Selects: How Extinction Works

Summary

Podcast Summary: "Selects: How Extinction Works"

Stuff You Should Know — iHeartPodcasts
Hosts: Josh Clark & Charles W. "Chuck" Bryant
Air Date: November 1, 2025

Episode Overview

In this "Selects" episode, Josh and Chuck revisit their popular 2014 deep dive into extinction—how it occurs, why it’s a natural part of life on Earth, and how human activity may be ushering in a new mass extinction. The duo breaks down scientific theories, discusses key extinction events from the past, and examines the complications (and controversies) around de-extinction and current biodiversity loss. The episode is peppered with their signature blend of humor, pop culture references, and accessible science explanations.

---

Key Discussion Points & Insights

1. Setting the Stage: Extinction as a Process

• Extinction is introduced as a normal part of the evolutionary process, not just a modern tragedy.
• Historical context: For most of scientific history, extinction was denied, largely for religious reasons.
  • Quote: “For a very long time, I guess, scientists believed that God created all the animals on Earth and that his will was too perfect…to even allow for extinction.” (Charles, 06:49)

Notable Figures:

• Georges Cuvier (1812): Asserted extinction was real and caused by cataclysmic events ("Especis perdus" or "Lost Species"). (07:23)
• Charles Darwin: Allowed for extinction, but saw it as a gradual process. This slow view dominated until late 20th century. (08:20)

2. Scientific Shifts: Sudden Extinction Events

• Mass extinctions can happen abruptly, not just slowly over time.
• Alvarez Hypothesis & the Dinosaurs:
  • In 1980, Walter Alvarez linked a clay layer full of iridium (rare on Earth, common in asteroids) to the end of the dinosaurs, proposing an asteroid impact 65 million years ago.
  • Confirmation came in 1991: A massive crater was found under the Yucatan, matching the extinction timeline. (09:05–10:57)

3. The “Big Five” Mass Extinctions

(29:09–34:45)

• The five recognized “mass extinction” events:

  1. Ordovician (c. 490mya): Rapid sea-level drop, loss of half of all animal families.
  2. Late Devonian (c. 360mya): Uncertain cause, about a quarter of marine families perished.
  3. Permian-Triassic (c. 250mya): “The Great Dying,” up to 96% of life gone—likely due to volcanic activity and acid rain.
  4. End-Triassic (c. 200mya): Marine life hard-hit, specifics still debated.
  5. Cretaceous-Paleogene (K–Pg, c. 65mya): Asteroid impact, end of dinosaurs.

• There’s no strict numerical definition, but the “you know it when you see it” rule applies—massive, rapid, global losses.

  • Quote: “There’s no real definition for it...these five were so massive that there’s virtually no debate.” (Charles, 33:28)

4. Background vs. Mass Extinction

• Typical (“background”) extinction rate is 1–5 species/year.
• Current rates estimate 100–1000 times greater due to human activity. (13:20–13:28)
• References: Elizabeth Kolbert’s "The Sixth Extinction," and other scientific articles & HowStuffWorks resources.

5. Human Impact & the Sixth Extinction

(40:11–48:49)

• Growing consensus we’re in the midst of a Sixth Mass Extinction (Anthropocene), driven by:
  • Habitat loss, overexploitation, pollution, invasive species, and climate change.
• Notable statistic: "Only 2% of rivers in the US run unimpeded. Everything else has been altered in some way." (Jerry, 47:22)
• Human actions causing "constant stress" rather than a single cataclysm, making current biodiversity loss unique—and potentially more damaging.
  • Quote: “Now there’s no stress relief, it’s just a constant. There’s no recuperation because it’s not over.” (Jerry, 35:21)

Sixth Extinction Causes:

• Overkill Theory: As humans spread, megafauna (giant animals) vanished, suggesting hunting and habitat destruction drove extinctions—debated but supported by correlation. (43:17)
• Climate Change Theory: Some argue natural climate cycles are primary, but modern rates and patterns point strongly to human involvement. (45:09)

6. De-Extinction & Rediscovered Species

• De-Extinction: Science can sometimes "bring back" extinct animals (e.g., Bucardo goat in 2003), but raises ethical and ecological questions.
  • Quote: “Just because we can, does that mean we should?” (Charles, 25:19)
• Lazarus Species: Some species, like the coelacanth and Cuban solenodon, thought extinct, were found alive—highlighting fossil record limitations. (19:52–21:49, 49:47–51:29)
• Risks of focusing on bringing species back instead of conserving those present are discussed.

7. Why Biodiversity Matters

• Ecosystem collapse can result from the disappearance of even small or seemingly unimportant species, due to complex food web interdependencies.
  • Examples: Bees (pollination), passenger pigeons, American buffalo. (23:28)

---

Notable Quotes & Memorable Moments

• Humorous Opener: “A viable living organism—one that, when we leave the studio, will probably become extinct.” (Chuck, riffing on the mix of scents in the studio, 03:02)
• On Scientific Humility: “We have no idea how many living species there are on the planet today. Or have been. It’s all just a good guess.” (Jerry, 21:49)
• On Human-Caused Change: “The world starts to try and recoup...with us, it’s constant stress, and no recuperation.” (Jerry, 35:21)
• On Oceans: “The drop in ocean pH levels that have occurred in the past 50 years… might exceed what’s happened in the past 50 million.” (Jerry, 48:49)
• Perspective: “All evidence is showing we are doing a lot to speed up extinction events...so much so that the big five is now possibly the big six.” (Charles, 36:55)

---

Timeline of Major Topics

| Timestamp | Segment Description | |-----------|---------------------------------------------------------------------| | 04:44 | Extinction: processes and misconceptions (religious/scientific) | | 06:00 | The coelacanth and "Lazarus species" concepts | | 09:05 | Acceptance of asteroid mass extinctions—the Alvarez hypothesis | | 13:20 | Normal vs. current extinction rates | | 19:49 | Rediscovered species and the coelacanth’s story | | 21:07 | "Pseudo-extinction" and fossil record challenges | | 23:28 | Biodiversity, ecosystem collapse, and human impacts | | 24:22 | De-extinction: science and ethical debate | | 29:09 | The "Big Five" mass extinction events | | 34:45 | How to define a mass extinction? | | 40:11 | Are we in the "Sixth Extinction"? | | 45:09 | Human-driven vs. natural (climate) causes—debate and data | | 47:52 | Human impacts: habitat change, CO2, ocean acidification | | 49:47 | Rediscovery of supposedly extinct animals ("Lazarus" examples) |

---

Takeaways

• Extinction is natural—but current rates are unprecedented and strongly linked to human activities.
• There is no unchanging baseline for life on Earth; ecosystems and dominant species shift constantly in response to extinction events—some gradual, some catastrophic.
• While de-extinction fascinates, the hosts caution against seeing it as a solution to current biodiversity loss.
• The "Sixth Mass Extinction" is not just a scientific concept but a real, pressing concern given ongoing human impact.
• The tension between hope (rediscovered species) and loss (mass extinction) runs through the episode’s tone, balanced by the hosts’ wit.

---

Further Reading / References

• Elizabeth Kolbert — "The Sixth Extinction" (book, New Yorker article)
• HowStuffWorks articles (notably "Will We Soon Be Extinct?" and "Why Is Biodiversity Important?")
• iO9 "Lazarus species" feature

---

Closing Thoughts

Josh and Chuck offer a nuanced, accessible exploration of extinction, mixing rigorous science, humor, and pop culture references. From mass extinctions long before humanity to the dilemma of de-extinction, listeners come away with a deeper appreciation for the fragility—and resilience—of life on Earth.

---

Note:
Advertisements and unrelated intros/outros were omitted from this summary. For the full episode and references, check Stuff You Should Know via iHeartPodcasts or your preferred podcast platform.

Transcript

[Host/Announcer]

This is an iHeart podcast. This podcast is sponsored by PayPal. Okay, let's talk holiday shopping. When you want to make the most of your money, head to the PayPal app before you check out. They give you the flexibility to pay in four no fees, no interest. And this is big. Bigger than the 12 foot snowman on your lawn right now. You can get 5% cash back when you pay later with PayPal. So whether you're shopping for your foodie friend or outdoorsy uncle, PayPal helps you make the most of your money this holiday. Save the offer in the PayPal app.

[Sponsor Voice]

Expires to December 31st. See paypal.com promoterms subject to approval. Learn more at paypal.com payin4paypal inc.nmls910457 Living.

[Josh Clark]

With a rare autoimmune condition comes with challenges but also incredible strength. Especially for those living with conditions like myasthenia gravis or mg and chronic inflammatory demyelinating polyneuropathy, otherwise known as cidp, for finding empowerment in the community is critical. Untold Stories Life with a Severe Autoimmune Condition, a Ruby Studio production in partnership with Argenics, explores people discovering strength in the most unexpected places. Listen to Untold Stories on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts. Hello friends, it's Josh and I'm back with the select. And this week I've selected our 2014 episode on extinction. In this episode we go over all the big extinctions and what probably caused them, including the one we're most likely in right now, which was probably caused by humans.

[Charles W. 'Chuck' Bryant]

And if you pay attention, you can.

[Josh Clark]

Start to notice a little glimmers, a little beginnings of what would become my side podcast, the End of the World with Josh Clark.

[Charles W. 'Chuck' Bryant]

And although we don't talk about any.

[Josh Clark]

Movies, I'm betting there's some glimmers of Chuck's long running side podcast Movie Crush in here too. Hope you enjoy this episode.

[Charles W. 'Chuck' Bryant]

It's a good one.

[Narrator/Ad Voice]

Welcome to Stuff youf Should Know, a production of iHeartRadio.

[Charles W. 'Chuck' Bryant]

Hey and welcome to the podcast. I'm Josh Clark. There's Charles W. Chucker's Bryant. Jerry is over there. I almost said your last name. Jerry.

[Josh Clark]

How weird.

[Charles W. 'Chuck' Bryant]

And then today we have a fourth character in the in the studio with this Chuck. This scent. Yeah, scent coming together to make like a tangible human being. So you are wearing patchouli.

[Jerry]

Not wearing.

[Charles W. 'Chuck' Bryant]

Well, you have patchouli on you as a result of one of Emily's sugar scrubs. Right From Mama.

[Host/Announcer]

Yeah.

[Charles W. 'Chuck' Bryant]

And it's loveyourmama.com.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

Okay. And then Jerry is contributing to that with an enchilada. So all of them combined, I would say there's, like. There's an extra person in the seat right here.

[Jerry]

What kind of person is that?

[Charles W. 'Chuck' Bryant]

Just another person.

[Jerry]

Okay.

[Charles W. 'Chuck' Bryant]

A viable living organism. One that, when we leave the studio, will probably become extinct.

[Jerry]

That's a good one.

[Charles W. 'Chuck' Bryant]

Did you like that? Yeah. I've had that planned since probably two weeks ago. Nice. How you doing, man?

[Jerry]

I'm good. I've been thinking of Busta Rhymes all day.

[Charles W. 'Chuck' Bryant]

Why did he have a song about extinction?

[Jerry]

He had an album called Extinction Level Event.

[Charles W. 'Chuck' Bryant]

Oh, yeah?

[Jerry]

Yeah. And that was in one of the.

[Charles W. 'Chuck' Bryant]

Songs that sounds super 90s.

[Jerry]

Well, it's Busta Rhymes. It has to be 90s.

[Charles W. 'Chuck' Bryant]

But I mean, even those words, extinction Level, Event, people were worried about stuff because of, like, the turn of the millennium. You remember X Files is a huge hit.

[Jerry]

Sure.

[Charles W. 'Chuck' Bryant]

Deep Impact and Armageddon.

[Jerry]

Oh, yeah.

[Charles W. 'Chuck' Bryant]

Came out, like, on the same day, basically. And both were hits. Like, people were just nervous.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And as a result, Busta Rhymes was very popular.

[Jerry]

That's right. Although he's not anymore.

[Charles W. 'Chuck' Bryant]

He's still good, though.

[Jerry]

He hadn't been doing much.

[Charles W. 'Chuck' Bryant]

No. But his body of work is.

[Jerry]

Oh, sure. Yeah. Leaders in the New School.

[Charles W. 'Chuck' Bryant]

And his early work with Tribe Called Quest.

[Jerry]

Oh, yeah. He guessed it. On one of my favorite songs.

[Charles W. 'Chuck' Bryant]

Yeah. What's the scenario?

[Jerry]

Was that the one?

[Charles W. 'Chuck' Bryant]

I think so. I mean, he was definitely on that one.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

But they. That was the one also where I think. Yeah. He makes fun of people with saggy pants because it was so new.

[Jerry]

Right.

[Charles W. 'Chuck' Bryant]

Apparently Busta Rhymes wasn't down with it yet.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

Which is pretty ironic because he got hardcore into that.

[Jerry]

That was raw. Raw like a dungeon dragon.

[Charles W. 'Chuck' Bryant]

Right, right, right.

[Jerry]

It was pretty awesome.

[Charles W. 'Chuck' Bryant]

It's a good song.

[Host/Announcer]

Yeah.

[Charles W. 'Chuck' Bryant]

So extinction is clearly what we're talking about right today. And I guess we should probably give a shout out to some of the extra reading material.

[Jerry]

Yeah, man.

[Charles W. 'Chuck' Bryant]

We picked up on. There's a woman named Elizabeth Colbert. Or Colbert, depending on. If you watch the Colbert Report.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

She is basically a leading expert as far as journalists go on extinction. She wrote a book called the Sixth Extinction.

[Jerry]

It's a good article.

[Charles W. 'Chuck' Bryant]

Yeah. And she wrote an article in the New Yorker. She's a New Yorker journalist that was basically the predecessor to the book. You know how they do. They're like, oh, I need an extra 20 grand. So I'll just write a synopsis of the book I'm writing.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And it's a good article, and we work from that. There's another one from the New York Review of Books called They're Taking over about the explosion of jellyfish on How Stuff Works. There's one that I wrote years back called Will We Soon Be Extinct?

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And there's another How Stuff Works, one that we've done an episode on called why Is Biodiversity Important?

[Jerry]

Yeah. And I found one in io9 for animals that we thought were extinct but miraculously pop back up.

[Charles W. 'Chuck' Bryant]

Nice.

[Jerry]

Which is always a good story.

[Charles W. 'Chuck' Bryant]

Oh, yeah. It's a heartwarming story of triumph over adversity and coming back when everybody thought you were down.

[Jerry]

Yeah. Some of them, like, basically rocky, hundreds of millions of years later, even.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

It's crazy.

[Charles W. 'Chuck' Bryant]

Like, the silicant.

[Jerry]

I think that's one of them. Is that the big fish? Yeah. They just caught that thing one day.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

And said, hey, wait a minute. Yeah, this thing's extinct.

[Charles W. 'Chuck' Bryant]

It's supposed to be. And we'll talk about how and why things fall off. But things do fall off. And it seems that there is a. That the whole thing is a very natural process. Extinctionists. But for a very long time, I guess, scientists believed that God created all of the animals on Earth and that his will was too perfect, his creation was too divine to even allow for extinction. So because they were aware of the fossil record, they rationalized these huge bones of animals they didn't see anywhere, as we just haven't found them yet.

[Jerry]

Well, yeah. And this was all the way up into the 19th century. And some really smart people like Thomas Jefferson thought, for instance, when he sent Lewis and Clark out west, that they might come across the great mastodon.

[Josh Clark]

Right.

[Jerry]

He's like, it's bound to be out there somewhere, guys, so be careful. But there were some other smarter people, like Georges Cuvier in 1812. He was pretty ahead of his time. In fact, in 1812, he was way ahead of his time because he published an essay called Revolutions on the Surface of the Globe. And he kind of asserted that no things can go extinct. And he called them Especis perdus, Lost Species.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

And basically hypothesized that there have been cataclysmic events that have caused extinctions.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

In so many words, this is basically.

[Charles W. 'Chuck' Bryant]

Flew in the face of this. That, like, not only was there extinction, but there were. There were huge events that caused it. And so the religious thinkers of the day said, okay, wait, wait, wait. We can work with this. Because, buddy, what you're talking about is like Noah's flood. So you, my friend, just proved the Bible correct using science.

[Jerry]

Yeah. Darwin wasn't on board though, although he did believe in extinction. He thought the only way it could happen is the gradual extinction.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

That is also true and we'll talk about that as well.

[Charles W. 'Chuck' Bryant]

And of course, Darwin is this huge hero of biology. So everybody's like, well, Darwin's right about just about everything. So literally until the 1990s, Darwin's view that extinction happens extremely slowly.

[Host/Announcer]

Yeah.

[Charles W. 'Chuck' Bryant]

Slower than speciation events. So ultimately you should always have more species, new species coming up, than you have going extinct.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

Until the 1990s, that's the way that it was. That's the way it seemed. Yeah. So Chuck, like I said, all of this stayed around until 1991.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And it was a result of like, think about it, think about how you think of mass extinctions now. You think of an asteroid hitting Earth, destroying everything. And it wasn't until 1991 that that view became widely accepted. And it was because of this dude named Alvarez. He was a geologist, I believe, Walter Alvarez. And in the 70s, he started studying this clay layer that was basically in the fossil record Right. At the time the dinosaurs suddenly died out.

[Jerry]

Right.

[Charles W. 'Chuck' Bryant]

And no one could quite explain what was going on here. They just knew that this must have happened gradually. So it must be a problem with the actual fossil record. Not our way of thinking.

[Host/Announcer]

Yeah.

[Jerry]

And there are plenty of problems with the fossil record which we'll get into as well.

[Charles W. 'Chuck' Bryant]

Right. But Walter Alvarez said, let me look at this in a little more detail. And he looked at the iridium and found that the iridium levels were off the charts, which shouldn't be because it's very, very rare. And we associate iridium on Earth as being brought here by say like an asteroid or whatever.

[Jerry]

Yeah, it's super abundant in asteroids.

[Charles W. 'Chuck' Bryant]

So all of a sudden this guy goes, oh, wait a minute, maybe we can explain this dying out of dinosaurs. Where the dinosaurs went 65 million years ago by an asteroid. And that was in 1980 that they proposed this hypothesis and they ran into a lot of resistance.

[Jerry]

Sure.

[Charles W. 'Chuck' Bryant]

And then finally in 1991, a year after a crater was discovered under the Yucatan Peninsula in Mexico, they dated it and said, yeah, it just so happens that this crater was formed just at the moment the dinosaurs died out. So the Alvarez hypothesis is probably right. And extinction can happen on a mass sudden scale and just as it can also happen on a very long term scale too.

[Jerry]

Yeah, that crater was 112 miles wide. So it fit the profile and basically ended the Cretaceous period in the Mesozoic era. And for a while they called it the Cretaceous Tertiary event, but now they call it the Cretaceous Paleogene event.

[Charles W. 'Chuck' Bryant]

And did you notice that they.

[Jerry]

Kpg.

[Charles W. 'Chuck' Bryant]

Right, they noticed the. That. Did you notice the Cretaceous, which is spelled with a C, is denoted with a K?

[Jerry]

Yeah, it did.

[Charles W. 'Chuck' Bryant]

Did you see why it's just German. It's just a German translation for it.

[Jerry]

I figured it was something like that.

[Charles W. 'Chuck' Bryant]

Yeah, it was just bugging me.

[Jerry]

So now we now believe an asteroid brought us into the Cenozoic era that we. That we enjoy today.

[Charles W. 'Chuck' Bryant]

Love the Cenozoic.

[Jerry]

It's pretty awesome.

[Charles W. 'Chuck' Bryant]

It's a good era.

[Jerry]

I mean, it's our era.

[Josh Clark]

Yeah.

[Charles W. 'Chuck' Bryant]

So you gotta love it.

[Jerry]

You gotta love it.

[Charles W. 'Chuck' Bryant]

So, Chuck, like I said, extinction can happen, and it does happen, and it's a natural process. If you talk to people about extinction today, though, they say, yeah, we're kind of in a huge extinction event.

[Jerry]

Yeah. And it makes sense. I mean, when you look at our past, they estimate Maybe up to 5 billion species have lived on Earth and more than 99% of those are gone. And I love how the New Yorker put it. I think that there's an old joke that all of life on Earth today could be accounted for with a simple rounding error.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

Like everything we know. So, yeah, we've lost 99% of things that have ever lived on this planet due to extinction.

[Charles W. 'Chuck' Bryant]

Right. Which again is like. It has such a terrible connotation these days, Extinction. Extinction. But it happens naturally. Apparently what they've found from looking at the fossil record, from studying life on Earth is that a species tends to have about a 10 million year lifespan. A speciation event occurs where it branches off from one species and produces an entirely new species. And that species, on average will stick around for about 10 million years. And then something happens and it dies out and other species take its place. This is the natural course of life from what we can tell. The thing is, it normally happens on a very slow timescale, like when it's what's called background extinction. Right.

[Jerry]

Yeah. The background rate is supposed to be between one and five species per year, but they think that now it could be like a hundred times that.

[Charles W. 'Chuck' Bryant]

I've seen up to a thousand times the normal rate. And I saw another study from 2014, so it's fresh. And it said that these researchers calculated the normal rates and they found that there's between 0.023 and 0.135 extinct species per million species per year.

[Jerry]

That doesn't really mean much.

[Charles W. 'Chuck' Bryant]

It means so much that it boggles the mind.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

You know, like, that's a really strange way of putting it, but basically they. They're saying, like, for every million species on Earth at any given point in time, during a year as low as.023 species will die out. So in a year, you shouldn't necessarily have that many species. In current times, though, like you said, between 100 and 1,000 times that rate is what we're seeing right now, which is, you could say, alarming.

[Jerry]

It is alarming. The reason they don't have hard numbers on this stuff is because, like we said, it's a tough thing to study because the fossil record is. Well, there's a lot of problems. One is it's incomplete. We don't really know how many species there have been on Earth since the beginning of Earth. It's just impossible to tell. Fossils form under really specific conditions, so you may think something is gone because it has disappeared from the fossil record. But all that means is there wasn't a fossil. It doesn't necessarily mean it's gone.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

So that's why things will pop back up that they'll think, hey, we haven't seen a fossil of this guy in 2000 years. But here it is all of a sudden.

[Charles W. 'Chuck' Bryant]

And even if it has gone extinct, just where it stopped showing up in the fossil record doesn't mean, like you said, that's when it went extinct.

[Host/Announcer]

Right.

[Charles W. 'Chuck' Bryant]

Then it could have been millions of years later.

[Jerry]

Well, because then you're supposing that the last thing of that species happened to make a fossil, which is just silly.

[Charles W. 'Chuck' Bryant]

Yeah. And also it makes you wonder how many species have lived and died on Earth that just never showed up in the fossil record.

[Jerry]

Yeah. Just weren't fossils at all.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

Yeah. Well, if it never crawled into amber or, you know, was buried by ash or something, that's luck.

[Charles W. 'Chuck' Bryant]

Or got trapped in brontosaurus poop.

[Jerry]

I don't know if that's good luck or bad luck.

[Charles W. 'Chuck' Bryant]

It's just. It is what it is.

[Jerry]

It's nature. So because of all these gaps in the fossil record, these researchers that love this topic tend to do a lot of math.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

And a lot of speculating with algorithms and mathematical formulas to figure this stuff out.

[Charles W. 'Chuck' Bryant]

Sure.

[Jerry]

And that's the only way to do it, really, is to speculate with numbers. It also helps them define things like the minimum viable population, which, if you go below that, then it's bad news for the species. It's the minimum amount you can have to still be considered to have a bright future.

[Charles W. 'Chuck' Bryant]

Right. As a thing or to just survive as a species. Right?

[Jerry]

Yeah, that's what I mean.

[Josh Clark]

Yeah.

[Jerry]

Dim future if you're not surviving.

[Charles W. 'Chuck' Bryant]

Yeah, math is pretty grim.

[Jerry]

It can be in this case for sure.

[Charles W. 'Chuck' Bryant]

So we'll talk about exactly what makes an extinction and then what makes up mass extinctions.

[Josh Clark]

But first, let's do a little breakage, huh?

[Host/Announcer]

This podcast is sponsored by PayPal. Okay, let's talk holiday shopping. When you want to make the most of your money, head to the PayPal app before you check out. They give you the flexibility to pay in four no fees, no interest. And this is big. Bigger than the 12 foot snowman on your lawn right now. You can get 5% cash back when you pay later with PayPal. So whether you're shopping for your foodie friend or outdoorsy uncle, PayPal helps you make the most of your money this holiday. Save the offer in the PayPal app expires December 31st.

[Sponsor Voice]

See paypal.com promoter subject to approval. Learn more at paypal.com payin4paypal inc.nmls910457.

[Josh Clark]

Living with a rare autoimmune condition comes with challenges but also incredible strength. Especially for those living with conditions like myasthenia gravis or mg, and chronic inflammatory demyelinating polyneuropathy, otherwise known as cidpo. Finding empowerment in the community is critical.

[Host/Announcer]

That's right, and in the latest season of Untold Life with a Severe Autoimmune Condition, a Ruby Studio production in partnership with Argenics host Martine Hackett explores what it means to reclaim your identity, discover resilience, and cultivate self advocacy.

[Josh Clark]

From the frustration of misdiagnosis to the small victories that fuel hope, every story told is meant to unite, uplift and empower. And that inspires us all to take one step closer to being a better advocate and seeing life from a different point of view.

[Host/Announcer]

So if you or a loved one are living with an autoimmune condition, find inspiration along your path. Listen to Untold Life with a Severe Autoimmune condition on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

[Guest/Additional Voice]

Let's talk about something you probably haven't thought about. Your couch.

[Narrator/Ad Voice]

Yeah, that thing you nap on, eat on, cry on.

[Guest/Additional Voice]

Turns out that most of the Silvas are basically bacteria playgrounds.

[Narrator/Ad Voice]

It's true. We looked it up. It's not good.

[Guest/Additional Voice]

But Anabie changes that. It's washable like fully washable. Take the covers off, throw them in the machine, Boom, clean.

[Narrator/Ad Voice]

Also, it's actually affordable, which is surprisingly rare.

[Guest/Additional Voice]

So, yeah, if you're gonna sit on something every day, maybe don't make it a biohazard. And here's the kicker. It's not just practical, it's affordable. Starting at just $699, you can make your sofa as clean as it is comfy.

[Narrator/Ad Voice]

Plus, with their early access Black Friday sale, you can even get up to 60% off your Anna Bay sofa right now.

[Guest/Additional Voice]

Because, let's be real, you deserve better than a germ factory. For a place to rest your head, check out washablesofas.com now and give your couch the upgrade. It's begging for.

[Charles W. 'Chuck' Bryant]

Stuff you should know. Okay, so, Chuck, you've been talking about animals, animal species going extinct and then showing up again. Like the coelacanth.

[Jerry]

Yeah. Or at least disappearing right from the record.

[Charles W. 'Chuck' Bryant]

But we as humans assume they were extinct. Like, again, the coelacanth is this fish they caught off the coast of South Africa. When did we talk about it? Was it in this day in history?

[Jerry]

I don't remember. We definitely have hit on that, though.

[Charles W. 'Chuck' Bryant]

I think it was because it's huge, right? Yeah, it's a big, ugly fish and it looks like an old dinosaur, but they thought it had died out like 50, 60 million years ago.

[Jerry]

Actually, way longer. They thought it disappeared 400 million years ago.

[Charles W. 'Chuck' Bryant]

Even more impressive.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

So then they caught one off the coast of South Africa in the 30s. Then they caught another one a couple decades later in Madagascar or Mauritius or something. And that made the coelacanth a Lazarus species, even though it hadn't really gone anywhere, we just thought it did. So we humans having the most important perspective on the entire planet, possibly in the entire universe, it was a Lazarus species to us.

[Jerry]

Yeah, Lazarus from the Bible. Raised from the dead.

[Charles W. 'Chuck' Bryant]

Yeah, like the coelacanth again with the biblical connotations with extinction.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

There's a lot at stake here that's true.

[Jerry]

Another way something might disappear and you might think it's gone is if it actually evolves into a new species. That's called pseudo extinction. And that's a great success story as well.

[Charles W. 'Chuck' Bryant]

It is, but it also. I don't understand why that's not just a speciation event. I mean, why is that pseudo extinction? Why is that any different from regular extinction?

[Jerry]

Yeah, maybe just because it didn't die out, actually just changed and evolved. Those are two different things.

[Charles W. 'Chuck' Bryant]

Yeah. It seems like a gray area to Me?

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

But for the most part, when an animal just disappears and we should say, like, even today we're still finding things that we thought were extinct, so called Lazarus species. Which goes to make the point, we have no idea how many living species there are on the planet today.

[Jerry]

Yeah. Or have been. It's all just a good guess.

[Charles W. 'Chuck' Bryant]

It is using math.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

Grim, grim math. But for the most part, we understand that when a species goes away, suddenly it went extinct. And as we've been saying again and again, extinction is kind of this natural process, or it is a very natural process, and it typically results from a change in the habitat of species and its inability to adapt. So it dies out.

[Jerry]

Yeah. Competition with other species, hunting by humans. Or perhaps the environment has been tainted by humans.

[Charles W. 'Chuck' Bryant]

Humans. Or a new bacteria or a new virus. The thing is, though, is so these big factors, habitat loss, competition with new species, hunting and contaminants in the environment, those are the big four reasons that something goes extinct, right?

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

Humans can and are responsible for all four of those.

[Jerry]

Yeah. And this is the extinction that happens over time. Obviously not a big asteroid hitting the planet.

[Josh Clark]

No.

[Charles W. 'Chuck' Bryant]

But it can happen pretty quickly in this. This is a Tracy Wilson joint. And in the introduction she mentions the Steller's sea cow, which was an Arctic resident. It was a big old manatee, basically.

[Host/Announcer]

Yeah.

[Charles W. 'Chuck' Bryant]

And they were first described by arctic explorers in 1741. By 1768, they were extinct. So it can happen on a pretty rapid scale.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

Especially when you introduce humans.

[Jerry]

Yeah. And it, you know, it has a domino effect too, because we talked about, and everyone knows about the dangers of losing bees. It's not just like, oh, well, there are no more bees. That's going to affect pollination. And plants. And those plants are being fed on by other animals. And it tends to have a snowball effect. Like, for example, at the end of the last ice age, mammals, small mammals, started to go extinct. And because of that, large animals started to go extinct because they like to eat the small animals.

[Charles W. 'Chuck' Bryant]

Exactly. Which is the answer to the question, why is biodiversity important? Well, because ecosystems thrive and survive on a wide number of species that exist pretty much naturally in balance.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

You know, a pretty good example of that stuff falling out of balance is the passenger pigeon. You familiar?

[Jerry]

Yeah. They're trying to de. Extinct that thing.

[Josh Clark]

Yeah.

[Charles W. 'Chuck' Bryant]

You want to talk about de extinction?

[Jerry]

Yeah. Well, de extinction is exactly what it sounds like. It is sort of Jurassic Park. Y. It is. In 2003, some scientists revived the Burcardo Bucardo. And that's A Spanish mountain goat. And they did it just sort of like Jurassic park from DNA that was frozen in time. Unfortunately, although it did work initially, the DNA only survived a matter of minutes. But they did. It did count as a de extinction.

[Charles W. 'Chuck' Bryant]

I think there was a live birth that survived a few minutes, wasn't it?

[Jerry]

Yeah. The animal itself only survived a few minutes though.

[Charles W. 'Chuck' Bryant]

Right. It was like, I should not be.

[Jerry]

That's true. And I mean, they basically said it's happening now and we have the capabilities and we may not be able to bring the woolly mammoth back, but we might be able to bring back something kind of close.

[Charles W. 'Chuck' Bryant]

Right. So. And that raises in this article that you sent just this moral question, like, should we be doing this just because we can, does that mean we should? And so like, if you bring back an animal that has been extinct for so long that its habitat is now gone.

[Jerry]

Yeah. Where are they going to live?

[Charles W. 'Chuck' Bryant]

Exactly. Where are you going to put it?

[Jerry]

A zoo?

[Charles W. 'Chuck' Bryant]

That doesn't seem like a good reason to bring an animal back so we could put it in a zoo.

[Jerry]

Yeah. And just like, maybe this is my opinion here, which we don't do a lot of, but seems like concentrating on the problems we face now with the extinction rates is something that we should concentrate on not bringing back the woolly mammoth.

[Charles W. 'Chuck' Bryant]

Right. And that also kind of dovetails with the point that if we have this ability and routinely exercise it, we may be less inclined to protect the stuff we have now if we're like, well, it's important enough, we'll just genetically re engineer it and bring it back later.

[Jerry]

Yeah. I think in the CNN article they liken it to just thinking we have an undo button on the world.

[Charles W. 'Chuck' Bryant]

Control.

[Jerry]

Yeah. No good.

[Charles W. 'Chuck' Bryant]

No. And it's funny because the author doesn't realize that Control Z works outside of Microsoft Word too. He specifically mentioned Control Z in Microsoft Word.

[Host/Announcer]

Oh, Word.

[Charles W. 'Chuck' Bryant]

Specifically Microsoft Word. He said it.

[Jerry]

Yeah. That's a little weird.

[Charles W. 'Chuck' Bryant]

He could be a shill. And he was just working it in maybe, you know.

[Jerry]

Well, on Macs though, it's not Control. Maybe he just meant Microsoft and awkwardly put in Word.

[Charles W. 'Chuck' Bryant]

Maybe.

[Jerry]

Or maybe that's the only program he knows.

[Charles W. 'Chuck' Bryant]

Maybe, you know, how do I work this? So you were saying that they're trying to bring back the passenger pigeon, right?

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

So the passenger pigeon is this really neat example of what happens when you have a lack of biodiversity.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

There were when European settlers came to the New World, apparently like one out of every four birds in North America was a passenger pigeon. A quarter of the entire bird population was passenger pigeons.

[Jerry]

That's a lot of pigeons.

[Charles W. 'Chuck' Bryant]

That is a ton of pigeons. There are so many that you could just like shoot into, like a flock and you would kill a couple hundred. Literally. It was. There were that many. The thing is, is if you. If you read 1493 or 1491, I can't remember which one it is. But both are excellent books by Charles C. Mann. He talks about the passenger pige and how they've recently realized that there were so many passenger pigeons. Because a century before, one of their great predators, the Native American, had been wiped out by disease that had been introduced to the continent about a century before that. So by the time the Europeans got here and really started to settle and encounter the passenger pigeon, they're like, God, look at all these pigeons. And didn't realize that the pigeon population had exploded because their natural predator had died off.

[Jerry]

Right.

[Charles W. 'Chuck' Bryant]

And so we in turn hunted them into extinction. So because of one near extinction, another species was allowed to thrive and explode. And then that when they were faced with their. Their predator again, humans, they were eventually wiped out and went extinct.

[Jerry]

Yeah. The American buffalo, We almost hunted them out of existence.

[Charles W. 'Chuck' Bryant]

Yeah. Were it not for Ted Turner.

[Host/Announcer]

Yeah.

[Jerry]

We tried our best to. They were just shooting those things for fun at one point.

[Charles W. 'Chuck' Bryant]

Man, that's disgusting.

[Jerry]

It is disgusting. You hear about the, like, trains.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

Just going through the west and just shooting out the windows at the buffalo for no reason.

[Charles W. 'Chuck' Bryant]

Yeah. And doing nothing. Just leaving them there to rot.

[Jerry]

Unbelievable.

[Charles W. 'Chuck' Bryant]

Remember we did an episode on the buffalo? That was a good one.

[Jerry]

So sad.

[Charles W. 'Chuck' Bryant]

No, it was good.

[Jerry]

Well, it was sad too, though.

[Charles W. 'Chuck' Bryant]

Oh, gotcha.

[Jerry]

So if you want to talk about extinction level events, that's a whole different deal.

[Charles W. 'Chuck' Bryant]

If you want to talk Busta rhymes.

[Jerry]

That'S not a slow, gradual extinction. That is some big thing that happens that wipes out a lot of living things all at once. And they estimate there's been more than 20 of these in the history of the world. But five of them, they call them the big five for a reason, for good reason. And we'll just go through those kind of quickly. Now, the Ordovician extinction, it's about 490 million years ago, and that wiped out about half of all animal families.

[Charles W. 'Chuck' Bryant]

And the reason it wiped out about half was because at the time, most of the stuff on Earth still lived in the sea. Glaciers formed at this time, lowering sea levels, which meant that animals that lived in a certain depth of the sea, usually toward the surface, lost their habitat.

[Jerry]

Boiled.

[Charles W. 'Chuck' Bryant]

Yeah, maybe. Yeah. Or were brought down to the level where their predators like to hang out and were eaten en masse. But that. That accounted for that extinction, which is kind of rare because as you'll see when we're talking about the big five or mass extinctions in general, it's very difficult to pinpoint exactly what happened. So that's one of the rare ones that we're like, pretty sure this is why all of these. All this life went extinct all of a sudden.

[Jerry]

Yeah. And one reason it's difficult is because it was almost 500 million years ago. That's another reason it's kind of tough here in 2014. Number two, I feel like Letterman. Number two on the top five extinction, the late Devonian extinction. They're still debating about that. And about a quarter of the marine families. And by the way, we should mention when they research these things, they home in on family and genera and the big classification group.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

They don't say, like, oh, look at these kingdoms that have disappeared, or these phylum. They go down to the smaller levels.

[Charles W. 'Chuck' Bryant]

Right. And family and genus are just above species as far as the taxonomy is concerned.

[Jerry]

Exactly. So what'd I say about half of the marine genera. And that was 360 million years ago.

[Charles W. 'Chuck' Bryant]

Right. No idea what caused that one?

[Jerry]

No idea.

[Charles W. 'Chuck' Bryant]

At least you and I have no idea.

[Jerry]

Yeah. I don't think they care about that one too much.

[Charles W. 'Chuck' Bryant]

The Permian Triassic extinction. This is a pretty big one.

[Jerry]

This is the biggest one ever.

[Charles W. 'Chuck' Bryant]

This is the one they call the Great Dying, right?

[Jerry]

I think so.

[Charles W. 'Chuck' Bryant]

I've seen estimates of as much as 95 to 96% of all life.

[Jerry]

That's crazy.

[Charles W. 'Chuck' Bryant]

Died off during this extinction event. In this article, it says 85% of marine genera and 70% of land species went extinct. And that was 250 million years ago. There's a lot of people who have different ideas about what did it, but they think it's possible it's volcanic activity creating acid rain. That's a big one. That possibly happened more than once.

[Jerry]

Was that the one where. I don't know. I think that was. The KPG event was the one where they think they're not exactly how it happened, but they may have been just broiled.

[Charles W. 'Chuck' Bryant]

Isn't that awesome?

[Jerry]

Broiled on the face of the Earth.

[Charles W. 'Chuck' Bryant]

Yeah. Which would have happened pretty quickly too, actually.

[Jerry]

And I think that one is if. Because they think it may have burst through the atmosphere, Right?

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

So just rained hot debris everywhere.

[Charles W. 'Chuck' Bryant]

That's the one that got rid of the dinosaurs.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

65 million years ago. What is it called? The K. Hyphen.

[Josh Clark]

PG.

[Jerry]

Yeah. The Cretaceous Paleogene event.

[Charles W. 'Chuck' Bryant]

Now, and that's the one where they, they are pretty sure that an asteroid hit Central America.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And sent all of this rock.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

Like basically vaporized rock away from Earth with so much force that this stuff made it out of the atmosphere.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And then started to come back down and as it did, it generated thermal heat enough to bring the broil down on Earth.

[Jerry]

Yeah. And that's the one of two sub explanations. The other is that the old familiar ash basically kept photosynthesis from it. Like it blacked out the sun.

[Charles W. 'Chuck' Bryant]

Yeah. Like a nuclear winter.

[Jerry]

Yeah.

[Josh Clark]

Yeah.

[Charles W. 'Chuck' Bryant]

Pretty nutso.

[Jerry]

But we skipped number four for no good reason. The end Triassic extinction killed about 20% of marine families, about half of marine genera. And that was 200 million years ago.

[Charles W. 'Chuck' Bryant]

Yeah. And again, like with a mass extinction, there's. There's no real definition for it. I found, I was looking to see, okay, who's, who's the body that says, like, okay, a mass extinction event took place? Again, the fossil record is incomplete enough and we're making guesses and mathematical guesses, but still guesses to the extent that we don't have a real definition for what constitutes a mass extinction. But those five were so massive that there's virtually no debate whatsoever that those account for mass extinction events.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

It'S kind of like a you know it when you see it kind of thing. But there's no agreement on pornography. Pretty much.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

There's no agreement on how fast it has to happen or how widespread it has to happen. But typically it's like a large percentage of all of the animals alive.

[Host/Announcer]

Yeah.

[Charles W. 'Chuck' Bryant]

Something like 20%, say of all living animal species. Not just animals. Animal species just die off.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And it's worldwide. That seems to be another factor in defining a mass extinction. Yeah.

[Jerry]

Like how widespread.

[Charles W. 'Chuck' Bryant]

Yeah, sure. So these events were pretty big.

[Jerry]

Yeah. And one of the, I think one of the researchers in the article you sent made a pretty good point that the current mass extinction that we're in now, which we're going to talk about in depth here in a minute, he said these are way more dangerous because in the event of an asteroid, let's say, while it might really suck, it's one bad event. And right afterward, the world starts to try and recoup. It may take a million years, but it tries its best to start reforming life and get going again, wherein now there's no stress relief, it's just a constant. There's no recuperation because it's not over.

[Charles W. 'Chuck' Bryant]

Right. Or the recuperation will come, but we won't be around to see it because the breaking point will be usually wiping ourselves out by wiping out the biodiversity. And there is a kind of this whole moralistic thing to the idea of extinction. There's this whole human guilt. But if you just kind of take a step back and look at mass extinction, intellectually, it doesn't wipe out life. It just changes everything. Right. So for one species, it might be a boom time. For everybody else, it's a dying off time. But it's all in your perspective.

[Jerry]

Well, yeah. This beautiful Earth that we know and love now isn't anything like it was 100 million years ago.

[Charles W. 'Chuck' Bryant]

Exactly. And there's not necessarily a set level or a baseline that Earth is supposed to be at.

[Jerry]

Right. Because nature doesn't care.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

And nature's not like, oh, we got all these people here now, and things seem pretty modern and they got smartphones, so maybe we should just protect this version.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

They're like, what was the cycle? Every, what, 10 million years for a species. For a species.

[Josh Clark]

Okay.

[Charles W. 'Chuck' Bryant]

That's the lifespan of a species on average.

[Jerry]

So basically every, what, 10,000.

[Charles W. 'Chuck' Bryant]

10 million.

[Jerry]

10 million years. The Earth just doesn't care.

[Charles W. 'Chuck' Bryant]

No, the point is, for a species, its lifespan is 10 million years, and the Earth is not caring every day of that. Yeah, it doesn't care.

[Jerry]

It's just stumbling toward the next event, basically.

[Charles W. 'Chuck' Bryant]

Exactly.

[Jerry]

That will one day probably happen.

[Charles W. 'Chuck' Bryant]

The thing is, all of this is not to say that humans are off the hook. All evidence that's coming in now is showing that we are doing a lot to speed up extinction events and create a mass extinction. So much so that the big five is possibly the big six. And we may be in the very beginning stages of the sixth one. And we'll talk about that right after this.

[Host/Announcer]

This podcast is sponsored by PayPal. Okay, let's talk holiday shopping. When you want to make the most of your money, head to the PayPal app before you check out. They give you the flexibility to pay in four no fees, no interest. And this is big. Bigger than the 12 foot snowman on your lawn right now. You can get 5% cash back when you pay later with PayPal. So whether you're shopping for your foodie friend or outdoorsy uncle, PayPal helps you make the most of your money this holiday. Save the offer in the PayPal app expires December 31st.

[Sponsor Voice]

See paypal.com promoter subject to approval. Learn more at paypal.com payin4paypal inc.nmls910457.

[Josh Clark]

Living with a rare autoimmune condition comes with challenges but also incredible strength. Especially for those living with conditions like myasthenia gravis or mg, and chronic inflammatory demyelinating polyneuropathy, otherwise known as cidp, finding empowerment in the community is critical.

[Host/Announcer]

That's right, and in the latest season of Untold Life with a Severe Autoimmune Condition, a Ruby Studio production in partnership with Argenics host Martine Hackett, explores what it means to reclaim your identity, discover resilience, and cultivate self advocacy.

[Josh Clark]

From the frustration of misdiagnosis to the small victories that fuel hope, every story told is meant to unite, uplift and empower. And that inspires us all to take one step closer to being a better advocate and seeing life from a different point of view.

[Host/Announcer]

So if you or a loved one are living with an autoimmune condition, find inspiration along your path. Listen to Untold Life with a Severe Autoimmune condition on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

[Guest/Additional Voice]

Let's talk about something you probably haven't thought about. Your couch.

[Narrator/Ad Voice]

Yeah, that thing you nap on, eat on, cry on.

[Guest/Additional Voice]

Turns out that most sofas are basically bacteria playgrounds.

[Narrator/Ad Voice]

It's true, we looked it up. It's not good.

[Guest/Additional Voice]

But Anabe changes that it's washable. Like fully washable. Take the covers off, throw them in the machine.

[Host/Announcer]

Boom.

[Guest/Additional Voice]

Clean.

[Narrator/Ad Voice]

Also, it's actually affordable, which is surprisingly rare.

[Guest/Additional Voice]

So yeah, if you're going to sit on something every day, maybe don't make it a biohazard. And here's the kicker. It's not just practical, it's a fun, affordable Starting at just $699, you can make your sofa as clean as it is comfy.

[Narrator/Ad Voice]

Plus, with their early access Black Friday sale, you can even get up to 60% off your annabe sofa right now.

[Guest/Additional Voice]

Because, let's be real, you deserve better than a germ factory For a place to rest your head, check out washablesofas.com now and give your couch the upgrade. It's begging for.

[Charles W. 'Chuck' Bryant]

Stuff you should know. So Chuckers, we've been talking about mass extinction events. There's a big five and a lot of people are saying no, there's six. And the sixth one is human caused. So much so that geologists are proposing that we call our current epoch the Anthropocene. Yeah, because humans are having such an impact on Earth that they imagine 10,000 years from now, geologists will be able to look and point to this layer and say, here's where humans started.

[Jerry]

Yeah, let's get in the wayback machine. Oh, yeah, let's crank this baby up.

[Charles W. 'Chuck' Bryant]

Does it have enough kerosene?

[Jerry]

Oh, it's got enough kerosene, buddy. Because we're going back about 50,000 years.

[Charles W. 'Chuck' Bryant]

You got enough?

[Josh Clark]

Okay, I'm bringing a spare can.

[Jerry]

And we're gonna go to Australia even, because it's just nice down there. And what I see around me are these huge wombat like things that are as big as hippos.

[Josh Clark]

Huge.

[Jerry]

And I see a tortoise over there that's the size of a VW beetle.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

And this weird short faced kangaroo. And he's 10ft tall.

[Charles W. 'Chuck' Bryant]

10 foot tall kangaroo. Look at the size of that thing.

[Jerry]

And everything is crazy. But let's just unpack here and let's start propagating, you and me.

[Josh Clark]

Okay.

[Charles W. 'Chuck' Bryant]

I'm gonna make this spear just for safety.

[Jerry]

All right.

[Charles W. 'Chuck' Bryant]

It sounds like I need it to fend you off too.

[Jerry]

And you know what, it's weird. Things are starting to disappear around us as we grow and as we expand and scene.

[Charles W. 'Chuck' Bryant]

That was nice. Can we get out of here? Because that 10 foot tall kangaroo's eyeing us.

[Jerry]

Well, not anymore, buddy. He's dead. Because they believe. A lot of people think that around 50,000 years ago, when humans started expanding their footprint, there was a very inconvenient correlation with species dying out as we spread about the earth.

[Charles W. 'Chuck' Bryant]

Yeah. This sixth mass extinction, I apologize for not being able to say sixth correctly.

[Jerry]

That's right.

[Charles W. 'Chuck' Bryant]

But there's a huge debate and it's still, it's not settled. Both sides are like, we're right. Another one is like, we're right. The thing is, both sides agree, like, yeah, we're in the midst of a 6 mass extinction and isn't that what matters? But is it human caused or is the result of climate change? And just because it's the result of climate change doesn't mean that if you take the trail back far enough, it isn't necessarily human caused. But these are the two debates. So one is the theory of overkill, which is the one you were just describing. Yeah.

[Jerry]

And that was describing Australia 50,000 years ago. If we want to get back in the wayback machine and go to North America, 11,000 years ago, 3/4 of our largest animals started to die out, like the mastodon and the woolly mammoth and the giant beaver, saber toothed tiger. And not coincidentally, probably that's right around the time where we first walked over the Bering land bridge and set up shop here in North America.

[Charles W. 'Chuck' Bryant]

Yeah. The thing is, you can also say, well, that kind of gives or takes a few thousand years and yeah, you can. That's definitely stretchable, but it's just not been proven. So there is a huge correlation between the spread of humans and the death of what are called megafauna huge land animals.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

And they say that that theory of overkill says that we came along with our smart little tool kits, which included like spearheads and arrows and axes and clubs and domesticated dogs after a certain point in time and over hunted either these huge like hippo sized marsupials or we hunted things that were slightly smaller that the huge hippo sized marsupials ate. Either way, we contributed directly to their mass extinction.

[Jerry]

Yeah. And they think generally that over hunting isn't, at the very least, it's not the sole cause because you probably just can't hunt enough. The amount of people that we had, especially in a place like Australia, which wasn't super heavily founded, you know, it wasn't like 10 million people moved to Australia overnight, you know.

[Josh Clark]

Right.

[Jerry]

So they say over hunting is probably not the sole cause, but may be a factor. But other things humans did, like maybe in Australia they started burning shrubs to clear land and maybe those shrubs were eaten by certain species and then that caused that domino effect again.

[Charles W. 'Chuck' Bryant]

Another, the other camp that basically says, no, it's climate change and it's fairly natural. Other people might say it's human caused climate change, but for the most part, if you are a climate change extinction proponent, you probably just believe that this is a natural process that the Earth is undergoing and humans didn't have enough of an impact early on to account for the loss of a lot of these species.

[Jerry]

Yeah.

[Charles W. 'Chuck' Bryant]

This one study pointed to a place called Sahul, which was Australia, New guinea and Tasmania all joined together in this mega continent.

[Jerry]

I bet that was a crazy place.

[Charles W. 'Chuck' Bryant]

It was several tens of thousands of years ago and they were saying that by the time humans arrived in Sahul or Australia, most of the megafauna was already gone. It was gone as a result of climate change. And there's no evidence that we had a toolkit capable of killing these animals at this time.

[Jerry]

Yeah, true.

[Charles W. 'Chuck' Bryant]

So the debate still rages on.

[Jerry]

Yeah. And you know, there's been several ice ages that didn't make things go extinct.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

So people point to that as maybe another counter argument.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

But the researchers you sent along did this pretty cool thing they did the first Global analysis of mapping large animals during this period, 132,000 to 1,000 years ago.

[Charles W. 'Chuck' Bryant]

Right.

[Jerry]

And it was the first time they were able to really get a fine point on this geographical variation and species loss. And they did find that 177 species of large mammals disappeared during that period where we were starting to spread out as a species.

[Charles W. 'Chuck' Bryant]

Right. Which apparently is, as it's put in this article, a massive loss.

[Jerry]

Yeah. And they said, you know, they expect these kind of things to happen on an island. Like if you go to Hawaii or, you know, any island, they say that survival is the exception when humans invade an island.

[Charles W. 'Chuck' Bryant]

Exactly.

[Jerry]

But for to happen on like a continent, it's pretty amazing to think about the human impact.

[Charles W. 'Chuck' Bryant]

Still an island.

[Jerry]

Well, yeah, I guess that's a good point.

[Charles W. 'Chuck' Bryant]

But the jury is still out though, on exactly what's causing this. Most scientists agree that we are in mass extinction event, and it's happening pretty quickly. Something like, I think a third of all coral reefs are in danger of extinction. A third of amphibians, I believe.

[Jerry]

Yeah. And a quarter of all mammals and an eighth of all birds are all classified as threatened with extinction.

[Charles W. 'Chuck' Bryant]

And this is happening around the world. So it's fitting the criteria for a mass extinction.

[Jerry]

Yeah, they're basically chalking up to the pace of human expansion. And if you consider that farming and logging and building roads and buildings and most of the world's waterways have been diverted or dammed at this point or manipulated Somehow, only 2% of rivers in the United States run unimpeded. 2%. Everything else has been altered in some way. Chemical plants affecting CO2 in the atmosphere, it's having an effect.

[Charles W. 'Chuck' Bryant]

And the CO2 actually in the atmosphere is having another effect called ocean acidification, which has been described as global warming's evil twin. As more and more CO2 gets released in the atmosphere, the oceans scramble to keep up by absorbing more and more. And it stores some of that by turning some of it into acid, which lowers the pH of the ocean, which is making the ocean unfit for a lot of life. But as to kind of demonstrate how mass extinction is bad for one species but great for another, jellyfish populations are booming.

[Jerry]

Oh, really? So probably because they like the lower ph.

[Charles W. 'Chuck' Bryant]

Yeah, yeah, they like it more acidic. And they're like seriously starting to cause some real problems. And we're just seeing the beginning of this. So it's entirely possible that the next thousand years we'll see the rise of the jellyfish as the rest of the life on Earth starts to die off.

[Jerry]

Well, here's a staggering stat. The drop in ocean ph levels that have occurred in the past 50 years they think might exceed what has happened in the past previous 50 million years.

[Charles W. 'Chuck' Bryant]

Wow.

[Jerry]

So in the past 50 years they've changed the basically changed the chemical makeup of the ocean more than the past 50 million.

[Charles W. 'Chuck' Bryant]

And speaking of 50 years, apparently in the next 50 years an estimated half half of all species on earth could be extinct.

[Jerry]

Sucks, man. I want to see a sloth as big as an elephant.

[Charles W. 'Chuck' Bryant]

Hey, get into de extinction.

[Jerry]

Well here you just saw when we.

[Charles W. 'Chuck' Bryant]

Were in, we were in Sahul.

[Jerry]

Well, yeah, it was nice but I wanted like I wanted to come in the Wayback Machine and bring it to Atlanta.

[Charles W. 'Chuck' Bryant]

No, I don't think that's a good idea, man. That thing looked like it would go berserk.

[Jerry]

And finally, unless you have anything else.

[Charles W. 'Chuck' Bryant]

I don't think so. I'm looking at everything.

[Jerry]

We have a few highlights of extinct animals that have been rediscovered, which is not the same thing as being re engineered.

[Charles W. 'Chuck' Bryant]

What Was this, an iO9 article?

[Jerry]

Yes, iO9 and some of those are pretty good.

[Charles W. 'Chuck' Bryant]

Sure.

[Jerry]

The Bermuda Patrel disappeared they thought in the 1600s, but rediscovered in 1951. There's about 180 of those alive today. Let me see here. What else is good? Well, we already talked about the coelacanth, the Cuban soledon. Solenodon, excuse me, discovered in 1861, has only been caught 37 times in the history of the world. In 1970 they thought it was extinct. It's like a weird rat like species. But then they found one in the 70s and then another one in 2003.

[Josh Clark]

Huh.

[Jerry]

So like welcome back. Cuban solenodon.

[Charles W. 'Chuck' Bryant]

So it was like caught during the 70s and then during the period of the 70s revival in the early 2000s.

[Jerry]

That's right.

[Charles W. 'Chuck' Bryant]

Nice.

[Jerry]

Gilbert's Poturu. Man, these have weird names.

[Charles W. 'Chuck' Bryant]

That's why they went extinct, because you couldn't say sloth, you know, we should save the. What?

[Jerry]

The Gilbert Poturu in 1841. This is a rabbit sized marsupial in Australia and it last appeared in 1879. And they thought, well, this thing's gone up until 1994, came back out and poked his head around and got caught in a few traps. But currently less than a hundred of those in the world. Yeah, so those are just a few of the 10. And there's more than 10, obviously, but it's always a good story.

[Charles W. 'Chuck' Bryant]

Sure it is heartwarming.

[Jerry]

We think this thing's dead.

[Charles W. 'Chuck' Bryant]

It's like. Yeah. Welcome back to the Mass extinction.

[Jerry]

Yeah, exactly.

[Charles W. 'Chuck' Bryant]

Still going on. If you want to know more about extinction, you should read each and every one of the articles we cited. And you can also read this article on howstuffworks.com by typing extinction into the handy search bar. And since I said that, it's time for listener mail.

[Jerry]

I'm going to call this police interrogation follow up.

[Josh Clark]

Okay.

[Jerry]

From Matt Pope. Hey. In Victoria, British Columbia.

[Charles W. 'Chuck' Bryant]

All right.

[Jerry]

Thank you to Vancouver, by the way, for two. Two great shows.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

After our great shows in Toronto.

[Charles W. 'Chuck' Bryant]

Yep. Thanks to Toronto and Vancouver.

[Jerry]

Very supportive people. And boy, that second crowd in Vancouver was drunk and rowdy. Hey, guys. Just listening to police interrogation, I thought I'd share a couple of quick personal stories that illustrate the pitfalls of relying on nonverbal cues to see if someone's guilty. I've never been in trouble with the law myself, but several years ago, I witnessed a crime called 911 to report. Report it. The cops nabbed the perpetrator and a few days later asked me to come down to provide a witness statement. When I arrived, an officer led me into a tiny room that was every bit as bleak as the ones you see on tv. It was a weird experience. Even though I wasn't accused of a crime and the cop was polite in his questioning, the interrogation room setting and the power differential between the uniformed cop with a gun and my unarmed self made me feel really nervous. I started sweating, my voice shook, and if you had been watching my body language, this the one way mirror, you would have thought I was guilty. Well, and he was just a witness.

[Josh Clark]

Yeah.

[Jerry]

The second story is very similar. Every year, our local courthouse has a public event where they give tours and put on a mock trial and actually hang someone. Kidding. I made up that part.

[Charles W. 'Chuck' Bryant]

That was pretty good.

[Jerry]

It's supposed to be educational and fun. My father is a lawyer, and one year asked me if I'd like to play the defendant in the trial. I'm no actor, but I said sure. My character was accused of a minor drug offense, and I went through the whole ordeal being on trial and testifying in my own defense. I'll spare you the details, but afterward my mom said, wow, you looked really guilty up there. I hope you never actually are on trial for anything because they'll lock you up and throw away the key. I learned from these situations, the very act of treating someone like a criminal can make him appear guilty.

[Charles W. 'Chuck' Bryant]

Yeah.

[Jerry]

Reminds me of the Stanford prison study that we've talked about.

[Charles W. 'Chuck' Bryant]

And there's a psychology is nuts about that. Psychology is nuts. Video on our YouTube channel about the Stanford Prison Experiment.

[Jerry]

Yeah, that's a good one. You should check that out. Hope you guys never have to find out the hard way you'll react to police interrogation. If you do, I hope you find a good lawyer. That is from Matt Pope once again in Victoria, bc.

[Josh Clark]

Huh.

[Charles W. 'Chuck' Bryant]

Well, thanks a lot, Matt. That's kooky about your town doing mock trials and stuff like that.

[Jerry]

Yeah, and like hanging a guy.

[Charles W. 'Chuck' Bryant]

Yeah, Crazy said.

[Jerry]

It's fun.

[Charles W. 'Chuck' Bryant]

The only thing that's okay about it is they make the guy look like Hitler.

[Jerry]

Right.

[Charles W. 'Chuck' Bryant]

So it's like hanging Hitler every year, which everybody can get behind.

[Jerry]

Yeah, they call it the Hitler Hang.

[Charles W. 'Chuck' Bryant]

If you want to send us an email that Chuck feels the need to make up stuff about, you can send us an email to stuffpodcastheartradio.com.

[Narrator/Ad Voice]

Stuff youf Should Know is a production of iHeartRadio. For more podcasts My Heart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever.

[Jerry]

You listen to your favorite shows.

[Josh Clark]

Living with a rare autoimmune condition comes with challenges but also incredible strength. Especially for those living with conditions like myasthenia gravis or mg, and chronic inflammatory demyelinating polyneuropathy, otherwise known as cidp, finding empowerment in the community is critical. Untold Stories Life with a Severe Autoimmune Condition, A Ruby Studio production in partnership with Argenics explores people discovering strength in the most unexpected places. Listen to untold Stories on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.

[Host/Announcer]

This podcast is sponsored by PayPal. Okay, let's talk holiday shopping. When you want to make the most of your money, head to the PayPal app before you check out. They give you the flexibility to pay in four no fees, no interest. And this is big. Bigger than the 12 foot snowman on your lawn. Right now, you can get 5% cash back when you pay later with PayPal. So whether you're shopping for your foodie friend or outdoorsy uncle, PayPal helps you make the most of your money this holiday. Save the offer in the PayPal app expires December 31st.

[Sponsor Voice]

See paypal.com promoterms subject to approval. Learn more at paypal.com payin4paypal inc.nmls910457 when.

[Host/Announcer]

It comes to small business, people want to talk to people. Not bots, not voicemail. Your customers or clients want a real human connection, and that's exactly what they get with Ruby. Ruby is the virtual receptionist company that takes care of your callers when you're unavailable in the middle of something or just don't want to pick up. They can answer, screen and transfer calls, as well as take messages, collect payments, book appointments, and more, all while saving you time and making the people you serve feel special. It's available 24 7, 365 days a year and is 100% based in the US. See how it [e-mail] or or better yet, give them a call at 844-900. Ruby this is an iHeart podcast.