Speaker 1: Hey, you welcome to stuff to blow your mind. My
Speaker 1: name is Robert Lamb and I'm Joe McCormick. And it's Saturday.
Speaker 1: Time to venture into the vault for an exploration of
Speaker 1: the Cambrian era. Oh yes, this is an exciting one.
Speaker 1: This one published just last year October. That's right, And
Speaker 1: so this was going to be an episode about Cambrian
Speaker 1: monster was going to be It was one, definitively say,
Speaker 1: it is one about about Cambrian animals and and their
Speaker 1: their monstrous characteristics, and about evolutionary biology. We get into
Speaker 1: some interesting theories about what caused the so called Cambrian explosion.
Speaker 1: So this was an October episode. We're running it in November.
Speaker 1: Are we cheating a little bit? We extending the October? Oh? Yeah,
Speaker 1: we're doing a little Halloween hangover, little Halloween hang around.
Speaker 1: I don't know that Halloween gets gets to last until
Speaker 1: the coming of Crampus in my book. So okay, haven't
Speaker 1: we Ultimately we have another month or so that we
Speaker 1: can continue to to dip into the monster bucket here. Um,
Speaker 1: I do want to say on this particular episode, we
Speaker 1: also have some merchandise to go along with it. We
Speaker 1: have a fabulous new logo design which takes our existing
Speaker 1: logo the sort of abstract symbol that you associated with
Speaker 1: Stuff to Blow your Mind, and it positions it within
Speaker 1: uh kind of a Cambrian sea of strange life forms.
Speaker 1: And that logo is available on a shirt, on a throat, pillow,
Speaker 1: on a sticker, UH, you name it. You can get
Speaker 1: it through our t public store. There's a link for
Speaker 1: that at the top of our homepage. It's Stuff to
Speaker 1: Blow your Mind dot com. And if you're looking at
Speaker 1: this particular episode on our website, there you'll also see
Speaker 1: that image front and center as the lead image for
Speaker 1: this episode. Can you get it engraved on a belt buckle?
Speaker 1: They do belt buckle. I don't know if they do
Speaker 1: belt buckles yet, but it's probably. There's there's a lot
Speaker 1: of of of possibility. You can do hoodies, you can
Speaker 1: do like various types of shirts. And I bring this up,
Speaker 1: I mean mainly because it's fun and it's a great
Speaker 1: way to share Stuff to Blow your Mind and the
Speaker 1: stuff to Blow your Mind message, I guess you would say,
Speaker 1: with everyone. But it's also a great way to support
Speaker 1: the show, UH. Spending a little money on some cool
Speaker 1: merchandise that is kind of a kind of a wink
Speaker 1: to other folks who may be listening as well. Alright, well,
Speaker 1: with that, i'd say let's jump right into our episode
Speaker 1: on the Cambrian Monster Mash. Hello Dr jessup, anybody here? Well, hello,
Speaker 1: good sir. I'm glad to see you have arrived. I
Speaker 1: apologize I can't be there to greet you in person,
Speaker 1: but please know that I am most appreciative of your attendance.
Speaker 1: It's so hard to find good volunteers these days. It's
Speaker 1: it's just if every undergraduate rely even a bit of
Speaker 1: backbonus simply vanished in the past six months. Huh okay,
Speaker 1: So am I in the right place? Ah? Well, well,
Speaker 1: perhaps instead you should ask whether you were in the
Speaker 1: right time. Uh well, the flyer said, you doing SIUR
Speaker 1: for test subjects in something called Middle Cambrian exposure. I'm
Speaker 1: not sure what that is, but if you're paying cash,
Speaker 1: I'm still on board. Excellent. Now tell me do you
Speaker 1: have any experience with time displacement? I don't think so,
Speaker 1: of course not, of course not. And tell me can
Speaker 1: you swim? You know I can, but it's one of
Speaker 1: those things I wouldn't say. I'm a great swimmer. Nobody's perfect.
Speaker 1: Do you see the throbbing light lucifortex in the center
Speaker 1: of the room or well, yeah, yeah, I do, excellent,
Speaker 1: go to it all right? Yes, yes, closer, closer? Doesn't
Speaker 1: feel right? What's that feeling? What's the matter, my little vertebrate?
Speaker 1: Haven't you ever wanted to feel? Five hundred million years younger?
Speaker 1: What is that? Is that? An ocean? Oh? My god,
Speaker 1: it's like the whole planet's an ocean. It's full of monsters.
Speaker 1: Welcome to Stuff to Blow your Mind from how Stuffworks
Speaker 1: dot Com. Hey, welcome to Stuff to Blow your mind.
Speaker 1: My name is Robert Lamb and I'm Joe McCormick and Robert.
Speaker 1: That was obviously a reference to some kind of journey
Speaker 1: we may be taking to the Cambrian period. That's right. Yeah,
Speaker 1: we had a little cameo by the late great Anton
Speaker 1: Jessa late did he die? I don't know. I mean
Speaker 1: there there are rumors of his death, but who knows
Speaker 1: for sure? That always exaggerated, is well? Anyway, today, I've
Speaker 1: got a little story I want to tell to lead
Speaker 1: us into our topic. Now. Obviously it is October. It's
Speaker 1: our favorite time of year to talk about monsters. We
Speaker 1: talked about monsters anyway, but this is the time where
Speaker 1: we really double down. It's clear mandate for monsters. And
Speaker 1: I got to take a monster science It's adventure this
Speaker 1: past month. So this this past month, early on one
Speaker 1: Sunday morning, my wife Rachel and I were in Canada
Speaker 1: and we woke up before dawn on this Sunday morning
Speaker 1: in the town of Golden British Columbia. It's in western Canada,
Speaker 1: the Canadian Rockies, and we had some coffee and bagels,
Speaker 1: and we filled up our backpacks with a bunch of
Speaker 1: layers of warm clothes, bottles of water, all that hiking stuff,
Speaker 1: and we drove along the steep mountain sides to this
Speaker 1: tiny town called Field in British Columbia. And there we
Speaker 1: parked beside a gas station and we waited to meet
Speaker 1: our guide and the rest of this tour group. So
Speaker 1: the guide was a paleontologist named David, and the hiking
Speaker 1: group was mostly French speaking families, some really lovely people
Speaker 1: and some very intelligent children with great questions like why
Speaker 1: do animals die? Uh? And so we hiked through the
Speaker 1: town of Field and along this uphill path through the
Speaker 1: forest up the side of Mount Stephen, and as we
Speaker 1: went on throughout the day, the trail got steeper and steeper,
Speaker 1: and we could see through the trees. The town we
Speaker 1: came from was becoming this tiny miniature model in the distance.
Speaker 1: And then right around midday we came out of the
Speaker 1: tree line and we walked up on this bare plane
Speaker 1: of flat rocks and they were pieces of the underlying
Speaker 1: shale formation that had chipped and broken off, and they
Speaker 1: gathered in this relatively flat part of the mountain side.
Speaker 1: And on this plane of rocks, you walk around and
Speaker 1: you pick up these mineral fragments and they're full of fossils.
Speaker 1: It's just fossils everywhere. Almost every other rock you find
Speaker 1: has the shape of an animal from millions of years
Speaker 1: ago printed into it. You're literally walking on thousands and
Speaker 1: thousands of fossils. So you're in this this mountainous environment
Speaker 1: and David, who by the way, i'm picturing as the
Speaker 1: Android from Prometheus and Alien Covenant, is guiding you and
Speaker 1: showing you these these prehistoric remnants in the rock. David
Speaker 1: was not Michael Fastbender, but David was excellent. He was
Speaker 1: a really, really good guy. And this place we came
Speaker 1: to where we were walking on fossils. This was the
Speaker 1: Mount Stephen Trial Bye beds. It is a graveyard of
Speaker 1: organisms from the Cambrian Period about five hundred million years ago. Now.
Speaker 1: Mount Stephen is in an area that's home to the
Speaker 1: Burgess Shale geological Formation, which is one of the most
Speaker 1: important sites of Cambrian Period fossils in the world. And
Speaker 1: if you ever get a chance to do one of
Speaker 1: these hikes, I highly highly recommended. I think it literally
Speaker 1: might be the coolest thing I've ever done. You have
Speaker 1: to book them through this organization called the Burgess Shale
Speaker 1: Geoscience Foundation, and they pair you with a guide. Our guide, David,
Speaker 1: the paleontologist, was an excellent science communicator. He was really
Speaker 1: good with the kids on the group, and he was
Speaker 1: a great hiking guide. So if you get a chance
Speaker 1: to go with David, big thumbs up to him. Be
Speaker 1: warned if you do try to do this, it's a
Speaker 1: tough hike. It's like eight kilometers round trip horizontally with
Speaker 1: a seven hundred and ninety five meter elevation gain, which
Speaker 1: is like two thousand, six hundred feet, and and that's
Speaker 1: starting at like twelve hundred or hundred meters of elevation
Speaker 1: at the at the base of the mountain. Uh So,
Speaker 1: the air is thin, and it's worth doing some other
Speaker 1: hikes at higher elevation to get yourself accustomed to the
Speaker 1: lack of oxygen. But I also don't want to scare
Speaker 1: you too much, obviously I will. I am no kind
Speaker 1: of athlete or experienced altitude hiker or anything like that,
Speaker 1: and I survived so beer advising listeners to wear their
Speaker 1: best flip flops on this particular Just be prepared, have
Speaker 1: some layers, have some water, do a little practice. If
Speaker 1: you can make the trip, it is absolutely worth it
Speaker 1: to see these fossils firsthand. You can pick them up.
Speaker 1: You can feel the ribs of these Cambrian organisms. You
Speaker 1: can you can feel the contours of their bodies as
Speaker 1: they printed on this ancient shale. But also it's really
Speaker 1: cool to be there, just because the area around field,
Speaker 1: including Mount Stephen, trial By Beds and the Burgess Shale
Speaker 1: Quarry quarries, are just arguably the most important Cambrian fossil
Speaker 1: sites in the world. They are a geological window in
Speaker 1: to a time stranger I would argue than any alien
Speaker 1: planet in any movie, any book, any video game, any
Speaker 1: Star Trek episode. I think the real alien monsters. Uh.
Speaker 1: And of course, as you if you know the show,
Speaker 1: you know we use the term monster affectionately. It's not
Speaker 1: a pejorative. The real alien monsters are not out there
Speaker 1: on some exoplanet. They were right here five hundred million
Speaker 1: years ago, and in this one amazing place you can
Speaker 1: sort of crunch through their frozen graveyard and it's awesome. Now, Joe,
Speaker 1: do you find yourself falling into the same admittedly dumb
Speaker 1: trap that I do when I when I think about
Speaker 1: about the nationalities that are sort of overlaid regarding fossil
Speaker 1: uh finds like these are Canadian Cambrian monsters or something
Speaker 1: like that. Like, yeah, because I was recently reading to
Speaker 1: my son about Terra saurs and was reading about the
Speaker 1: about about Bavarian fossils of Terra saurs, and is as
Speaker 1: silly as it is, I couldn't help but think of
Speaker 1: of Bavarian Terra stars thinking about the very in rhistoric creature,
Speaker 1: like wearing later hosen the big big stein of beer.
Speaker 1: And it's so unfair. You know, I've done the same
Speaker 1: thing thinking of Mongolian fossil finds in our previous episode,
Speaker 1: we talked about various raptors. I believe Kim remember it
Speaker 1: was the velociraptor or dononicus. But I could not help
Speaker 1: but then think about them in terms of like human
Speaker 1: history regarding that area, and it yeah, part of his pack.
Speaker 1: Uh yeah, yeah, I know exactly what you're talking about.
Speaker 1: And that does highlight the need to sort of explain
Speaker 1: how the Cambrian world was so different than our world,
Speaker 1: not just that it had different animals in it, but
Speaker 1: that planet Earth was different than So when I say
Speaker 1: it was an alien planet, I mean that quite literally.
Speaker 1: It's not just that it had different fauna, it was
Speaker 1: a It was a totally different place to live. And
Speaker 1: so before we get into exploring these monsters of the
Speaker 1: Cambrian Period, these beautiful and bizarre creatures that you couldn't
Speaker 1: even dream up if you tried, I think we should
Speaker 1: take a look at the Cambrian period itself and explain
Speaker 1: what it was like to be Terra five million years ago.
Speaker 1: So the Cambrian Period lasted from about five hundred forty
Speaker 1: to about four hundred and eighty five million years ago,
Speaker 1: and if you were dropped from today straight into the
Speaker 1: Cambrian period, you would not recognize planet Earth. The Earth,
Speaker 1: for one thing, revolved faster than it does now, so
Speaker 1: days were only about twenty one hours long, and there
Speaker 1: were about four hundred and twenty of them in a year.
Speaker 1: The air would be hot, so the average global surface
Speaker 1: temperature would have been about ten degrees celsius hotter than today.
Speaker 1: That's a good bit hotter. The atmosphere, while it did
Speaker 1: have significant free oxygen, at this point, was not quite
Speaker 1: what it is today. It would have felt a little
Speaker 1: bit thick with carbon dioxide in your lungs. If you
Speaker 1: happen to see dry land, it would probably look more
Speaker 1: like the surface of Mars than Earth today. Because land
Speaker 1: dwelling plants didn't exist yet. It's kind of hard to
Speaker 1: imagine Earth that way. And without plant roots to hold
Speaker 1: the soil in place, land surfaces eroded very easily in
Speaker 1: the wind and the churning water. So you know, the
Speaker 1: continents are constantly just kind of burning away into the
Speaker 1: oceans and being reformed. So to call back to a
Speaker 1: previous episode we did, was this was definitely a world
Speaker 1: before fire. Oh yeah, because what would it what would
Speaker 1: it burn? Right? Yeah? I mean, I can't be sure
Speaker 1: it was totally without fire, but I mean, yeah, obviously
Speaker 1: not fire on the scale we see of wildfires in
Speaker 1: forests today because there was oxygen in the atmosphere at
Speaker 1: this point. But yeah, what what would burn? What would
Speaker 1: the fuel be? All Right, So we have this alien
Speaker 1: world with just a barren land when visible, and then
Speaker 1: we have this this ocean, this strange ocean, and the
Speaker 1: Cambrians earth that that's not a story about land at all.
Speaker 1: That is a story about ocean. It was the ocean
Speaker 1: planet at that point. You could probably make the argument
Speaker 1: it's the ocean planet right now, but it definitely was then.
Speaker 1: According to Cambrian Ocean World Ancient Sea Life of North
Speaker 1: America by John Foster uh, the level of the seas
Speaker 1: rose steadily in this saw tooth rise and fall pattern
Speaker 1: throughout the Cambrian period. So at the beginning of the
Speaker 1: period sea level was actually a little bit lower than
Speaker 1: it is today, But by the end of the Late
Speaker 1: Cambrian sea level was about a hundred and sixty meters
Speaker 1: or five and thirty feet higher than it is today.
Speaker 1: So in today's terms, New York Underwater Rome underwater, paris underwater,
Speaker 1: bag Dad underwater, even parts of Moscow underwater, and the
Speaker 1: high sea level in the Cambrian led to flooding of
Speaker 1: about forty percent of the area of Earth's continental masses.
Speaker 1: Compared that to today, we're only about five percent of
Speaker 1: that continental area is covered in water. So most of
Speaker 1: our planets dry land mass was gathered together closer to
Speaker 1: the south pole, and the continent that became North America
Speaker 1: was then called Laurentia, not than called by people who
Speaker 1: have been but people today called that continent than Laurentia.
Speaker 1: And you sort of have to imagine North America turned sideways,
Speaker 1: mostly flooded, straddling the equator. Also adding to the alien
Speaker 1: quality in the Cambrian, astronomy would have been a little
Speaker 1: bit different. So the Moon was more than twenty kilometers
Speaker 1: closer to Earth than meaning that its gravity was stronger,
Speaker 1: meaning the high and low tides on Earth were higher
Speaker 1: and lower. Okay, because you know, my son was just
Speaker 1: talking to him to me the other day about the
Speaker 1: size of the moon and prehistoric times. Oh yeah, like
Speaker 1: he knew that the moon was bigger in prehistoric times. Yeah,
Speaker 1: and uh, and knows that it will be it will
Speaker 1: be smaller in future times. Did he into it that
Speaker 1: or did he find that out somewhere. He consumes a
Speaker 1: lot of Dinosaur Train and he really likes this podcast,
Speaker 1: Wow in the World, that's great science podcast for for kids.
Speaker 1: So and then you know, we talked to him a
Speaker 1: lot about science. Man, I wish I was that cool
Speaker 1: when I was a kid. I probably just would have
Speaker 1: told you about like which ninja turtle was bigger in
Speaker 1: the prehistoric times? Yeah, so far Ninja turtles will probably
Speaker 1: come in and wash it all the way. But for now,
Speaker 1: he's really really into the science, like an alien ocean
Speaker 1: driving away the continents. Okay, So if we looked under
Speaker 1: that ancient ocean, that's where the real craziness comes in,
Speaker 1: because we would find this vast realm of gorgeous, terrifying,
Speaker 1: surreal monsters that would look completely unlike the kind of
Speaker 1: Earth life we're familiar with today. Because the Cambrian period
Speaker 1: is the geological layer where we see evidence of one
Speaker 1: of the most fascinating and mysterious events in the history
Speaker 1: of life on Earth, known as the Cambrian explosion. So explosion.
Speaker 1: What exploded? Was this like a bunch of volcanoes or something. No,
Speaker 1: the Cambrian explosion is a story about bio diversity. So, Robert,
Speaker 1: how old is the Earth? Oh, it's so at four
Speaker 1: and a half billion years old. Yeah, that's the general
Speaker 1: astronomical idea. So four and a half billion years old.
Speaker 1: We've had this planet roughly, and we know there's been
Speaker 1: single celled life on the planet for at least maybe
Speaker 1: three and a half billion years or so, based on
Speaker 1: fossil traces left behind by these organisms. And new findings
Speaker 1: keep pushing the debatable frontier of earliest life farther and
Speaker 1: farther back into the darkness of Earth time. One example,
Speaker 1: I just came across So the other day, just earlier
Speaker 1: this year, in March, there was an article published in
Speaker 1: Nature arguing that apparent microbe fossils in the New vo
Speaker 1: Agatuck Belt in Quebec are about three point eight billion
Speaker 1: and possibly four point three billion years old, somewhere in
Speaker 1: that range, and these single celled life forms would have
Speaker 1: been surviving around hydrothermal vents and had this biochemistry based
Speaker 1: on eating and excreting iron. That's pretty rough and tumble.
Speaker 1: That's like a comic book film, right, yeah, the iron eat.
Speaker 1: And the crazy thing is that if these findings are correct,
Speaker 1: life on Earth would have began within just a few
Speaker 1: hundred million years of the planet first accreting together in space.
Speaker 1: It's kind of hard to believe, but whether life on
Speaker 1: Earth began like four point two billion years ago or
Speaker 1: more recently, we know that for a long, long time,
Speaker 1: life on Earth wasn't becoming much more complex, right. There
Speaker 1: was no serious multicellular life. So no animals, no fish
Speaker 1: and reptiles, no birds, no plants, no mushrooms, just microbial
Speaker 1: organisms like bacteria and archaea floating around in the oceans,
Speaker 1: forming mats and films and occasionally occasionally building these giant
Speaker 1: mineral brains in the surf called stromatallites. So this would
Speaker 1: be if this were a science fiction film, this would
Speaker 1: be the least cinematic alien life form encounter unless it
Speaker 1: made people like, you know, horribly sick obviously, or possessed them.
Speaker 1: Biofilm planet, yeah, yeah, the Planet of Slime. Yeah. There
Speaker 1: was the episode of of Star Trek that that does
Speaker 1: not does not make it to to the series. Yeah,
Speaker 1: and that's you know, that would have been the story
Speaker 1: of Earth for most of Earth's history, not having any
Speaker 1: kind of interesting animals or anything like that. Not to
Speaker 1: say that microbes aren't interesting in themselves, but maybe less
Speaker 1: interesting to look at. It would have been slime planet. Yeah. Generally,
Speaker 1: this is the stuff that occupies one, maybe two pages
Speaker 1: of a of a large prehistoric life book before you
Speaker 1: get onto the more exciting things, the things that children
Speaker 1: can imagine fighting each other. But it's most of the
Speaker 1: life that's ever happened. And then billions of years later,
Speaker 1: at the beginning of the Cambrian Period, something happens very suddenly.
Speaker 1: Loads of insane animals show up. And when I say suddenly,
Speaker 1: I have to qualify that that's suddenly from a geological
Speaker 1: point of view, which in reality means it took millions
Speaker 1: of years about five hundred and forty million years ago
Speaker 1: to about five hundred million years ago. But that's still
Speaker 1: pretty suddenly compared to the age of the Earth. And
Speaker 1: this g illogically rapid spike in animal diversity delivers creatures
Speaker 1: with bilateral symmetry, with large bodies, with eyes, with legs,
Speaker 1: with shells, with segmented body parts. You've got all of
Speaker 1: these crazy different types of creatures suddenly showing up, and
Speaker 1: it's like, where did they all come from? Yeah, it's
Speaker 1: like all these prototypes are rolled out at once. It's
Speaker 1: like the segment in is it is a RoboCop one
Speaker 1: or two where we get all the crazy prototypes that, oh,
Speaker 1: that's a RoboCop two. Yes, yeah, it's one of our
Speaker 1: favorite points of comparison on the show for biology. Yeah
Speaker 1: uh yeah. You have suddenly all these different, you know,
Speaker 1: seemingly crazy examples of life, and many of many of
Speaker 1: which don't seem to to fall in easily into that
Speaker 1: category of well, this is a precursor to something we
Speaker 1: have later on. It's a precursor to something we have
Speaker 1: today now. Of course, for some people with negative attitudes
Speaker 1: towards evolutionary science, this provides some kind of rhetorical ammunition,
Speaker 1: right indeed, I mean the explosion is often exploited by
Speaker 1: evolution of knives. Even Darwin, we have to note thought
Speaker 1: that the explosion was at odds with the normal evolutionary process,
Speaker 1: which in a funny way could be true, but not
Speaker 1: in the way an evolution denier would mean a couple
Speaker 1: of thoughts. Evolution is we're familiar with it today, tends
Speaker 1: to take place within ecosystems in which every niche is
Speaker 1: already filled. So basically every way there is for a
Speaker 1: creature to make a living, there's already something trying to
Speaker 1: do that, So if you want to compete, you've got
Speaker 1: to outcompete these other organisms. The global ocean of the Cambrian,
Speaker 1: on the other hand, represented a world in which it
Speaker 1: seems like there was still tremendous ecological opportunity to occupy,
Speaker 1: Like there was territory in the ecology that didn't have
Speaker 1: any existing competition. So it was a time in which
Speaker 1: an animal could start doing something to eat or to
Speaker 1: otherwise survive, and no other species was already doing that thing.
Speaker 1: There was just sort of like free land to grab. Yeah,
Speaker 1: like yeah, land grab call the frontier, uh, except without
Speaker 1: other organisms already occupying it. So that there could be
Speaker 1: one explanation for why evolution seems to be working differently
Speaker 1: at this one period in history than it has since.
Speaker 1: But also the Young Earth creationist who exploits ongoing debates
Speaker 1: in biology to sort of resort to the supernatural. They're
Speaker 1: employing a fallacy in rhetoric known as the argument from
Speaker 1: ignorance fallacy, which means like I don't know what caused something,
Speaker 1: therefore the cause is x uh example, you don't know
Speaker 1: who committed the Jack the Ripper murders. Therefore it was
Speaker 1: interdimensional sasquatches. Now the version employed here, of course, says,
Speaker 1: you can't all agree. We don't know on what caused
Speaker 1: the sudden or geologically sudden biodiversity of the Cambrian explosion.
Speaker 1: Therefore the cause is supernatural. Now, this line of thinking
Speaker 1: obviously doesn't get you anywhere once you examine it. But
Speaker 1: the disagreement and debate over the cause is a fascinating,
Speaker 1: outstanding question, and it's something I think we want to
Speaker 1: entertain a few answers to day. Now, some of the
Speaker 1: hypotheses are primarily environmental and chemical. Right, so some scientists
Speaker 1: have proposed that the cause of the camera and explosion
Speaker 1: could be a rise in the content of oxygen in
Speaker 1: the atmosphere, which leads to an increase in the level
Speaker 1: of dissolved oxygen in the oceans. Now, of course, remember
Speaker 1: that Earth's original atmosphere did not have free oxygen, right,
Speaker 1: that was added to the atmosphere gradually as a waste
Speaker 1: product of photosynthesis. You have all these microbes out there
Speaker 1: and they're eating the sunlight and then their geoengineering the
Speaker 1: atmosphere with their waste products. Which included oxygen. The gradual
Speaker 1: natural terraforming of our world. Yeah, the microbial terraforming of Earth,
Speaker 1: which absolutely did happen in the past. And that's where
Speaker 1: we get our oxygen. Now, when you think about it,
Speaker 1: large fast moving animals need lots of oxygen to feed
Speaker 1: their energy hungry tissues. Like think of the way that
Speaker 1: when you move your muscles a lot, your body starts
Speaker 1: greedily gulping down more and more air. In the same way,
Speaker 1: if you think about these organisms in the past, suddenly
Speaker 1: you wanted to have organisms with large bodies. They would
Speaker 1: have needed access to oxygen. So maybe when that oxygen
Speaker 1: became available, suddenly you could build these big, fast moving
Speaker 1: bodies and you get all this animal biodiversity. Okay, so
Speaker 1: previously the oxygen economy would not support this kind of growth, right,
Speaker 1: But the idea is then it would. So did a
Speaker 1: sudden increase in oxygen drive the explosion. Well, some recent
Speaker 1: studies have cast doubt on this hypothesis, including one published
Speaker 1: in Nature and by Spurling at all uh and it
Speaker 1: basically did not find evidence of a significant increase of
Speaker 1: oxygen in ocean water at the beginning of the Cambrian
Speaker 1: so evidence shows that if there was an increase in
Speaker 1: oxygen at the Cambrian transition, it was kind of a
Speaker 1: small one. All right, Well, what else do we have? Well,
Speaker 1: other hypotheses are more biological and ecological, Like what if
Speaker 1: there was one type of biological innovation, some new way
Speaker 1: for animals to make a living or new thing. Animals
Speaker 1: could do that rapidly accelerated competition with an ecosystems, which
Speaker 1: would speed up natural selection and cause new species to
Speaker 1: form much more rapidly. How about the example of site
Speaker 1: Oh yeah, this is a big one. Yeah, so previous
Speaker 1: animals they might have had some kind of photosensitive spots
Speaker 1: or receptors that would have allowed them to, for example,
Speaker 1: move towards the sunlight. But the Cambrian is the first
Speaker 1: period in history where we have evidence of complex site organs,
Speaker 1: you know, eyes. It's the age of organisms with compound eyes.
Speaker 1: So imagine how much adaptive pressure would be put on
Speaker 1: you if you lived in a world where all creatures
Speaker 1: were basically blind and then suddenly some of your competitors
Speaker 1: could see. Yeah, this is this is a crazy thing
Speaker 1: to try to imagine, but yeah, just just think of
Speaker 1: sight coming online in a world and all the additional
Speaker 1: stuff that this entail. Suddenly pigmentation begins to matter. I mean,
Speaker 1: it's hard to even apply. You're one is tempted to
Speaker 1: apply this to human arms race um, which is which
Speaker 1: is often an an apt comparison. But I mean, what
Speaker 1: can we even look to in human technology and human
Speaker 1: weapons systems. I mean, I'm just thinking maybe you could
Speaker 1: apply it. You can compare it to flight and say
Speaker 1: that well, once, once human technology allowed us to take
Speaker 1: to the air, that created an entire new theater of war,
Speaker 1: and they also changed the existing theaters of war. And
Speaker 1: I think you could make that comparison pretty well, like
Speaker 1: flight changed the nature of warfare forever, Like suddenly just
Speaker 1: having like lots of ground troops didn't didn't matter a
Speaker 1: whole lot, right, But this, this seems more extensive than that.
Speaker 1: You know, It's like it's it's the opening of another
Speaker 1: dimension of competition in a way. Yeah and yeah, and
Speaker 1: you think so you you mentioned pigmentation, Suddenly the colors
Speaker 1: you are matter, like blending in matters. But also think
Speaker 1: about the way it would make movement matter. We would
Speaker 1: make the shapes of bodies matter, would just completely change
Speaker 1: all the dynamics of how creatures interacted with one another. Yeah,
Speaker 1: not only prey predator interactions, but of course just interspecies communication,
Speaker 1: uh and as well as mating. I mean everything changes
Speaker 1: because of this. Yeah. So we'll come back to look
Speaker 1: at more of these answers to this question throughout the episode,
Speaker 1: but I think we should take our first break and
Speaker 1: then we come back. We will look at one of
Speaker 1: the first major inhabitants of our Cambrian monster House. Thank you,
Speaker 1: thank Alright, we're back. So as we roll through these,
Speaker 1: I also want everyone to think of potential Halloween costume ideas,
Speaker 1: because I think we have some We have some wonderful
Speaker 1: prehistoric monsters here that I think are more inventive listeners
Speaker 1: might be able to to turn into a mask or
Speaker 1: a full body cost Okay, So I want you Starship
Speaker 1: Troopers fans out there to get a little bit excited
Speaker 1: about Stone Bug Planet, Okay. Fans of the book or
Speaker 1: the movie, well, I mean they both got bugs, that's okay.
Speaker 1: So in eight teen six, there's a Canadian geologist by
Speaker 1: the name of Richard McConnell, and he's visiting the town
Speaker 1: of Field, the same town I went to when I
Speaker 1: began the walk up Mount stephen Field, British Columbia, where
Speaker 1: some railroad workers told him they had found something creepy
Speaker 1: on the slopes of nearby Mount stephen They were these
Speaker 1: things that they called quote stone bugs, and these were
Speaker 1: in fact trialo bytes, the best known inhabitants of the
Speaker 1: Cambrian oceans. Now trio bytes are not a single species,
Speaker 1: but there are a class of extinct animals from the
Speaker 1: phylum arthur Poda, and so that would be the same
Speaker 1: phylum that includes, for example, insects and crustaceans, lobsters or arthropods.
Speaker 1: Insects and spiders or arthropods. These exoskeleton creatures now trialo bytes,
Speaker 1: were an enormously successful form of life, beginning in the
Speaker 1: Cambrian and surviving for about three hundred million years until
Speaker 1: they were wiped out about two hundred and fifty million
Speaker 1: years ago in the Permian Triassic extinct Shinn event, also
Speaker 1: known as the Great Dying, which was the biggest mass
Speaker 1: extinction in the history of planet Earth. About of all
Speaker 1: marine species went extinct. It's kind of hard to imagine,
Speaker 1: but until then trial bytes were like sort of like
Speaker 1: the insects of today, just this enormously successful type of
Speaker 1: creature found everywhere. They were a swarm upon the face
Speaker 1: of the deep or I kind of want to think
Speaker 1: of them as the infinity bugs. I like it. So
Speaker 1: the trialo byte body structure kind of resembles like a
Speaker 1: roly poly or a pill bug, maybe crossed with a
Speaker 1: horseshoe crab. It's got these articulated segments lining its back
Speaker 1: and if you look at it from the top down,
Speaker 1: you'll see this flat, hard shell made of a matrix
Speaker 1: of tiny calcite needles. And if you look at it
Speaker 1: on the vulnerable underside, you'll see the legs and the
Speaker 1: gills and the mouth. And actually it does kind of
Speaker 1: look like a like a roly poly or a pill
Speaker 1: bug on the underside too, if you ever see them. Yeah,
Speaker 1: I have to say Trilobyte, of all the creatures were
Speaker 1: going to discuss today, well, first of all, it's the
Speaker 1: most famous, I think, so most of you have probably
Speaker 1: seen images of it before. But it also does look
Speaker 1: a lot more like existing creatures. It doesn't if you,
Speaker 1: if you didn't know better, you could easily see an
Speaker 1: image of this and think that it could be something
Speaker 1: living today. Yeah, I think the creepiness of the trial
Speaker 1: Bye World comes not from seeing their body plans, because
Speaker 1: you can see stuff that looks kind of like them.
Speaker 1: Like you say, it's just how many of them there were,
Speaker 1: and thinking of this being one of the dominant body
Speaker 1: plans on the planet, or the dominant body plan on
Speaker 1: the planet. And if you're still drawing a blank as
Speaker 1: to what this looks like, I'm going to include images
Speaker 1: of of all the species that we're discussing here on
Speaker 1: the landing page for this episode. It's stuff to blow
Speaker 1: your mind dot com. Alright, so we've had a look
Speaker 1: at the creature's legs. Let's turn this puppy around. Okay,
Speaker 1: turn it so if you look at it from the
Speaker 1: top down, you can basically deve via a trilobyte in
Speaker 1: three both ways. So if you look at it lengthwise,
Speaker 1: you're looking at head on. Lengthwise, there is bilateral symmetry,
Speaker 1: and this is the cameraan period. We see these animals
Speaker 1: with bilateral symmetry really taking over. You can fold them
Speaker 1: in half and they're like a book. They match on
Speaker 1: both sides. And in that lengthwise direction, the trilobyte is
Speaker 1: divided into three lobes. You've got the axial lobe, which
Speaker 1: runs down the middle from the head to the tail,
Speaker 1: kind of like the spine of the book, or like
Speaker 1: the spine of a vertebrate. And then you've got the
Speaker 1: two plural lobes on each side which you're shielding the
Speaker 1: legs from above. There were these you know, shelled lobes
Speaker 1: stick out on the side and they cover up where
Speaker 1: the legs would be moving underneath. Now you rotate at
Speaker 1: ninety degrees, and then you've got another three sections. You've
Speaker 1: got the head known as the cephalon, the middle section
Speaker 1: known as the thorax, and the rear section known as
Speaker 1: the pagidium. Now, one thing you might wonder, why do
Speaker 1: we see these articulated segments on the shell of a trilobyte, Like,
Speaker 1: why doesn't it have something more like a big solid
Speaker 1: turtle shell? You know, why why the different plates overlapping? Well,
Speaker 1: there are multiple answers, but one is that apparently some
Speaker 1: TrailO bites were able to partially curl up and protect
Speaker 1: their soft underbellies like an armadillo or a pillbug. Yeah
Speaker 1: it so do you do you use the word pillbug
Speaker 1: or roly poly? Do I think they're the same thing? Yes,
Speaker 1: I believe the same creature or the same you know,
Speaker 1: classification of creatures at the very least. But yeah, I
Speaker 1: grew up with roly poly. I think I did too,
Speaker 1: And somehow in my adulthood transition to pillbug, I've sold
Speaker 1: out my childhood wonders. It does sound significantly less silly. Well, anyway,
Speaker 1: trialo bite fossils are that. That's what you're walking on
Speaker 1: in the Mount Stephen Trialo by beds, right, So you
Speaker 1: walk around, you crunch through these things. You pick up
Speaker 1: these rocks and they've got these little shells in them.
Speaker 1: And the trio bite fossils are so common you can
Speaker 1: get the sense that these animals must have been stacked
Speaker 1: a mile high when they actually existed. Right, There were
Speaker 1: a lot of them in the Cambrian but they're perhaps
Speaker 1: overrepresented in the fossil record because many of the fossilized
Speaker 1: shells we find are not the animals themselves, but the
Speaker 1: discarded shells left over from the molting process. So, like
Speaker 1: Arthur pods today, trial bites were himmed in by this
Speaker 1: protective shell and if they wanted to grow bigger, they
Speaker 1: had to molt, which meant discarding that protective outer layer.
Speaker 1: And temporarily risking a soft bodied existence in order to
Speaker 1: grow that larger, harder shell. It would be like if
Speaker 1: there were a prehistoric hominid creature that left multiple skeletons,
Speaker 1: you know, which is of course impossible, but with an
Speaker 1: exoskeleton is is completely is very possible. Well, the vulnerability
Speaker 1: of molting makes me think about the comparison to a
Speaker 1: human newborn. You know, when when babies are born, they
Speaker 1: don't necessarily have all their their hard protective skeletal parts yet,
Speaker 1: and I have a lot of unfused together the unfused
Speaker 1: skull for example, and the soft cartilaginous body arts where
Speaker 1: you really do make yourself vulnerable when you're firstborn. But
Speaker 1: of course they're depending on the fact that mammals have
Speaker 1: protective parents that will try to prevent injury to their
Speaker 1: offspring when they're young and vulnerable trialo bites. I don't
Speaker 1: know if they're they're quite so protective of they're young.
Speaker 1: I mean you could say that puberty is kind of
Speaker 1: a molten period where where where we tend to be
Speaker 1: soft and vulnerable, if not in if not in mentally,
Speaker 1: at least mentally. Yeah. Uh so that's interesting to think
Speaker 1: of the molten process having an impact on the sheer
Speaker 1: number of fossilized remains. But but then on top of that,
Speaker 1: of course, it makes you analyze, and we've discussed this
Speaker 1: on the show before, like what makes a creature more
Speaker 1: liable to be fossilized? And I mean, you look at
Speaker 1: the creatures that are fossilized in any great number. It's
Speaker 1: not going to be an apex predator living in a
Speaker 1: dry region. It's going to be something like a low
Speaker 1: level and burd invertebrate that lives in the muck. Yea
Speaker 1: something that gets buried quickly. Uh, and that leaves behind
Speaker 1: hard body parts near water, especially right. So the great
Speaker 1: the Great Land squid of old rights have not been preserved,
Speaker 1: but their beaks are many. Oh yes, that's right. We
Speaker 1: would get the beaks, yeah, these beds of beaks, and
Speaker 1: we'd wonder what they are. Yeah. But because there are
Speaker 1: so many trialobite fossils, and because they're so strange and
Speaker 1: so alien to the modern life forms we encounter in
Speaker 1: our day to day lives, I mean, they might be
Speaker 1: they might bear some resemblance to insects for example. Right,
Speaker 1: And this is why railroad worker might call them stone bugs,
Speaker 1: but it's no surprise that they show up in human
Speaker 1: culture too. I wanted to mention one cool example I
Speaker 1: came across. Remember Adrian Mayor who wrote the first Fossil Hunters.
Speaker 1: We talked about her in our in our what was
Speaker 1: it the geomethology? Yes, yes, this we had to do
Speaker 1: with how did ancient people look at fossilized remains, didn't
Speaker 1: think they were monsters? That they think they were dragons? Yeah? Yeah?
Speaker 1: And did did these ideas of mythical monsters come from
Speaker 1: people finding fossils? So she's got another boat called Fossil
Speaker 1: Legends of the First Americans, and she writes of how
Speaker 1: trio bite fossils were apparently used as protective amulets by
Speaker 1: some of the Ute people of Utah. So this one
Speaker 1: story is in the early nineteen hundreds, there was an
Speaker 1: amateur natural historian named Frank Beckwith and he noticed a
Speaker 1: trio bite necklace at a Ute burial site. So he
Speaker 1: asked some friends of his name, Joseph and Tedford pick
Speaker 1: of It, who were members of the tribe, what this meant,
Speaker 1: and they told him that the fossil was called timpei
Speaker 1: kanitsa Pavacci which meant little water bug in Stone and
Speaker 1: Beckwith also records that the men told him that their
Speaker 1: elders believed that wearing the trio bites could protect against
Speaker 1: sickness and bullets. But I thought that's kind of cool that.
Speaker 1: Look somehow the fossils were intuited to have been water
Speaker 1: dwelling creatures, and I wonder how people would have figured
Speaker 1: that out back then. I thought that was really interesting. Yeah,
Speaker 1: especially given that there would be there would be plenty
Speaker 1: of terrestrial invertebrates to compare it to. I guess maybe
Speaker 1: they maybe they saw more of the of the crab
Speaker 1: in this creature than they did, uh, you know, terrestrial bucks.
Speaker 1: I know, I wouldn't have been that perceptive. I would
Speaker 1: have called it like roly Poly or something. Well, anyway,
Speaker 1: considering that all these there are all these shells everywhere,
Speaker 1: another possible answer to the question of what caused the
Speaker 1: Cambrian explosion comes up. What if the Cambrian explosion is
Speaker 1: an illusion? What if it is not so much an
Speaker 1: event in history where all these animals suddenly emerged, but
Speaker 1: a misperception created by the types of evidence available to us.
Speaker 1: So this would be like a reporting error exactly. It
Speaker 1: would be a sampling bias. How would that be. Well,
Speaker 1: like we've been talking about, we know fossilization has this
Speaker 1: serious preference for hard body parts, and it appears to
Speaker 1: be around the Cambrian period that biomineralization, right, the forming
Speaker 1: of these mineral based body parts like skeletons and shells,
Speaker 1: that that became common in many different animals. It's the
Speaker 1: age of shells and exoskeletons. So it could be that
Speaker 1: many animal forms had precedent in the Precambrian era, that
Speaker 1: there were there were animals sort of like them living before,
Speaker 1: and it's simply that we don't have good records of
Speaker 1: them because they weren't making hard body parts yet. Okay,
Speaker 1: so this makes sense. So it's not it's it's not
Speaker 1: that just suddenly there are all these creatures around with
Speaker 1: their hard shells. There were plenty of creatures around beforehand.
Speaker 1: It's just those were not preserved. Those are not as
Speaker 1: president the fossil record, right, because they didn't have the
Speaker 1: hard shells. Yeah. On the other hand, even soft animals
Speaker 1: leave some fossil traces like tracks and burrows, and generally,
Speaker 1: I think paleontol just think that these types of fossils
Speaker 1: are not as abundant as they would seem to be
Speaker 1: if the Precambrian world was basically a soft flappy copy
Speaker 1: of the Cambrian But either way, this leads us to
Speaker 1: a kind of new way of framing the Cambrian question.
Speaker 1: If the Cambrian explosion is characterized as this explosion of
Speaker 1: animal body plans, and especially those with hard body parts,
Speaker 1: why do the hard body parts show up? Like? Where
Speaker 1: do they come from? Why evolve shells? And this leads
Speaker 1: us to another possible answer to the to the cause
Speaker 1: of the Cambrian explosion. What if it was caused by
Speaker 1: a biological innovation like predation? Oh so like you, So
Speaker 1: you have all of these creatures that have that have
Speaker 1: evolved and then suddenly they realize, Hey, we can just
Speaker 1: eat each other. I can I can just eat these guys.
Speaker 1: Why should I compete for the same same meal when
Speaker 1: I can make them my meal and then I'm essentially
Speaker 1: eating what they already ate, Right? Why would I waste
Speaker 1: my time filter feeding when I can just eat ted
Speaker 1: over there? Yeah? So Eric Sperling, the Stanford paleontologist who
Speaker 1: is the lead author on one of the papers I
Speaker 1: mentioned earlier in this episode, he explained in a Nature
Speaker 1: News article earlier this year, or actually know it was
Speaker 1: last year, that he thinks a very modest increase in
Speaker 1: dissolved oxygen could have been enough to push the the
Speaker 1: ocean chemistry over the edge to allow for the emergence
Speaker 1: of predation and carnivory as an ecological niche, which would
Speaker 1: have thereafter driven evolution across the animal spectrum as this
Speaker 1: arms race between predator and prey emerged. In a world
Speaker 1: of predators, you need shells and you need to be
Speaker 1: able to move. Yeah, alright, well, this this sounds the
Speaker 1: sounds plausible, and there's some evidence that this is what
Speaker 1: was happening. Here's an odd fact. Sometimes trialobyte fossils are
Speaker 1: missing chunks, not because the fossils have been damaged, but
Speaker 1: apparently because the animals were One example, a specimen of
Speaker 1: the trial trialobyte illinoid is found in Walcott's Quarry at
Speaker 1: the Burge of Shale, has this distinct W shape missing
Speaker 1: from its left side, as if something took this kind
Speaker 1: of two fanged bite out of it. So in this
Speaker 1: alien ocean, and you have to imagine me uh in
Speaker 1: the voice of ripley and aliens whose laying the eggs,
Speaker 1: what's taking the bites out of these trilobites. Maybe it's
Speaker 1: less dramatic if if you put it that way, but
Speaker 1: but yeah, there's gotta be something something else out there,
Speaker 1: some sort of predator that is that is chomping down
Speaker 1: on these guys. And this leads us to the second
Speaker 1: monster in our Cambrian monster house, the weird shrimp. All right,
Speaker 1: hold that thought, because we're gonna take a quick break,
Speaker 1: and when we come back, we will we will get
Speaker 1: to know the weird shrimp, which is truly unless you're
Speaker 1: already you know, super familiar with this time period, I
Speaker 1: would say it's the first really alien creature of the
Speaker 1: Cambrian period. Alright, we're back, Okay. So in a British
Speaker 1: Canadian paleontologist named Joseph Frederick Witty Eves was trying to
Speaker 1: figure out how to classify some odd Cambrian fossils that
Speaker 1: looked like headless shrimp shells. You can look at pictures
Speaker 1: of these online, but um, you could see these five
Speaker 1: hundred million year old imprints of these clawed tails and bodies,
Speaker 1: but the heads were always missing. Yeah, they look kind
Speaker 1: of They basically looked like entrees. Yeah. Yeah, it's like
Speaker 1: somebody pulled the head off the shrimp and served it
Speaker 1: to you in a little cocktail glass. Now. He named
Speaker 1: the organism Anomala carus, which means weird shrimp or strange
Speaker 1: shrimp or odd shrimp, however you prefer. Meanwhile, Burgess Shale
Speaker 1: pioneer Charles Walcott, which who is the guy who the
Speaker 1: Walcott's Quarry at the Burgess Shield was named after, he
Speaker 1: collected and described a fossil of a different animal. These
Speaker 1: preserved remains only showed a large, disembodied mouth, a thick,
Speaker 1: muscular ring shape surrounded by a circle of jagged teeth
Speaker 1: facing inward. And Walcott believed this mouth to be the
Speaker 1: remains of a jelly fish that he named Patoya. All right,
Speaker 1: so this would be the mouth of an otherwise soft creature,
Speaker 1: that was his argument. And all we have left is
Speaker 1: the mouth, right. And it wasn't until many decades later
Speaker 1: that researchers Harry Whittington and Derek Briggs figured out that
Speaker 1: these two weird anomalous animals were weird and anomalous because
Speaker 1: they were different parts of the same creature. A huge
Speaker 1: Cambrian predator that retained the name of Anomala carus. The
Speaker 1: weird shrimp were actually a pair of clawed appendages basically
Speaker 1: mouth tentacles for snatching up prey and shoving it into
Speaker 1: the mouth parts, and the mouth parts were the toothy ring,
Speaker 1: which had previously been identified as patoya. If you've never
Speaker 1: seen an image of Anomala cars this is another thing
Speaker 1: to look up, well, or maybe we'll try to include
Speaker 1: a picture on the landing. Yeah, we'll include a picture
Speaker 1: of this this creature because it's just too it's too weird.
Speaker 1: If if need be, we will draw one and uploaded
Speaker 1: to the side. It's sort of like impossible to make
Speaker 1: yourself believe that this thing really existed on Earth. But
Speaker 1: I've seen the fossils now, and so the reason these
Speaker 1: disembodied parts were originally is identified was a common problem
Speaker 1: in paleontology. As we've mentioned several times now, fossilization is
Speaker 1: strongly biased toward hard body parts like shells and bones.
Speaker 1: Anomala Carus did not have a hard exoskeleton covering its
Speaker 1: whole body, but probably had a very light, kitanous outer
Speaker 1: layer like a shrimp shell. On some parts of its body,
Speaker 1: and when it died and decomposed, its body probably fell
Speaker 1: apart into different pieces, and not all of those pieces
Speaker 1: were preserved at the same rate. So it's rare to
Speaker 1: find fossils that preserve any information about soft body parts,
Speaker 1: and even rarer still to find soft bodies intact, all
Speaker 1: in one place. Rare, but not entirely impossible, because since
Speaker 1: the original discovery of what amounted to Anomala cars is
Speaker 1: killing equipment, more fully preserved Anomala Carus specimens have been discovered.
Speaker 1: For example, one fossil discovered in nineteen two shows the
Speaker 1: spiked feeding arms branching off of the head within reach
Speaker 1: of the shing mouth ring, and all contained within the
Speaker 1: imprint of this elongated soft body lined with lateral lobes
Speaker 1: that probably undulated to power swimming. So if you're trying
Speaker 1: to imagine this thing right now, you have to picture
Speaker 1: a kind of wide, flat lobed jellyfish snake undulating along
Speaker 1: through the ancient seas, with a gaping mouth ring on
Speaker 1: the underside that could squeeze with teeth but never fully close,
Speaker 1: and then sticking out of its face a couple of
Speaker 1: hooked fang tentacles lined with spikes. Yeah, this this looks
Speaker 1: like a creature that belongs in a Star Wars Cantina. Yeah. Yeah,
Speaker 1: it should be like having a drink and telling you
Speaker 1: it doesn't like you, and it probably doesn't like you.
Speaker 1: Now you're you might be thinking, okay, so how big
Speaker 1: were these things? Right? Like? A few inches long? Parts
Speaker 1: found in fossil sites in China indicate that Anomalocarras type
Speaker 1: organisms may have grown to almost two meters long, which
Speaker 1: is around six feet. You know, people do those like
Speaker 1: booking a swim with the dolphins thing. I think people
Speaker 1: should book swim with the anomal of carrass. They should
Speaker 1: use some kind of DNA engineering to bring these things
Speaker 1: back well you know, and then have you swim with
Speaker 1: them at the resort. Well, you know, the predation explosion
Speaker 1: hypothesis is correct, especially, I mean, this was eating other
Speaker 1: animals was a growth industry, so it it does make
Speaker 1: sense that that the the successful model for eating other
Speaker 1: creatures would produce larger and larger organisms, right. Yeah. So,
Speaker 1: but the question I guess is if these things are
Speaker 1: preying on the you know, the widespread trilobites of the
Speaker 1: ancient seas, I don't know, would they take a bite
Speaker 1: out of you if they could. So you're in the
Speaker 1: water with them, you do obviously don't look or smell
Speaker 1: like their normal prey, but then again, they might just
Speaker 1: want to see what you taste like. It's hard to know.
Speaker 1: We kind of get into that whole shark and gorilla area.
Speaker 1: I don't know if I've mentioned this on the podcast,
Speaker 1: but I don't think so. Well, every time I go
Speaker 1: to the ocean, I comfort my self regarding the risk
Speaker 1: or apparent risk of sharks and and of course just
Speaker 1: shark media in general by thinking about the just like
Speaker 1: a brief clip on The Simpsons where a shark jumps
Speaker 1: out of the water and grabs a gorilla out of
Speaker 1: a tree, which is ridiculous for several reasons, but it
Speaker 1: drives home like this is this is something that does
Speaker 1: not happen. Is not part of the the the the
Speaker 1: the energy model for either species, you know. Uh, And
Speaker 1: and that's essentially what I am. I am a gorilla
Speaker 1: in the water, and the shark has not evolved to
Speaker 1: eat me exclusively. It can if need be, but it's
Speaker 1: not out there looking for gorillas, right. It might have also, though,
Speaker 1: evolved a sort of like prey diversity, curiosity, it might
Speaker 1: take a little nibble on you to see what you're like, right, right,
Speaker 1: So I guess that would be the main concern. But
Speaker 1: I'm guessing you would have this element of surprise because
Speaker 1: by the way, I don't mean to be promoting like
Speaker 1: fear of sharks. We're not their primary prey, right, But
Speaker 1: but I'm guessing with with h means, if if we
Speaker 1: were to go with our opening scenario and you were
Speaker 1: just dropped into the waters among these things, I would
Speaker 1: hope you would have this this element of surprise over them,
Speaker 1: and they would be a bit shocked and uncertain and
Speaker 1: hesitant to approach you. So another thing that's really cool
Speaker 1: about Anomala carras is that they have these amazing eyes.
Speaker 1: For a long time, detailed evidence of non biomineralized arthropod
Speaker 1: eyes had been hard to find. But in two thousand
Speaker 1: eleven there was a letter to Nature that detailed this
Speaker 1: amazing find at the Emu Bay Shale of South Australia,
Speaker 1: and what they had found was preserved Anomala carus eyes,
Speaker 1: and they found that they had a pair of two
Speaker 1: to three centimeter eyes about five fifteen million years old,
Speaker 1: and they were compound eyes made of at least sixteen
Speaker 1: thousand hexagonally packed lenses, meaning these eyes would have been
Speaker 1: about as acute as the most powerful arthropod eyes today,
Speaker 1: like dragonfly eyes. And the authors think that this is
Speaker 1: that this evidence of acute vision lends support to the
Speaker 1: idea that anomal a caress was a powerful, fast moving
Speaker 1: apex predator going all throughout the water column, which and
Speaker 1: this would have accelerated the arms race that triggered Cambrian
Speaker 1: biodiversity and biomineralization. You know this also this makes me wonder, though,
Speaker 1: would a creature like this have anything to fear? Well,
Speaker 1: I mean probably not. I mean, if it's the apex
Speaker 1: predator of an ancient ocean, what, it's the biggest thing
Speaker 1: out there and it's got the most powerful killing equipment.
Speaker 1: What does it have to worry about? Nothing? Until you know,
Speaker 1: the time traveling human shows up and starts clubbing them.
Speaker 1: I guess that club they brought. You'd have to bring
Speaker 1: your own club. That's the key here. But nothing dead
Speaker 1: will go. Ah, well, you know, maybe a still living
Speaker 1: tree branch will work. Oh yeah, maybe that. Somebody should
Speaker 1: have told kyleys about that. I guess that wouldn't have
Speaker 1: been all that effective against the determinator. Yeah, where are
Speaker 1: they going to get a tree branch and the desolate
Speaker 1: post apocalypse future. Okay, we're on a tangent here, so
Speaker 1: we're gonna look at some more uh Cambrian monsters. But
Speaker 1: one more thing about anomally carriss before we move on.
Speaker 1: There is still a fascinating debate going on about how
Speaker 1: and what Anomala carress ate. So some of these wounded
Speaker 1: trial bytes that we discussed earlier have injuries that really
Speaker 1: seemed to match the two pronged grasping appendages of the
Speaker 1: anomal carrass and some experts believe that its mouthparts would
Speaker 1: not have been powerful enough to prey upon trial bytes
Speaker 1: with their hard outer shells. So that kind of creates
Speaker 1: a question like what was was it eating something else?
Speaker 1: Like how could it have gotten through these hard outer shells?
Speaker 1: There are a few options. Maybe maybe they were just
Speaker 1: really beefy and they could crunch through those shells. Maybe
Speaker 1: they had some method of prying the shells off of
Speaker 1: weaker trialobytes and sucking up all the soft parts inside.
Speaker 1: Or there's also an interesting possibility I learned about from
Speaker 1: the guide on our hike, David. Maybe they took a
Speaker 1: tip from the crab shack down the shore and they
Speaker 1: sought out soft shells trial bytes who were in the
Speaker 1: process of molting. So you you release your hard shell,
Speaker 1: put that aside to be fossilized for people to find
Speaker 1: millions of years later, and then you stay soft for
Speaker 1: a little bit while you, you know, you grow. What
Speaker 1: if they sought those out, the molten trial bytes and
Speaker 1: nominomomb Oh man, Yeah, I mean that could be. That
Speaker 1: could be the very uh niche that they are exploiting.
Speaker 1: When you turn to the model of of of eating
Speaker 1: other creatures, what better time than the molting period. Yeah, okay,
Speaker 1: So the trial bytes and anomalo carras type creatures are
Speaker 1: some of the main players that we see in UH
Speaker 1: in Cambrian evolution, but there are also all of these
Speaker 1: fascinating bizarre periphery organisms. Like Robert, would you like to
Speaker 1: take us on a tour of the rest of the
Speaker 1: Cambrian monster house. Sure? Yeah, we have some wonderful UH
Speaker 1: specimens here to discuss here, and there's not there's not
Speaker 1: necessarily as much data behind all of them. I mean
Speaker 1: there's data, but it's maybe not as as sexy as
Speaker 1: a trilobyte. However, they still have some some fascinating features,
Speaker 1: and I think many of them would make excellent Halloween costomes.
Speaker 1: I would say they're much sexier than the trilobyte, maybe
Speaker 1: just not as a robust. So the first one here
Speaker 1: I want to discuss is um opabinia. I've often called
Speaker 1: the stock eyed vacuum cinabyte. That's a good description one
Speaker 1: that I think evokes the alien qualities of this creature.
Speaker 1: So if you're not looking at a picture of this
Speaker 1: right now and stuff to blow your mind dot com,
Speaker 1: I want you to imagine something like a shrimp orl lobster,
Speaker 1: but with rows of side lobes along its sides, paddling
Speaker 1: along like the ores of like a galley so spiking ship.
Speaker 1: You's got these lobes on the sides, kind of like
Speaker 1: we described with the nominal caras that undulate to move
Speaker 1: it along throughout the water. Right And you know, it
Speaker 1: is not that remarkable at the the end, Like I said,
Speaker 1: if you were just catching it a glimpse of it
Speaker 1: out of the corner of your eye, that the back
Speaker 1: portion doesn't look that different from again, like a lobster
Speaker 1: or shrimp or something. But it's the front end of
Speaker 1: the creature that is is rather interesting because it has
Speaker 1: a long, flexible proboscis tipped with grasping spines, and the
Speaker 1: creature itself was about three inches long, not counting this
Speaker 1: uh weird cool richie tentacle. Yeah, five eyes to right,
Speaker 1: five eyes on stalks, yes, five eyes just standing right
Speaker 1: at you on stalks like they put them on stalks.
Speaker 1: It's like just a mess with us. Yeah, and I
Speaker 1: think this all sounds very love crafty and but but
Speaker 1: according to the Smithsonian National Museum of Natural History, a
Speaker 1: reconstructed image of the creature resulted in laughter at a
Speaker 1: nine two scientific meetings. So instead of looking at this
Speaker 1: thing and thinking, oh, this sounds horrific, it's like, got
Speaker 1: this reaching arm that you know is up to no
Speaker 1: good with its spikes on the end. But yeah, apparently
Speaker 1: when it was first presented, uh, other other scientists laughed
Speaker 1: at the prospect of something this ridiculous looking. So you
Speaker 1: have to think, So, it's got this reaching appendage that's
Speaker 1: sort of like its mouth appendage thing, So what's sort
Speaker 1: of like maybe sort of like an ant eater, I guess,
Speaker 1: but it's obviously not a vertebrate, not a mammal. Yeah,
Speaker 1: it was. The idea here is that this would have
Speaker 1: haunted the soft seabed and it would have would have
Speaker 1: reached into sand burrows with this, So this spiked terminating
Speaker 1: wriggly arm to grab delicious worms and uh and actually
Speaker 1: have a quote here. This is from HB. Whittington from
Speaker 1: the enigmatic animal Opabinia regalis Middle Cambrian Burgess Shale, British Columbia.
Speaker 1: This was presented the Royal Society b quote. Opabinia regalius
Speaker 1: may have plowed shallowly in the bottom mud, propelled by
Speaker 1: movement of the lateral lobes. The eyes are presumed to
Speaker 1: have been capable of detecting movements in the surrounding waters,
Speaker 1: and the frontal process to have been is to explore
Speaker 1: the mud for food and bring it to the backward
Speaker 1: facing mouth. The frontal process that is the most amazing
Speaker 1: euphemistic term for killing equipment. And then they put the
Speaker 1: frontal process through the thorax the way that my son
Speaker 1: uh describes it with the animals when he's like drawing dinosaurs.
Speaker 1: He says that this is the part that makes the
Speaker 1: animal's eyes close and then die. Yeah, so you know,
Speaker 1: the frontal process is the part that makes the trial
Speaker 1: by its eyes closed. So this is this is the
Speaker 1: cool specimen. It's it's unique, it's enigmatic, it's silly looking,
Speaker 1: but it's also, you have to admit, a very sensible
Speaker 1: organism when you really think about it. Um, it's it
Speaker 1: needs something to grab those worms. It has a single
Speaker 1: you know, grabber to do it. Now, it's also interesting
Speaker 1: that this one remains unassigned to any other extinct or
Speaker 1: currently living major group. That there are some theories, but
Speaker 1: for most part, this is one of those um, you know,
Speaker 1: abandoned prototypes you can think of. You know, there's there's
Speaker 1: nothing out there that that we know of that is
Speaker 1: a descendant of this thing. That's interesting because when I
Speaker 1: think about organisms like this, I think about the relationship
Speaker 1: between manipulation limbs and the evolution of intelligence. I mean,
Speaker 1: there's one way of looking at the evolution of hominid intelligence,
Speaker 1: and it's to say that, Okay, one thing that may
Speaker 1: have driven humans and other you know, great apes to
Speaker 1: have larger brains and more intellectual power than the average
Speaker 1: mammal is that they've got free limbs that they don't
Speaker 1: always have to use for walking and stuff like that
Speaker 1: to manipulate objects, and that the manipulation of objects allowed
Speaker 1: them to, you know, have advantages in the manipulation of
Speaker 1: tools and stuff like that. Yeah, you can't help but
Speaker 1: imagine like what if this had been a successful uh
Speaker 1: limb of of of evolutionary ascension, and then it ended
Speaker 1: up with all of these different like monolimbed creatures, you know,
Speaker 1: plowing about in the seas, climbing up onto land and
Speaker 1: maybe getting to the point where they're using that that
Speaker 1: one spiky tentacle to to type on computer keyboards. Yeah, yeah,
Speaker 1: you see it in octopy to you know, having these free,
Speaker 1: these free limbs that they can manipulate things with. I
Speaker 1: wonder could opabinia if it hadn't gone extinct yet, could
Speaker 1: it have become the tool using creature before they were
Speaker 1: even mammals. But instead it just remains this this weird
Speaker 1: dead end that looks it looks like if you decided
Speaker 1: to make an animal out of random Lego pieces and
Speaker 1: you stuck that. I think they still have that that
Speaker 1: sort of twisty grabber mechanism and the Lego kids today. Alright,
Speaker 1: the next creature on our list. Here is the hallucigenia.
Speaker 1: Hallucigenia well named. Yeah, it almost doesn't need a cool nickname,
Speaker 1: but I know you have one thought up already. How
Speaker 1: about the creeping headless spike worm. Yes, yeah, that's because
Speaker 1: it works because we're essentially looking at a tube of
Speaker 1: flesh with two rows of spines on one side and
Speaker 1: one row of mouth tipped tentacles on the other, and
Speaker 1: on either end, if we're keep in mind here we're
Speaker 1: working from the fossils. Here on either end, there's kind
Speaker 1: of a dark stain. Presumably one of them is the head.
Speaker 1: And presumably the idea here is that, or at least
Speaker 1: the early ideas that it walked about on those spines
Speaker 1: and it waved its tentacles above it. Uh, so you
Speaker 1: had this still walking tentacle waiver something with no modern analogy,
Speaker 1: no modern analogy. It looks like something that you would
Speaker 1: see illustrated in a Wayne Barlow alien book, you know, Yeah, yeah, absolutely,
Speaker 1: or like something um, I don't know. It looks kind
Speaker 1: of like one of those blobs that sometimes shows up
Speaker 1: in a Gary Larson cartoon when he's just trying to
Speaker 1: create a weird alien shape. Yeah, I mean it looks
Speaker 1: like something that would come out of a dream, thus
Speaker 1: its name. You know, it looks it's hallucigen you it's
Speaker 1: something that is that that seems like a fever dream
Speaker 1: of brought to life in a fossil. Now. I think
Speaker 1: this was first first put together by paleontologists in the seventies,
Speaker 1: right right, and then they had there was a subsequent
Speaker 1: find from China that showed a similar creature with a
Speaker 1: second row of tentacles tipped with claws, and then they realized, oh,
Speaker 1: we have it upside down. The creature walked on the
Speaker 1: tentacles and the spikes provided an upward facing protective array.
Speaker 1: So that's a lot. I mean, it's still a weird
Speaker 1: looking critter, don't get me wrong, but that's a lot
Speaker 1: more in keeping us what we might expect. You know,
Speaker 1: that's not that different from say a turtle with legs
Speaker 1: on the bottom and the protective display on the top,
Speaker 1: or any you know, various examples from the invertebrate world.
Speaker 1: I don't know, is that less weird? I'm trying to think. Okay,
Speaker 1: so it's it's like a worm and it's got these
Speaker 1: long tentacles with mouths on them that it walks on. Yeah,
Speaker 1: I mean, it's still weird and it's got spikes sticking up. Okay, yeah,
Speaker 1: I guess a little less weirder than walking on the spikes. Yeah,
Speaker 1: I guess. It's kind of a fun experiment you can
Speaker 1: play anytime you see like a crazy alien illustration. Try
Speaker 1: to decide is it more alien if you turn it
Speaker 1: upside down? Uh? Because yeah, you can either improve upon
Speaker 1: the design or figure out how they came up with
Speaker 1: it to again with maybe. Alright, so let's talk about
Speaker 1: it a little bit bit more here. So, University of
Speaker 1: Durham invertebrate paleontologist Martin R. Smith, who is an interesting
Speaker 1: chap He has a nice online presence. He placed the
Speaker 1: fossil of one of these creatures in an electron microscope
Speaker 1: in an attempt to figure out more about it, and
Speaker 1: one of the pressing questions was name, like which which
Speaker 1: end is the head and which one is the anus? Well, yeah,
Speaker 1: I mean that that's sort of. I knew there was
Speaker 1: some problem with locating its head, and that comes through
Speaker 1: in my name nomenclature of it, the headless spike worm. Now,
Speaker 1: I mentioned the stains earlier, right like, basically from the fossils.
Speaker 1: We knew. We knew that there was like a big
Speaker 1: stain on one end and a smaller stain on the other,
Speaker 1: and one was presumably the head. So the larger stain
Speaker 1: was was for a long time interpreted as a balloon
Speaker 1: like head on this creature. But it turns out it
Speaker 1: was very much a stain. It was the quote, decay
Speaker 1: fluids that had been squeezed out of one end of
Speaker 1: the guts of the organisms. Yeah, so this was the
Speaker 1: anus and the head was on the other side. And
Speaker 1: when they looked to the head, you know what, they
Speaker 1: found hockey mask. Close they found a smiley face. Yeah,
Speaker 1: a pair of eyes with a semicircular grin. Uh. And
Speaker 1: so it was sort of like a they say, it
Speaker 1: was sort of like a caterpillar looking creature. Yeah. Now
Speaker 1: when I say smiley face, it's it's kind of abstract.
Speaker 1: I'm looking at an image of it here. But but
Speaker 1: we can't help but look at it with our with
Speaker 1: our human failings and say, oh, well that's a smiley face.
Speaker 1: Oh hallucigenia, you devil you. Yeah, so hallucigenia is a
Speaker 1: fun one for sure. Stealing my heart, take me somewhere,
Speaker 1: even weirder Robert, all right, well, the next one is
Speaker 1: will Whack see a Boy? And uh, I believe you?
Speaker 1: Did you? Did you come up with a name for
Speaker 1: this one or did I? Okay, I think I actually
Speaker 1: came up with a few different ones here. So it
Speaker 1: looks kind of like a prehistoric iron maiden. It also
Speaker 1: looks like an organic battle him or perhaps a grim
Speaker 1: dark Pokemon, and it provides another splash of of the
Speaker 1: bizarre to the Cambrian seas. So two rows of long
Speaker 1: spines and a kind of plate mail armor of leaf
Speaker 1: shaped ribbed plates again on something that looks like a hat.
Speaker 1: It it looks like a spiked hat like plate mail
Speaker 1: kind of scenario. I can't stress the armor analogy enough.
Speaker 1: It's kind of like a half of a walnut with
Speaker 1: with plate mail on it and knives sticking out. Yeah,
Speaker 1: it looks like something an orc would wear on its head.
Speaker 1: And uh, A lot of the fossils here are essentially
Speaker 1: that we have of this thing are essentially flattened remains
Speaker 1: of this natural armor. Again, it's the hard parts that
Speaker 1: were left with and we just have to try and
Speaker 1: interpret what the soft tissue would have consisted of. And
Speaker 1: there are different interpretations here. Now, Martin Smith, who I
Speaker 1: just mentioned earlier, he favors the mollus interpretation. He says
Speaker 1: that their mouths, which would have been a radula bearing
Speaker 1: two rows of teeth, have several similarities with the teeth
Speaker 1: of modern mollus and uh and then they look nothing
Speaker 1: like worm teeth. Because that's the other argument is that
Speaker 1: these are essentially worm creatures. Specifically they would be bristle worms.
Speaker 1: But that's more of a controversial interpretation. So there's not
Speaker 1: a lot of depth for that particular organism other than
Speaker 1: it just looks really strange. And when you when you
Speaker 1: see illustrations of the Cambrian Sea, you will often find
Speaker 1: it will get will get in there somewhere. It won't
Speaker 1: be the central organism, but it will it will have
Speaker 1: a place in the in the in the illustration. Now
Speaker 1: I've got a question round, Yes, among this ancient Embrillan
Speaker 1: monster house, this sea full of bizarre alien creatures, we
Speaker 1: have to imagine that modern day life forms can trace
Speaker 1: their roots back to organisms that inhabited these oceans, especially
Speaker 1: when you think about very successful modern philo like vertebrates. Yeah,
Speaker 1: because the whole idea here is not that like everything
Speaker 1: dies often and life begins a new Uh, that some
Speaker 1: of these models would would have descendants alive today, I'll
Speaker 1: be rather different to organisms, and we have just such
Speaker 1: a case with Pecaia. Though it's a controversial example, right, Yes, Yeah,
Speaker 1: that this is not this is not set in stone
Speaker 1: that the fossils, of course are. Yeah. You you referred
Speaker 1: to this as the ancestor fish slug or potential potential ancestor.
Speaker 1: So if you're not looking at an image of this creature,
Speaker 1: imagine a sea slug that swims like a modern fish,
Speaker 1: and you've got a clear vision of Pecaia, or at
Speaker 1: least its clear vision as anyone. The crazy thing about
Speaker 1: it is that that scientists point to its not a chord,
Speaker 1: a precursor to the spinal cord, and also a key
Speaker 1: aspect of this creature's swimming mechanics as a reason that
Speaker 1: it could just be an ancestor of all vertebrates, including humans.
Speaker 1: But we're also throwing a curve in all this because
Speaker 1: it has a two lobed head that doesn't sound like
Speaker 1: any vertebrates I've ever heard of. Yeah, scientists remain split
Speaker 1: on this. Now. A nineteen discovery of a primitive fish
Speaker 1: in the Lower Cambrian also suggests that it in Pekaia
Speaker 1: had an even more ancient common ancestor. Okay, so it
Speaker 1: might be that this thing wasn't a direct ancestor of
Speaker 1: existing vertebrates, but that it might have been an offshoot
Speaker 1: of whatever was a direct ancestor of living vertebrates. And
Speaker 1: I think it will make a great Halloween costume for
Speaker 1: anyone out there who's who's not sold on the previous specimens.
Speaker 1: Grandma fish slug. Yeah, yeah, I mean I can just
Speaker 1: imagine it moving like you get used to see ing
Speaker 1: footage of sea slugs and uh similar creatures and the
Speaker 1: way they move. But this would have moved if I'm
Speaker 1: if I'm reading it correctly, more more like a fish,
Speaker 1: more like an eel. So imagine like an eagle slug,
Speaker 1: and that's what you have here totally. Now there's one more.
Speaker 1: I I thought it would be good to mention because
Speaker 1: it's got a slightly love crafty and face, right leon
Speaker 1: Colia the Blind whip Hunter. Yes, it looks kind of
Speaker 1: it's this one's kind of hard to explain really, but
Speaker 1: you know, it looks shrimpy, looks a little flea like
Speaker 1: but imagine a blind monster that stumbles around in the
Speaker 1: murk just bull whipping everything in its vicinity with flails
Speaker 1: and then just really whipping the heck out of potential prey,
Speaker 1: so whips coming out of its face. Yes, and that's
Speaker 1: what we have with leon Colia. Now we assume it
Speaker 1: was blind because we haven't found evidence of I stalks yet,
Speaker 1: which if the thing, of course is that given these
Speaker 1: previous examples, it's entirely likely that that that could occur.
Speaker 1: At some point a future fossil find will reveal, oh, well,
Speaker 1: they did have eye structures and they look like this,
Speaker 1: but for the time being, the ideas that they were
Speaker 1: seemingly blind. The creature here was about two inches long,
Speaker 1: and it's usually classified as an as an arthropod, though
Speaker 1: sometimes it's thrown into the arachnomorph subgroups, which would connect it,
Speaker 1: you know, more to scorpions in trilobytes. But still it's
Speaker 1: a fascinating creature to try and imagine, especially in this
Speaker 1: this changing time where eyesight is coming online for various
Speaker 1: organisms and new new methods of exploiting other organisms are
Speaker 1: becoming possible, and this one is just whipping things with
Speaker 1: its face un fel it can eat something. Yeah, So
Speaker 1: I guess that's going to have to conclude our tour
Speaker 1: of the Cambrian monsters. But I do want to ask you, Robert.
Speaker 1: So clearly we have not exhausted all of the fascinating
Speaker 1: questions about the Cambrian period and the the emergence of biodiversity,
Speaker 1: animal biodiversity, especially in the Cambrian periods. So I want
Speaker 1: to ask you which of the Cambrian explosion theories we've
Speaker 1: discussed today appeals to you the most. Obviously we haven't
Speaker 1: covered all of the possibilities. There are other possible explanations
Speaker 1: out there. But what what what? What strikes true to you? Like?
Speaker 1: What sounds right? Does it? Could it have been site
Speaker 1: as the thing that triggered all of this biodiversity, or
Speaker 1: the innovation of predation and carnivary, or the chemistry for biomineralization,
Speaker 1: or is it just this sampling bias where you know,
Speaker 1: maybe that there isn't as much bio innovation in this
Speaker 1: period as it seems just from the fossil record. I mean,
Speaker 1: I guess I could play it safe and say a
Speaker 1: little bit of all of those, but but I guess
Speaker 1: I tend to buy more into the predation and and
Speaker 1: cite arguments with some support by by by some of
Speaker 1: the additional arguments. But but those are the two that
Speaker 1: I guess I feel like they have the most meat
Speaker 1: for me. But then again, I'm not a I'm not
Speaker 1: a a scientist, you know, specializing in this time period.
Speaker 1: But but those are the ones that I feel like
Speaker 1: the most. Maybe it's just calling to the five year
Speaker 1: old of me. It's the it's the explanation that involves
Speaker 1: creatures warring with each other and battling each other, and
Speaker 1: therefore that's the one that I can imagine. Yeah, it's
Speaker 1: hard to resist, now, I know, I've I think I
Speaker 1: read at some point that one of the arguments against
Speaker 1: the site hypothesis is just that site doesn't generally matter
Speaker 1: in the water, and especially in the deep water, as
Speaker 1: much as it does on land. And not that it
Speaker 1: doesn't matter at all, it does, but that you know,
Speaker 1: things like smell and hearing and stuff like that are
Speaker 1: more useful in the ocean. But yeah, I don't know,
Speaker 1: I'm not sure which I'm most convinced by. The predation
Speaker 1: one seems very interesting to me that if animals weren't
Speaker 1: really capitalizing on getting their energy from other more large
Speaker 1: sized animals before and suddenly they started doing that. That
Speaker 1: that could be you know, a game changer. It's also
Speaker 1: kind of an original sin type scenario too. It feels
Speaker 1: very mythic, right like that that the first creature to
Speaker 1: figure out that it can it can prey on its
Speaker 1: fellow organisms. And how does that occur? Like obviously it's
Speaker 1: it's not just a situation of one day, Uh this
Speaker 1: this creature just takes a bite out of another one
Speaker 1: Like it's going to be a more gradual process and uh,
Speaker 1: you know, and I'm likely begins with some sort of
Speaker 1: gray area of competition for food, like for instance, a
Speaker 1: creature it becomes adapt at stealing food from either maybe
Speaker 1: stealing food from its mouth, and what happens if you
Speaker 1: steal food from another creature's belly? Yeah, you know, I
Speaker 1: mean that That is the difficulty of this hypothesis is
Speaker 1: you have to imagine what's the process that gets you
Speaker 1: there by gradual evolutionary change, Even if it's geologically rapid,
Speaker 1: it still would have been gradual in biological terms. Um,
Speaker 1: trying to you know, go from an organism organisms that
Speaker 1: are all basically vegetarian to some organisms eating other animals. Yeah, yeah,
Speaker 1: Like another example that comes to mind, as of course,
Speaker 1: animals that will consume their own young or their own eggs.
Speaker 1: We've talked about, you know, the parental cannibalism to sort
Speaker 1: of re absorb essentially lost energy, and how that could
Speaker 1: seemingly be an avenue into the UH into inter predation,
Speaker 1: because if you're absorbing your own biomatter back into yourself,
Speaker 1: then it becomes a less of a leap to absorb
Speaker 1: the biomatter of another. I can also see a scavenging
Speaker 1: to predation route that maybe uh, the the gradual changes
Speaker 1: that allow you to better and better extracts nutrition from
Speaker 1: dead animals that you find on the bottom of the
Speaker 1: ocean could eventually become useful in killing live animals right right.
Speaker 1: Or you could just always do it and an angel
Speaker 1: told you not to until a snake suggested otherwise, just
Speaker 1: another possibility that could be it. Well, Robert, I don't
Speaker 1: I don't get the feeling that we're done with the
Speaker 1: Cambrian period. I think we may come back here in
Speaker 1: the few true to explore some other scientific issues and
Speaker 1: when there may be other things to discuss with the
Speaker 1: Burdge of Shale as well. Yeah, and uh, and in general,
Speaker 1: I'd love to do some more episodes in the future
Speaker 1: regarding prehistoric creatures. I feel like this is something we
Speaker 1: come back to time and time again, well at least
Speaker 1: on what a bi monthly uh kind of pattern, I guess. So,
Speaker 1: I mean it's it's the seven year old in me.
Speaker 1: I've I've never gotten over how much I love dinosaurs
Speaker 1: and other weird organisms that don't exist today. It's it's
Speaker 1: part of my love for monsters, and it's part of
Speaker 1: what keeps bringing me back to paleontology. All right, well,
Speaker 1: we'll leave it at that, but in the meantime, definitely
Speaker 1: check out Stuff to Blow your Mind dot Com. I'll
Speaker 1: check out the landing page for this episode because again
Speaker 1: I'm gonna try to try to include images, illustrations of
Speaker 1: fossil representations, whatever I can find for each of the
Speaker 1: organisms presented here, so you can have some additional visual
Speaker 1: idea of what we're talking about. And I'll include links
Speaker 1: back to some of our other episodes that have dealt
Speaker 1: with prehistoric organisms. And if you want to get in
Speaker 1: touch with us directly with feedback about this episode or
Speaker 1: any other to suggest future episode topic. You can always
Speaker 1: email us at blow the Mind at how stuff works
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