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
Speaker 1: today is going to be part two of a two
Speaker 1: part episode about the aquatic Humanoid. Now, last time, we
Speaker 1: really focused on the mythology and cultural beliefs about our
Speaker 1: aquatic counterparts, the humanoid types who live in the depths
Speaker 1: and there. This is a trope all throughout fiction. You
Speaker 1: find it in u in all kinds of human cultures.
Speaker 1: But one thing I think we didn't discuss last time,
Speaker 1: or if we did, it's my memory is not serving
Speaker 1: me well. Is the movie Leviathans. Oh. Yes, one of
Speaker 1: the one of the several nineteen eighty nine underwater Peril
Speaker 1: movies that that we keep chatting about, and at least
Speaker 1: in a previous episode. I'm not sure if we we
Speaker 1: talked about it in The Aquatic Humanoids Part one or not.
Speaker 1: We've talked about it so much recently I can't even
Speaker 1: recall when it happened. But anyway, Yeah, so nine you
Speaker 1: had James Cameron's The Abyss, but you also had Deep
Speaker 1: Star six Leviathan, Lords of the deep for some reason,
Speaker 1: everybody went nuts making underwater sci fi movies. Yeah, we've been,
Speaker 1: so I'm just trying to piece together in a casual
Speaker 1: way why that was, you know what what was happening
Speaker 1: in the world. Was it I did have to do
Speaker 1: with the with recent underwater exploration that really inspired everybody
Speaker 1: at the same time, or did everyone just know that
Speaker 1: the abyss was coming and it made sense for all
Speaker 1: the various cinematic lamp preyests to converge upon it. Now,
Speaker 1: Leviathan is a I think you'll back me up here,
Speaker 1: a terrible movie, but a great terrible movie. It is. Ah,
Speaker 1: it is a thoroughly enjoyable, flawed film. It's the that's
Speaker 1: the type of bad movie that I just really eat
Speaker 1: up that ends up in I think inspiring me more
Speaker 1: than good underwater movies. Yeah, it's such an alien rip off.
Speaker 1: The DVD I had of it it actually said, is
Speaker 1: alien underwater? That's the whole quote. Yeah, it is highly derivative,
Speaker 1: but it god that the cast is so good and
Speaker 1: the look of the film like it has a Stan
Speaker 1: Winston Studios monster in it, so you know that's gonna
Speaker 1: look like a million bucks, and the the the overall
Speaker 1: sets that are used, especially the interior sets for this
Speaker 1: underwater station, are tremendous. Like the set does as much
Speaker 1: as the cast does, really to create a sense of
Speaker 1: backstory for these characters. You know, in a way, the
Speaker 1: sleaziness of Daniel Stearns performance in the movie is kind
Speaker 1: of a set in its own. It's like a landscape
Speaker 1: of sleez and obnoxiousness. Yeah, he plays this sleazy character
Speaker 1: named six Pack, I believe, and it's easy to think
Speaker 1: back on the film and think that their moments where
Speaker 1: the character reaches peak sleaziness, but he really just achieves
Speaker 1: a high plateau of sleaziness throughout his time in the film. Okay,
Speaker 1: let's not dwell on Leviathan too much, but it does
Speaker 1: relate to what we're gonna talk about today. So today
Speaker 1: we wanted to address some of the biological ideas about
Speaker 1: aquatic humanoids. And so one of the things in Leviathan
Speaker 1: is you spoiler alert for this nineteen eighty nine B movie.
Speaker 1: You find out that the Russians in the movie, you're
Speaker 1: trying to create an aquatic humanoid through genetic alteration. Right,
Speaker 1: of course that ends up creating a monster. A monster
Speaker 1: I should add that is in many ways kind of
Speaker 1: an ichno centaur, which we discussed in the first episode,
Speaker 1: this sort of hybrid of different parts creating this this
Speaker 1: kind of large centaur esque chimera. So, yeah, you've got
Speaker 1: this giant monster that's basically got a catfish head and
Speaker 1: then it's got Daniel Stearn's face sticking out of its
Speaker 1: back and some other random tentacles and Lamprey's poking off
Speaker 1: of it. But this was, in the context of the film,
Speaker 1: an attempt to create Homo aquaticus, the human version of
Speaker 1: an underwater creature, or maybe the underwater version of the
Speaker 1: human today. We want to look at could such a
Speaker 1: creature exist and what would it look like biologically? And
Speaker 1: if the quatic humanoids could exist in reality, how would
Speaker 1: they figure into our our picture of human evolution. Yeah,
Speaker 1: it's it's a fascinating question, of course that you know.
Speaker 1: The the easy answer is, of course, yes, all life
Speaker 1: came from the sea, and we have plenty of cases
Speaker 1: of terrestrial life returning to the sea. So we're not
Speaker 1: talking about just complete whackadoodle ideas about about life emerging
Speaker 1: from one or descending into the other. Right, you are
Speaker 1: correct to point out that that leaving the water for
Speaker 1: terrestrial existence can happen, and then leaving terrestria is that
Speaker 1: the now, and I guess leaving the land for a
Speaker 1: watery existence can also happen. These are totally biologically plausible
Speaker 1: scenarios and they happen all the time. But could it
Speaker 1: happen with us? And in fact, has it already happened
Speaker 1: with us? So I guess it's time to venture into
Speaker 1: something that people have asked us to discuss on the
Speaker 1: show before. We we've never done it before, but it
Speaker 1: is a fringe hypothesis and human evolution called the aquatic
Speaker 1: ape hypothesis. Yes, and and of course that instantly summons
Speaker 1: the images of a guerrilla mermaid. I will not, I
Speaker 1: will not try to convince you to dismiss that that
Speaker 1: apparition from your mind. But but it is almost impossible
Speaker 1: not to think of that. So now you're saying, like
Speaker 1: fish tail with guerrilla top, not like not like mermaid
Speaker 1: top with guerrilla legs. No no, no fish fish on
Speaker 1: the bottom, uh, silverback grilla on the top. That's the
Speaker 1: only way to put it together, Marilla. Yeah, not exactly,
Speaker 1: but close. Now, before we get into the specifics, of
Speaker 1: the hypothesis. I just want to start by cautioning that
Speaker 1: this is not a hypothesis that is widely accepted by
Speaker 1: scientists or biologists. It's generally frowned upon by paleo anthropologists
Speaker 1: and other people who study the history of human evolution.
Speaker 1: But I think it's worth addressing, especially since people have
Speaker 1: asked about it before, and it fits into this model
Speaker 1: of the aquatic humanoid and creates at least a plausible
Speaker 1: sounding scenario in which there could have been an aquatic humanoid. Yeah,
Speaker 1: if we entered into it as a as an alternate hypothesis,
Speaker 1: if we enter into it as a thought experiment, and
Speaker 1: we do not enter into it trying to make an
Speaker 1: argument for the existence of Triton's or or mer people
Speaker 1: or some sort of underwater race, then I think we're
Speaker 1: in safe waters. Okay, So it starts with a simple observation.
Speaker 1: Our closest relatives in the animal kingdom are the other
Speaker 1: great apes, also known as hominids or the family Homonide.
Speaker 1: This includes orangutans, guerrillas, chimpanzees, and binobos, and genetically we
Speaker 1: are extremely similar to these animals, especially to chimpanzees and
Speaker 1: binobo's anatomically, we're also extremely similar to them. If you
Speaker 1: look at all of our body parts in the way
Speaker 1: they fit together. We're very, very close to these animals.
Speaker 1: But there are a few key differences, and some of
Speaker 1: the most major of these key differences are that we
Speaker 1: are mostly hair us bipeds were naked, smooth skinned, and
Speaker 1: we walk on two legs. And meanwhile, all these other
Speaker 1: animals are hairy quadrupeds. They're covered from head to toe
Speaker 1: in in hair for and usually walk on four legs.
Speaker 1: So why that difference? What happened in the history of
Speaker 1: only the human branch of this family to drive our
Speaker 1: ancestors to become relatively smooth and bipedal while the rest
Speaker 1: of our closest cousins didn't. Now just a note, I've
Speaker 1: often seen this framed in terms of questions like, quote,
Speaker 1: how did we get from chimpanzees to humans? That question
Speaker 1: is obviously nonsense, because we didn't get from chimpanzees to humans.
Speaker 1: Both chimpanzees and humans came from something that lived more
Speaker 1: than four million years ago. Chimpanzees are our cousins, not
Speaker 1: our ancestors. But the question is why do humans look
Speaker 1: different from them? And from every other hominid given that
Speaker 1: were such close cousins. Well, in March nineteen sixty a
Speaker 1: British marine biologist named Alistair Hardy published an article and
Speaker 1: New Scientists arguing for a pretty startling answer to this.
Speaker 1: Hardy said, in the distant past, our ancestors distinguished themselves
Speaker 1: from the other great apes or the other great ape
Speaker 1: ancestors by becoming an aquatic organism. So the idea here's
Speaker 1: our ancestors adapted to life in the water for a
Speaker 1: while and then return to land exactly, and that that
Speaker 1: shaped the differences between humans today and the other great apes.
Speaker 1: And so in this article, Hardy summarized his hypothesis about
Speaker 1: how quote man's immediate ancestors diverged from quote more ape
Speaker 1: like forms as follows. My thesis is that a branch
Speaker 1: of this primitive ape stock was forced by competition from
Speaker 1: life in the trees to feed on the seashores and
Speaker 1: to hunt for food shellfish, sea urchins, etcetera, in the
Speaker 1: shallow waters off the coast. I suppose that they were
Speaker 1: forced into the water, just as we have seen happen
Speaker 1: in so many other groups of terrestrial animals. I'm imagining
Speaker 1: this happening in the warmer parts of the world, in
Speaker 1: the tropical seas, where man could stand being in the
Speaker 1: water for relatively long periods, that is, several hours at
Speaker 1: a stretch. I imagine him waiting at first, perhaps still
Speaker 1: crouching almost on all fours, groping about in the water,
Speaker 1: digging for shellfish, but becoming gradually more adept at swimming.
Speaker 1: Then in time I see him becoming more and more
Speaker 1: of an aquatic animal, going farther out from the shore,
Speaker 1: I see him diving for shellfish, prizing out worms, burrowing
Speaker 1: crabs and bivalves from the sands at the bottom of
Speaker 1: shallow seas, and breaking open sea urchins, and then with
Speaker 1: increasing skill, capturing fish with his hands. And of course
Speaker 1: this match is of the what we know about human
Speaker 1: cultures that have a legacy of existing close to the
Speaker 1: sea and upon the sea. Yeah, now this is describing
Speaker 1: what we might call a semi aquatic existence rather than
Speaker 1: a fully aquatic existence. Right, So it's not that we
Speaker 1: became whales and lived entirely in the water, but that
Speaker 1: the hypothesis is that we sort of became like Homo beachkus,
Speaker 1: that we live adjacent to the water and spent a
Speaker 1: whole lot of time in it. Homo biwa chicas like it. Now,
Speaker 1: this might sound crazy, and as we said, it is
Speaker 1: certainly not accepted by mainstream biologists or paleo anthropologists, but
Speaker 1: I want to say that there's nothing in principle wrong
Speaker 1: with the idea of a land dwelling mammal evolving to
Speaker 1: become an aquatic creature. We mentioned this earlier, but just
Speaker 1: to reiterate, like, where do you think whales and dolphins
Speaker 1: came from? More than fifty million years ago, The ancestors
Speaker 1: of whales and dolphins were four legged, land dwelling mammals
Speaker 1: that went through many stages of evolution deeper and deeper
Speaker 1: into the water. They started as these creatures that lived
Speaker 1: adjacent to the water and spent more and more time
Speaker 1: in the water over the generations, becoming more and more
Speaker 1: adapted to it, from the semi aquatic waiting lifestyle of
Speaker 1: pachactas and into high us to like this more otter
Speaker 1: like existence of this creature called ambulositis, and then eventually
Speaker 1: two creatures like the Dora down which start to look
Speaker 1: sort of like modern whales with eyes on the side
Speaker 1: and the breathing hole dorsally migrated up toward the top
Speaker 1: of the head. And there's a similar story with pinnipeds
Speaker 1: like seals and sea lions. They're believed to have evolved
Speaker 1: from land dwelling quadrupeds that were something more like bears
Speaker 1: or musta Lloyd's meaning things like skunks, raccoons, or weasels.
Speaker 1: So evolution of land dwelling mammals into water dwelling mammals
Speaker 1: is not only possible, it has happened lots of times.
Speaker 1: This is something that's totally biologically plausible. The plausibility of
Speaker 1: that scenario is not something that's necessarily a problem with
Speaker 1: the aquatic a hypothesis. The problems come in later because
Speaker 1: what's the real question, did it specifically happen to our ancestors? Right?
Speaker 1: Because if it, if it did happen, we should be
Speaker 1: able to find some evidence of it. Right. So, as
Speaker 1: we said, this, this hypothesis is not popular with scientists
Speaker 1: and experts in the field, but it has really continued
Speaker 1: to capture the interest of the public since it was
Speaker 1: first introduced. So it was first proposed by, as we said,
Speaker 1: the British marine biologist Alastair Hardy in nineteen sixty but
Speaker 1: it was really most popularized by a Welsh author named
Speaker 1: Elaine Morgan in the nineteen seventies and eighties, primarily through
Speaker 1: she She wrote about it in a book called The
Speaker 1: Descent of Woman, but then also in a book called
Speaker 1: The Aquatic Ape. And so Morgan's argument for the aquatic
Speaker 1: ape hypothesis is interesting, and she she summarized it in
Speaker 1: a TED talk in two thousand nine before she passed
Speaker 1: away in two thousand thirteen. And so I think maybe
Speaker 1: we should look at some of the specifics of her argument.
Speaker 1: Uh so then we can. We can think about them
Speaker 1: and see how they stack up. All right, But before
Speaker 1: we do that, let's take a quick break, and when
Speaker 1: we come back, we'll dive in to the aquatic ape
Speaker 1: theory some more than thank alright, we're back, alright. So
Speaker 1: Morgan's talk has a lot of framing material in it
Speaker 1: where she sort of lays the context for her argument
Speaker 1: by talking about the idea of paradigm shifts and science
Speaker 1: and about how scientific consensus has often been wrong in
Speaker 1: the past. That's absolutely true. Scientific consensus has very often
Speaker 1: been disproved um. But one of the things I think
Speaker 1: we should be cautious about is when you start to
Speaker 1: hear somebody using that fact as an argument for their argument,
Speaker 1: if you know what I mean, it's often the opening
Speaker 1: argument of somebody who's about to lay some some some
Speaker 1: really fringe theory on you. Right, So, it is true
Speaker 1: that scientific consensus has often been wrong, but the fact
Speaker 1: that it has often been wrong is not evidence that
Speaker 1: your particular bucking of it is correct. Now, so what
Speaker 1: is the evidence that Morgan presents for her hypothesis. Well, so,
Speaker 1: first of all, she looks at the really obvious thing.
Speaker 1: Where's all the hair, right, the naked skin. When you
Speaker 1: look for other mammals without body hair like us, they're
Speaker 1: almost all, she says, water dwelling creatures, the dugong, the walrus, dolphins, whales,
Speaker 1: the hippopotamus, the manateee. Yeah. The only other example that
Speaker 1: comes to mind is, of course, the naked mole rat um,
Speaker 1: which is also kind of a special case given in
Speaker 1: it's a subterranean rodent that lives with a with a
Speaker 1: hive like structure. Yeah, she mentions it actually, uh, And
Speaker 1: then she says, wait a minute, wait a minute, what
Speaker 1: about the elephant. That's a land dwelling mammal without much
Speaker 1: body hair? Well, Morgan says, it turns out that more
Speaker 1: recent studies have found that the elephant had an aquatic ancestor.
Speaker 1: I looked this up to make sure she's she's sort
Speaker 1: of correct about this. The elephants are related to an
Speaker 1: ancient mammal called the more ethereum, which apparently was semi
Speaker 1: aquatic lived in around swamps and rivers. Maybe not necessarily
Speaker 1: a direct ancestor of the elephant, but a very close
Speaker 1: ancient relative of elephants. She says, there's a strong correlation
Speaker 1: between nakedness and water. There's some hairy or furry mammals
Speaker 1: that do live in the water, right, You can think
Speaker 1: of a few, Oh yeah, I mean the otters, beavers.
Speaker 1: If you want to make a stretch. You can even
Speaker 1: look at things like like the polar bear, which does
Speaker 1: is not an aquatic mammal per se, but does spend
Speaker 1: a lot of time in the water and is an
Speaker 1: adept swimmer. Yeah, but there, She says. There are almost
Speaker 1: no hairless or smooth mammals that do not either live
Speaker 1: in the water or have fairly recent ancestors that lived
Speaker 1: in the water, and she claims that the only exception,
Speaker 1: as we mentioned, is the naked Somalian mole rat, which
Speaker 1: she says, quote never puts its nose above the surface
Speaker 1: of the ground. Then there's the question of bipedality, right,
Speaker 1: there's no real comparison in nature because we're the only
Speaker 1: mammal that walks consistently on two legs. According to Morgan,
Speaker 1: all the things rear up at the time. You know,
Speaker 1: at times a cat will rear up on two legs
Speaker 1: and look exceedingly creepy, but that's at leg the rest
Speaker 1: of the time. Now that's mammals. Of course, once you
Speaker 1: start looking into birds and dinosaurs, of course you get
Speaker 1: basically humanoids by this characteristic. But the some four legged animals,
Speaker 1: of course, as we say, can occasionally stand up on
Speaker 1: two legs. When do our closest ape relatives walk on
Speaker 1: two legs? Well, Morgan claims there's only one circumstance when
Speaker 1: they always walk on two legs, and it's when they're
Speaker 1: wading through water. You should remember that, because I want
Speaker 1: to take issue with that in a bit. Then she
Speaker 1: she marshals some more evidence. She says that how about
Speaker 1: subcutaneous fat. Morgan says, we have a layer of fat
Speaker 1: running underneath our skin and other great apes don't have this.
Speaker 1: They're fat is stored more internally around their kidneys and
Speaker 1: so forth, and our fat is stored largely in this
Speaker 1: layer under our skin, similar to other water dwelling animals,
Speaker 1: kind of a blubber layer basically. Yeah, I mean, it's
Speaker 1: kind of an unfair comparison to make here, but we've
Speaker 1: all seen these images of a hairless guerrilla and they're
Speaker 1: just completely jacked, just conceedingly ripped in ways. It's like
Speaker 1: hilarious muscles, comic book cover muscles. Yeah, that it is
Speaker 1: a comic book physique, and the kind of which you
Speaker 1: you rarely see in in the average human. Here's another one.
Speaker 1: She says, how about speech. This is a pretty big difference, right,
Speaker 1: Oh yeah, I mean that's one of the defining properties
Speaker 1: of of humans. Yeah. In fact, you know, there are
Speaker 1: a lot of people who would make the case, including
Speaker 1: somebody we've had on the show in the past. Friends
Speaker 1: at evolved that a lot of the distinctions we try
Speaker 1: to make that really separate humans and other animals by
Speaker 1: some hard line of division, The lines a lot blurrier
Speaker 1: than you might think. But one thing he sort of
Speaker 1: made allowances for is maybe language that we that is
Speaker 1: the closest thing we've got to like a real edge
Speaker 1: on other animals. And so how come we can talk
Speaker 1: and other hominids can't. Well, Morgan claims that the difference
Speaker 1: between a human and a gorilla is not in the
Speaker 1: speech producing organs of the throat and the lungs, but
Speaker 1: in the ability to consciously control the use of breath.
Speaker 1: And this is interesting to me because I think I've
Speaker 1: asked this on the show before. But why are some
Speaker 1: body processes controlled entirely by the unconscious nervous system while
Speaker 1: others are conscious and others can be toggled on and
Speaker 1: off between conscious and unconscious control. Like you can't consciously
Speaker 1: toggle on and off your digestion or your heartbeat or
Speaker 1: your metabolism. But even though most of the time your
Speaker 1: breathing is unconscious and automatic, you can take it over
Speaker 1: with your executive control and consciously toggle your breath on
Speaker 1: and off if you want to, like what causes this difference? Yeah,
Speaker 1: I mean, if memory serves me correctly, thinking back to
Speaker 1: our John C. Lily episodes in the past, uh, dolphins
Speaker 1: UH have such manual control over their breathing that they
Speaker 1: can arguably decide to just shut it down and to
Speaker 1: drown themselves. Wow. Well, I mean that would be an
Speaker 1: example that would sort of go with her hypothesis. Right.
Speaker 1: The idea is that, uh, the only reason we would
Speaker 1: be able to evolve this conscious control of our breath
Speaker 1: is if our past ancestors were shaped by a selection
Speaker 1: pressure that favored the ability to like hold the breath
Speaker 1: and dive underwater. She says, This would explain a lot.
Speaker 1: I do think that's a really interesting question of why
Speaker 1: we can do that. I'm not sure I'm going to
Speaker 1: go along with her on this being an exclusively human
Speaker 1: and aquatic mammal trait because I don't know. I've seen
Speaker 1: videos of dogs diving deep underwater and other mammals doing that.
Speaker 1: It seems that they have some kind of ability to
Speaker 1: hold their breath and they're not semi aquatic mammals. Yeah,
Speaker 1: I would agree with that. Okay, Another thing, she says,
Speaker 1: how about hydrodynamics. We are anatomically streamlined. Do you ever
Speaker 1: think about why is the human body basically a straight line?
Speaker 1: Why are we sort of dart ape where we can
Speaker 1: dive smoothly into the water. She says, quote, try to
Speaker 1: imagine a guerrilla diving into water. I think I've seen
Speaker 1: it done in a cartoon, but that's about it. Well,
Speaker 1: they it's like a cannonball, right, they make a big splash.
Speaker 1: Morgan says, we're halfway between being a chimp into fish
Speaker 1: and so Morgan, after marshaling this evidence, she says that
Speaker 1: she wants to insist the idea is not lunatic fringe.
Speaker 1: And I'd say I largely agree. I think it's probably wrong,
Speaker 1: but I don't think it's like the ancient aliens hypothesis
Speaker 1: or something. I think it is an extraneous hypothesis that
Speaker 1: that we don't really need to resort to, and so
Speaker 1: it's not parsimonious, but I think it's like reasonable to
Speaker 1: play around with this idea. Yeah, I would agree it
Speaker 1: is certainly not ancient aliens. But there are some some issues,
Speaker 1: some some problems, and some gaps that have not been
Speaker 1: filled in by uh fossil evidence for example. Right, But
Speaker 1: the real question is like, what is the substance of
Speaker 1: the critique from biology and paleo anthropology. Why would they
Speaker 1: not accept this hypothesis. So, starting with a few answers,
Speaker 1: probably the biggest weakness for the hypothesis is and this
Speaker 1: might sound kind of silly when we say it, but
Speaker 1: there's no direct evidence for it. There's no fossil evidence
Speaker 1: whatsoever that we've ever had any instance of an aquatic humanoid. Right,
Speaker 1: show me the remains of the aquatic humanoid, and it
Speaker 1: is the directive, and we do not have an answer. Yeah,
Speaker 1: nothing like that. Now, So this means it's all inference
Speaker 1: and speculation. It doesn't make it necessarily wrong because we're
Speaker 1: talking about the ancient past, and sometimes when we're trying
Speaker 1: to figure stuff out about the ancient past, we don't
Speaker 1: have direct evidence. Sometimes we're just in that situation and
Speaker 1: all you've got is inference in speculation. So you just
Speaker 1: try to find the best most plausible inference and speculation
Speaker 1: to form your eye ideas around. But we have to
Speaker 1: acknowledge that there is no direct evidence for it, and
Speaker 1: so it's kind of in a weak starting place. Physical
Speaker 1: evidence would make a huge difference. Now. I came across
Speaker 1: another criticism of the aquatic aphypothesis by the paleo anthropologist
Speaker 1: John Hawks of the University of Wisconsin Madison. UH. He
Speaker 1: runs a popular paleo anthropology blog, and he put a
Speaker 1: post on his blog about this idea. UH some of
Speaker 1: the points he makes are are pretty interesting. One of
Speaker 1: the things is that Hawks claims the aquatic ap hypothesis
Speaker 1: is not parsimonious. Now, parsimony refers to the idea of
Speaker 1: the number of assumptions you have to make without evidence
Speaker 1: in order to entertain a hypothesis. So, for a quick example,
Speaker 1: imagine you leave a sandwich sitting on your desk at work.
Speaker 1: You walk away for a minute, you come back, there
Speaker 1: is a human bite shaped chunk of the sandwich missing. Okay,
Speaker 1: Now you look around, everybody's just working like normal. Noe,
Speaker 1: no direct evidence of what happened. So you have to
Speaker 1: make an inference. Right by the way, I am picturing
Speaker 1: the scenario taking place in the movie Leviathan of those coworkers. Right, So, yeah,
Speaker 1: did did Daniel Stern take a bite out of your sandwich?
Speaker 1: Or what happened? Since there's no unusual behavior, no sign
Speaker 1: of anything wrong, you've just got to come up with
Speaker 1: a hypothesis that seems reasonable. Now, you could hypothesize that
Speaker 1: Daniel Stern or another one of your coworkers took a
Speaker 1: bite out of the sandwich, or you could hypothesize that
Speaker 1: a polar bear snuck into your office undetected, and this
Speaker 1: was a polar bear that had undergone a surgical body
Speaker 1: modification so that its mouth had an uncharacteristically human shaped bite.
Speaker 1: And then it took a bite out of your sandwich
Speaker 1: with its surgical human mouth, and it didn't like it,
Speaker 1: and it snuck away without being noticed. Yeah, that that
Speaker 1: explanation is is much further removed from reality and requires
Speaker 1: a number of different steps to get there. But like
Speaker 1: the aquatic a hypothesis, it's internally consistent, right, I mean,
Speaker 1: there's nothing on the face of it that makes that impossible.
Speaker 1: It's just it requires a bunch of extra assumptions. Yeah, well,
Speaker 1: I mean, like one, it's basically like any investigation, right, Like,
Speaker 1: if you were investigating an actual sandwich incident in your workplace,
Speaker 1: it's far more likely that someone in the office did
Speaker 1: it than someone from a neighboring office who would have
Speaker 1: a harder time accessing the location in which the sandwich
Speaker 1: is stored. Yeah, then you'd also have to hypothesize them
Speaker 1: sneaking in and all that, And like the further away
Speaker 1: you get from the sandwich from your office, they the
Speaker 1: moral leap. It becomes. Right, So the main reason you'd
Speaker 1: favor the coworker hypothesis is that you have to make
Speaker 1: many fewer assumptions without evidence to assume it, and so
Speaker 1: at first glance, this kind of thinking can make something
Speaker 1: like the aquatic a hypothesis look good actually, because hey,
Speaker 1: wait a minute, it's just one assumption you have to
Speaker 1: make in order to explain all this different stuff. But
Speaker 1: the more you examine it, the more it becomes clear
Speaker 1: that the aquatic a hypothesis actually requires a lot of
Speaker 1: assumptions of things not in evidence that just sort of
Speaker 1: get rolled up into one big scenario you're picturing. You
Speaker 1: can say that all how about all evolutionary increments and
Speaker 1: all steps in evolution of all creatures are caused by
Speaker 1: the ghost of biology, which is a spirit that lives
Speaker 1: in the sky that decides that a creature should change
Speaker 1: and then makes little mutations to change it over time.
Speaker 1: That's just one assumption that explains absolutely everything in biology.
Speaker 1: But yeah, but it's a big assumption that that defies
Speaker 1: or at least goes beyond the laws of science. It's
Speaker 1: like saying a ghost took a bite out of the sandwich. Yeah,
Speaker 1: it's only one step, but it's a step that that
Speaker 1: goes beyond uh, the scientific understanding of the workplace or
Speaker 1: the world itself. But then actually Hawks makes another point
Speaker 1: that I think is a crucial extension of this idea.
Speaker 1: So it's not just what we've already meant and about
Speaker 1: some types of assumptions appearing parsimonious, but actually requiring a
Speaker 1: lot of assumptions even though they only seem to be
Speaker 1: one scenario. Hawks actually shows a second way that it's
Speaker 1: not parsimonious, and he writes, quote, certainly, it makes sense
Speaker 1: that hominids would develop new anatomies to adapt to such
Speaker 1: an alien environment. He's talking about adapting to the water.
Speaker 1: But once those hominids returned to land, forsaking their aquatic homeland,
Speaker 1: the same features that were adaptive in the water would
Speaker 1: now be maladaptive on land. What would prevent those hominids
Speaker 1: from reverting to the features of their land based ancestors,
Speaker 1: as well as nearly every other medium sized land mammal.
Speaker 1: More than simple phylogenetic inertia is required to explain this,
Speaker 1: since the very reasons that the aquatic ape theory rejects
Speaker 1: the Savannah model would apply to the descendants of the
Speaker 1: aquatic apes once they moved to the savannah. This is
Speaker 1: far from trivial, since fossil hominids did inhabit open woodlands
Speaker 1: starting by eight million years ago and did move to
Speaker 1: the open savannah by three million years ago. Okay, so
Speaker 1: the idea here is that want you could maybe reasonably
Speaker 1: make the argument that all right, the aquatic humanoids move
Speaker 1: out of the water, but they're still living close enough
Speaker 1: to the water. They're still going in the water. Uh,
Speaker 1: you know, there's still a coastal species. You can say, well,
Speaker 1: maybe they retain some of those features. But if they're
Speaker 1: moving further inland, if they're becoming an inland species of
Speaker 1: savannah species, then they wouldn't need those adaptations anymore. The
Speaker 1: the the economy of natural selection would drive those away. Yeah.
Speaker 1: One thing to be clear about here is that a
Speaker 1: very commonly still believed but actually now obsolete hypothesis is
Speaker 1: the idea that anatomical modernity in human beings evolved on
Speaker 1: the savannah, that we became basically the animals we are
Speaker 1: now on the savannah landscape. That used to be believed,
Speaker 1: and now that's not true anymore. What what generally is
Speaker 1: believed is that we became basically Homo sapiens in a
Speaker 1: woodland environment and in something you know, basically a tree
Speaker 1: oriented existence, and then later moved to the savannah. Now,
Speaker 1: the aquatic a hypothesis is saying, no, somewhere in there
Speaker 1: before we got to the savannah, we were in the
Speaker 1: water if if that's true, though, we eventually moved back
Speaker 1: to the savannah, and these traits that we've still got
Speaker 1: had to somehow be adaptive to the savannah. So why
Speaker 1: aren't you just assuming that they're the traits that were
Speaker 1: adaptive on the savannah. Yeah, this is this is a
Speaker 1: strong point. Yeah, and so to continue, hawks says quote.
Speaker 1: In other words, the aquatic ape theory explains all of
Speaker 1: these features, but it explains them all twice. Every one
Speaker 1: of the features encompassed by the theory still requires a
Speaker 1: reason for it to be maintained after hominids left the
Speaker 1: aquatic environment. So it feels like it becomes less of
Speaker 1: an exercise and explaining what we are with this aquatic explanation,
Speaker 1: and it becomes more about shoehorn earning the aquatic period
Speaker 1: into our evolutionary history. Another thing I think we should
Speaker 1: do is just look a little bit closer at some
Speaker 1: of those individual planks of the argument that people like
Speaker 1: Hardy and Morgan brought up because a lot of them
Speaker 1: they sound so synsical, right, They sound very, very truthy
Speaker 1: at a distance, but they become a lot weaker, I
Speaker 1: think once you start looking up close at them. For example,
Speaker 1: the idea of hairlessness. Right, Morgan talks about the strong
Speaker 1: link between aquatic existence in mammals and hairlessness. Now, first
Speaker 1: of all, I think it's worth pointing out that we
Speaker 1: are not hairless. It's true we do have hair, some
Speaker 1: more than others, but it's there. Yeah, our body hair
Speaker 1: coverage is not total. It's not nearly at the level
Speaker 1: of the other great apes, but neither is the body
Speaker 1: hair coat. You know, the body hair coverage of other
Speaker 1: great apes is also not total. Our hair patterns are different,
Speaker 1: but we do still have a pretty decent amount of
Speaker 1: natural body hair. Also, the distinction between hairy land dwelling
Speaker 1: mammals and smooth aquatic mammals isn't a start stark, as
Speaker 1: Morgan suggests. Now, she does to be fair acknowledge otters
Speaker 1: and stuff like that, but there are also so many
Speaker 1: other hairy and furry semi aquatic mammals we mentioned furry beavers.
Speaker 1: But there's also the furry platypus, the water opossum, which
Speaker 1: is furry Alan swamp monkey, which is native Central Africa.
Speaker 1: It's covered in brown, gray and green fur. Semi aquatic cats,
Speaker 1: semi aquatic her pestids like the crab eating mongoose. You've
Speaker 1: got polar bears that we mentioned earlier. You've got water
Speaker 1: diving bats. So a semi aquatic lifestyle clearly doesn't always
Speaker 1: lead to the loss of hair or fur. Furthermore, there
Speaker 1: are other hypotheses that could explain why we have relatively
Speaker 1: less hair than our closest relatives. So there was an
Speaker 1: explainer in Scientific American where a researcher named Mark Pagel,
Speaker 1: the head of the evolutionary biology group at the University
Speaker 1: of Reading in England and the editor of the Encyclopedia
Speaker 1: of Evil Ouan, explained some recent thinking. One of the
Speaker 1: most common ideas about why humans lost a lot of
Speaker 1: their body hair has to do with thermoregulation. It says
Speaker 1: we lost a lot of body hair because we needed
Speaker 1: a better way to keep cool. Now, this could have
Speaker 1: been a pressure introduced by other changes in our ancestors
Speaker 1: survival needs. Maybe if we migrated from a cooler climate
Speaker 1: like underneath a thick tree canopy to a hotter climate
Speaker 1: like an open, sun exposed woodland or savannah, we might
Speaker 1: need to lose the hair or if our survival niche
Speaker 1: became more oriented around intense, prolonged exercise, such as the
Speaker 1: prolonged chasing of prey animals. Yeah, exactly. Another explanation. This
Speaker 1: one's pretty interesting to me. Parasite resistance. Oh yeah, because
Speaker 1: when you think of of animals with hair, you think
Speaker 1: of the various nasty parasites that can be crawling around
Speaker 1: in there. I mean, we've talked about the the extent
Speaker 1: to which mammalian especially i'mate social bonding is based around grooming,
Speaker 1: sitting around and picking stuff out of other people's hair. Yeah,
Speaker 1: and I mean you think of the constant thread of lice.
Speaker 1: I mean, my child is in an elementary school, so
Speaker 1: that the threat of that the head life explosion uh
Speaker 1: is always there. Uh. So, by by losing the body here,
Speaker 1: we've kind of what driven the lice to the head
Speaker 1: in the pubic region, right. Yeah, I mean they should
Speaker 1: solve that by having just like grooming time where the
Speaker 1: kids sit around and pick lice out of each other's hair.
Speaker 1: They probably go for that. So Pagel and a colleague
Speaker 1: named Walter Bodmer published research in two thousand three in
Speaker 1: Royal Society Biology Letters supporting the hypothesis that we lost
Speaker 1: our body hair to protect ourselves against parasites as as
Speaker 1: we all know, you know, ticks and lice and biting
Speaker 1: flies all they all make this happy home in thick
Speaker 1: body hair. They love it. And these ecto parasites are
Speaker 1: not only annoying, they can spread disease. Like we don't
Speaker 1: want our kids to get lice, but lots of these
Speaker 1: kinds of parasites are are worse than lice. They can
Speaker 1: give you something that will kill you. Yeah, I just
Speaker 1: I'll direct our listeners back to our episode on on
Speaker 1: on ticks if you want some more information there. But
Speaker 1: here's something interesting to think about. Once our ancient ancestors
Speaker 1: could build fires and construct clothing, suddenly they just did
Speaker 1: not need as much hair to keep warm at night
Speaker 1: when it got cold. But the hair could still serve
Speaker 1: as a refuge for these disease spreading parasites. So once
Speaker 1: you can build fires, and once you can wear other
Speaker 1: animal skins and stuff, is clothing there would have been
Speaker 1: a pressure against body hair, because body hair is this
Speaker 1: parasite vulnerability without much comparative benefit to make up for it.
Speaker 1: If you can keep warm anyway, why have this parasite
Speaker 1: vulnerability hanging around. Yeah, Like when we were talking about
Speaker 1: aquatic apes supposedly returning to the land, like, I instantly thought, well,
Speaker 1: when I get out of a shower, I grab a towel.
Speaker 1: So perhaps you know, the naked ape emerges, it murders,
Speaker 1: a hairy animal of some of some form, puts on
Speaker 1: its fur. Like. It's one thing to think of that,
Speaker 1: but then this, the the use of fire technology would
Speaker 1: be an even greater step. Yeah, so, Pagel writes, quote
Speaker 1: human lice infections, which are confined to the hairy areas
Speaker 1: of our bodies, seem to support the parasite hypothesis. Naked
Speaker 1: mole rats, animals that can be described as resembling quote,
Speaker 1: overcooked sausages with buck teeth, also seemed to support the theory.
Speaker 1: They live underground in large colonies in which parasites would
Speaker 1: be readily transmitted, but the combined warmth of their bodies
Speaker 1: and the confined underground space probably negate the problem of
Speaker 1: losing heat. To cold air for these animals, allowing them
Speaker 1: also to become naked. So the same kind of like
Speaker 1: other warmth sources that could have selected for body hair
Speaker 1: loss in humans, can also select for body hair loss
Speaker 1: in naked mole rats. And then there's a totally different
Speaker 1: kind of answer sexual selection. Sexual selection occurs when a
Speaker 1: pressure on some type of trait in the body is
Speaker 1: selected for, not because it provides a survival advantage, but
Speaker 1: because members of the opposite sex prefer to breed with
Speaker 1: people possessing that that trait, And so, like the peacock's tail,
Speaker 1: relatively smooth and hairless skin could have been selected for
Speaker 1: because it's a way to advertise to mates that you
Speaker 1: have good health and a lack of parasites. It's a
Speaker 1: way of showing off that you don't have parasites on you. Yeah.
Speaker 1: I hadn't really thought about that, but but yeah, you
Speaker 1: have a hairless, shirtless hominid walking around it showing showing
Speaker 1: itself off and saying, look, do you how many bites
Speaker 1: do you see? How many? How many crawling parasites do you? Say? None?
Speaker 1: I'm a desirable mate, I'm in good shape. Here's the question.
Speaker 1: I actually don't know the answer to this, is there
Speaker 1: a reason I can't think of Harry body Builders? Is that, like,
Speaker 1: is there a biological reason that like super muscle e
Speaker 1: dudes don't have hair on their chests or do they
Speaker 1: shave it off or what I think generally what's happening
Speaker 1: is they're they're having it waxed. Yeah, better off the muscles.
Speaker 1: I mean, there are plenty of muscular, hairy dudes. I mean,
Speaker 1: you can can do a search on that and you
Speaker 1: will get some answers. But but yeah, my understanding is
Speaker 1: that it's a it's about waxing of the body hair
Speaker 1: so that you can show off the muscle. I'm just
Speaker 1: thinking about like the movie Pumping Iron, where there's just
Speaker 1: like it's just really really smooth. Oh yeah, yeah, you
Speaker 1: those guys are waxing in shave and I'm sure. Well, anyway,
Speaker 1: it's not clear to me that there's an obvious winner
Speaker 1: among the proposed ideas about how we lost our body hair.
Speaker 1: But uh, any any of these are still viable ideas
Speaker 1: awaiting the arrival of new supporting evidence, And so I
Speaker 1: don't see a reason that the aquatic a hypothesis is
Speaker 1: like a better alternative that you have to go to
Speaker 1: now to address another plank. The argument the bipedality like
Speaker 1: that's also a great ongoing debate. The old theory, of course,
Speaker 1: was that we had to stand up to see over
Speaker 1: tall grass on the savannah. That's been debunked. Now we
Speaker 1: you know, we were in a more woodland type environment
Speaker 1: when we when we evolved bipedality. But anyway, what made
Speaker 1: us stand upright in that woodland environment? Charles Darwin thought
Speaker 1: we might have evolved bipedalism to free up our hands
Speaker 1: for tool use. This seems unlikely since there's fossil evidence
Speaker 1: for bipedalism from before we have evidence of ancient tools.
Speaker 1: But there are other ideas like perhaps bipedalism emerged from
Speaker 1: a gathering lifestyle where our ancestors began to walk on
Speaker 1: two legs so they could use two arms to carry things. Uh,
Speaker 1: this seems possible given observations that chimpanzees tend to walk
Speaker 1: on two legs and use two arms to carry food
Speaker 1: items that they consider rare or having great value. Now,
Speaker 1: going back to Morgan's argument about bipedality, she says, you know,
Speaker 1: wind to our closest tape, relatives walk on two legs.
Speaker 1: She said, as they always walk on two legs when
Speaker 1: they're wading through water, and that's the only time they
Speaker 1: always walk on two legs. Uh, this is apparently not
Speaker 1: true because, as we've said, like chimpanzees will walk on
Speaker 1: two legs and use two arms if they're carrying something valuable. Also,
Speaker 1: I was like, well, let's let's see. I bet there's
Speaker 1: video of gorillas waiting through water on the internet. I
Speaker 1: looked it up. Uh, nope, I mean there are lots
Speaker 1: of videos of guerrillas waiting in the water, and most
Speaker 1: of the time they're doing it on four legs. I
Speaker 1: mean there are a few instances where they'd rear up
Speaker 1: on two legs. Uh. So this doesn't totally disprove the hypothesis,
Speaker 1: but it really kind of undermines this plank of it. Well,
Speaker 1: I mean, it makes sense because if you're going into
Speaker 1: the water, there's a good chance you you want to
Speaker 1: use your hands to feel for things. And granted, primates
Speaker 1: don't have exactly the same hand foot scenario is as humans,
Speaker 1: but you're probably going in there you want to feel
Speaker 1: the feel around for the rocks, You want to feel
Speaker 1: around for something that you're scavenging for, right, Yeah, exactly
Speaker 1: and so definitely li guerrillas will walk on four legs
Speaker 1: in the water. I've seen it. But I guess we
Speaker 1: have to come back to this question of like, obviously
Speaker 1: we can't wholly judge. I mean, it's it's possible that
Speaker 1: something like the aquatic ap hypothesis has some grain of
Speaker 1: truth to it. But uh, if the biologists and paleo
Speaker 1: anthropologists are correct that this hypothesis is wrong, it's not
Speaker 1: not parsimonious, there's no reason to resort to it. Why
Speaker 1: is it so tenacious? Like we have had lots of
Speaker 1: people right to us and say, do the aquatic ape theory?
Speaker 1: You know, we we want to hear about it. And
Speaker 1: it's not that I don't think it's interesting to talk about,
Speaker 1: but it's it's not really taken seriously by experts in
Speaker 1: the field. So why is it so captivating in the
Speaker 1: public imagination. Well, I think part of the answer is
Speaker 1: our entire first episode, where we talked about our mythological
Speaker 1: and fictional obsession with the idea of of humans that
Speaker 1: live in the water, a humans that live beneath the waves.
Speaker 1: But there is a there is a deep cultural attraction
Speaker 1: to that idea, and it kind of bleeds over into
Speaker 1: aquatic a theory sometimes. I mean even even in cases
Speaker 1: when it's you know, it's not somebody saying, hey, I
Speaker 1: think mermaids are real and here's some science to pack
Speaker 1: it up, right. Yeah, it's one of it's kind of
Speaker 1: a sticky hypothesis. It's one of those things that, like
Speaker 1: I said, you know, I want to be fair to it.
Speaker 1: I don't think it's like lunatic fringe. I don't think
Speaker 1: it is ancient aliens, but I don't think there's a
Speaker 1: good reason to resort to it. But it's one of
Speaker 1: those things that's just so interesting to the mind. It's
Speaker 1: so fun to picture and so fun to entertain that
Speaker 1: it's sort of like overrides our sense of disinterest in
Speaker 1: other things that seem, you know, not necessary to believe in. Uh.
Speaker 1: There's actually a paper from nine in the Journal of
Speaker 1: Human Evolution by John H. Langdon called Umbrella Hypotheses and
Speaker 1: Parsimony and Human Evolution a critique of the aquatic a hypothesis,
Speaker 1: and Langdon talks about this idea of these umbrella hypotheses,
Speaker 1: which he says, our quote aesthetically a peeling because they
Speaker 1: appear to be parsimonious, so they're internally consistent, and by
Speaker 1: offering this one umbrella hypothesis that explains a range of things,
Speaker 1: and they appear to explain a whole lot, as we
Speaker 1: were talking about earlier, without making you, without requiring you
Speaker 1: to assume a whole lot, but they actually are requiring
Speaker 1: you to assume more than they appear to. And so,
Speaker 1: in trying to explain why these types of ideas stay
Speaker 1: popular with the public, he says, quote one reason for
Speaker 1: this is that simple answers, however wrong, are easier to
Speaker 1: communicate and are more readily accepted than the more sound
Speaker 1: but more complex solutions. Evolutionary science must wrestle with this problem,
Speaker 1: both in its own community and in the education of
Speaker 1: the public. I agree. I mean we see we see
Speaker 1: this time and time again, and it reminds me of
Speaker 1: ongoing discussions regarding climate change, which we've discussed on the
Speaker 1: on the show, and just sort of the challenges of
Speaker 1: science communication in general. Yeah, there are so many ideas
Speaker 1: that just because they're simple to communicate and easy to
Speaker 1: say and easy to remember, they there's almost like a
Speaker 1: survival advantage they have. There's like a selection pressure against
Speaker 1: things that are hard to explain, and a multiplication incentive
Speaker 1: on ideas that are interesting visually to imagine and have
Speaker 1: sort of like the the truthiness feeling, the feeling of
Speaker 1: explaining a lot, and are easy to communicate, And I
Speaker 1: think the aquatic a hypothesis falls in that category. Yeah. Like,
Speaker 1: for instance, I come back to what a physicist Brian
Speaker 1: Green said about climate science and the most recent World
Speaker 1: Science Festival in New York. He talked about how he decided, right,
Speaker 1: I'm gonna do it. I'm gonna bone up on climate
Speaker 1: science so that I can talk about it and defend it.
Speaker 1: And he just he gave up on it because and
Speaker 1: this is a this is a lifetime of work. It's
Speaker 1: a lifetime of work, and this is an accomplished physicist
Speaker 1: saying yeah, I can't I can't get up to speed
Speaker 1: on this in the way that would be required for
Speaker 1: me to go to bat for it against climate change
Speaker 1: deniers and so forth. So but on the same hand,
Speaker 1: it seems like it would be it would be far
Speaker 1: easier for Brian Green, uh, for you or I as
Speaker 1: well to bone up on aquatic ape theory. You know,
Speaker 1: if someone said, all right, Joe, you're going on Fox
Speaker 1: News tomorrow to defend aquatic ape theory. I could do it. Yeah,
Speaker 1: I mean I wouldn't want to, but I could do it.
Speaker 1: It's gotten his favor, that truthiness gravity. Yeah, all right
Speaker 1: on that. Now we're gonna take a quick break and
Speaker 1: when we come back, we're gonna talk to genetics a
Speaker 1: little bit. All right, we're back. Hey. You know so
Speaker 1: in the break, I was just thinking about this. Uh,
Speaker 1: I wonder if I have aquatic humanoids, if this, if
Speaker 1: this words true, would they have an easier time urinating
Speaker 1: in the water. Best off conversation ever, No, I know
Speaker 1: what you're talking about. Like you can kind of when
Speaker 1: somebody's peeing in the water, you can, like you were saying,
Speaker 1: you can see it on their face. Yeah, there's a look,
Speaker 1: there's a there's kind of a stillness to the body.
Speaker 1: I mean in my own case, like if I'm not
Speaker 1: in the pool, but if I'm in the ocean or something,
Speaker 1: I feel like I I have a I have to
Speaker 1: really go into a certain um, you know, state of
Speaker 1: mind to pull it off, and I'd probably look like
Speaker 1: I'm peeing in the ocean. Thanks a lot, Robert colluding
Speaker 1: the ocean for the rest of us, well, you know,
Speaker 1: the fish do it, the mr folk do it, So
Speaker 1: you know, why should I have to walk back to
Speaker 1: the conduct. I know exactly what you're talking about. There's
Speaker 1: this kind of like, uh, you see people with like
Speaker 1: the the kind of the eyes roll up and they
Speaker 1: kind of tents up and grit their teeth a little bit. Yeah,
Speaker 1: So I wonder if if this would be something, if
Speaker 1: this would be in favor of the aquatic ape, like
Speaker 1: it's something that we lost we would have lost upon
Speaker 1: returning to land. Or is it just evidence that we
Speaker 1: were never uh, some sort of an aquatic committed species
Speaker 1: that was totally at ease peeing in the pool. Okay,
Speaker 1: let's get beyond the aquatic ap hypothesis, which imagines this
Speaker 1: semi aquatic uh period in in human history. As as
Speaker 1: we've said, we're not convinced by this idea. It's not
Speaker 1: absolutely impossible, but I don't think there's a good reason
Speaker 1: to go there. However, if we want to entertain the
Speaker 1: idea of a totally aquatic humanoid, a humanoid of the deep,
Speaker 1: what would we be, what would we be looking at?
Speaker 1: What would that entail? Well, I suppose there are basically
Speaker 1: two ways to look at it, right, either something humanoid
Speaker 1: evolves independently of humans in the deep, or a hominid
Speaker 1: variety splits and evolves into a primarily aquatic species. Okay,
Speaker 1: so this would be an example of either convergent evolution
Speaker 1: where some kind of aquatic species converges on basically the
Speaker 1: humanoid form, or it would be a divergent but basically
Speaker 1: the same kind of thing we see in the evolution
Speaker 1: of whales and dolphins. They were land dwelling mammals, then
Speaker 1: they became semi aquatic mammals, and then they became totally
Speaker 1: aquatic mammals. Right now, I think the idea of covergent
Speaker 1: evolution in the deep. I mean, I can't think of
Speaker 1: anything that that lives is a primarily aquatic lifestyle that
Speaker 1: looks anything like a human being. Sometimes you get some
Speaker 1: kind of creepy human behavior convergence with octopi. That's true.
Speaker 1: I'm sorry, I said octopi. Octopuses, Yeah, there there are
Speaker 1: there are some some cephalopods that have kind of a
Speaker 1: walking technique on on the bottom of the sea. There
Speaker 1: are some fish that quote unquote walk on the bottom
Speaker 1: of the sea. They move around with their fins. But
Speaker 1: that's a far cry from having something that that really
Speaker 1: has anything like a human body like even in just
Speaker 1: you know, very broad strokes. You know, we've touched on
Speaker 1: a number of the different examples though, of of of
Speaker 1: creatures that have got the other direction, mammals that have
Speaker 1: returned to the sea. But I think perhaps the manatee
Speaker 1: and its skin are our best examples to look to
Speaker 1: for you know, for what for what a creature like
Speaker 1: this would would be, what what an aquatic humanoid would
Speaker 1: consist of? Right? And you know, we called them the
Speaker 1: Sirenians for a reason. It's ironic that these these are
Speaker 1: creatures that partially inspired our visions of mermaids. So we're
Speaker 1: talking about the manates here and the doo gong. Uh.
Speaker 1: They're the world's only marine mammal herbivores, and the only
Speaker 1: her herbivorous mammals ever to have become totally aquatic. I've
Speaker 1: never thought about that, the only marine mammal herbivores, while
Speaker 1: all the others eat eat the flesh. Yeah, even if
Speaker 1: it's very tiny bits of flesh, very tiny creatures, they're
Speaker 1: still eating creatures. So Sirenians have existed for more than
Speaker 1: fifty million years, having diverged from the Panugu lata clade.
Speaker 1: The closest living land relatives to the Sirenians are the
Speaker 1: elephants and the high axes. Now a, this is a
Speaker 1: pretty interesting In two thousand and sixteen, studied by Maria
Speaker 1: Hikina and Nathan Clark looked at three major independent evolutionary
Speaker 1: events in which mammals returned to the sea and what
Speaker 1: sort of evl utionary tradeoffs took place. So they used
Speaker 1: a fifty nine placental mammal genomes to calculate the relative
Speaker 1: rates of evolution for all branches. In eighteen thousand and
Speaker 1: forty nine gene trees, they calculated a genome wide average
Speaker 1: rate of evolution across all species. Basically, they wanted to
Speaker 1: see if these uh oceanic returns entailed and evolutionary acceleration
Speaker 1: or deceleration. That's interesting. So they identified three main themes
Speaker 1: a burst of adaptation, then relaxation, and additional constraint. They
Speaker 1: identified marine accelerated genes to the tune of about nine percent,
Speaker 1: and they related to these different features new functions for
Speaker 1: genes forming skin and connective tissue, sensory systems, muscle function,
Speaker 1: skin and connective tissue lung function. So an example here
Speaker 1: would be accelerated adaptation for a gene encoding a lung
Speaker 1: surfactant protein that may have been necessary for diving, and
Speaker 1: then lipid metabolism. But they also identified marine decellered accelerated
Speaker 1: genes even more than the you know, the accelerated and
Speaker 1: these related to a general loss of the number of
Speaker 1: sensory genes for smell and taste. No, no more taste
Speaker 1: once we got in the water. Yeah, I mean, it's
Speaker 1: it seems to be the case that that aquatic mammals
Speaker 1: have have a much decreased sense of taste. So I
Speaker 1: guess once you're a sperm whale and you're like trying
Speaker 1: to eat giant squids, you just don't want to be
Speaker 1: tasting that well, uh, something like that. Now. Other marine
Speaker 1: decelerated genes included molecular molecular maintenance strategies such as DNA repair,
Speaker 1: chromosometal maintenance, immune response, and program cell death. So all
Speaker 1: of this, they said, meshes with the increased constraint on
Speaker 1: somatic cell maintenance for such creatures. And I have a
Speaker 1: quote from the paper here, quote hundreds of genes accelerated
Speaker 1: their evolute sctionary rates in all three marine mammal lineages
Speaker 1: during their transition to aquatic life. These marine accelerated genes
Speaker 1: are highly enriched for pathways. The control recognized functional adaptations
Speaker 1: in marine mammals, including muscle physiology, lipid metabolism, sensory systems,
Speaker 1: and skin and connective tissue. The accelerations resulted from both
Speaker 1: adaptive evolution as seen in skin and lung genes, and
Speaker 1: loss of function as in gustatory and olfactory genes. In
Speaker 1: regard to sensory systems, this finding provides further evidence that
Speaker 1: reduced senses of taste and smell are ubiquitous in marine mammals.
Speaker 1: So naturally, this is not a blueprint for evolved aquatic humanoids,
Speaker 1: but I think it does give give us some sort
Speaker 1: of idea of the genetic changes that might take place
Speaker 1: over millions of years until we reached the point that
Speaker 1: we're Kevin Costner from from water World. But but how
Speaker 1: do we reach the point that we're Dennis Hopper in
Speaker 1: water World? Well, all I can say is that Kevin
Speaker 1: Costner's character or would probably not have a good sense
Speaker 1: of taste based on this research. It's a bummer man. Yeah,
Speaker 1: All right, So let's come back to the reverse though,
Speaker 1: something from the deep evolving to life on the surface.
Speaker 1: This is of course the story of all terrestrial life,
Speaker 1: dating back to the terrestrial land invasion of the Devonian era.
Speaker 1: But when we try and think of a humanoid creature
Speaker 1: evolving under the water, it gets a little sticky. We
Speaker 1: get into the creature from the Black Lagoon territory, we
Speaker 1: get into uh Z or Bloodwaters of dr Z territory.
Speaker 1: Because in these cases uh they often will bring up
Speaker 1: certain fish that can walk on land as examples of
Speaker 1: of how this might work, or fish that can breathe
Speaker 1: both above and below the water. And we do have
Speaker 1: ambulatory fish walking fish such as the mud skipper. We
Speaker 1: have that the hand fish and frog fish, which quote
Speaker 1: unquote walk on the seafloor with specialized fins, and of
Speaker 1: course they're the there's the walking catfish of Southeast Asia,
Speaker 1: which we should be clear does not so much as
Speaker 1: walk as it flops and flips and wriggles around. And
Speaker 1: uh the lungfish, the fish highlighted in the creature movies.
Speaker 1: This creature does boast a lung and gil combo existing
Speaker 1: as a sort of call back to the three seventy
Speaker 1: five million year old evolution of landwell and creatures from
Speaker 1: a long extrict species of lobe thin fish. But it
Speaker 1: still doesn't give us quite the recipe for a gill
Speaker 1: man that we would we would like. Yeah, there are
Speaker 1: a lot of problems I can see here for a
Speaker 1: humanoid evolving in the water itself, I mean bipedality, whatever
Speaker 1: you want to think about it, like, even if you're
Speaker 1: still attracted to the aquatic a hypothesis, um, which I
Speaker 1: don't necessarily think you should be. But even if you're
Speaker 1: attracted to that, it says bipedality was sort of a
Speaker 1: transitionary feature, right, It was a product of wading in
Speaker 1: maybe deep water, but not totally deep water, not like
Speaker 1: water deeper than you could stand in. And so having
Speaker 1: like a bipedality and legs is not really useful if
Speaker 1: you are a fully aquatic creature, you would eventually lose them.
Speaker 1: It would be much better to have fins, right, Well,
Speaker 1: I get The only case I can see to be
Speaker 1: made here is that the creature from the Black Lagoon
Speaker 1: must come out of the lagoon to acquire prey and
Speaker 1: of course women. But but you know it, it is
Speaker 1: it is not an obligate um marine creature. It is
Speaker 1: a creature that that that must come out of the
Speaker 1: water to prey, a creature that is perhaps in the
Speaker 1: process of becoming a land creature. So yeah, almost anything
Speaker 1: you could think of as a humanoid in shape at
Speaker 1: all would really need to be semi aquatic, right. It
Speaker 1: would need to be at least or mostly aquatic. It
Speaker 1: would need to have some reason to come out of
Speaker 1: the water if it was going to have legs like
Speaker 1: human legs, because legs are made for for fighting gravity.
Speaker 1: Legs are not made for swimming around in a you know,
Speaker 1: in a buoyancy situation. That's true. And if you don't
Speaker 1: have a switch to magically turn your fins in defeat,
Speaker 1: then you're probably out of luck. Yeah. So I think
Speaker 1: if there were an aquatic humanoid, it would more likely
Speaker 1: be a mermaid with a fish butt than a humanoid
Speaker 1: like the gill man with legs, I think. So. I
Speaker 1: think that makes the most sense. In fact, since they
Speaker 1: spend most of their time under the water, even if
Speaker 1: they did come out of the water, what I guess
Speaker 1: is that would be a mermaid with a fish butt
Speaker 1: that would crawl around with its upper arms. Yeah, and
Speaker 1: we do see that model sometimes the what is it
Speaker 1: the Cabin in the Woods movie? Oh yeah, I had
Speaker 1: a had a Merman creature that comes comes crawling across
Speaker 1: the floor after its victims. Here's another question, though, how
Speaker 1: do you think if there were such a thing as
Speaker 1: an aquatic humanoid, how would tool use evolve differently at
Speaker 1: the bottom of the ocean. Oh yeah, that brings us
Speaker 1: back to some some discussions with out in the past,
Speaker 1: particularly as it pertains to the use of fire technology
Speaker 1: and the idea of any technology existing without fire. Um.
Speaker 1: I mean I keep coming back to. I guess it
Speaker 1: would a lot of it would have to be sort
Speaker 1: of biologically based, you know, I mean you could would
Speaker 1: it would it could not be fire based because you
Speaker 1: you cannot really have fire under water. I mean, you
Speaker 1: see some things that get kind of classified as rudimentary
Speaker 1: tool use by by like octopuses right where they I mean,
Speaker 1: maybe this isn't tool use, but the idea of like
Speaker 1: pulling a rock over the entrance of their dwellings they
Speaker 1: can cover it up and protect themselves. That that's interesting behavior. Yeah,
Speaker 1: I mean that's the use of I believe the distinction
Speaker 1: is that's a nature fact, that is taking something in
Speaker 1: nature and using it for purpose. Now and then you
Speaker 1: could say, well, I can imagine an underwater humanoid making
Speaker 1: an artifact, taking something and sharpening it into a skewer
Speaker 1: or shaping it to better protect them, so that that
Speaker 1: level of technology I could I see. I mean one
Speaker 1: thing though, is that under the water, both the resistance
Speaker 1: density of the water and the buoyancy effects all would
Speaker 1: kind of mitigate against some of the benefits you get
Speaker 1: from say stone tools are our most basic tools are
Speaker 1: very often things that are designed to maximize kinetic energy delivery, right,
Speaker 1: So it would be something that you could throw really
Speaker 1: hard and hit something and kill it, or something that
Speaker 1: you could hit another thing with and break it, and
Speaker 1: kind of a gravity assisted swinging motion, all of which
Speaker 1: is a little bit harder to do underwater because you
Speaker 1: can't swing as fast underwater do the resistance of the water.
Speaker 1: I mean, I don't know. I wonder if you could
Speaker 1: have a tool using creature evolve under the water. Well,
Speaker 1: more than more than likely you have to depend upon
Speaker 1: them originally being an alien species crash landed in the water. Um. Yeah,
Speaker 1: this is reminding me a lot of the the old
Speaker 1: nautical maps which were on which you had mermaids and
Speaker 1: sea monsters, but also all of these different hybrids. Sea lion,
Speaker 1: a sea lion that is not like our sea lion,
Speaker 1: but an actual lion with a fish uh portion to
Speaker 1: its body. And a lot of this was based on
Speaker 1: the idea that the ocean contains a parallel version of
Speaker 1: everything that we have on the surface and it and
Speaker 1: you can extrapolate that to include not only the animals
Speaker 1: but the resources, and say so you end up falling
Speaker 1: into the trap of thinking, well, the underwater creatures they
Speaker 1: would have their own minerals somehow, they would somehow, you know,
Speaker 1: smelt them and and craft them into weapons. Without really
Speaker 1: thinking about it. That the the the aquatic world is,
Speaker 1: it's a part of our world, but is a very different,
Speaker 1: very alien environment compared to the surface. Yeah, it's not
Speaker 1: exactly the mirror world. It's more through a glass darkly
Speaker 1: all right. So there you have it. Uh. In these
Speaker 1: two episodes, I hope we've we've given everybody a lot
Speaker 1: of fresh perspective to consider not only the evolution of
Speaker 1: humans maybe, but but also just our our myths, our
Speaker 1: fictions regarding underwater people and underwater hybrids. And of course,
Speaker 1: we want to hear back from everybody concerning their favorite
Speaker 1: uh underwater humanoids in myth in UH in literature and cinema.
Speaker 1: What's your favorite nine Underwater Peril movie? Totally? I know
Speaker 1: we've got some deep Star six partisans out there. Yeah,
Speaker 1: I think people get attacked. What is it a killer
Speaker 1: clam or something in that movie? It's I haven't rewatched
Speaker 1: it yet, um, but it's some sort of an underwater
Speaker 1: critter yeah. Um. Oh. And also Mermaid movies? What's your
Speaker 1: favorite did you like? Did you grow up like me
Speaker 1: watching Splash on VHS over and over again? I didn't
Speaker 1: know that about you, Rob. Yeah, it's a solid mermaid
Speaker 1: romantic comedy. Okay, I'll have to check it out. Yeah, yeah,
Speaker 1: Tom Hanks, Darryl Hannah, John Candy, tremendous. Did they ever
Speaker 1: do a Jetson's Meet the Flintstones kind of thing with
Speaker 1: Leviathan and Splash with Leviathan? Oh? You mean did Leviathan
Speaker 1: meat Splash movie? I don't think it exists, or at
Speaker 1: least not yet. Movie executives, high powered industry players out there,
Speaker 1: if you're listening, take note. Yes, opportunity knocks, all right, Hey,
Speaker 1: In the meantime, check out stuff to Blow your Mind
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Speaker 1: thanks as always to our excellent audio producers Alex Williams
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Speaker 1: might want us to cover in the future. Uh to
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