Speaker 1: The oldest tree we know of is Methuselah, a great
Speaker 1: basin bristle cone pine that is almost five thousand years old.
Speaker 1: Methuselah began putting down its roots during the Age of
Speaker 1: the Pyramids in ancient Egypt. It also lived through the
Speaker 1: rise and the fall of ancient Greece and ancient Rome
Speaker 1: as well. Pamarabi, Nephertidi, Buddha, Pythagoras, Confucius, Socrates, Alexander the Great, Cleopatra,
Speaker 1: Genghis Khan, Joan of Arc, Da Vinci, Copernicus, Ivan the Terrible, Shakespeare, Pocahontas, Newton, Hamilton, Mozart, Napoleon, Lincoln, Darwin, Nightingale, Pasture, Edison, Gandhi, Hitler, Parks,
Speaker 1: Mandela Martin, Luther King Junior, and Betty White. Generations of
Speaker 1: humans have struggled and strove, some making the world better,
Speaker 1: some making it worse, but all of them lived out
Speaker 1: their entire lives in just a sliver of the time
Speaker 1: during which Methuselah has been patiently growing in the White
Speaker 1: Mountains of California. There's something both bewildering and awe inspiring
Speaker 1: about incredibly old trees, and today we're going to be
Speaker 1: talking about what we know about them, how do we
Speaker 1: age trees, and how and why do some trees live
Speaker 1: so long? Welcome to Daniel and Kelly's extraordinarily tremendous universe.
Speaker 2: Hi. I'm Daniel. I'm a particle physicist, and I round
Speaker 2: myself up to fifty years old.
Speaker 1: Hello. I am Kelly Wiener Smith. I study parasites and space,
Speaker 1: and I round myself down to forty. You're even older
Speaker 1: than I am than I had realized. Daniel.
Speaker 2: Oh wow, what a wonderful thing to hear.
Speaker 1: All about how you round. Although you know, I thought
Speaker 1: we had both agreed that we round up on average,
Speaker 1: But at only forty two, I think I'm gonna go
Speaker 1: ahead and round down.
Speaker 2: Yeah. No, I think that's fair. Who really needs more
Speaker 2: significant digits than one? Right?
Speaker 1: That's right? That's right. Do you have a favorite tree?
Speaker 2: Do I have a favorite tree? I love the redwoods,
Speaker 2: you know, out here in California. I gotta say that's
Speaker 2: something spectacular about California and the mystery, the majesty of
Speaker 2: being the presence of these super tall and super old
Speaker 2: beings and thinking about all the things they've seen experienced.
Speaker 2: I love it. I just love old trees in general.
Speaker 2: Like when you drive down a street in a neighborhood
Speaker 2: that's like one hundred years old, and the trees like
Speaker 2: cross over the street or have all these wiggles and
Speaker 2: branches where it's like a new suburb with these like
Speaker 2: tiny little potted plant trees, it's just a little sad.
Speaker 2: So old trees are wonderful because it's something you got
Speaker 2: to earn. It just takes time. You know, you can't
Speaker 2: like fast grow a tree to a huge size.
Speaker 1: I totally agree. When I lived in California, I had
Speaker 1: to go see the Redwoods and I realized that I'd
Speaker 1: been like looking up at one of those trees with
Speaker 1: my mouth open, and I was like so glad nothing
Speaker 1: had fallen into it, because I was just like I
Speaker 1: must have stood there for, you know, fifteen minutes just
Speaker 1: looking at the same tree being like, Ah, the things
Speaker 1: that you've seen or you know, have been alive through.
Speaker 1: It's just incredible. And then I had the great pleasure
Speaker 1: of working at Race University for a while, which I
Speaker 1: know is where you did your undergrad and they've got
Speaker 1: that running track around the outside of the university that
Speaker 1: is surrounded by live oaks, and they're the ones that
Speaker 1: have those like tortuous arms that like go back, they down,
Speaker 1: they touch the ground, they come back up again. Oh,
Speaker 1: they're so gorgeous. I actually don't know how old those
Speaker 1: live oaks are, but there's something about a big tree
Speaker 1: that I love.
Speaker 2: Yeah, and Rice has so many trees. I think there's
Speaker 2: something in the charter that they have to have more
Speaker 2: trees on campus than students, that they really preserve the
Speaker 2: trees on the campus.
Speaker 1: I can't believe they've got more trees on campus than students.
Speaker 1: If so, they got to shut that place down. Man,
Speaker 1: I don't think that's working out.
Speaker 2: Well. I gotta ask you call of the obvious question.
Speaker 2: Given California's redwoods and the majesty of our old trees,
Speaker 2: what does Virginia have to compare. I'm giving you an
Speaker 2: opportunity here.
Speaker 1: Oh my god, this is easy. So California is beautiful.
Speaker 1: But have you been to Shanandoah National Park?
Speaker 2: Oh? I have land of many uses.
Speaker 1: Many uses? What do you mean, like you're gonna cut
Speaker 1: my trees down?
Speaker 2: No? I just remember camping in the Blue Ridge Mountains
Speaker 2: one time, and there was a sign when you enter,
Speaker 2: It's like welcome to the Blue Ridge Mountains a land
Speaker 2: of many uses, and well, I wonder what that means.
Speaker 1: Yeah, I don't remember seeing that on the side, but
Speaker 1: like you've gone camping and the Blue Ridge answer is obvious.
Speaker 1: It's just so gorgeous seeing all of those rolling hills
Speaker 1: with all the trees and the like mist coming up
Speaker 1: over them in the mornings and seeing the sunset. There's
Speaker 1: like no more beautiful view in all of the United
Speaker 1: States than what you get. I'm laying down the gauntlet, man.
Speaker 2: I was with you up until that point. I mean,
Speaker 2: I like the Blue Ridge Mountains for mountains, they're cute.
Speaker 2: I mean, they're not that tall or that.
Speaker 1: Point d That's why they're so nice to walk.
Speaker 2: I like a nice granite topped mountain, you know, like
Speaker 2: above the tree line. That's my jam. And the Sierras,
Speaker 2: for example, Oh yeah. And I just don't think you
Speaker 2: can compare to the majesty of the coastal Redwoods. You know,
Speaker 2: nothing stands up to that. In my opinion, those are beautiful.
Speaker 1: I'll give you that. I don't feel like I want
Speaker 1: to pit one natural beauty against another, but I can
Speaker 1: say that in grad school I tried hiking White Mountain
Speaker 1: where the Bristol Cone Pines are. So we talked about
Speaker 1: Methusela in the opening, and you know, I was climbing
Speaker 1: up there and the air was getting thin and I
Speaker 1: was like feeling miserable, and you know, so no, give
Speaker 1: me Shanandoah any day where I could breathe. It's like
Speaker 1: I don't want to go to space. I don't want
Speaker 1: to go to White Mountain.
Speaker 2: Yeah. No, it's beautiful, absolutely, I'll give you that. And
Speaker 2: you're right, we shouldn't pit one against the other. There's
Speaker 2: lots of different ways to be beautiful and we should
Speaker 2: appreciate all of it.
Speaker 1: Amen. All right, And so we had this absolutely incredible
Speaker 1: question from a listener's son about old trees, and that's
Speaker 1: what we're going to be talking about today. But before
Speaker 1: we listen to the question, I want to remind you
Speaker 1: that you can send us your questions or you can
Speaker 1: send us your kids questions at questions at Daniel and
Speaker 1: Kelly dot org.
Speaker 2: We really love hearing from you, and we love hearing
Speaker 2: from your kids. Thank you to everybody who listens to
Speaker 2: the pod with your kid. It's a great way to
Speaker 2: start conversations about science.
Speaker 1: Yay, all right, So let's hear the question that we're
Speaker 1: chatting about today.
Speaker 3: Hi, Daniel Kelly, I have a question, why does some
Speaker 3: trees live longer than other trees? And why do they
Speaker 3: live longer than people?
Speaker 2: This is a great question because this is a question
Speaker 2: I've had since I was a kid, looking at those
Speaker 2: redwoods and wondering like, why do they live so long?
Speaker 2: How do they live so long? What's going on?
Speaker 1: Yeah, it's a fantastic question, and it was one where
Speaker 1: when I listened to it, I thought, oh, this is
Speaker 1: another one where I don't really know the answer, and
Speaker 1: so I was thrilled to have an opportunity to do
Speaker 1: some research. And so let's start this conversation by talking
Speaker 1: about how we even go about are in the first place.
Speaker 1: I think a lot of us are familiar with the
Speaker 1: idea that you can age trees based on their rings,
Speaker 1: but it's a little bit more complicated, So.
Speaker 2: You can't just chop down the tree and count the rings.
Speaker 1: Danduel, Yes, but then you're a monster.
Speaker 2: Well it reminds me of that Far Side cartoon where
Speaker 2: the guy is standing there with his son and axe
Speaker 2: and he's chopped down some big tree and he's going
Speaker 2: through the history of the tree, all the things. The
Speaker 2: tree has survived until of course that day that he
Speaker 2: chopped it.
Speaker 1: Down, right, but it couldn't survive us. Uh, that's sad.
Speaker 2: So tell me then, how do we know how old
Speaker 2: a tree is without chopping it down and counting its rings.
Speaker 1: Well, for a while there, we were using relational ages,
Speaker 1: so you would say, oh, well, the tree was planted
Speaker 1: around the time the Parthenon was built or something like that.
Speaker 1: And so Pliny was using these relational ages where he
Speaker 1: would age trees based on historical stuff that was happening
Speaker 1: at the same time.
Speaker 2: But how would you know what historical stuff was happening
Speaker 2: at the same time. How would you know this tree
Speaker 2: was planted at the same time the Parthenon or something.
Speaker 1: I think records and institutional memory. But you're right, I mean,
Speaker 1: you don't know unless somebody happens to know local knowledge.
Speaker 2: And that you can trust that knowledge.
Speaker 1: Yeah, I bet they got a lot of ages wrong.
Speaker 1: But that can't work great, I.
Speaker 2: Mean, I'm sure there's a lot of mythology, right. People
Speaker 2: are like, there's trees thousands of years old, and because
Speaker 2: people are bad at deep time, you know, oh.
Speaker 1: My gosh, so bad. And I was reading this book
Speaker 1: called Elder Flora, and it talks about sort of the
Speaker 1: history of our relationship with old trees and how we
Speaker 1: often get the ages wrong, and how trees become important
Speaker 1: for religious ceremonies and stuff, and so anyway, anyone who's
Speaker 1: interested in old trees, that's a good book worth checking out.
Speaker 1: But towards the end of the nineteenth century, and I'm
Speaker 1: surprised this wasn't common earlier, we started getting a handle
Speaker 1: on aging trees by counting their rings. So let's talk
Speaker 1: about the science behind where these rings come from.
Speaker 2: Yeah, why do trees have rings? And why do they
Speaker 2: have one ring per year? Anyway?
Speaker 1: Yeah, right, great question. Why doesn't the inside of a
Speaker 1: tree all look the same?
Speaker 2: Yeah, I mean I don't have rings. If you cut
Speaker 2: me open, you couldn't count my age.
Speaker 1: Well, we don't really know until we try.
Speaker 2: Maybe we should start with a core sample.
Speaker 1: That's right, Yes, that's right. I'll get off my increment borer.
Speaker 1: But we'll get to that. So, so here's how trees grow.
Speaker 1: All right, Say you do do the horrible act of
Speaker 1: cutting down a tree, which of course sometimes you have
Speaker 1: to do, and we all use paper so anyway, no judgment.
Speaker 1: So you cut down a tree, you're looking at the
Speaker 1: center of a tree. The center part of the tree
Speaker 1: is called heartwood. And if it's a big tree, that
Speaker 1: center part is actually dead.
Speaker 2: Why is it called heartwood if it's dead.
Speaker 1: Trees are weird, and that's going to be the theme
Speaker 1: of today's show, I think, is that trees are weird. So,
Speaker 1: you know, the listener wanted to know why humans don't
Speaker 1: live as long as trees, and I think the answer
Speaker 1: is trees are weird. And you know, I'll do a
Speaker 1: better job of answering that at the end of the episode.
Speaker 1: But that's the take home point. So the center is dead,
Speaker 1: and it's dead because it no longer has access to
Speaker 1: water and nutrients that are come up through the xylum,
Speaker 1: which will get you. So the next level you've got
Speaker 1: is the sapwood, and the sapwood is the level where
Speaker 1: you still get water that's coming up through the xylum.
Speaker 1: So you've got essentially I think of it as like
Speaker 1: a series of tubes, but it's really like specialized cells
Speaker 1: that go from the roots up through the trunk of
Speaker 1: the tree and into the canopy. And so the sapwood
Speaker 1: is getting access to that water and to the nutrients.
Speaker 1: Next to the sapwood is the cambrium, and the cambrium
Speaker 1: maybe the cambrium we all know how good I am
Speaker 1: at pronouncing things is going to be very important for
Speaker 1: the rest of this episode. So this is the layer
Speaker 1: where you have the growth happening. So on one side,
Speaker 1: towards the outside of the tree, the cambrium starts producing bark,
Speaker 1: and that bark is going to build up over time,
Speaker 1: and that's going to protect the tree. Towards the inside
Speaker 1: of the tree, it's producing the sapwood, so it's producing
Speaker 1: more of that like woody tissue that you would build
Speaker 1: a house out of, for example.
Speaker 2: Woody tissue otherwise known as wood. Yeah, well for us folk.
Speaker 1: But wouldn't bark be woody tissue? Kind of Also, I
Speaker 1: don't know, I see, but you wouldn't necessarily build the
Speaker 1: house out of bark. So I was trying to be
Speaker 1: a little more specific.
Speaker 2: But yeah, well, I don't want to blow my nose
Speaker 2: on a woody tissue, So I guess it has lots
Speaker 2: of meanings.
Speaker 1: That's right, that's right.
Speaker 2: Well, before you dig deeper, my first question is, like,
Speaker 2: are these hard divisions is there like an edge between
Speaker 2: the heartwood and the sapwood, or is it like a
Speaker 2: spectrum where like in the middle it's something that's sort
Speaker 2: of hearty sappy, or is it really like a hard
Speaker 2: bright line there.
Speaker 1: Yeah, that's a great question. So I'm thinking back at
Speaker 1: the tree cookies as they're called, that I've looked at.
Speaker 1: So this is like you slice through a tree at
Speaker 1: two different parts, and it's sort of shaped in a circle,
Speaker 1: kind of like a cookie. And I feel like often
Speaker 1: it looks like there's a pretty clear delineation between what
Speaker 1: would be the heartwood and what would be the sapwood.
Speaker 1: The heartwood's like a different color, but it probably does
Speaker 1: have like layers that are gradations in the process of dying,
Speaker 1: essentially interesting versus cells that are still being fed, would
Speaker 1: be my guess, right.
Speaker 2: And so the Cambrian is the thing that's making more
Speaker 2: soapwood on the inside and more bark on the outside.
Speaker 2: Is that the only part of the tree that's growing.
Speaker 2: The tree is not like expanding uniformly, sort of like
Speaker 2: the way the universe expands. It's like only making new
Speaker 2: rings around the outside.
Speaker 1: Yeah, it's only making new rings around the outside. And
Speaker 1: so say you were to like put a nail into
Speaker 1: the side of a tree, and you came back fifty
Speaker 1: years later, that nail would still be at the same
Speaker 1: height that you had put in, but it would be
Speaker 1: essentially getting like absorbed by the tree, like layers would
Speaker 1: have grown around it, and so either that nail wouldn't
Speaker 1: be visible anymore unless you actually cut into the tree.
Speaker 1: And as someone who lives out in the woods in
Speaker 1: an area where there used to be a lot of
Speaker 1: barbed wire fencing, it's amazing how often we'll cut into
Speaker 1: a tree and the chainsaw blade will get messed up
Speaker 1: because it turned out there was a barbed wire like
Speaker 1: in the middle of the tree and the tree had
Speaker 1: just grown around it. It was like, nice, try humans,
Speaker 1: I grow around you.
Speaker 2: And so if I had like two models of growth
Speaker 2: in my head, one where like every part of the
Speaker 2: tree is expanding, so heartwood is always heartwood just becomes bigger.
Speaker 2: Sounds like you're suggesting a different model where like sapwood
Speaker 2: becomes heartwood. Is that what's happening here?
Speaker 1: Yeah, So sapwood and heartwood are both made out of
Speaker 1: xylum cells, which are the cells where you get water
Speaker 1: and the stuff that's dissolved in the water that goes
Speaker 1: from the ground through the roots and up towards the
Speaker 1: top of the tree. Both sapwood and heartwood are dead.
Speaker 1: Those xylum cells are dead, and as those xylum cells
Speaker 1: get more and more compressed, they become heartwood. So the
Speaker 1: difference between sapwood and heartwood is that the xylum cells
Speaker 1: have been compressed so much that water can't move up
Speaker 1: them anymore, and that happens as you move towards the
Speaker 1: center of the tree. So sapwood becomes heartwood over time.
Speaker 2: And then that heartwood basically never changes right because it's
Speaker 2: dead and now it's just structural.
Speaker 1: So in most trees, that heartwood stays structural and it
Speaker 1: stays there. And so when you bore through the center
Speaker 1: of a tree, you can pull out a plug where
Speaker 1: you can see all of the lines throughout the entire
Speaker 1: life of the tree. But there are some kinds of trees,
Speaker 1: like the Boa bab in Africa, where the inside is
Speaker 1: sort of not the same consistency of wood that most
Speaker 1: of us think of, and it tends to sort of
Speaker 1: decay and rode away, and so you can't use increment
Speaker 1: bars for a lot of those trees because the inside
Speaker 1: is no longer there.
Speaker 2: But for most trees, basically the living part of it
Speaker 2: is like a hollow cylinder's more like a tube than
Speaker 2: like a filled in cylinder. And that's expanding and leaving
Speaker 2: behind its corpses.
Speaker 1: Yeah, isn't that crazy?
Speaker 2: That is crazy, totally nuts. It's like the opposite of
Speaker 2: a snake. A snake like sheds its skin, but the
Speaker 2: living part is on the inside. This is like if
Speaker 2: the skin was the living part.
Speaker 1: Yeah.
Speaker 2: Wow, trees are weird.
Speaker 1: Yes, trees are so weird. Okay, but so why does
Speaker 1: that growth leave behind rings instead of just like a
Speaker 1: homogeneous center.
Speaker 2: Or why is it linked to the year instead of
Speaker 2: something else?
Speaker 3: Right?
Speaker 2: What's going on every year that makes this mark inside
Speaker 2: the tree?
Speaker 1: Right? So you get rings in areas where there's clear
Speaker 1: seasonal differences, and that could be winter summer, but it
Speaker 1: could also be wet season and dry season. So not
Speaker 1: all trees have rings, and in particular, these rings are
Speaker 1: either like much fainter or maybe even impossible to see.
Speaker 1: And areas where conditions are more homogeneous or more similar
Speaker 1: all year long, like a born place like California probably,
Speaker 1: But anyways.
Speaker 2: If by boring you mean consistently wonderful, then yes, all.
Speaker 1: Right, fine, Okay. So at the beginning of a season,
Speaker 1: the wood is a little bit lighter, and it is
Speaker 1: more aimed at being able to transport nutrients and water
Speaker 1: up and down during the massive growth that starts at
Speaker 1: the beginning of the spring. And so that kind of
Speaker 1: wood is called early wood, because apparently these folks are
Speaker 1: just as clever at naming things as the people who
Speaker 1: named the rings of Jupiter. If was that Jupiter or
Speaker 1: Saturn where the rings are abc.
Speaker 2: That's definitely Saturn, probably a Jupiter, though I haven't looked
Speaker 2: that up.
Speaker 1: Okay. And then after the earlywood, you get do you
Speaker 1: want to go ahead and guess.
Speaker 2: Daniel, I'm gonna guess latewood.
Speaker 1: Yeah, yep, you get lightwood. And lightwood I think is
Speaker 1: more about structure, and so it tends to be tighter
Speaker 1: and closer together.
Speaker 2: I see. So the kind of new wood that's grown
Speaker 2: depends on the conditions on the ground, and that changes
Speaker 2: through the year, and that changes the kind of wood
Speaker 2: that it's grown.
Speaker 1: Yep. So every year you get this pattern of like
Speaker 1: light than dark, and those are the rings that you see.
Speaker 2: And I think, say again, why the latewood is darker
Speaker 2: than the early wood.
Speaker 1: My understanding is that the late wood is meant to
Speaker 1: be more about structure, so it doesn't need to be
Speaker 1: so loose, so that water can go up to feed
Speaker 1: the many leaves that are growing at the beginning of
Speaker 1: the season. When you're at the point where you've got
Speaker 1: all your leaves, or maybe even the leaves are starting
Speaker 1: to come down, the new growth is mostly just about structure,
Speaker 1: and so it's a different kind of cell that looks
Speaker 1: a little bit different.
Speaker 2: Yeah, you make it sound like it's intentional, like the
Speaker 2: tree got together and it's like, all right, I think
Speaker 2: we're ready for some structure. In reality, of course, is
Speaker 2: just sort of what has worked right and we're reverse
Speaker 2: engineering it.
Speaker 1: Yeah. It also is responding to the environment and so
Speaker 1: on very wet years or years with really good growth conditions,
Speaker 1: the distance between rings is much bigger because the Cambrian
Speaker 1: was able to put in more rows of cells, and
Speaker 1: so you get a greater distance, whereas in years where
Speaker 1: there's droughts or conditions are bad for some other reasons,
Speaker 1: the distance between the rings are much smaller.
Speaker 2: And do you always get a ring, Like what about
Speaker 2: the year without a summer, or when there's like a
Speaker 2: volcanic eruption and we just don't see the sun. Can
Speaker 2: you trick trees into thinking a year hasn't passed?
Speaker 1: So I don't know the answer to that. I have
Speaker 1: aged fish based on their scales, so I have some
Speaker 1: knowledge of how the environment impacts aging dynamics, and there
Speaker 1: are definitely some years where it's very hard to tell
Speaker 1: the difference between the rings, or to tell if there
Speaker 1: is a ring in this particular place or not. I'm
Speaker 1: guessing the same thing happens with trees. I would also
Speaker 1: guess that when you age a tree and you say
Speaker 1: it's four thousand, five hundred and eighty seven years, you
Speaker 1: really mean like four five hundred and eighty seven plus
Speaker 1: or minus thirty or something like that. Oh sure, yeah,
Speaker 1: But you can use this tool called an increment borer
Speaker 1: to go through the center of a tree and pull
Speaker 1: out a tiny little pencil shaped chunk where you can
Speaker 1: go through, and you can age it by counting the rings.
Speaker 1: But you don't need to kill the tree. It can
Speaker 1: just handle this little bit of damage. It's like drawing
Speaker 1: blood from a human or something. And if you get
Speaker 1: enough of these, you can actually look at climate patterns
Speaker 1: in a region over time, and so trees give us
Speaker 1: a little bit of window into the past. One tree
Speaker 1: doesn't really do it, because it could be like one
Speaker 1: year it was underneath a bigger tree and so it
Speaker 1: got shaded out so it didn't grow as much. And
Speaker 1: then if that tree dies, you know, the next year
Speaker 1: its growth is bigger. And so there's some other stuff
Speaker 1: to pay attention to as well. But we could look
Speaker 1: at climactic patterns by using these tree rings.
Speaker 2: Yeah, I remember reading that they use old trees for
Speaker 2: things like understanding the atmospheric carbon content and all sorts
Speaker 2: of stuff. It's like an incredible record of what's happened
Speaker 2: on Earth because it's so sensitive. It's so lucky that
Speaker 2: it works this way. I mean, I can imagine lots
Speaker 2: of other ways trees could have evolved that they didn't
Speaker 2: respond in this cyclical way.
Speaker 1: I know. And also for managing fish populations. It's amazing
Speaker 1: that scales tell you how old they are. We really
Speaker 1: lucked out that nature works in this way.
Speaker 2: Nature is a good record keeper, right, They're hints all
Speaker 2: over the world about what happened on this planet. We
Speaker 2: just have to be good detectives and like figure out
Speaker 2: how to read them. And one thing I love about
Speaker 2: science is all this work that people have done, you know,
Speaker 2: this like Yeoman work to figure out, like how we
Speaker 2: can use some part of nature to reveal secrets of
Speaker 2: the universe. Right, you don't just sit around and like
Speaker 2: let the universe download it into your brain. You've got
Speaker 2: to go out there and do the work and figure
Speaker 2: out like, oh, we can use this weird rock and oh,
Speaker 2: terms out trees do this weird thing, or fish do
Speaker 2: this weird thing. Like there's so much of experimental science
Speaker 2: that's people's realizing they could take advantage of a quirk
Speaker 2: of nature.
Speaker 1: Yeah, and then there's so many things you can do
Speaker 1: with it. It's like one of the favorite things that
Speaker 1: came across was that archaeologists are using tree rings to
Speaker 1: try to date structures. So if you find, for example,
Speaker 1: a beam in an old house and you assume that
Speaker 1: it was cut down to build the house, then you
Speaker 1: can look at other tree cores in the area and
Speaker 1: sort of match up the fast growth years with the
Speaker 1: slow growth years, and then you can back date to
Speaker 1: figure out when that structure was built, even if you
Speaker 1: don't have that record anywhere. It's so amazing. The more
Speaker 1: you understand about the world, you get all of these
Speaker 1: surprising linkages that you can use to learn even more.
Speaker 1: It's super cool. It's incredible, Okay, But to get back
Speaker 1: to carbon fourteen dating, it turns out that carbon fourteen
Speaker 1: dating is also a method that we use to date
Speaker 1: some of the trees that we come across. So we
Speaker 1: already talked about the baobab, which sometimes rots in the inside,
Speaker 1: and so you can't use an inc bor to like
Speaker 1: get a little sample of the tree to age it
Speaker 1: because it doesn't really have a center. But you can
Speaker 1: use carbon fourteen dating and pull the innermost wood that
Speaker 1: you can find to get an estimate for how old
Speaker 1: the tree is. So these are the various methods that
Speaker 1: we use to age trees.
Speaker 2: So, like some of the interior records essentially have been destroyed,
Speaker 2: but you still have a few and so you can
Speaker 2: say the tree is at least eleven hundred years old
Speaker 2: or at least seventy five years old or whatever, but
Speaker 2: you don't know what you're missing.
Speaker 1: Yep, that's exactly right.
Speaker 2: Yeah, fascinating. Well, it's incredible to me how long these
Speaker 2: trees live. And you know, trees to me are just
Speaker 2: stunning creatures, you know, Like if we didn't have trees,
Speaker 2: or if I'd never seen a tree and you describe
Speaker 2: them to me, like, hey, there are these things that
Speaker 2: build themselves out of air over time, drinking sunlight and
Speaker 2: reproduce themselves and provide oxygen. I'd be like, that's some
Speaker 2: crazy science fiction nonsense. But they're real.
Speaker 1: It's amazing, and they're beautiful and we can use them
Speaker 1: to build our homes.
Speaker 2: All right, Well, I want to hear all about the
Speaker 2: world herd holders for oldest trees in the world, but
Speaker 2: first we have to take a quick break. Okay, we're
Speaker 2: back and we're talking about the weird, the amazing, the beautiful,
Speaker 2: the fantastical, the California and the Virginian, the worldwide tree.
Speaker 2: It's everywhere, and it provides us with oxygen and teaches
Speaker 2: us about the history of our own planet. So Kelly,
Speaker 2: tell us, where are the oldest trees in the world
Speaker 2: and are they in California?
Speaker 1: Maybe they're in California. There are a couple other contenders
Speaker 1: for oldest tree in the world, but at the moment,
Speaker 1: I think the most widely accepted oldest tree in the
Speaker 1: world is Methuselah, which we talked about in the intro,
Speaker 1: somewhere between forty five hundred and five thousand years old.
Speaker 1: The coordinate are not public because they don't want people
Speaker 1: to go and like carve their names into the side
Speaker 1: of it, because humans do stuff like that. Guys, do
Speaker 1: we just.
Speaker 2: Hold on for a moment, like back up, Like, wow,
Speaker 2: five thousand years old? What was happening on Earth five
Speaker 2: thousand years ago? So this tree is like older than
Speaker 2: the Great Pyramids.
Speaker 1: This tree put down its roots during the age of
Speaker 1: the Pyramids. I think this is the Old Kingdom.
Speaker 2: Wow.
Speaker 1: Yeah, incredible. So it saw the fall of ancient Egypt,
Speaker 1: the rise and fall of ancient Rome, and ancient Greece.
Speaker 1: Like we said in the intro, so many generations of humans.
Speaker 1: It's wind boggling. I'm not very eloquent. I can't capture
Speaker 1: this adequately. It's just incredible.
Speaker 2: It really just gives you a sense for the tiny
Speaker 2: blip of time that we exist on this planet. And
Speaker 2: of course even that by five thousand years is a
Speaker 2: tiny blip of time for the planet. That's the thing
Speaker 2: that these old trees do for me. They give me
Speaker 2: this like tiniest taste of the deepness of time, the
Speaker 2: incredible vastness of time in the universe more broadly, and
Speaker 2: then of course on Earth. So do you think that
Speaker 2: these trees are going to see, you know, the fall
Speaker 2: of our current civilization? How long new bristle cone pines live? So?
Speaker 1: I think the bristle cone pines that are five thousand
Speaker 1: years old are not looking young. But I do think
Speaker 1: that there are some clonal organisms that we'll talk about later,
Speaker 1: like those stands of quaking aspens that can live for
Speaker 1: over ten thousand years. And I hope that we live
Speaker 1: longer than the quaking aspen stands that are alive today.
Speaker 1: We as a species, not me personally, but I don't know.
Speaker 1: We'll have to wait and see. What do you think?
Speaker 1: Are we an imminent declined Daniel?
Speaker 2: All that remains to be seen. I was mostly asking
Speaker 2: about the lifetime of these trees. Oh, if you find
Speaker 2: a population of trees and the oldest ones are about
Speaker 2: five thousand years old, that means either they evolved five
Speaker 2: thousand years ago and they're going to live a long
Speaker 2: long time, or that's roughly as long as they can.
Speaker 2: Like have bristle cone pines been living for five thousand
Speaker 2: issh years for millions of years, And this is just
Speaker 2: sort of like how long they typically live and we're
Speaker 2: visiting the old folks Home for bristle cone pine.
Speaker 1: I don't know, and I don't think that most people know.
Speaker 1: What would you have to know in order to answer
Speaker 1: that question? I guess you would have to find dead
Speaker 1: bristle cone pines. You could age when they died and
Speaker 1: determined that they had been alive for five thousand years.
Speaker 1: I suppose in these dry environments that kind of petrified
Speaker 1: would could exist, but I don't know if it does exist.
Speaker 2: Yeah, well, we can tell when the tree dies, right
Speaker 2: because of carbon fourteen dating, and you could count its rings,
Speaker 2: So in principle it should be possible to know.
Speaker 1: You could count its rings if it didn't. Like so,
Speaker 1: most of the trees on my property eventually they rode
Speaker 1: away and decay. You can't find them anymore. But if
Speaker 1: it petrified and you could find it, I don't know
Speaker 1: the answer, But my guess would be that they have
Speaker 1: been living for a very long time. But if you
Speaker 1: go out to a long enough time period, you have
Speaker 1: to start thinking about things like, well, where were they
Speaker 1: when the last glacial event happened.
Speaker 2: Oh yeah, And it.
Speaker 1: Turns out that bristle cone pines tended to be up
Speaker 1: in the mountains, high enough and out of the way
Speaker 1: enough that they weren't bothered by the last glacial event.
Speaker 1: But it could be that there are trees out there
Speaker 1: that would live for a very long time, but they
Speaker 1: happened to be in habitats where when the last glacier
Speaker 1: came through, it knocked them all out because they can't
Speaker 1: run away like we can. That's one of the downsides
Speaker 1: of being a tree.
Speaker 2: Right, That's amazing. These guys live so long. You have
Speaker 2: to think about the changing conditions of the earth when
Speaker 2: they were babies or when they were growing up. That's incredible,
Speaker 2: it is, all right, So Methuselah is maybe a contender
Speaker 2: for one of the oldest trees on Earth. What else
Speaker 2: do we find in the old folks home for trees.
Speaker 1: Well, so there was a tree called Prometheus that was
Speaker 1: also a bristle cone pine. But usually the contenders have
Speaker 1: to be trees that are still alive. But unfortunately Prometheus
Speaker 1: was cut down in its five thousand year prime.
Speaker 2: Oh no, was it by some terrible tourist.
Speaker 1: No, it was by I think a grad student, so
Speaker 1: I know, okay, So there was this misconception that old
Speaker 1: trees were probably the biggest trees, and that makes sense,
Speaker 1: you know, you look at the redwoods and you're like, oh,
Speaker 1: you might be so old. But actually there's this trend
Speaker 1: where the older trees within a species tend to be
Speaker 1: the smaller ones that started their lives growing more slowly
Speaker 1: and maybe even over time didn't get to be as big.
Speaker 1: They're just sort of like tiny and stodgy, and I
Speaker 1: love it. And so I think this student didn't realize
Speaker 1: that they were dealing with what might be the oldest
Speaker 1: tree on the planet, and so they were trying to
Speaker 1: get the age. The exact details of the story have
Speaker 1: been sort of lost to history, but a version of
Speaker 1: the story is that the student was trying to get
Speaker 1: the age using an increment bor, so this thing where
Speaker 1: you hand crank it into the tree, and that just
Speaker 1: wasn't working out, and so they actually did get permission
Speaker 1: from the park Service to cut the tree down. Oh no,
Speaker 1: and then when they cut the tree down, it just
Speaker 1: turned out that it was five thousand years old. Oh
Speaker 1: my god, maybe the oldest tree ever.
Speaker 2: That must have been heartbreaking.
Speaker 1: Yeah. I think that student did report later that they
Speaker 1: regretted for the rest of their life that they cut
Speaker 1: that tree down.
Speaker 2: Imagine surviving for five thousand years. And then some grad
Speaker 2: students like, oh.
Speaker 1: Man, yeah, the glaciers didn't get you, but the grad
Speaker 1: student did.
Speaker 2: Academia comes for us all eventually.
Speaker 1: Oh man, yep, it gets us. So anyway, tragic story.
Speaker 1: So there's also a tree in Chile, the Alersie Tree,
Speaker 1: and again sorry my apologies of mispronouncing it, but there
Speaker 1: is a tree in Alerseay Castero National Park that is
Speaker 1: eighty percent likely to be over five thousand years old.
Speaker 1: It's estimated to be five four hundred and eighty four
Speaker 1: years old, and so that tree could win.
Speaker 2: Where do you think that eighty percent uncertainty comes from?
Speaker 2: Is that from like the rings being fuzzy or what
Speaker 2: we were talking about earlier, like not every ring is
Speaker 2: present or visible.
Speaker 1: The rings being fuzzy, I think is a problem. Another
Speaker 1: problem is that sometimes where you go through the tree
Speaker 1: can influence how many rings you see, and so people
Speaker 1: tend to do the boring, like you know, to get
Speaker 1: your sample at about like chest height. But I think
Speaker 1: if you go down even lower. Sometimes you can get
Speaker 1: some additional rings. It's just complicated. No answer is ever
Speaker 1: as clear as you want it to be.
Speaker 2: In science, well, I appreciate that there's uncertainties, you know.
Speaker 2: I've seen talks in biology where you see like data
Speaker 2: plotted with no uncertainties and like a line drawn through
Speaker 2: in it, and you're like, what are we doing here, folks?
Speaker 2: So I'm always very impressed when I see biology with air.
Speaker 1: Bars so used to you, hey man, A lot of
Speaker 1: us understand error bars and confidence intervals and would never
Speaker 1: publish a paper without them.
Speaker 2: I'm still glad to hear it.
Speaker 1: M all right. Anyway, we had talked about that tree,
Speaker 1: the African baobab, where the inside sometimes hrats out, but
Speaker 1: with carbon fourteen dating and then attemp at aging the
Speaker 1: trees using the rings for the trees where that works,
Speaker 1: we think that they can live to be as old
Speaker 1: as two thousand, five hundred years.
Speaker 2: Wow.
Speaker 1: There's about twenty five species of trees that we know
Speaker 1: of that we think can live to be a thousand
Speaker 1: years old or older. But it's important to note that
Speaker 1: not all trees live to be super old. Like right now,
Speaker 1: it's spring in Virginia, so it's more beautiful here than
Speaker 1: anywhere else. And the dogwoods are going to be blooming
Speaker 1: pretty soon. And dogwoods live to be like twenty or
Speaker 1: thirty years. They can live to be as much as
Speaker 1: like eighty years, I think, but like a lot of
Speaker 1: them only live to be twenty or thirty years, So
Speaker 1: it's not the case that all trees do outlive humans.
Speaker 2: Well what about the famous redwoods. These are old trees also,
Speaker 2: but they're not in like the top ten oldest trees.
Speaker 2: But there must be hundreds of years old.
Speaker 1: Right, Yeah, so redwoods and giant sequoias are amongst the
Speaker 1: species of trees that can live to be over a
Speaker 1: thousand years old, So they're found amongst those twenty five
Speaker 1: ish species we know of, But I don't know that
Speaker 1: there are any redwoods that are contenders for the oldest tree.
Speaker 2: Hmm, all right, So then why is there such a
Speaker 2: huge range. Dogwoods live happily for just a couple of decades,
Speaker 2: bristle cone pines scratch out a thorny existence for thousands
Speaker 2: of years. Redwoods become enormous over about a millennium. Why
Speaker 2: do these things live such an incredible range?
Speaker 1: So this is ecology m M. So what do you
Speaker 1: think the.
Speaker 2: Answer is, we don't know.
Speaker 1: Yeah, we don't know. Yeah, both of those work. So
Speaker 1: the papers that I read, it seems like, so, you know,
Speaker 1: there are those twenty five species that I mentioned, Yeah,
Speaker 1: in many cases they are not closely related tree species,
Speaker 1: or they're not super closely related, And it seems like
Speaker 1: we have a different answer for a lot of those
Speaker 1: different species. So, for example, part of why we think
Speaker 1: the bristle cone pines have lived so long is that
Speaker 1: they manage to eke out in existence in an environment
Speaker 1: that is very dry and is up at the top
Speaker 1: of a mountain, and it's not a nice environment for
Speaker 1: other competitors or for pests, and when they escape from
Speaker 1: these competitors, in these pests, they can just focus on
Speaker 1: slow growth and they can live for a really long
Speaker 1: time because they don't have to worry about these other competitors.
Speaker 1: But then you get the redwoods in these moist environments
Speaker 1: with lots of competitors and lots of pests, and they
Speaker 1: do manage to live for a long time. And so
Speaker 1: it seems like you'd need a whole different explanation to
Speaker 1: figure out why redwoods are able to live for so long.
Speaker 2: It seems to be sort of connected to the question
Speaker 2: we talked to Katie about, you know, our strategists and
Speaker 2: case strategists like, from a species point of view, it
Speaker 2: doesn't really matter if you live a long time. Another
Speaker 2: totally valid strategies to just like have a kid every
Speaker 2: thirty years and then die off and make room for
Speaker 2: your kids, right Like, they're definitely different strategies from an
Speaker 2: evolutionary point of view that could work to propagate you
Speaker 2: species down through history.
Speaker 1: Right, yeah, exactly. And additionally, our data set is complicated
Speaker 1: by things like what we've talked about already, which is,
Speaker 1: you know, during the last period when the glaciers came through,
Speaker 1: maybe there were a bunch more species that would have
Speaker 1: lived for five thousand years, but they all got wiped
Speaker 1: out by the glaciers. Another problem is that humans have
Speaker 1: been cutting down trees for a really long time to
Speaker 1: build our houses and you know, to build our skyscrapers,
Speaker 1: just to build a lot of different stuff, and so
Speaker 1: we have removed a lot of trees from the landscape,
Speaker 1: and so what we have left to age is maybe
Speaker 1: a subset that is less informative than it would have
Speaker 1: been if all of the trees had still been there,
Speaker 1: or every once in a while you get an outbreak
Speaker 1: or something like the United States used to have tons
Speaker 1: of chestnuts, Like everywhere I look now there's pines and oaks.
Speaker 1: If I had lived here before, a chestnut, like the
Speaker 1: most common tree in my area would have been a chestnut.
Speaker 1: But now we don't have any of them in the area,
Speaker 1: And so we have a bias subset from which to
Speaker 1: try to answer these questions why do some trees live
Speaker 1: longer than others?
Speaker 2: But we always have a bias subset, right, We just
Speaker 2: have a subset that happened to survive, that made it
Speaker 2: through the deaf gauntlet of the present conditions. We never know,
Speaker 2: like on average, over a thousand parallel earths, what would
Speaker 2: have survived. We just got the ones that happen to
Speaker 2: get lucky and happen to survive this time. Right. Isn't
Speaker 2: that always true of evolutionary history?
Speaker 1: Yes, I'd say it's also sort of always true with
Speaker 1: physics too, Like, you know, you only have the information
Speaker 1: that you've already created tools for. You don't know what
Speaker 1: you're missing, And so I think in general, a big
Speaker 1: part of being a scientist should involve being humble about
Speaker 1: what you do and don't know.
Speaker 2: No, it's important to always put this in context, right
Speaker 2: and remember that we have a tiny fraction of the information,
Speaker 2: and that fraction is biased for sure.
Speaker 1: So one thing to note that we talked about earlier
Speaker 1: is that growing slowly seems to be associated with longer
Speaker 1: life for trees, and that can either be at the
Speaker 1: species level or within a species. So it looks like
Speaker 1: individuals that tend to grow slowly early in life are
Speaker 1: also the ones that tend to live longer. So if
Speaker 1: they're growing more slowly, they're investing in a denser, higher
Speaker 1: quality would and maybe they're also investing in stronger roots
Speaker 1: or some chemicals that can fight off pests, and so
Speaker 1: this investment in strength helps them when, for example, a
Speaker 1: hurricane or tornado comes by. Maybe they're likely to be
Speaker 1: still standing when that's done. Whereas if an individual grows quickly,
Speaker 1: then the quality of the wood that they produce is
Speaker 1: less good and so something is more likely to take
Speaker 1: them out if something like a hurricane or a tornado
Speaker 1: comes through. So individuals who grow more slowly tend to
Speaker 1: be the ones that live longer.
Speaker 2: Well, how does this map two long and short lifetimes
Speaker 2: for other critters, like in mammals with the longest lived mammal.
Speaker 1: Yeah, so this idea does map pretty well to the
Speaker 1: rn K strategy stuff that we were talking about with
Speaker 1: Katie when she was on the show. You end up
Speaker 1: with some species that grow fast and some species that
Speaker 1: grow slow. There's also this idea where if you are
Speaker 1: not growing as fast as the other mammals and you
Speaker 1: invest in growing really quickly to try to catch up,
Speaker 1: the quality of that fast grown muscle or fast grown
Speaker 1: you know, bones, anything that you grew fast is probably
Speaker 1: not as good as if you had grown sort of
Speaker 1: slowly and invested in doing it right. So in multiple
Speaker 1: flora and fauna, we see the signature of fast growth
Speaker 1: sometimes coming at the expense of the quality of that growth.
Speaker 2: I guess I wasn't that interested in mammals in particular,
Speaker 2: more like animals, because I know that you know, there's
Speaker 2: some sharks that have lived for hundreds of years and
Speaker 2: turtles lived for hundreds of years, whereas like I know,
Speaker 2: mice live for just a few years, but they're also tiny.
Speaker 2: So just like size and age correlation work more broadly.
Speaker 1: I don't know it would be fun to do a
Speaker 1: whole episode on aging at some point. I know greenland
Speaker 1: sharks can live to be like hundreds of years old,
Speaker 1: but I don't know why we think greenland sharks in
Speaker 1: particular live that long. Somebody might know, but I don't know.
Speaker 2: Somebody's probably gone down and trying to take a core
Speaker 2: sample of a greenland shark and a bit that didn't
Speaker 2: go very well.
Speaker 1: No, No, they do not look like happy show. They
Speaker 1: look old. You look at them, and they've got like
Speaker 1: sadness in their eyes. Not that all old people are said.
Speaker 1: I'm backing up. I'm backing up.
Speaker 2: Old trees don't look sad. Old trees have a grace
Speaker 2: and a beauty that's very hard to match.
Speaker 1: Oh my gosh, they do. That is true for so
Speaker 1: many ancient individuals.
Speaker 2: Yeah, all right, so let's hold some reverence for the
Speaker 2: old folks among us and take another break so we
Speaker 2: can gather our energy and talk about how trees live
Speaker 2: so long and to answer the listeners question about why
Speaker 2: they live longer than people. Okay, we're back, and we're
Speaker 2: talking about how California is beautiful and filled with the oldest,
Speaker 2: the tallest, the biggest, and probably the most beautiful trees in.
Speaker 1: The world because there's not a lot of competition, because
Speaker 1: what trees would want to live there? If they could
Speaker 1: live in Virginia.
Speaker 2: You're saying, if you could survey trees and offer them
Speaker 2: a spot in Shindoah, they would all pick up and move.
Speaker 1: Yeah, I bet who would?
Speaker 2: You might be right, You might be right. It is beautiful,
Speaker 2: all right. So tell us these oldest trees, how is
Speaker 2: it that they go about living so long? What tricks
Speaker 2: do they have under their bark that let them survive
Speaker 2: for thousands upon thousands of years?
Speaker 1: So trees are so weird and so unlike anything I've
Speaker 1: come to expect as a mammal. There are things I
Speaker 1: expect bodies to do, and trees just don't follow any
Speaker 1: of those rules. Okay, So one and this is kind
Speaker 1: of amazing. So we talked about that cambrial layer, the
Speaker 1: layer that is growing the bark while also growing the
Speaker 1: wood inside of the tree. The cells in that layer
Speaker 1: don't show evidence of sinescence.
Speaker 2: What sinescence?
Speaker 1: So sinessence is like getting old and sorry everybody, but
Speaker 1: you know the quality of the cell sort of deteriorating
Speaker 1: over time.
Speaker 2: So you're saying, in some trees, you can see these
Speaker 2: cambria layers aging, but in the trees that live a
Speaker 2: very long time, they just keep going.
Speaker 1: I think that you don't see cambril cells aging in
Speaker 1: like any trees. Oh, and this is why trees in
Speaker 1: general on average tend to live a long time.
Speaker 2: Oh fascinating.
Speaker 1: We're still trying to figure out why this happens. But
Speaker 1: the cells just seem to have this like fountain of
Speaker 1: youth thing going on. And so because the cells aren't aging,
Speaker 1: the things that usually kill trees isn't you know, it
Speaker 1: just got old and stopped working. But it tends to
Speaker 1: be things like fire or insects or erosion or hurricanes.
Speaker 1: It's you know, things external to the tree that end
Speaker 1: up being the cause of the tree death.
Speaker 2: So it sort of seems like the trees constantly replicating itself,
Speaker 2: like every years you basically have a new tree built
Speaker 2: around the body of the old tree.
Speaker 1: So I'm gonna jump out of place in my outline now,
Speaker 1: because yes, it has this amazing way of replicating itself.
Speaker 1: Where for some trees, if it like for example, falls over,
Speaker 1: or if some of the branches touch moist soil, the
Speaker 1: branches or the part of the tree that fell over
Speaker 1: can start putting down roots and a new sapling comes
Speaker 1: up from there.
Speaker 2: What that's crazy. It's like if I put my elbow
Speaker 2: in a bowl of oatmeal and like turned into.
Speaker 1: A person, another Daniel. You know, it wouldn't be like
Speaker 1: it produced one of your kids. It's like producing a
Speaker 1: clone of you. Oh so, like another Daniel emerges from
Speaker 1: your oatmeal. I'm glad I didn't give you oatmeal when
Speaker 1: you were at our place, So.
Speaker 2: Because you can't take more than one of me, that's
Speaker 2: for sure.
Speaker 1: No, that's actually a world full of Daniels would have
Speaker 1: been great.
Speaker 2: But nobody believes you. All right. So these trees having
Speaker 2: these weird ways of cloning themselves.
Speaker 1: Yeah, so they've got these weird ways of cloning themselves,
Speaker 1: and they also have other weird ways of fixing themselves.
Speaker 1: Throughout the tree, there are these buds, and some of
Speaker 1: the buds will like turn into branches and stems and
Speaker 1: leaves and stuff like that. But some of those buds
Speaker 1: stay dormant, and while the leaves are growing, a hormonal
Speaker 1: message is getting sent to those buds that says, stay put,
Speaker 1: don't develop, stay a bud, And so it stays a
Speaker 1: bud and doesn't do anything. But then if something happens
Speaker 1: and like that branch falls off or something, and those
Speaker 1: leaves are no longer sending the message, that bud snaps
Speaker 1: into action and starts, you know, building a new stem
Speaker 1: or something like that. So trees have all of these
Speaker 1: different parts that are waiting to emerge. So it would
Speaker 1: be like, if you are fingers, we're sending a message
Speaker 1: to your wrist saying we've got enough fingers, don't worry
Speaker 1: about it. But then if you lost your fingers, that
Speaker 1: message is no longer being sent to your wrist, and
Speaker 1: your wrist is like time to grow more fingers, and
Speaker 1: so it's just ready to regenerate what had been lost.
Speaker 1: And it's just kind of like standing in wait.
Speaker 2: Wow, that's incredible. That's so different from the way our
Speaker 2: bodies work. It feels so alien.
Speaker 1: So alien. Yeah, okay, And so another thing that's amazing
Speaker 1: about these trees is you know, part of them is alive,
Speaker 1: but a lot of them can be dead. And so
Speaker 1: for example, some trees, and not all trees, but some
Speaker 1: trees have this system where essentially the like pipes that
Speaker 1: provide water to the top part of the tree the xylum.
Speaker 1: Instead of essentially like servicing all of the tree, the
Speaker 1: pipes service a very particular part of the tree. What yeah,
Speaker 1: And so like with bristle cone pines, erosion exposes the
Speaker 1: roots to like dry air, and it kills some of
Speaker 1: the roots. But as long as some of those roots
Speaker 1: are still in good shape, they can provide water and
Speaker 1: nutrients to like a branch or a couple different branches.
Speaker 1: And so you can end up with like I don't know,
Speaker 1: eighty percent of the tree being dead, but twenty percent
Speaker 1: sliver still having leaves, still being able to produce seed
Speaker 1: and still being alive. And so it's like a very
Speaker 1: slow process of death, but it still counts as alive
Speaker 1: because it can still reproduce and it you know, it's
Speaker 1: still producing green leaves.
Speaker 2: I never thought about that how one root doesn't service
Speaker 2: the whole tree. It's like this root is for that branch,
Speaker 2: and this root is for that branch, And so if
Speaker 2: you kill some of the roots, you killing part of
Speaker 2: the tree. You're not just weakening the whole tree. That's fascinating.
Speaker 2: It's like if I had ten mouths and I need
Speaker 2: to like feed this one for that leg and this
Speaker 2: one for the other leg, and like, oops, there wasn't
Speaker 2: any oatmeal left from my right arm, so that's just
Speaker 2: going to be hungry today, and that's weird.
Speaker 1: There are tree species where like one root has you know,
Speaker 1: like multiple we'll call it pipes that come out of it,
Speaker 1: and it feeds different parts of the tree. But there
Speaker 1: are some species of tree where you get this more
Speaker 1: tight link between a certain set of branches and a
Speaker 1: certain root, and in that way it's able to sort
Speaker 1: of die in sections and eke out in existence for longer.
Speaker 2: It's almost more like a community than an individual, right.
Speaker 2: They're just like a budge of brain systems that are
Speaker 2: sort of like growing together, and some of them die
Speaker 2: off and some of them continue. It's like a little
Speaker 2: community of mini trees.
Speaker 1: So I think that comparison works better for our next example.
Speaker 1: I feel like what we just talked about would be
Speaker 1: more like, you know, everything, but my hand could die,
Speaker 1: but my hand is still alive, and so you'd still
Speaker 1: call me alive.
Speaker 2: That sounds like a horror movie I don't want to see.
Speaker 1: Yeah, no, me as well. But the final example for
Speaker 1: how trees managed to live so long is cloning. So
Speaker 1: you have these trees called quaking aspens in the Rocky mountains,
Speaker 1: and they're absolutely gorgeous. They're like, you know, these long
Speaker 1: white trees. They turn beautiful colors in the fall, and
Speaker 1: their roots are able to put out what's called a
Speaker 1: rammit Ramit is a general word for an individual clone
Speaker 1: when you have like a clonal organism, but it produces
Speaker 1: a stem will come out from the root and it
Speaker 1: will turn into a tree, and then that tree will
Speaker 1: produce more roots, and then it will also have a rammit,
Speaker 1: so a stem that comes out. It's all all the
Speaker 1: same genotype. They're all connected by their roots and can
Speaker 1: take up over one hundred acres of land, and it's
Speaker 1: all the same genotype. And so you know, you can say, okay,
Speaker 1: well that doesn't really match how I think of an individual,
Speaker 1: and so it's cheating to say that you get to
Speaker 1: count all of that living stuff. But they can live
Speaker 1: for like ten thousand years, we think, And so you know,
Speaker 1: if you're willing to count that as an individual because
Speaker 1: it's all the same genotype, it has all the same
Speaker 1: genetic makeup. I'm sure there's some mutations in there, but
Speaker 1: you know, very similar. Then that can live for up
Speaker 1: to ten thousand years.
Speaker 2: Well, that's interesting and really challenges your philosophy of like
Speaker 2: what is an individual? I mean, if we had human
Speaker 2: cloning and you turned eighty five and we decided to
Speaker 2: make a new Kelly, would you consider that Kelly to
Speaker 2: be the same as you? And then when you died,
Speaker 2: you feel like, no, I'm still alive.
Speaker 1: I see your point, But like this tree is able
Speaker 1: to do that with no help, Like it's incredible to me.
Speaker 1: And they're also able to produce seed, so they can
Speaker 1: produce this way, but they can also produce seeds that
Speaker 1: can go off and start this whole thing, you know,
Speaker 1: going somewhere else. I think it's an interesting philosophical debate
Speaker 1: about whether all of those trees and one hundred acres
Speaker 1: counts as the same individual or not. But one way
Speaker 1: or another, it's an amazing evolutionary strategy to replicate an
Speaker 1: organism's genes and get them spread throughout the environment.
Speaker 2: I guess it does depend on what you consider to
Speaker 2: be the individual, because in my case, to feel like
Speaker 2: I'm still alive, I would want to keep my memories,
Speaker 2: my personality, all of my experiences, and I feel like
Speaker 2: butt off a new Daniel on my elbow probably wouldn't
Speaker 2: have all those experiences, and so it wouldn't really be
Speaker 2: me even if it had the same genotype. So this
Speaker 2: whole nature versus nurture aspect, Yeah, fascinating. Wow.
Speaker 1: Yeah. So the listener wanted to know why do humans
Speaker 1: not live as long as trees? And I think the
Speaker 1: answer is that trees have just gone down such a
Speaker 1: different evolutionary path than humans have that they are able
Speaker 1: to sort of die incrementally and sort of really stretch
Speaker 1: the process out. There are a lot of pieces that
Speaker 1: all need to be working in order for our bodies
Speaker 1: to keep going, whereas trees are able to do things
Speaker 1: like compartmentalized to eke out in existence for a lot longer.
Speaker 2: Yeah. I'm sometimes surprised that I'm living as long as
Speaker 2: I am when I have all these bits that all
Speaker 2: have to work all the time. Yeah, and they all
Speaker 2: seem sort of complicated, like we are a very elaborate
Speaker 2: meat machine. It's amazing that we keep going as long
Speaker 2: as we do.
Speaker 1: I absolutely agree. And it's amazing that we don't encounter
Speaker 1: even more problems along the way, given how many things
Speaker 1: have to go perfectly in order for us to continue
Speaker 1: existing the way we do well.
Speaker 2: One thing that I think humans will continue to do
Speaker 2: as we age is to be curious about the world
Speaker 2: and to wonder and to build knowledge. And I'm just
Speaker 2: glad the human knowledge builds from generation to generation. We
Speaker 2: can path this down. You don't have to be five
Speaker 2: thousand years old to have five thousand years worth of
Speaker 2: knowledge because we're able to inherit it from all the
Speaker 2: folks that were curious before us.
Speaker 1: Yes, And it became so clear to me while researching
Speaker 1: this just how important that knowledge is and how it
Speaker 1: builds on each other and how you know, dendro chronology,
Speaker 1: which is the aging of trees helps you with archaeology.
Speaker 1: And it's just we're very lucky to have all of
Speaker 1: this cultural ability to transmit knowledge.
Speaker 2: It is incredible, And I love the depth of nerndomb
Speaker 2: that existed so many little facets of science, you know,
Speaker 2: people who have figured out how this works for trees
Speaker 2: and helps us in other areas like that requires an
Speaker 2: individual to be like super fascinated by this topic and
Speaker 2: devote their life to it. And wow, I'm just so
Speaker 2: grateful that there are people out there who are curious
Speaker 2: and pushing knowledge forward. In every direction simultaneously.
Speaker 1: Thank you for being curious and listening to our show,
Speaker 1: and we hope to see you at the next episode.
Speaker 2: Tune in next time.
Speaker 3: Thank you for answering my question. You answered it really well,
Speaker 3: and it's how trees can be alive and some places
Speaker 3: and data and other places at the same time.
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