Speaker 1: Welcome to you stuff you should know from house Stuff
Speaker 1: Works dot com. Hey, and welcome to the podcast. Don't
Speaker 1: Josh Clark, there's Charles W. Chucker's Bryant. Jerry is over there.
Speaker 1: I'm gonna said your last name, Jerry. How weird. And
Speaker 1: then today we have a fourth character in the in
Speaker 1: the studio with this Chuck. This a scent scent coming
Speaker 1: together to make like a changeable human being. So you
Speaker 1: are wearing Patuli, uh not wearing well, you have Petulia
Speaker 1: on you as a result of one of Emily's sugar
Speaker 1: scrubs right from Mama and it's Love your Mama dot com. Okay.
Speaker 1: And then Jerry is contributing to that with um an enchilada,
Speaker 1: so that all of them combined, I would say, there's
Speaker 1: like there's an extra person in the seat right here.
Speaker 1: What kind of person is that? Just another person? Okay,
Speaker 1: a viable living organism, one that when we leave the
Speaker 1: studio we'll probably become extinct. That's a good one. Did
Speaker 1: you like that? Yeah? I've had that plan since probably
Speaker 1: two weeks ago. How are you doing, man, I'm good.
Speaker 1: I've been thinking of Busta Rhymes all day. Why did
Speaker 1: he have a song about extinction had an album called
Speaker 1: the Extinction Level Event. Oh yeah, yeah, and that was
Speaker 1: in one of the songs that sounds super nineties. Well
Speaker 1: let's Buster Rhymes has. But I mean even those words
Speaker 1: extinction level Event. People were worried about stuff because of
Speaker 1: like the turn of the millennium. You remember, Exiles is
Speaker 1: a huge hit Deep Impact and Armageddon came out of
Speaker 1: like on the same day basically, and both were hits.
Speaker 1: Like people were just nervous and um. As a result,
Speaker 1: Buster Rhymes is very popular, that's right, although he's not anymore. Uh,
Speaker 1: he's still good though he hadn't been doing much no,
Speaker 1: but his body of work is yeah, leaders in the
Speaker 1: New School and his early work with Chip call Quest.
Speaker 1: Oh yeah, he guessed it on one of my favorite
Speaker 1: songs is What's the Scenario? Was that the one I
Speaker 1: think so? I mean it was definitely on that one,
Speaker 1: but they that was the one also where I think, um, yeah,
Speaker 1: he makes fun of people with saggy pants because it
Speaker 1: was so new. Apparently Bustter Rhames wasn't down with it yet. Yeah,
Speaker 1: just pretty ironic because he got hardcore into that. That
Speaker 1: was raw, raw, like a dungeon dragon, right, it's pretty awesome.
Speaker 1: So extinction is clearly what we're talking about today. Uh
Speaker 1: and uh, I guess we should probably give a shout
Speaker 1: out to some of the extra reading material. Yeah, man,
Speaker 1: we picked up on UM. There's a woman named Elizabeth
Speaker 1: um Colbert or Corp Colbert depending on what if you
Speaker 1: watch the Colbert Report. Um and she is basically a
Speaker 1: leading expert as far as journalists go on extinction. She
Speaker 1: wrote a book called The Sixth Extinction. That's a good
Speaker 1: it's a good article. Yeah, and like she wrote an
Speaker 1: article in the New Yorker. She's a New Yorker journalist
Speaker 1: that was basically the predecessor to the book. You know
Speaker 1: how they do. Like, I need an extra twenty grand,
Speaker 1: so I'll just write a synopsis of the book I'm writing.
Speaker 1: Um And it's a good article, and we worked from that.
Speaker 1: There's another one from the New York Review of Books
Speaker 1: called They're taking Over about the explosion of jellyfish. UM.
Speaker 1: On how stuff Works, there's one that I wrote years
Speaker 1: back called will We Soon Be Extinct? And there's another
Speaker 1: how stuff Works one that we've done an episode on
Speaker 1: called wise bio Diversity Important. Yeah, and I found one
Speaker 1: in an I O nine for animals that we thought
Speaker 1: were extinct but miraculously pop back up nice, which is
Speaker 1: always a good story. Oh yeah, it's a it's a
Speaker 1: heartwarming story of triumph of raversity and coming back when
Speaker 1: everybody thought you were down. Yeah, some of them like
Speaker 1: basically rocky, hundreds of millions of years later. Even Yeah,
Speaker 1: it's crazy, like the Silicon I think that's when I
Speaker 1: was at the Big Fish. They just caught that thing
Speaker 1: one day, yeah, and said, hey, wait a minute, Yeah,
Speaker 1: this thing's extinct. It's supposed to be. And we'll talk
Speaker 1: about how and why things fall off. But things do
Speaker 1: fall off, and it seems that there is a um
Speaker 1: that the whole thing is a very natural process. Extinctionists.
Speaker 1: But for a very long time, I guess scientists um
Speaker 1: believed that the God created all of the animals on
Speaker 1: Earth and that his will was too perfect, his creation
Speaker 1: was too divine to even allow for extinct and so
Speaker 1: because they were aware of the fossil record, they rationalized
Speaker 1: these huge bones of animals that he didn't see anywhere
Speaker 1: as we just haven't found him yet. Well yeah, and
Speaker 1: this was all the way up and you know, into
Speaker 1: the nineteenth century and some really smart people like Thomas
Speaker 1: Jefferson thought, for instance, when he sent Lewis and Clark
Speaker 1: out west, that they might come across the great Mastodon.
Speaker 1: He's like, it's found to be out there somewhere, guys,
Speaker 1: to be careful. But there were some other smarter people,
Speaker 1: um like George Cuvier in eighteen twelve, he was pretty
Speaker 1: ahead of his time. In fact, in eighteen twelve he
Speaker 1: was way ahead of his time because he published an
Speaker 1: essay called Revolutions on the Surface of the Globe and
Speaker 1: he kind of asserted that now things can go extinct,
Speaker 1: and he called them a species produced lost species and
Speaker 1: basically hypothesized that there have been cataclysmic events that have
Speaker 1: caused extinctions. In so many words, this is basically flew
Speaker 1: in the face of this that like, not only was
Speaker 1: their extinction, but there were there were huge events that
Speaker 1: caused it. And so the the religious thinkers of the
Speaker 1: day said, okay, wait, wait, wait, we can work with this,
Speaker 1: because buddy, what you're talking about is like Noah's flood.
Speaker 1: So you, my friend, just proved the Bible correct using science. Yeah.
Speaker 1: Darwin wasn't on board though, Although he did believe in extinction,
Speaker 1: he thought it was the only way it could happen
Speaker 1: is the gradual extinction. That is also true, and we'll
Speaker 1: talk about that as well. And of course Darwin is
Speaker 1: this huge hero of biology so well, Darwin's right about
Speaker 1: just about everything, so literally, until the nineteen nineties, Darwin's
Speaker 1: view that extinction happens extremely slowly, slower than speciation events,
Speaker 1: so ultimately you should always have more species, new species
Speaker 1: coming up, then you have going extinct. Until the nineteen nineties,
Speaker 1: that's the way that it was, That's the way it seemed,
Speaker 1: so Chuck, like I said, all of this um stayed
Speaker 1: around until and it was the result of like think
Speaker 1: about it, think about how you think of mass extinctions now,
Speaker 1: you think of a asteroid hitting Earth, destroying everything. And
Speaker 1: it wasn't until that that view became widely accepted. And
Speaker 1: it was because of this dude um named Alvarez. He
Speaker 1: was a geologist, I believe, Walter Alvarez, and in the
Speaker 1: seventies he started studying this clay layer that was basically
Speaker 1: in the fossil record right at the time the dinosaurs
Speaker 1: suddenly died out, and no one could quite explain what
Speaker 1: was going on here. They just knew that this must
Speaker 1: have happened gradually, so it must be a problem with
Speaker 1: the actual fossil record, not our way of thinking. And
Speaker 1: there are plenty of problems with the fossil record, which
Speaker 1: we'll get into as well. But UM Walter Alvarez said,
Speaker 1: let me, let me look at this in a little
Speaker 1: more detail, and he looked at the iridium and found
Speaker 1: that the iridium levels were off the arts, which shouldn't
Speaker 1: be because it's very, very rare, and we associate a
Speaker 1: ridium on Earth as being brought here by, say, like
Speaker 1: an asteroid or whatever. Yeah, it's superabundant asteroids. So all
Speaker 1: of a sudden, this guy goes, oh, wait a minute,
Speaker 1: maybe we can explain this dying out of dinosaurs where
Speaker 1: the dinosaurs went sixty five million years ago by an asteroid.
Speaker 1: And that was in nineteen eighty that they proposed this hypothesis,
Speaker 1: and they ran into a lot of resistance UM and
Speaker 1: then finally in n UM, a year after a crater
Speaker 1: was discovered under the Yucatan Peninsula in Mexico, UM they
Speaker 1: dated it and said, yeah, it just so happens that
Speaker 1: this crater was formed just at the moment the dinosaurs
Speaker 1: died out. So Valvareus hypothesis is probably right, and extinction
Speaker 1: can happen on a mass sudden scale, just as it
Speaker 1: can also happen on a very long term scale too. Yeah,
Speaker 1: that crater was a hundred and twelve miles wide, so
Speaker 1: it fit the profile and basically ended the Cretaceous period
Speaker 1: in the Mesozoic era. And for a while they called
Speaker 1: it the Cretaceous Tertiary event, but now they call it
Speaker 1: the Cretaceous paleogene event. And did you notice that the
Speaker 1: right they noticed the that. Did you notice the Cretaceous,
Speaker 1: which is spelled at the sea is denoted with the K.
Speaker 1: Did you see why? It's just German. It's just a
Speaker 1: German translation for it. I figured out something like that. Yeah,
Speaker 1: it was just bugging me. So now we now believe
Speaker 1: in asteroid brought us into the Cenozoic era that we
Speaker 1: that we enjoyed today. Love the Cnozoic. It's pretty good,
Speaker 1: pretty awesome. I mean it's our era, so you gotta
Speaker 1: love it. You gotta love it. Um, So Chuck, like
Speaker 1: I said, the extinction, extinction can happen, and it does happen,
Speaker 1: and it's a natural process. Um. If you talk to
Speaker 1: people about extinction today though, they say, yeah, we're kind
Speaker 1: of in a huge extinction event. Yeah, and it makes sense.
Speaker 1: I mean when you look at the our past. They
Speaker 1: estimate maybe up to five billion species have lived on
Speaker 1: Earth and more than those are gone. And I love
Speaker 1: how the New Yorker put it. I think that there's
Speaker 1: an old joke that all of life on Earth today
Speaker 1: could be accounted for with a simple rounding error, like
Speaker 1: everything we know. Um, so, yeah, we've lost of things
Speaker 1: that have ever lived on this planet due to extinction, right,
Speaker 1: which again is like it has such a terrible connotation
Speaker 1: these days, extinction, extinction, but it happens naturally. Apparently. What
Speaker 1: they've found from looking at the fossil record from studying
Speaker 1: life on Earth is that a species tends to have
Speaker 1: about a ten million year lifespan, and there a speciation
Speaker 1: event occurs where it branches off from one specie produces
Speaker 1: an entirely new species, and that species on average will
Speaker 1: stick around for about ten million years, and then something
Speaker 1: happens and it dies out and other species take its place.
Speaker 1: This is the natural course of life from what we
Speaker 1: can tell. The thing is, it normally happens on a
Speaker 1: very slow time scale, like when it's what's called background extinction, right, Yeah,
Speaker 1: the background rate uh is supposed to be between one
Speaker 1: and five species per year, but they think that now
Speaker 1: it could be like a times that I've seen up
Speaker 1: to a thousand times the normal rate, and I saw
Speaker 1: another study from two thousand fourteen, so it's fresh and
Speaker 1: it it said that they these researchers calculated the normal
Speaker 1: rates and they found that there's between point zero two
Speaker 1: three and point one three five extinct species per million
Speaker 1: species per year. That doesn't really mean much. It means
Speaker 1: so much that it boggles the mind, you know, Like
Speaker 1: that's a really strange way of putting it. But basically
Speaker 1: they're saying, like, for every million species on on earth
Speaker 1: at any given point in time during a year, as
Speaker 1: low as point zero two three species will die out.
Speaker 1: So in a year, you shouldn't necessarily have that Maine
Speaker 1: species in two In current times though, like you said,
Speaker 1: between a hundred and a thousand times that rate is
Speaker 1: what we're seeing right now, which is you could say, alarming.
Speaker 1: It is alarming. The reason they don't have hard numbers
Speaker 1: on this stuff is because, like we said, it's a
Speaker 1: tough thing to study because the fossil record is well,
Speaker 1: there's a lot of problems. One is it's incomplete. We
Speaker 1: don't really know how many species have been on Earth
Speaker 1: since the beginning of Earth. It's just impossible to tell um.
Speaker 1: Fossils forum under you know, really specific conditions. So you
Speaker 1: may think something is gone because it has disappeared from
Speaker 1: the fossil record, but all that means is there wasn't
Speaker 1: a fossil doesn't necessarily mean it's gone. So that's why
Speaker 1: things will pop back up that they'll think, hey, we
Speaker 1: haven't seen the fossil of this guy and two thousand years,
Speaker 1: but here it is all of a sudden, And even
Speaker 1: if it has gone extinct, just where it stopped showing
Speaker 1: up from the fossil record doesn't mean, like you said,
Speaker 1: that's when it went extinct, right then it could have
Speaker 1: been millions of years later. Well, because then you're supposing
Speaker 1: that the last thing of that species happened to make
Speaker 1: a fossil, which is just silly um. And also it
Speaker 1: makes you wonder how many species have lived and died
Speaker 1: on Earth that just never showed up in the fossil record. Yeah,
Speaker 1: just weren't fossils at all. Yeah, Well, if it never
Speaker 1: crawled into amber or you know, was buried by ash
Speaker 1: or something that's luck, or got trapped in Bronosaurus poop.
Speaker 1: I don't know if that's good luck or bad luck.
Speaker 1: It's just it is what it is. It's nature. So
Speaker 1: because of all these gaps in the fossil record, UM,
Speaker 1: these researchers that love this topic tend to do a
Speaker 1: lot of math and a lot of speculating with algorithms
Speaker 1: and mathematical formulas. This up out, sure, and that's the
Speaker 1: only way to do it, really, to speculate with numbers. UM.
Speaker 1: It also helps them define things like the minimum viable population,
Speaker 1: which if you go below that then it's bad news
Speaker 1: for the species. It's the minimum amount you can have
Speaker 1: to still be considered to have a bright future right
Speaker 1: as a thing, or to just survive as a species. Right, Yeah,
Speaker 1: that's what I mean, damn future if you're not surviving. Yeah,
Speaker 1: math is pretty grim. It can be in this case
Speaker 1: for sure. UM. So we'll talk about exactly what makes
Speaker 1: an extinction and and then what makes up mass extinctions. UM.
Speaker 1: But first let's do a little break it un Okay, So, Chuck,
Speaker 1: you've been talking about um animals, animal species, going extinct
Speaker 1: and then showing up again like the Ceila can't or
Speaker 1: at least disappearing from the record, but we as humans
Speaker 1: assume they were extinct like a again, the Cela cant
Speaker 1: is this fish um that they caught off the coast
Speaker 1: of South Africa. When did we talk about it wasn't
Speaker 1: into this day in history. I remember we definitely have
Speaker 1: hit on that though. I think it was. It's huge, right, Yeah,
Speaker 1: it's a big, ugly fish and it looks like an
Speaker 1: old dinosaur. But they thought it had died out like
Speaker 1: like fifties, sixty million years ago, actually way longer. They
Speaker 1: thought it disappeared four million years ago, even more impressive.
Speaker 1: So then they caught one off the coast of South
Speaker 1: Africa in the thirties. Then they caught another one a
Speaker 1: couple of decades later in Madagascar or Mauritius or something,
Speaker 1: and um that made the Seila cant a Lazarus species.
Speaker 1: You know, I hadn't really gone anywhere. We just thought
Speaker 1: it did. So we humans, having the most important perspective
Speaker 1: on the entire planet, possibly in the entire universe, it
Speaker 1: was a Lazarus species to us, Lazarus from the Bible
Speaker 1: race from the dead like the sea cant again with
Speaker 1: the biblical connotations with extinction. Yeah, a lot at stake here,
Speaker 1: that's true. Another way something might disappear and you might
Speaker 1: think it's gone is if it actually evolves into a
Speaker 1: new species. That's called pseudo extinction. And that's a great
Speaker 1: success story as well. It is, but it also I
Speaker 1: don't understand why that's not just a speciation event. I mean,
Speaker 1: why is that pseudo extinction? Why is that any different
Speaker 1: from regular extinction? Um, yeah, maybe just because it's uh,
Speaker 1: it's didn't die out actually just changed and evolved. Those
Speaker 1: are two different things. Yeah, it seems like a gray
Speaker 1: area to me. But for the most part, when an
Speaker 1: animal just disappears, and we should say, like even today,
Speaker 1: we were still finding things that we thought were extinct,
Speaker 1: so called Lazar species, which goes to make the point
Speaker 1: we have no idea how many living species there are
Speaker 1: on the planet today, Yeah, or have been. It's all
Speaker 1: just a good guess it is using math, grim grim math.
Speaker 1: But for the most part we understand that when uh
Speaker 1: species goes away, suddenly it went extinct. And as we've
Speaker 1: been saying again and again, extinction is kind of this
Speaker 1: natural processor. It is a very natural process, um. And
Speaker 1: it typically results from a change in the habitat of
Speaker 1: species and it's inability to adapt so it dies out. Yeah.
Speaker 1: Competition with other species, hunting by humans, or perhaps the
Speaker 1: environment has been tainted by humans, humans, or a new
Speaker 1: bacteria or a new virus. The thing is, though, is
Speaker 1: so these these big factors, habitat loss, competition with new species, hunting,
Speaker 1: and contaminants in the environment. Those are the big four
Speaker 1: reasons that something goes extinct, right, Humans can and are
Speaker 1: responsible for all four of those. Yeah, and the and
Speaker 1: these are This is the extinction that happens over time.
Speaker 1: Obviously not a big asteroid hid in the planet. No,
Speaker 1: But it can't happen pretty quickly. In this this is
Speaker 1: a Tracy Wilson joint and in uh in the introduction,
Speaker 1: she mentions the stellar sea cow, which was an Arctic resident.
Speaker 1: It was a big old manateee basically, and they were
Speaker 1: first described by Arctic explorers in seventeen forty one. By
Speaker 1: seventeen sixty eight they were extinct. So it can't happen
Speaker 1: on a pretty rapid um scale. Yeah, especially when you
Speaker 1: introduce humans. Yeah, and it you know, it has a
Speaker 1: domino effect too, because we talked about and everyone knows
Speaker 1: about the dangers of losing bees. It's not just like, oh,
Speaker 1: well there're no more bees. That's gonna affect pollination and plants,
Speaker 1: and those plants are being fed on by other animals,
Speaker 1: and it tends to have a snowball effect. Um. Like,
Speaker 1: for example, the end of the last ice age, mammals,
Speaker 1: small mammals started to go extinct and because of that,
Speaker 1: large animals started to go extinct because they liked to
Speaker 1: eat the small animals. Exactly. Which is the answer to
Speaker 1: the question why is biodiversity important? Well, because ecosystems thrive
Speaker 1: and survive on a wide number of species that are
Speaker 1: exists pretty much naturally imbalanced. Um. You know. A pretty
Speaker 1: good example of that stuff falling out of balance, um
Speaker 1: is the passenger pigeon. Are you familiar. Yeah, they're trying
Speaker 1: to de extinct to that thing. Yeah. You want to
Speaker 1: talk about the extinction, Yeah, Well, the extinction is um,
Speaker 1: exactly what it sounds like. It is sort of Jurassic
Speaker 1: parky it is. In two thousand three, some scientists revived
Speaker 1: the Burcardo Bucardo, and that's a Spanish mountain goat and
Speaker 1: they did it just sort of like Jurassic Park from
Speaker 1: DNA that was frozen in time. Unfortunately, although it did
Speaker 1: work initially. Uh, the DNA only survived a matter of minutes,
Speaker 1: but they did they did count as a d extinction.
Speaker 1: I think there was a live birth that survived a
Speaker 1: few minutes, wasn't it. Yeah, the the animal itself only
Speaker 1: survived a few minutes, though it was like, I should
Speaker 1: not be that's true. Uh, And I mean they basically said,
Speaker 1: it's happening now, and we have the capabilities and we
Speaker 1: may not be able to bring the wooly mammoth back,
Speaker 1: but we might be able to bring back something kind
Speaker 1: of close, right. So, and that raises in this article
Speaker 1: that you sent um this this moral question, like should
Speaker 1: we be doing this just because we can? Does that
Speaker 1: mean we should? And so like, if you bring back
Speaker 1: an animal that has been extinct for so long that
Speaker 1: its habitat is now gone where they're gonna live, exactly
Speaker 1: where you're gonna put it a zoo, that doesn't seem
Speaker 1: like a good reason to bring an animal back. So
Speaker 1: we could put it in a zoo? Yeah, and just
Speaker 1: uh like maybe it This is my opinion here, which
Speaker 1: we don't do a lot of, but it seems like
Speaker 1: concentrating on the problems we face now with the extinction
Speaker 1: rates is something that we should concentrate on, not bringing
Speaker 1: back the wooly mammoth. Right, And and that also kind
Speaker 1: of dovetails of the point that if we have this
Speaker 1: ability and routinely UM exercise it, we may be less
Speaker 1: inclined to protect the stuff we have now, for like, oh,
Speaker 1: it's important enough, we'll just genetically re engineer and bring
Speaker 1: it back later. Yeah. I think they in the scene
Speaker 1: an article they liken it to just thinking we have
Speaker 1: an undo button on the world controls the Yeah, no, good, No,
Speaker 1: it's funny because the author doesn't realize that controls the
Speaker 1: works outside of Microsoft word too. He specifically mentioned control
Speaker 1: Z and Microsoft word, oh words, specifically Microsoft word. He said, yeah,
Speaker 1: that's a little weird. He could be a schill and
Speaker 1: he was just working it in maybe you know, well
Speaker 1: on max though it's not control UM. Maybe he just
Speaker 1: smit Microsoft and awkwardly put in word maybe, or maybe
Speaker 1: that's the only program he knows. You know, how do
Speaker 1: I work this? UM? So you're saying that they're trying
Speaker 1: to bring back the the passenger pigeon. Right, So the
Speaker 1: passenger pigeon is this really neat example of what happens when, um,
Speaker 1: you have a lack of biodiversity. Um, there were when
Speaker 1: European settlers came to the New World, apparently like one
Speaker 1: out of every four birds in North America was a
Speaker 1: passenger pigeon. A quarter of the entire bird population was
Speaker 1: passenger pigeons. There's a ton of pigeons. There are so
Speaker 1: many that you could just like shoot into like a flock,
Speaker 1: and you would kill a couple hundred. Literally, it was
Speaker 1: that there were that many. The thing is is, um
Speaker 1: if you live, if you read one. I can't remember
Speaker 1: which one it is, but both are excellent books by
Speaker 1: Charles C. Man. He talks about the passenger pigeon and
Speaker 1: how they've recently realized that there were so many passenger
Speaker 1: pigeons because a century before they're one of one of
Speaker 1: their um great predators. The native American had been wiped
Speaker 1: out by disease that had been introduced to the continent
Speaker 1: about a century before that. So by the time the
Speaker 1: Europeans got here and really started to settle and encounter,
Speaker 1: the passenger pigeon, they're like, God, look at all these pigeons,
Speaker 1: and didn't realize that the pigeon population had exploded because
Speaker 1: their natural predator had died off, and so we in
Speaker 1: turned hunted them into extinction. So because of one near extinction,
Speaker 1: the another species was allowed to thrive and explode, and
Speaker 1: then that when they were faced with their their predator again, humans,
Speaker 1: they were eventually wiped out and when extinct. Yeah, the
Speaker 1: American Buffalo, we almost sounded them out of existence. Yet
Speaker 1: we're not for Ted Turner. Yeah, we tried our best too.
Speaker 1: They were just shooting those things for fun at one point, man.
Speaker 1: That's disgusting. Disgusting. You hear about the trains just going
Speaker 1: through the West and just shooting out the windows at
Speaker 1: the Buffalo for no reason and doing nothing, just leaving
Speaker 1: them there to rot. Remember we did an episode on
Speaker 1: the Buffalo that was a good one. So sad um
Speaker 1: So it was good. Well it was sad dude though. So, uh,
Speaker 1: if you want to talk about extinction level events, that's
Speaker 1: a whole different deal. You want to talk that's not
Speaker 1: a slow gradual extinction, that is, uh, some big thing
Speaker 1: that happens that wipes out a lot of living things
Speaker 1: all at once, and they estimate there's been more than
Speaker 1: twenty of these in the history of the world, but
Speaker 1: um five of them. They call him the Big Five
Speaker 1: for a reason, for good reason, and we'll just go
Speaker 1: through those kind of quickly. Now, Uh, the Ordo Viscian extinction,
Speaker 1: it's about four ninety million years ago, and that wiped
Speaker 1: out about half of all animal families. And the reason
Speaker 1: it wiped out about half is because at the time
Speaker 1: most of the stuff on are still lived in the sea.
Speaker 1: Glaciers formed at this time, lowering sea levels, which meant
Speaker 1: that animal is that lived in a certain depth of
Speaker 1: the sea, usually towards the surface, lost their habitat boiled
Speaker 1: yeah maybe yeah, or were brought down to the level
Speaker 1: where their predators like to hang out and we're eating
Speaker 1: non mass. But that that accounted for that extinction, which
Speaker 1: is kind of rare because, as you'll see when we're
Speaker 1: talking about the Big Five or mass extinctions in general,
Speaker 1: it's very difficult to pinpoint exactly what happened. So that's
Speaker 1: one of the rare ones that were like pretty sure,
Speaker 1: this is why all of these, all this life went
Speaker 1: extinct all of a sudden. Yeah, And one reason it's difficult.
Speaker 1: It's because it was almost five million years ago. It's
Speaker 1: kind of tough. Here in number two, I feel like
Speaker 1: letterman number two on the top five extinction UM, the
Speaker 1: Late Devonian extinction UM, they're still debating about that, and
Speaker 1: about a quarter of the marine families. And by the way,
Speaker 1: we should mention when they research these things, they home
Speaker 1: in on family and genera and the big um classification group.
Speaker 1: They don't say like, oh, look at these kingdoms that
Speaker 1: have disappeared or these phylum. They go down to the
Speaker 1: smaller levels and family and genis are just above species
Speaker 1: as far as the taxonomy is concerned, exactly. UM. So
Speaker 1: what I say about half of the marine genera and
Speaker 1: that was three hundred and sixty million years ago, No
Speaker 1: idea what caused that one? No idea? At least you
Speaker 1: and I have no idea. Yeah. I don't think they
Speaker 1: care about that one too much. The Permian Triassic extinction,
Speaker 1: this is um. This is a pretty big one. This
Speaker 1: is the biggest one ever. This is the one they
Speaker 1: called the Great Dying, right I think so. I've seen
Speaker 1: estimates of as much as nine to nineties six percent
Speaker 1: of all life died off during this this extinction event. Um.
Speaker 1: In this article it says of marine genera and seventy
Speaker 1: of land species when extinct, and that was two hundred
Speaker 1: and fifty million years ago. There's a lot of people
Speaker 1: who have different ideas about what did it. But do
Speaker 1: they think it's possible as volcanic activity creating acid rain. Um,
Speaker 1: that's a big one that possibly happened more than once.
Speaker 1: Was that the one where I don't know, I think
Speaker 1: that was the the KPg event was the one where
Speaker 1: they think, um, they're not exactly how it happened, but
Speaker 1: they might have been just broiled and then awesome broiled
Speaker 1: on the face of the Earth, which would have happened
Speaker 1: pretty quickly to actually and I think that one is
Speaker 1: if because they think it may have burst through the
Speaker 1: atmosphere right, yes, it rained hot debris everywhere. That's the
Speaker 1: one that got ride of the dinosaurs six million years ago.
Speaker 1: What is it called the k K hyphen PG, Yeah,
Speaker 1: the Cretaceous Paleogene event now, and that's the one where
Speaker 1: they they are pretty sure that an asteroid hit um
Speaker 1: Central America and sent all of this rock like basically
Speaker 1: vaporized rock with away from Earth with so much force
Speaker 1: that this stuff made it out of the atmosphere and
Speaker 1: then started to come back down, and as they did,
Speaker 1: it generated thermal heat enough to bring the broil down
Speaker 1: on Earth. Yeah. And that's the one of two um
Speaker 1: sub explanations. The other is that, uh, the old familiar
Speaker 1: um ash basically kept photosynthesis from it, like it blacked
Speaker 1: out the sun like a nuclear winner. Um. Pretty nuts though,
Speaker 1: But we skipped number four for no good reason. Um.
Speaker 1: The end Triassic extinction killed about of marine families, about
Speaker 1: half of marine genera, and that was two million years ago. Yea.
Speaker 1: And again, like with a mass extinction, there's there's no
Speaker 1: real definition for it. I found. I was looking to see, Okay,
Speaker 1: who's who's the body that says, like, okay, a mass
Speaker 1: extinction event took place. It's again, the the fossil record
Speaker 1: is incomplete enough, and we're making guesses and mathematical guesses,
Speaker 1: but still guesses to the extent that we don't have
Speaker 1: a real definition for what constitutes a mass extinction. But
Speaker 1: those five were so massive that there's virtually no debate
Speaker 1: whatsoever that those account for mass extinction events. Yeah. Um,
Speaker 1: it's kind of like you know it when you see it,
Speaker 1: kind of thing, but there's no agreement on how pretty much. Um.
Speaker 1: There there's no agreement on how fast it happened it
Speaker 1: has to happen, or how widespread it has to happen.
Speaker 1: But typically it's like a large percentage of all of
Speaker 1: the animals alive, something like say, of all living animals species,
Speaker 1: not just animals. Animal species just die off. Um, and
Speaker 1: it's worldwide. That's another that seems to be another um
Speaker 1: factor in defining a mass extinction widespread. Yeah, so um,
Speaker 1: these events were pretty big. Yeah, and one of them,
Speaker 1: I think one of the researchers in the article you
Speaker 1: sent made a pretty good point that the current mass
Speaker 1: extinction extinction that we're in now, which we're gonna talk
Speaker 1: about in depth here in a minute, uh, he said,
Speaker 1: these are way more dangerous because in the event of
Speaker 1: an asteroid, let's say, while it might really suck, it's
Speaker 1: one bad event, and right afterwards, the world starts to
Speaker 1: try and recoup. It may take a million years, but
Speaker 1: it tries its best to start reforming life and get
Speaker 1: going again. Where right now there's no stress relief, it's
Speaker 1: just a constant there's no recuperation because it's not over
Speaker 1: right or the recuperation will come, but we won't be
Speaker 1: around to see it because it the the breaking point
Speaker 1: will be us wiping ourselves out by wiping out the biodiversity.
Speaker 1: And there is a kind of this whole moralistic thing
Speaker 1: to the to the idea of extinction. This there's this
Speaker 1: whole human guilt. But if you just kind of take
Speaker 1: a step back and look at mass extinction um intellectually,
Speaker 1: it doesn't wipe out life. It just changes everything. Right,
Speaker 1: So for for one species it might be a boom time.
Speaker 1: For everybody else it's a dying off time. But it's
Speaker 1: all in your perspective. Well, yeah, this, this beautiful earth
Speaker 1: that we know and love now isn't anything like it
Speaker 1: was a hundred million years ago exactly. And there's not
Speaker 1: necessarily a set level that or a baseline that Earth
Speaker 1: is supposed to be at, right because nature doesn't care
Speaker 1: and nature is not like, Oh, we got all these
Speaker 1: people here now and things seem pretty modern and they
Speaker 1: got smartphones, so maybe we should just protect this version. Uh,
Speaker 1: they're like, what was the cycle every what ten million
Speaker 1: years for a species? For species? OK, that's a lifespan
Speaker 1: of a species on average, So basically every what ten
Speaker 1: million years the Earth, it just doesn't care. No, The
Speaker 1: point is is, for a species, it's lifespan is ten
Speaker 1: million years, and the Earth is not caring every day
Speaker 1: of that. It doesn't care. It's just stumbling toward the
Speaker 1: next event, basically exactly that will one day probably have.
Speaker 1: The thing is is all of this is not to
Speaker 1: say that humans are off the hook. All evidence that's
Speaker 1: coming in now is showing that we are doing a
Speaker 1: lot to speed up extinction events and create a mass extinction,
Speaker 1: so much so that the Big Five is possibly the
Speaker 1: Big six, and we may be in the very beginning
Speaker 1: stages of the sixth one. And we'll talk about that
Speaker 1: right after this. So, Chuckers, we've been talking about mass
Speaker 1: extinction events. There's a Big five, and a lot of
Speaker 1: people are saying, no, there's six, and the sixth one
Speaker 1: is human caused, so much so that geologists are proposing
Speaker 1: that we call our current epoch the anthroposcene because humans
Speaker 1: are having such an impact on Earth that they imagine
Speaker 1: ten thousand years from now, geologists will be able to
Speaker 1: look and point to this layer and say, here's where
Speaker 1: human started. Yeah, let's get in the way back machine.
Speaker 1: Oh yeah, let's crank this baby up? Does they have
Speaker 1: enough charisee? Oh, it's got enough kerosene, buddy, because we're
Speaker 1: going back years, you got, okay? And we're we're going
Speaker 1: to go to Australia even because it's just nice down there.
Speaker 1: And what I see around me are these huge wombat
Speaker 1: like things that are as big as hippos. Huge. And
Speaker 1: I see a tortoise over there that's the size of
Speaker 1: a VW beetle, and this weird short faced kangaroo and
Speaker 1: these ten ft tall ten ft tall kangaroo looks the
Speaker 1: size of it and everything is crazy. But um, let's
Speaker 1: just unpack here and let's start propagating you and me. Okay,
Speaker 1: I'm gonna make it far just for safety, all right.
Speaker 1: It sounds like I needed to fend you off too.
Speaker 1: And you know what, it's weird. Things are starting to
Speaker 1: disappear around us as we grow and as we expand,
Speaker 1: and uh and seen, can we get out of here
Speaker 1: because that teen foot tall kangaroos eyeing us, well not anymore,
Speaker 1: but he's dead because they believe a lot of people
Speaker 1: think that around fifty years ago, when humans started expanding
Speaker 1: their footprint, Um, there was a very inconvenient correlation with
Speaker 1: species dying out as we spread about the earth. Yeah,
Speaker 1: the the this sixth mass extinction. I apologize for not
Speaker 1: being able to say sixth correctly. But um, there there's
Speaker 1: a huge debate and it's still it's not settled. Both
Speaker 1: sides are like, we're right, right, another one is like,
Speaker 1: we're right. The thing is both sides agree like, yeah,
Speaker 1: we're in the midst of a six maths extinction and
Speaker 1: isn't that what matters? But is it human caused or
Speaker 1: is the result of climate change? And just because it's
Speaker 1: the result of climate change doesn't mean that if you
Speaker 1: take the trail back far enough, it isn't necessarily human cause.
Speaker 1: But these are the two debates. So one is the
Speaker 1: theory of overkill, which is the one you were just describing. Yeah,
Speaker 1: and that was describing Australia fifty years ago. Um, if
Speaker 1: we want to get back in the way back machine
Speaker 1: and go to North America eleven thousand years ago, uh,
Speaker 1: three quarters of our largest animals started to die out,
Speaker 1: like the mascodon and the Willie mammoth and the giant beaver,
Speaker 1: sabretooth tiger and not coincidentally, probably that's right. Around the
Speaker 1: time where we first walked over the bearing Land Bridge
Speaker 1: and set up shop here in North America. Yeah. The
Speaker 1: thing is is you can also say, well that kind
Speaker 1: of gives or takes a few thousand years, and yeah,
Speaker 1: you can. That's definitely stretchable, but it's just not been proven.
Speaker 1: So there is a huge correlation between the spread of
Speaker 1: humans and the death of what are called mega faun
Speaker 1: a huge land animals. And they say that that theory
Speaker 1: of overkill says that we came along with our smart
Speaker 1: little tool kits, which included like spearheads and arrows and
Speaker 1: axes and clubs and domesticated dogs after a certain point
Speaker 1: in time and over hunted either these huge like hippo
Speaker 1: sized marsupials, or we hunted things that were slightly smaller
Speaker 1: that the huge hippo sized marsupials. Eight. Either way, we
Speaker 1: contributed directly to their mass extinction. Yeah, and they think,
Speaker 1: um generally that over hunting isn't the very least, it's
Speaker 1: not the soul cause because you probably just can't hunt enough.
Speaker 1: The amount of people that we had, especially in a
Speaker 1: place like Australia which wasn't super heavily uh founded, you know,
Speaker 1: it wasn't like ten million people moved to Australia overnight,
Speaker 1: you know. So they say over hunting is probably not
Speaker 1: the soul cause, but maybe a factor. UM. But other
Speaker 1: things humans did, like maybe um in Australia they started
Speaker 1: burning shrubs to clear land, and maybe those shrubs were
Speaker 1: eaten by a certain species and then that caused that
Speaker 1: domino effect again another um. The other camp that basically says, no,
Speaker 1: it's climate change and it's fairly natural. Other people might
Speaker 1: say it's human cause climate change. But for the most part,
Speaker 1: if you are a climate change extinction proponent, you're probably
Speaker 1: just believed that this is a natural process that the
Speaker 1: Earth is undergoing, and humans didn't have enough of an
Speaker 1: impact early on to account for the loss of a
Speaker 1: lot of these species. This one study pointed to a
Speaker 1: place called Sahul, which was Australia, New Guinea and Tasmania
Speaker 1: all joined together in this megacontinent. There was several tens
Speaker 1: of thousands of years ago, and they were saying that
Speaker 1: by the time humans arrived in Sahul or Australia, most
Speaker 1: of the megaphone it was already gone. He has gone
Speaker 1: as a result of climate change and there's no evidence
Speaker 1: that we had a tool kit capable of killing these animals, um,
Speaker 1: you know, at this time. So the debate still rages on.
Speaker 1: And you know, there's been several ice ages that didn't
Speaker 1: make things go extinct, so people point to that as
Speaker 1: maybe another counter argument. But the researchers you sent along
Speaker 1: did this pretty cool thing. They did the first global
Speaker 1: analysis um of mapping large animals during this period a
Speaker 1: hundred and thirty two thousand to a thousand years ago,
Speaker 1: and it was the first time they were able to
Speaker 1: really get a fine point on this geographical variation in
Speaker 1: the and species loss. And they did find that a
Speaker 1: hundred and seventy seven species of large mammals disappeared during
Speaker 1: that period where we were starting to spread out as
Speaker 1: a species, and which apparently is as this put in
Speaker 1: this article, a massive loss. Yeah, and they said, you know,
Speaker 1: they expect these kind of things to happen on an island,
Speaker 1: like if you go to Hawaii or you know, any island.
Speaker 1: They say that that survival is the exception when humans
Speaker 1: invade an island, But for to happen on like a continent,
Speaker 1: it's it's pretty uh, it's pretty as going to think
Speaker 1: about the human impact. It's still an island. Well, yeah,
Speaker 1: I guess that's a good point. Um. But the jury
Speaker 1: is still out though, and exactly what's causing this. Most
Speaker 1: scientists agree that we are in an mass extinction event,
Speaker 1: and it's happening pretty quickly. Um, something like I think
Speaker 1: a third of all coral reefs are in danger of extinction.
Speaker 1: A third of amphibians, I believe, Yeah, and a quarter
Speaker 1: of all mammals and an eighth of all birds are
Speaker 1: all classified as threatened with extinction and um, and this
Speaker 1: is happening around the world, So it's faking the criteria
Speaker 1: for a mass extinction. Yeah, they're basically chalking up to
Speaker 1: the pace of human expansion. And you know, if you
Speaker 1: consider that, uh, farming and logging and building roads and buildings,
Speaker 1: and most of the world's waterways have been diverted or
Speaker 1: damned at this point or manipulated somehow. Um. Only two
Speaker 1: percent of rivers in the United States run unimpeded. Everything
Speaker 1: else has been altered in some way. Chemical plants um
Speaker 1: affecting you know CEO two in the atmosphere, it's having
Speaker 1: an effect. And the c O two actually in the
Speaker 1: atmosphere is having another effect um called ocean acidification, which
Speaker 1: has been described as global warming's evil twin. As more
Speaker 1: and more C O two gets released in the atmosphere um,
Speaker 1: the oceans scramble to keep up by absorbing more and
Speaker 1: more and it stores some of that by turning some
Speaker 1: of it into acid, which lowers the pH of the ocean,
Speaker 1: which is making the ocean unfit for a lot of life.
Speaker 1: But as to kind of demonstrate how mass extinction is
Speaker 1: bad for one species great for another, jellyfish populations are booming,
Speaker 1: so probably because yeah, they like it more acidic, and
Speaker 1: they're like seriously starting to cause some real problems. And
Speaker 1: we're just seeing the beginning of this. So it's entirely
Speaker 1: possible that the next thousand years will see the rise
Speaker 1: of the jellyfish. Is the rest of the life on
Speaker 1: Earth starts to die off. Well, here's a staggering stat
Speaker 1: the drop in ocean pH levels that have occurred in
Speaker 1: the past fifty years. They think might exceed what has
Speaker 1: happened in the past previous fifty million years. So in
Speaker 1: the past fifty years they've changed the basically changed the
Speaker 1: chemical makeup of the ocean more than the past fifty
Speaker 1: million and speaking of fifty years, apparently in the next
Speaker 1: fifty years and estimated half half of all species on
Speaker 1: Earth could be extinct. Sucks, man, I want to see
Speaker 1: a sloth as big as an elephant. Hey, get into
Speaker 1: the extinction. Well here, Um, you just saw when we
Speaker 1: were in we were in Sahol. Well, yeah, it was nice,
Speaker 1: but I want to like I wanted to come in
Speaker 1: the way back machine and bring it to Atlanta. I
Speaker 1: don't think that's a good idea. Man. That thing looked
Speaker 1: like it would go berserk. Uh. And finally, unless you
Speaker 1: have anything else, I don't think so. I'm looking at everything. Um.
Speaker 1: We have a few highlights of extinct animals that have
Speaker 1: been rediscovered, which is not the same thing as being
Speaker 1: re engineered. What was this in I O nine Particle nine?
Speaker 1: And some of those are pretty good. The Bermuda, petrel
Speaker 1: and uh disappeared they fought in the sixteen hundreds, but
Speaker 1: rediscovered nineteen fifty one. There's about a hundred and eighty
Speaker 1: of those alive today. Uh. Let me see here what
Speaker 1: else is good? Well? We also we already talked about
Speaker 1: the Celo camp, the cuban, uh, soulan, don, Solenodon, excuse me.
Speaker 1: Discovered in eighteen sixty one. Um has only been caught
Speaker 1: thirty seven times in the history of the world. In
Speaker 1: in ninev they thought it was an extinct it's like
Speaker 1: a weird rat like species. But then they found one
Speaker 1: in the seventies, and then another one in two thousand three. Huh,
Speaker 1: so like welcome back Cuban Solenodon. So it's like caught
Speaker 1: during the seventies and then during the period of the
Speaker 1: seventies revival in the early two thousands. That's right. Nice, uh,
Speaker 1: Gilbert's po po turu and these have weird names. That's
Speaker 1: why they went extinct, because you couldn't say, you know
Speaker 1: that we we should save the the what yeah, forty
Speaker 1: one This is a rabbit size marsupial in Australia and
Speaker 1: it last appeared in eighteen seventy nine. And they thought,
Speaker 1: while this thing's gone up until came back out and
Speaker 1: poked his head around and got caught in a few traps.
Speaker 1: But currently less than a hundred of those in the world.
Speaker 1: And so those are just a few of the ten,
Speaker 1: and there's more than ten, obviously. But it's always a
Speaker 1: good story. Sure, it is heartwarming. We think this thing
Speaker 1: is dead. It's like, yeah, welcome back to the mass
Speaker 1: extinction still going on. If you want to know more
Speaker 1: about extinction, you should read each and every one of
Speaker 1: the articles we cited. Uh and you can also read
Speaker 1: this article on how stuff works dot com by typing
Speaker 1: extinction into the handy search bar. And since I said that,
Speaker 1: time for listener mail, I'm gonna call this police interrogation
Speaker 1: follow up from Matt pope Hey in Victoria, British Columbia.
Speaker 1: All right, thank you to Vancouver, by the way, for
Speaker 1: two great shows after our great shows in Toronto and Vancouver.
Speaker 1: Very supportive people. And boy that second crowd Vancouver was
Speaker 1: drunk and rowdy. Hey, guys, just listen to police interrogation.
Speaker 1: I thought i'd share a couple of quick personal stories
Speaker 1: to illustrate the pitfalls of relying on nonverbal cues to
Speaker 1: see if someone's guilty. I've never been in trouble with
Speaker 1: the law myself, but several years ago I witnessed a
Speaker 1: crime called nine one to report it. Cops snabbed the
Speaker 1: perpetrator and a few days later asked me to come
Speaker 1: down to provide a witness statement. When I arrived, an
Speaker 1: officer led me into a tiny room that was every
Speaker 1: bit as bleak as the ones you see on TV.
Speaker 1: The weird experience, even though I wasn't accused of a
Speaker 1: crime and the cop was polite and it's questioning the
Speaker 1: interrogation room setting, the power differential between the uniform cop
Speaker 1: with a gun and my unarmed self made me feel
Speaker 1: really nervous. I started sweating, my voice shook, and if
Speaker 1: you had been watching my body language did the one
Speaker 1: way mirror, you would have thought I was guilty and
Speaker 1: he was just a witness. The second story is very similar.
Speaker 1: Every year a local courthouse as a public event where
Speaker 1: they give tours and put on a mock trial and
Speaker 1: actually hang someone kidding. That was pretty good. It's supposed
Speaker 1: to be educational and fund My father is a lawyer.
Speaker 1: In one year asked me, I would like to play
Speaker 1: the defendant in the trial. I'm no actor, but I
Speaker 1: said sure. My character was accused of a minor drug offense,
Speaker 1: and I went through the whole ordeal, being on trial
Speaker 1: and testifying my own defense. I'll spare you the details,
Speaker 1: but afterwards my mom said, wow, you looked really guilty
Speaker 1: up there. I hope you never actually are on trial.
Speaker 1: For anything, because they'll lock you up and throw away
Speaker 1: the key. I learned from these situations. The very act
Speaker 1: of treating someone like a criminal and make him appear
Speaker 1: guilty reminds me of the Stanford prison study that we've
Speaker 1: talked about. And there's a psychologist nuts about that psychologies
Speaker 1: Nuts video and are you tube channel about the Stanford
Speaker 1: prison experiment. Yeah, that's a good one. You should check
Speaker 1: that out. I hope you guys um never have to
Speaker 1: find out the hard way you'll react to police interrogation
Speaker 1: if you do. I hope you find a good lawyer.
Speaker 1: That's from Matt Pope once again in Victoria, BC. Well
Speaker 1: thanks a lot, Matt, Um. That's cookie about your town
Speaker 1: doing mock trials and stuff like that. Yeah, like hanging
Speaker 1: a guy, Yeah, crazy said, it's fun. The only the
Speaker 1: only thing that's okay about is they make the guy
Speaker 1: look like Hitler, right, So it's like hanging Hitler every year,
Speaker 1: which everybody can get behind. Yeah, they call it the
Speaker 1: Hitler hanging. If you want to send us an email
Speaker 1: that Chuck feels the need to make up stuff about
Speaker 1: you can, Well, you can send us an email. You
Speaker 1: can also tweet to us at s y s K Podcast.
Speaker 1: You can join us on Facebook, dot com, slash stuff
Speaker 1: you Should Know, You can send us an email to
Speaker 1: Stuff Podcast at how stuff works dot com, and as always,
Speaker 1: check out our home on the web, Stuff you Should
Speaker 1: Know dot com. For more on this and thousands of
Speaker 1: other topics, visit how stuff Works dot com m