes me think, of course,
Speaker 1: of the phrase cradle to the grave and with it
Speaker 1: with the hydra. The cradle to the grave is kind
Speaker 1: of a straight line with reproduction taking place at all
Speaker 1: levels until something happens to kill it. Whereas most of
Speaker 1: them models that that we look at, most of the
Speaker 1: models we looked at in researching this episode, it's more
Speaker 1: of a of a rise rising and lowering. There's a
Speaker 1: rise towards like peak sexual maturity, peak reproductive maturity, and
Speaker 1: then a decline. Yeah uh yeah, And then it gets
Speaker 1: even stickier, right because we we've just tried to be
Speaker 1: very careful and how we're defining this. But then I
Speaker 1: realized that I said the it's a decline in the
Speaker 1: ability to survive and reproduce, not due to disease or injury.
Speaker 1: But a lot of the things that are the characteristic
Speaker 1: signals of aging are sometimes thought of as diseases, even
Speaker 1: though maybe they're not caused by say a germ or something. Uh.
Speaker 1: There are all kinds of things like diabetes melitas, or
Speaker 1: like rheumatoid arthritis that are totally characteristic signs of aging
Speaker 1: and human beings, and they're thought of as diseases, but
Speaker 1: they're not so much something that gets done to the
Speaker 1: body by external forces. There are a thing that happens
Speaker 1: when the body is around for a long time under
Speaker 1: certain conditions. It makes me think back to our episode
Speaker 1: on Chinese immortality and about the the idea of the
Speaker 1: the older body being kind of an alien body, Like
Speaker 1: it's a different biology we're changing into a different being
Speaker 1: with different physical characteristics. Generally characterists that that leaned towards
Speaker 1: towards weakness. Absolutely, But then again, you can also look
Speaker 1: at aging through the microscope, look at it on the
Speaker 1: cellular level, and this is where you'll often see people
Speaker 1: using words like sinescence. Defined by by Nature's scientific glossary quote,
Speaker 1: senescence is the process by which sells irreversibly stop dividing
Speaker 1: and inter a state of permanent growth arrest without undergoing
Speaker 1: cell death. Senescence can be induced by unrepaired DNA damage
Speaker 1: or other cellular stresses. So this is looking at it
Speaker 1: on the microscopic level and saying in essence, often used
Speaker 1: as as a synonym for aging, happens when the cells
Speaker 1: stop making new rejuvenated cells. This is kind of the
Speaker 1: lack of upkeep keep model. It's the idea that well,
Speaker 1: the house is falling apart because nobody's working on it,
Speaker 1: nobody's maintaining, or at least the maintenance has really been
Speaker 1: scaled back or it's all. It's it's been my experience
Speaker 1: thus far with aging that you find the maintenance requests
Speaker 1: are are kind of rolled out in in a logical
Speaker 1: way where you're you're like, you may think to 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 super tendon of an apartment building, it
Speaker 1: would be like, there's a water leak in the basement
Speaker 1: that has not been fixed for months, and your repair
Speaker 1: person 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 roof,
Speaker 1: and things got fixed. Why did things not got to
Speaker 1: get fixed anymore? That is a great question, and I
Speaker 1: guess we should try to look at some answers to
Speaker 1: that when we come back from this next break. Thank alright,
Speaker 1: we're back, all right, So let's look at some historical
Speaker 1: and lay answers to the question why do we age?
Speaker 1: What's the point? Why does it happen? One common example
Speaker 1: that seems to make sense to people is the idea
Speaker 1: that our body is, over time quote get worn out. Uh.
Speaker 1: So in his nine seven paper Pleotropy, Natural Selection and
Speaker 1: the Evolution of Senescence, which we will definitely come back
Speaker 1: to in the second episode, here, the American biologist George C.
Speaker 1: Williams pointed out that one problem explaining the true biological
Speaker 1: reason behind aging is that many people think they already
Speaker 1: understand what aging is and why it happens, and they're wrong.
Speaker 1: They're wrong. But if you think you've already got the answer,
Speaker 1: you'll never go asking the question and writing of these
Speaker 1: kind of folk explanations for aging. He says, quote the
Speaker 1: most injurious of these is the identification of sinescence with
Speaker 1: the quote wearing out that is shown by human artifacts.
Speaker 1: And doesn't this seem very sensical? Right? Our tools get
Speaker 1: worn out over time. If you use a knife a
Speaker 1: whole lot, eventually it'll lose the sharpness of its blade.
Speaker 1: Uh any tool you use too much. I'm thinking about
Speaker 1: a broom that we used to have for years around
Speaker 1: our house that eventually got worn down to nubs. There
Speaker 1: were just really no bristles on it anymore. Shouldn't our
Speaker 1: bodies be the same. This reminds me I've had to
Speaker 1: explain this to my my son recently, where he'll get
Speaker 1: some sort of cheap toy, you know, as a prize
Speaker 1: or something, and he'll be really into it. I'll have
Speaker 1: to explain to him that this is not the sort
Speaker 1: of toy that lasts very long. You know, toys like
Speaker 1: this may last a week or so, and and he's like, no,
Speaker 1: if some some toys last forever. And I'm like, well,
Speaker 1: they don't. They don't really, And you have to try
Speaker 1: to explain how pretty much everything that is made by
Speaker 1: man is going to fall apart. Okay, after I finished
Speaker 1: my children's book about ming the Clam, I'm writing a
Speaker 1: second children's book called Toys Die. What it reminds me
Speaker 1: of the short story that that A I was was
Speaker 1: based on. Oh yeah, I forget the exact title, but
Speaker 1: to believe it was super Toys Last All Summer, which
Speaker 1: I always thought was a rather fun title. That is great,
Speaker 1: but knowing knowing that we also know that they won't
Speaker 1: last forever, like you, like you say, so, going back
Speaker 1: to what Williams wrote, quote, A moment of serious consideration
Speaker 1: should convince a biologist of the fundamental dissimilarity between these
Speaker 1: two processes, meaning the body wearing out and tools wearing out.
Speaker 1: The breakdown of human artifacts is strictly mechanical and is
Speaker 1: readily cured by mechanical repairs. The system is a static one,
Speaker 1: since the same material is continuously present and there is
Speaker 1: no endogenous change with the passage of time. An organism,
Speaker 1: on the other hand, is an open system in a
Speaker 1: state of material flux. Even such structures as bones maintain
Speaker 1: constant exchanges with the environment. Moreover, an organism produces itself
Speaker 1: by a morphogenetic process. It is indeed remarkable that after
Speaker 1: a seemingly miraculous feat of morphogenesis, and that means like
Speaker 1: growing into the adult shape, a metazoan should be unable
Speaker 1: to perform the much simpler task of merely maintaining what
Speaker 1: is already formed. I think this is a fantastic point.
Speaker 1: I mean, it doesn't make sense to say we get
Speaker 1: old because over time our bodies just get worn out,
Speaker 1: because our bodies have the ability to rejuvenate tissues. They
Speaker 1: built tissues in the first place. They could just keep
Speaker 1: building them as long as they wanted. Yeah, I mean,
Speaker 1: I think part of this is the I mean part
Speaker 1: of it is just that we are so close to
Speaker 1: the aging process. We experience it, and we see it
Speaker 1: in others. Uh, We're almost too close to it to
Speaker 1: have an objective view of it. And then to your point,
Speaker 1: we're informed by what happens to our tools. And then
Speaker 1: I also they're tying into the experience as well, and
Speaker 1: the wearing out of things. I think dental health has
Speaker 1: a has a huge impact on it because we observe
Speaker 1: this happening with our very teeth, the teeth of others
Speaker 1: that you get that those adult teeth in and those
Speaker 1: are the ones you're gonna have for the rest of
Speaker 1: your life as long as you can keep them. You know,
Speaker 1: they are going to wear out, and unlike other organisms,
Speaker 1: there's not going to be an additional h set there
Speaker 1: that are going to lock into place. Third children's book
Speaker 1: for when children get their baby teeth knocked out, it's
Speaker 1: called this is your Last Chance. Yeah. I've actually heard
Speaker 1: uh parents, I think half joking, we talk about not
Speaker 1: worrying with brushing that much for young children because now
Speaker 1: they're gonna gore gonna get that second pit. You know
Speaker 1: they're gonna be These are not even These are just
Speaker 1: the baby teeth. Wait till the adult teeth come in
Speaker 1: and then start worrying. Yeah. Now, beyond these simple folk explanations,
Speaker 1: we know that there have been lots of thinkers throughout
Speaker 1: history who must have tried to explain why aging happens
Speaker 1: before we had modern modern genetics to really understand the
Speaker 1: true mechanisms. Right, Yeah, this is you know, aging is
Speaker 1: part of the human experience, and so some of the
Speaker 1: great thinkers and human history have pondered it. We have
Speaker 1: a few examples here to run through. For instance, Lucretius
Speaker 1: through fifty five b c uh he wrote about it
Speaker 1: in his text on the Nature of Things, and he
Speaker 1: argued that aging and death are beneficial because they make
Speaker 1: room for the next generation. This is probably another folk
Speaker 1: explanation a lot of people would employ. Right, totally seems
Speaker 1: to make sense. You can't just keep living forever because
Speaker 1: you've gotta make room for the next generation. Yeah. It
Speaker 1: especially makes a sort of sense, I think for human
Speaker 1: populations when you have, say, individuals who have over the
Speaker 1: course of their lifetime accumulated certain benefits and powers and possessions,
Speaker 1: and then the idea as well, when they fall away,
Speaker 1: those resources spread to someone else, you know, I mean
Speaker 1: we we we have always lived in a world of
Speaker 1: of finite resources. And I want to be clear, it
Speaker 1: is good that that happens. The next generations actually do
Speaker 1: benefit from the fact that older generations grow old and die. Uh,
Speaker 1: But there are some serious problems with thinking about this
Speaker 1: as the reason biologically that they grow old and die. Yeah.
Speaker 1: Though this this observation persisted well up into the twentieth century.
Speaker 1: For instance, nineteenth century German biologist August Weissmann also believe
Speaker 1: that the death mechanism created room for the next generation
Speaker 1: of young to thrive at And you know, I have
Speaker 1: to men as well that I always it always always
Speaker 1: kind of felt this was the case, you know, at
Speaker 1: a gut level, without putting a lot of serious thought
Speaker 1: behind it. Oh yeah, before I investigated this, I assumed
Speaker 1: something along these lines. But then I started to doubt
Speaker 1: myself because I was like, oh, wait a minute, that's
Speaker 1: group selection, and I always feel iffy about that. The
Speaker 1: problem here is pointed out by Daniel Fabian of the
Speaker 1: Institute of Population Genetics in in the publication nature is
Speaker 1: that quote, the cost of death to individuals likely exceeds
Speaker 1: the benefit to the group or species. And because long
Speaker 1: lived individuals leave more offspring than short lived individuals given
Speaker 1: equivalent 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 go get going here, I do want to
Speaker 1: point out I I am going to be the last
Speaker 1: person to to criticize Aristotle. Uh uh. I feel like
Speaker 1: he uh he did did a lot with the wisdom
Speaker 1: of the day, obviously, and that's an understatement. Uh, but
Speaker 1: he was not able. We're not going to take the
Speaker 1: opinion that Aristotle was dumb though I was talking. I
Speaker 1: was actually talking about this with my my wife last
Speaker 1: night when I was running through the material I'm about
Speaker 1: to uh to relate here, and she said, well, that
Speaker 1: would actually make a wonderful like BuzzFeed style article like
Speaker 1: six things that dummy Aristotle got wrong. I mean, he
Speaker 1: got a lot of stuff wrong, but I mean everybody
Speaker 1: in the ancient world did. Yeah, I mean he people
Speaker 1: just didn't know what we knew today, right, And he
Speaker 1: was attempting and attempting to figure it out. He threw
Speaker 1: out a number of hypotheses that were not They did
Speaker 1: not shake out. So here are just a few quotes
Speaker 1: from the work that will give you an idea of
Speaker 1: where he was going the re sa since 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, same question we're asking why
Speaker 1: does it happen? And then he goes on to say
Speaker 1: race is inhabiting warm countries have longer life, those living
Speaker 1: in cold climates have a shorter time. Likewise, there are
Speaker 1: similar differences among individuals occupying the same locality. I don't
Speaker 1: know if that's true. I mean, we already touched on
Speaker 1: the greenland shark, and I think we've gone more in
Speaker 1: depth in the greenland shark in the past on this show.
Speaker 1: But part of it is its environment, which is quite cold. Uh.
Speaker 1: He also commented on the connection between the soul and
Speaker 1: the body. The soul must stand in a different case
Speaker 1: in respect of its union with the body. And then
Speaker 1: this at least rings true, hints to all things are
Speaker 1: at all times in a state of transition and are
Speaker 1: coming into being and passing away. Okay, so this could
Speaker 1: be interpreted to mean something kind of like the fact
Speaker 1: that we're constantly undergoing cell division and our bodies maintain
Speaker 1: them I mean, obviously Aristotle didn't know this, but that
Speaker 1: our bodies maintain themselves through cell division and repair of tissues. Yes.
Speaker 1: And then there's this quote speaking generally, the longest lived
Speaker 1: things occur among the plants, uh, example of the date palm. Next,
Speaker 1: in order we find them among the sanguineous animals rather
Speaker 1: than among the bloodless, and among those with feet rather
Speaker 1: than among the denizens of the water. Hence, taking these
Speaker 1: two characters together, the longest lived animals fall among sanguineous
Speaker 1: animals which have feet. Uh. Men and elephants. Well, clearly
Speaker 1: 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 hard and
Speaker 1: fast rule, though I think there are probably some weak
Speaker 1: correlations along these lines. I think so. I mean, we
Speaker 1: already touched on the dinosaur thing, but but certainly there
Speaker 1: are some examples of rather large animals that have longer
Speaker 1: lifespans within typical longevity. Now Aristotle's working theory, though, is
Speaker 1: that 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 them. 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. So I don't know, you can
Speaker 1: maybe a point for Aristotle, there maybe a point for
Speaker 1: modern science. We'll see, um. But anyway, that's that's that's
Speaker 1: 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 organ is m
Speaker 1: level decline in the chances of survival and reproduction. So
Speaker 1: why would organisms that have been evolving for billions of
Speaker 1: years still age, deteriorate, lose the ability to reproduce and
Speaker 1: eventually die. Shouldn't we have evolved to maximize survival and
Speaker 1: reproduction as long as possible. Shouldn't we survive and keep
Speaker 1: making babies until a leopard bites our head off? But
Speaker 1: obviously this is not how things are. So what's the
Speaker 1: answer to this mystery? We'll explore that in the next episode.
Speaker 1: That's right, we have a cliffhanger. Will it be cruel
Speaker 1: twist of fate? Accident? Uh? Biological mechanism that serves a purpose?
Speaker 1: I don't know. We'll find out maybe our genome has
Speaker 1: been evolving to feed leopards all right. Well, in the meantime,
Speaker 1: while you're waiting for that next episode, head on over
Speaker 1: to Stuff to Blow your Mind dot com. That's the
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Speaker 1: You'll find videos, blog post links out to our various
Speaker 1: social media accounts such as Facebook, Twitter, Instagram. Big thanks
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