Speaker 1: Welcome to Stuff you should know, a production of I
Speaker 1: Heart Radio. Hey, and welcome to the podcast. I'm Josh,
Speaker 1: and there's Chuck and Jerry's here too, and this is
Speaker 1: stuff you should know, the brainiac condition. That's right. I
Speaker 1: was trying to think of something and I was truly blank.
Speaker 1: That's uh, that's how appropriate. It totally Chuck, because we
Speaker 1: are talking today about human intelligence in the origin of
Speaker 1: human intelligence, and it just seems super stuff you should
Speaker 1: know me for us to not be able to come
Speaker 1: up with a decent joke, you know, well Ed did
Speaker 1: that for us, actually, because I did want to shut out.
Speaker 1: We usually don't mention like section titles and stuff like
Speaker 1: that that's actually in our notes, but Ed drops because
Speaker 1: it's you know, it's for our eyes. But Ed dropped
Speaker 1: to Simpson's reference in his section title one of the
Speaker 1: great Simpsons references chimpan A to Chimpanzee was so great.
Speaker 1: That was from the Planet of the Apes musical, right,
Speaker 1: that's right. And I just I like to think is
Speaker 1: that as a little gift from Ed to us? Yeah,
Speaker 1: it definitely was, and it was well received too, So
Speaker 1: thanks ed Um and the reason Ed created a section
Speaker 1: called chimpaneze to chimpanzees because we're gonna talk about the
Speaker 1: lineage of humanity like where humans came from UM And
Speaker 1: despite that hilarious and clever um section title, we did
Speaker 1: not actually evolve from chimpanzees, but we do share a
Speaker 1: common ancestor from chimpanzee. So chimps and humans split off
Speaker 1: from a shared ancestor about six to eight million years
Speaker 1: ago UM, and that really kicked off a long line,
Speaker 1: very long process um of evolution where intelligence started to
Speaker 1: develop fairly early on. It just was really slow to start,
Speaker 1: and then over time it kind of picked up speed. Yeah,
Speaker 1: you found this some kind of cool statistic. There's a
Speaker 1: researcher writer named Richard Leakey and H Richard, and I
Speaker 1: think most people agree. They posit that there was what's
Speaker 1: called a big bang of human culture around the Upper
Speaker 1: Paleolithic time period where things were, like you said, slow
Speaker 1: going for so long, and things were measured in in
Speaker 1: eras before that, very very slowly over like hundreds of millennia,
Speaker 1: and then all of a sudden, like sixty two thirty
Speaker 1: thousand years ago or so, things started to really ramp
Speaker 1: up in terms of innovation and intelligence. And uh, just
Speaker 1: really moving the ball forward to use a football metaphor,
Speaker 1: and we're talking about you know, clothing and uh, social
Speaker 1: structure and in art and creativity and stuff like that.
Speaker 1: So it's kind of cool to think, and you know,
Speaker 1: we're going to talk about why that might have happened,
Speaker 1: but uh, the fact that that did happen got us
Speaker 1: on the moon in short order over the last few
Speaker 1: thousand years. It's kind of like if you look at
Speaker 1: the development of intelligence as a train that's starting from
Speaker 1: a stop, it starts out with kind of a chuck
Speaker 1: good chug good chug chug chugga chug a chuga, and
Speaker 1: then that um, that Upper Paleolithic Revolution, the big bang
Speaker 1: of culture. That's the cho choo part that really punctuates
Speaker 1: the whole thing. I was thinking more along the lines
Speaker 1: of it like a Japanese bullet train. But sure, I
Speaker 1: don't think we're OK. We still do some really stupid stuff.
Speaker 1: So we can also create a bullet train. We can,
Speaker 1: but we just can't be the bullet train intellectual. Oh man,
Speaker 1: mind blown. So chuck. The fact that thirty to sixty
Speaker 1: thousand years ago there was that Upper Paleolithic Revolution where
Speaker 1: humanity just suddenly blossom into what we recognize today as humanity.
Speaker 1: It's really tempting to think that human intelligence just was
Speaker 1: suddenly born all of a sudden, like geologically speaking, overnight
Speaker 1: at that time. But that's just not the case. Um.
Speaker 1: It seems like something definitely happened there, like some wire
Speaker 1: connected with another wire that really made a big difference.
Speaker 1: But instead, again, it was this part of this very
Speaker 1: long line of seemingly random and unconnected um developments in
Speaker 1: the in the history of humanity. And I guess our
Speaker 1: our genus Homo um that led to that point and
Speaker 1: actually led to that point today, because we're still evolving
Speaker 1: and developing. Yeah, I guess uh. If you look at
Speaker 1: it on a timeline, it looks like a mechanic came
Speaker 1: along and said, well, here's your problem. You forgot to
Speaker 1: plug you forgot to plug it in. That's right, you
Speaker 1: gotta plug these two wires together and then you're all
Speaker 1: set totally. But we like to talk about Homo sapiens
Speaker 1: in in terms of human intelligence for good reason. Homo sapiens,
Speaker 1: that is to say, us a k a. Modern humans
Speaker 1: evolved about three hundred thousand years ago, um. But we
Speaker 1: are just one of a collection of uh in in
Speaker 1: this big lovely family called the Hominem's yeah, cominens comin
Speaker 1: in Yeah, I think it's at ms. Yeah. So the
Speaker 1: hominins are everybody that um that started off branching from
Speaker 1: that common ancestor with chimps. That's the hominin line, and
Speaker 1: humans in our genus Homo that Homo sapiens are a
Speaker 1: part of, is just part of that hominin. There are
Speaker 1: other entirely different genus or genie i that make up
Speaker 1: the hominin line, right, that's right, And we should point
Speaker 1: out that sapiens actually is taken from the Latin word
Speaker 1: for knowledge, so it kind of all makes sense. It does.
Speaker 1: So the whole thing starts out it seems like as
Speaker 1: far back because we can tell um something again, like
Speaker 1: somewhere around six or so million years ago, there was
Speaker 1: a group of homonyms called Artipithecus um who basically walked upright.
Speaker 1: But that was essentially the big difference between them and chimpanzees.
Speaker 1: But as we'll see, that was a really really big difference, right, Yeah,
Speaker 1: I mean we'll we'll get into this in more detail,
Speaker 1: but obviously if you're walking up right, then you have
Speaker 1: a very important thing at your disposal, which is use
Speaker 1: of your hands. Right, So then, um, you've got Australopithecus uh,
Speaker 1: and some a few other different kinds of branches that
Speaker 1: kind of branch off. It's a really tangled, convoluted family tree, um,
Speaker 1: where some kind of lead to blind alleys, others lead
Speaker 1: to others. But um, they think that Australopithecus is was
Speaker 1: a really big, long lasting group that was a little
Speaker 1: more human, definitely more human than art Epithecus um, but
Speaker 1: not quite as human as the genus Homo um, which
Speaker 1: off all of these different species of human Because we're
Speaker 1: we're alive today, we're on you know, planet Earth, living
Speaker 1: here in two and every single human alive is a
Speaker 1: member of the same species. So like there's different kinds
Speaker 1: of cats, there's different kinds of fish species, there's different
Speaker 1: kinds of bird species. Um, there's only one kind of
Speaker 1: human species. But that wasn't always the case. There are
Speaker 1: plenty of different human species, some living alongside one another
Speaker 1: for tens or hundreds of thousands of years, that's right.
Speaker 1: And almost all the hominins used tools, it seems like,
Speaker 1: and make made tools, and for a long time we
Speaker 1: thought that that was sort of it, that only the
Speaker 1: Homo genus was the one who did use tools, which
Speaker 1: is and you know, we talk about things like being
Speaker 1: bipedal and using tools as sort of some of the
Speaker 1: building blocks of what would become human intelligence. But now
Speaker 1: we know that there are uh some older you know,
Speaker 1: we found evidence that they use tools before that. Uh
Speaker 1: that's kind of fairly recently, right, Yeah. We we wanted
Speaker 1: to say that toolmaking started sometime after the Homo genus
Speaker 1: showed up of a couple million years ago, um, but
Speaker 1: we found even older tools. So it seems like austral Epithecus,
Speaker 1: which again their hominance, they're part of the branch that
Speaker 1: led to us humans, but they're not human in any way,
Speaker 1: shape or form um. So the fact that they're using
Speaker 1: tools was kind of mind blowing, and it also really
Speaker 1: kind of undermined kind of like what you were saying,
Speaker 1: like our idea of using tools, like that's a big
Speaker 1: sign of intelligence, and and humans are intelligent, so it's
Speaker 1: weird to find out that non humans were using tools
Speaker 1: millions of years ago. That's right. Um, should we move
Speaker 1: on to the hardware software thing? Yeah, So if if
Speaker 1: tools and fire are not, um, because we found use
Speaker 1: of fire dating back at least a million years. UM.
Speaker 1: So if if tools fire hanging out with one another collectively,
Speaker 1: if these aren't like the indicators that make human intelligence,
Speaker 1: we've got to like get a little more granular. Unfortunately
Speaker 1: for you and I sitting here today, chuck, UM, scientists
Speaker 1: have done that, and they've come up with some really
Speaker 1: interesting like ways of looking at this. Yeah, and UM,
Speaker 1: there's a bit more of a preamble before we get
Speaker 1: actually to the intelligence. UM. And I like the way
Speaker 1: ed put this, sort of like talking about hardware versus software. Um,
Speaker 1: they were very intertwined and um, you know, sort of
Speaker 1: happening at the same time. So it's not like one
Speaker 1: couldn't happen without the other as far as the hardware
Speaker 1: software thing goes. But Uh, if we're looking at hardware
Speaker 1: and we're talking about um changes that made us like
Speaker 1: better at walking up right, Like you can you all
Speaker 1: of a sudden just don't stand up and start walking
Speaker 1: like this happens over a long long period of time.
Speaker 1: Our hind legs got longer, Uh, the shape of our
Speaker 1: pelvis changed. Um. There's something called the Foreman magnum, which
Speaker 1: is a hole in the base of the skull where
Speaker 1: the spinal cord and lots of nerves and things passed
Speaker 1: like sort of open up those neural pathways, and that
Speaker 1: changed its location. So these literal physical changes are happening
Speaker 1: over great periods of time in order just to be
Speaker 1: able to walk up right right and and bipedalism it's
Speaker 1: like the defining characteristic of prominence. Right. There's there's not really,
Speaker 1: as far as I can tell, any other animals that
Speaker 1: that walk upright like by default. Um, so there had
Speaker 1: to be physiological changes, but they're not entirely certain why
Speaker 1: we started walking up right. But the fact that we
Speaker 1: did and it's lasted for this long means that there
Speaker 1: was some advantage to it because enough people walking upright
Speaker 1: were able to pass along their genes. And they think
Speaker 1: one one big theory is that it helped us survive
Speaker 1: climate change where maybe things got colder and there were
Speaker 1: less trees. So since we weren't arboreal anymore, we didn't
Speaker 1: hang out and live and eating trees. We were able
Speaker 1: to kind of move around and find different like food
Speaker 1: sources in different shelters, whereas the like our cousins the chimps,
Speaker 1: were in big trouble. They were up the proverbial creek. Yeah,
Speaker 1: and I love that you point out that we, uh,
Speaker 1: we're the only ones who walk upright by default, because
Speaker 1: I think we can all agree there's nothing more fun
Speaker 1: than YouTube videos of like a dog or a cat
Speaker 1: or something just walking on its hind legs for some reason. Definitely,
Speaker 1: and and it's the coolest and most fun thing ever.
Speaker 1: It totally is. And I mean, now I'll take like
Speaker 1: a Jesus lizard running across some water once in a
Speaker 1: while too. There's nothing wrong with watching. Is that what
Speaker 1: those are called? Yeah? I think I saw one of
Speaker 1: those in Mexico, but that was surprising. Are they not there?
Speaker 1: I don't know. I'm just saying I've I've never seen
Speaker 1: one in real life, so I'm sure that was surprising
Speaker 1: to see. I saw a lizard that was walking, and
Speaker 1: it wasn't walking on water, but I think it was
Speaker 1: one of those kinds that can I just didn't know
Speaker 1: the name of it. Had you recently eaten the worm
Speaker 1: from the bottom of the bottom of most cow? Very funny.
Speaker 1: Another thing we should point out is that walking upright
Speaker 1: is an energy saver. I mean, it's they've done studies
Speaker 1: and they found that um, you use about the energy
Speaker 1: um rather than you know, bounding around on all fours
Speaker 1: like a chimp mte right or like a chimp does.
Speaker 1: But to save that energy, to conserve it um, our
Speaker 1: pelvis has had to change shape. Like you mentioned, that
Speaker 1: was just a consequence of walking upright. Um. And the
Speaker 1: reason to change shape is when you walk up right,
Speaker 1: if you're a chimp, your body swings side to side.
Speaker 1: You have to hold your arms up to balance yourself.
Speaker 1: That takes a lot of energy. UM. So we developed
Speaker 1: like gluteal muscles and other muscles that can cling to
Speaker 1: a specific shaped in size pelvis so that we don't
Speaker 1: have to spend all the energy. Our muscles are just
Speaker 1: kind of keeping us much more balanced. But one of
Speaker 1: the consequences of that of walking upright and our pelvis
Speaker 1: changing means that the size of the birth canal afforded
Speaker 1: by the hole in the all of us the child
Speaker 1: passes through during birth. UM got smaller, a lot smaller.
Speaker 1: And it's really strange to think that this the the
Speaker 1: decreasing in size of the birth canal actually was one
Speaker 1: of the factors that led to an increase in intelligence. Yeah,
Speaker 1: and you know, we should point out this is just
Speaker 1: the first of what will be a lovely cascade of
Speaker 1: theories that we're gonna lay lay on your brains today. Uh,
Speaker 1: and that, like you said earlier, there there is no one,
Speaker 1: single one. It's kind of when you put all of
Speaker 1: this stuff together. I think that's sort of the beauty
Speaker 1: of of human intelligence, is it took all of these
Speaker 1: great things sort of coalescing um. But the whole thing
Speaker 1: with the brain is interesting because the size of the
Speaker 1: brain is is one of nature's kind of controversies. Like
Speaker 1: we know that as far as humans go, just because
Speaker 1: you have a bigger brain doesn't mean that you definitely
Speaker 1: will be smarter. But there are some correlations cross species
Speaker 1: in nature, uh, and in humans there can be, you know,
Speaker 1: evidence that bigger brain means you're more intelligent. But it's
Speaker 1: not one of those things where it settles science where
Speaker 1: they just say, hey, if you've got a bigger brain,
Speaker 1: you're gonna be smarter. No, And in fact, like there's
Speaker 1: all sorts of evidence in nature that suggests that's not
Speaker 1: the case. Because our brain to body size ratio among
Speaker 1: humans is one to forty, So our brain makes up
Speaker 1: about our body mass, and that's the same ratio that
Speaker 1: a mouse has. My mice just I don't care how
Speaker 1: you cut it. They're just not as intelligent as humans.
Speaker 1: But on the other hand, an elephants brain to body
Speaker 1: ratio is one to five hundred and sixty and elephants
Speaker 1: are super smart. So, um, you you can't really find
Speaker 1: much there that says, you know, there's no direct correlation
Speaker 1: where it's like the bigger the brain, the more intelligent
Speaker 1: the being. Um. But there does have to be some
Speaker 1: minimum amount of brain size because it seems like the
Speaker 1: connections of the brain is we'll see, are what really matter.
Speaker 1: And the more brain tissue you have up to a
Speaker 1: certain point, the more connections that can be made. Right,
Speaker 1: So that brings us back to the birth canal situation.
Speaker 1: Like you mentioned you're walking upright, that changes in the
Speaker 1: shape of the pelvis, you have a much smaller birth
Speaker 1: canal all of a sudden. So evolutionarily speaking, you might think, well,
Speaker 1: does that mean we're going to have to have babies
Speaker 1: with tiny, tiny little heads and therefore tiny tiny little
Speaker 1: brains that may not be able to grow very fast
Speaker 1: because it's enclosed in a skull that's sort of locked down,
Speaker 1: but that didn't happen to us. What happened was we
Speaker 1: have Fontanell's and we have this delayed fusing of the
Speaker 1: skull kind of you know, closing for good, and so
Speaker 1: it allows and it's you know, it's remarkable still to
Speaker 1: think about this to me, but it allows that little
Speaker 1: baby head to squish down to get through the birth canal,
Speaker 1: and it through the vagina and out into the world
Speaker 1: and stay that way for a while. And it's during
Speaker 1: that for a while period before that skull completely fuses
Speaker 1: that a human brain really really grows a lot, and
Speaker 1: chimps don't have that ability. No, a chimp, uh, their
Speaker 1: skull fuses mostly in the womb, and their brain, as
Speaker 1: a consequence, grows mostly to what size it's going to
Speaker 1: reach in the womb. So, on the one hand, a
Speaker 1: chimp baby, you could say, is much smarter and much
Speaker 1: less helpless than a human baby. But given enough time,
Speaker 1: the human baby is going to start to exceed the
Speaker 1: chimp's abilities very quickly. And it's because our development is delayed.
Speaker 1: We do a lot of developing outside of the womb,
Speaker 1: and that's afforded by that skull that's not fused. For
Speaker 1: a couple of years after birth. And this was not
Speaker 1: there is no intelligent design, so there this was not like, um,
Speaker 1: like a good solution or work around. This was just
Speaker 1: a natural selected, naturally selected trait, the skull not fusing.
Speaker 1: That was a solution to the smaller birth canal, not
Speaker 1: to not to increase intelligence, but the advent of babies
Speaker 1: being born that didn't have few skulls allowed for the
Speaker 1: advent of intelligence. Yeah, a solution to the problem of
Speaker 1: walking up right, which is really interesting to think about. Yeah,
Speaker 1: And it also just goes to show like it's like
Speaker 1: nature is not always like elegantly simple. Sometimes it's really
Speaker 1: convoluted and organisms including us are held together by like
Speaker 1: duct tape and bubblegum, you know. And that's a good
Speaker 1: example of it. I think that's a good time for
Speaker 1: the break, yea, yea. And we'll come back and drop
Speaker 1: some plasticity on your brain right after this, So, Chuck,
Speaker 1: this is the point we're about to talk about brain plasticity.
Speaker 1: This seems to be, uh, what if anything explains human intelligence,
Speaker 1: and certainly the burst of intelligence that happened thirty to
Speaker 1: sixty thou years ago. Yeah, And I think the opening
Speaker 1: statement to this whole thing is all you gotta do
Speaker 1: is look at the fact that we learn almost everything
Speaker 1: as humans, like from the moment we're born. There there
Speaker 1: is some maybe instinctive knowledge, but like you said, like
Speaker 1: human babies are kind of helpless, little dumb dumbs. And
Speaker 1: from that point forward, our brains are are learning and
Speaker 1: they're growing, and they're capable of learning, and they're capable
Speaker 1: of adapting. And this all has to do with plasticity, right, So,
Speaker 1: just if you aren't familiar, plasticity is the brain's ability
Speaker 1: to um basically rewire and create new connections as new
Speaker 1: experiences come along. Uh, And you can even take old
Speaker 1: experiences that you experience more than once and the second
Speaker 1: and third and fourth time, those neural connections are going
Speaker 1: to become more sophisticated and more connected than they were before.
Speaker 1: So our brains are plastic. They can be molded and
Speaker 1: shaped kind of like in the rhinoplastic um sense of
Speaker 1: the word. They're not made of plastic. They can be
Speaker 1: molded and they're molded by the connections that they make.
Speaker 1: So it's not necessarily that you have a giant brain.
Speaker 1: It's that you human being have a brain that is
Speaker 1: really highly capable of creating new connections, and it's those
Speaker 1: connections that forms the basis of intellect. Yeah, and that
Speaker 1: really frees up, Like once you have a brain that's
Speaker 1: plastic and that can evolve, you know, to figure out
Speaker 1: a pro ablem rather than taking eons and eons to
Speaker 1: have like genetic to genetically adapt to a solution to
Speaker 1: a problem. If all of a sudden you have a
Speaker 1: brain that can figure something out, you do it so
Speaker 1: much quicker, and that frees you up to do more
Speaker 1: and learn more, and it creates this feedback loop all
Speaker 1: of a sudden where the process really really speeds up.
Speaker 1: And that's you know, basically what we saw thirty sixty
Speaker 1: years ago. Yeah, and the reason and we're still seeing
Speaker 1: it today, Chuck. I mean, like you know, a thirty
Speaker 1: to sixty thousand years ago, it was a huge burst
Speaker 1: of creativity and intelligence, but we're still talking about changes
Speaker 1: that took place over thousands of years. Now. We're seeing
Speaker 1: changes to the human condition in our society that takes
Speaker 1: place over like tens of years. So it still seems
Speaker 1: to be speeding up and we're still going through the
Speaker 1: same process. But the I guess the best way to
Speaker 1: think about what you've just described as evolution, which typically
Speaker 1: you know, UM forces changes on us based on environmental conditions,
Speaker 1: goes into the brain, and now it's the brain that's
Speaker 1: able to change, and like you said, it changes much faster,
Speaker 1: and that leaves genetic evolution or genetic natural selection to
Speaker 1: focus on UM selecting for traits that create more and
Speaker 1: more intelligence. So it creates that positive feedback loop like
Speaker 1: you said, and speeds things up. It's pretty brilliant. So
Speaker 1: there's been a lot of really interesting research, especially in
Speaker 1: that it seemed like the early to mid nineteen nineties
Speaker 1: about plasticity UM. There are a couple of researchers name
Speaker 1: to Be and Cosmides great names, and they had a
Speaker 1: theory basically that human intelligence UH evolved with all these
Speaker 1: UM encapsulated cognitive models, so they did not have the
Speaker 1: ability to excess each other. Each each of these modules,
Speaker 1: and each one was very specialized for a very specialized
Speaker 1: problem or task that was trying to do our problem
Speaker 1: that was trying to solve, and that's like a language module, UH,
Speaker 1: spatial relation module. UH, here's how to make and use
Speaker 1: a tool that kind of a module. And that all
Speaker 1: these modules are still around, uh and basically the same
Speaker 1: form that they were back then, because it's there on
Speaker 1: the timeline of you know, humanity, that that hasn't been
Speaker 1: a lot of time to undergo any kind of modifications basically,
Speaker 1: So I disagree with that. I think I think on
Speaker 1: a speaking about classic evolution natural selection, that's true, but
Speaker 1: brain based evolution and natural selection like cultural natural selection,
Speaker 1: I think that that's false. You hear that to be. So.
Speaker 1: The the idea about all this is that these modules
Speaker 1: that we developed over time is like we came upon
Speaker 1: new problems in our environments and had to figure out
Speaker 1: new solutions to them. They started to kind of get
Speaker 1: cross referenced here there, Like you could say, um, you know,
Speaker 1: the same the same ability to UM to to follow
Speaker 1: the sunset, right, Yeah, I wish I would have come
Speaker 1: up with something better can also can also be used
Speaker 1: to UM to follow herds of game, right. And so
Speaker 1: all of a sudden we now not only just know
Speaker 1: to to follow the sunset if we want to follow
Speaker 1: the sunset, we also know we can use that same
Speaker 1: ability to follow game around. And all of a sudden,
Speaker 1: our diet expands that kind of thing. So as these
Speaker 1: different modules started cross referencing themselves and and got more
Speaker 1: and more connected. We were able to apply these different
Speaker 1: things to more and more situations and got more and
Speaker 1: more intelligent. All right, So that's UM. That's one sort
Speaker 1: of grand theory which I love. Another one that we're
Speaker 1: going to talk about is I think super interesting because
Speaker 1: some of this stuff is so kind of rudimentary in
Speaker 1: it when you just sort of look at it from
Speaker 1: a macro view, but when you really have to think
Speaker 1: about how important that ended up being, it's it's fascinating
Speaker 1: to me. And in this case, we're talking about the
Speaker 1: fact that UM. One of the sort of side and
Speaker 1: again it's going back to bipedalism. One of the side
Speaker 1: effects bipedalism is that we lost our ability, UM, with
Speaker 1: our feet to be able to like hang onto things
Speaker 1: like chimpanzees do. They were these boots were all of
Speaker 1: a sudden made for walking, and they weren't made for grabbing.
Speaker 1: And if they weren't made for grabbing, then you couldn't
Speaker 1: hang on to mama like a chimp could with hands
Speaker 1: and feet. So mama had to hang on to human baby.
Speaker 1: And mama can't hang on to human baby all the
Speaker 1: time because mama still has to get things done around
Speaker 1: the you know, savannah. So what you have to do
Speaker 1: then is leave that baby somewhere and go do stuff
Speaker 1: like go down to the river and uh and do
Speaker 1: things and uh. If you leave a baby somewhere, what
Speaker 1: you go down to the river and do and things?
Speaker 1: Two things you know unen uh and if you leave
Speaker 1: that baby And this is all leading to this statement,
Speaker 1: if you leave that baby somewhere, you want to be
Speaker 1: able to go back and find that baby. And it
Speaker 1: seems so rudimentary and basic, but that is a huge
Speaker 1: thing in the development of the early human brain, is
Speaker 1: simply to spatially map and remember, like where I have
Speaker 1: left this child. It's important to go back and get
Speaker 1: that child, and I can do that. Yeah, and then um.
Speaker 1: Consequently to that, another adaptation seems to have arisen from
Speaker 1: the same problem, the problem of not being able to
Speaker 1: cling to the mother anymore, and then also the problem
Speaker 1: of the baby being otherwise helpless, way more helpless than
Speaker 1: a baby chimp. Right, So they think that around the
Speaker 1: same time baby's cries developed, like you don't hear other
Speaker 1: things necessarily crying like a human baby, And they don't
Speaker 1: think that babies cried like that until around this time,
Speaker 1: because there was that problem. So even if a mom
Speaker 1: couldn't remember where she put her baby, she could listen
Speaker 1: out for the baby crying. And they also think around
Speaker 1: this time that an urge or desire to soothe the
Speaker 1: baby from its crying would have developed, and that it's possible, Chuck,
Speaker 1: And this makes so much awesome sense that language actually
Speaker 1: developed out of what's called mother ease, that kind of
Speaker 1: soothing baby talk that calms the baby, that mothers know
Speaker 1: how to do just naturally. They think that it's possible
Speaker 1: that that is what formed the basis of language. Yeah,
Speaker 1: and I'm gonna go beyond that even because what I
Speaker 1: noticed when I had a baby in the house was that,
Speaker 1: even beyond the soothing thing, if you are holding your
Speaker 1: baby and you have to put your baby down to
Speaker 1: go wash the dishes or whatever, generally, and I think
Speaker 1: I speak for most parents, you don't just go set
Speaker 1: your baby down, go in the other room and do stuff.
Speaker 1: You're you're talking to that baby from the very beginning,
Speaker 1: and you're saying, all right, let's go over to our
Speaker 1: little place here. I'll be right back. I'm gonna be
Speaker 1: right here in the other whom that baby doesn't know
Speaker 1: what you're talking about, obviously, but there's there just seems
Speaker 1: to be this evolutionary instinct to to say things to
Speaker 1: it right out of the gate. It's really interesting. It
Speaker 1: is interesting, and then wrapped up in this also there's
Speaker 1: a better example than following the stupid sunset that I
Speaker 1: came up with. I love sunsets. But if you can
Speaker 1: now all of a sudden like remember where landmarks are
Speaker 1: and then wayfind your your way back to you know,
Speaker 1: the starting point. Now you can start to use that
Speaker 1: to follow game further and further afield, and you're expanding
Speaker 1: your range and you can expand your diet. So that's
Speaker 1: a really good example of one thing kind of leading
Speaker 1: to another, and all of it being um arising from
Speaker 1: environmental pressers brought on by changes to buy of us. Yeah,
Speaker 1: I love it me too. Um. This next one is
Speaker 1: kind of fits in a little bit with a plasticity
Speaker 1: I think. Uh. The idea of the cognitive niche um,
Speaker 1: which is, you know, typically figuring out like a solution
Speaker 1: to a problem. But this theory is that maybe intelligence
Speaker 1: evolved as a universal adaptation to all kinds of uh,
Speaker 1: evolutionary pressures that we're bearing down. So um and ed
Speaker 1: has a pretty great example. If you've got a an
Speaker 1: island with a tree that has a certain um fruit
Speaker 1: seed that's really beneficial for your body, Um, but you
Speaker 1: can't crack into it. There's you know, it would take
Speaker 1: a bird, uh, you know, hundreds to thousands or millions
Speaker 1: of years to develop and evolved to have a beak
Speaker 1: that can crack that thing open. But if all of
Speaker 1: a sudden, you know how to make a tool, you
Speaker 1: can just walk over and steal that thing from that
Speaker 1: dumb bird and just crack it open with the tool.
Speaker 1: So it's not filling, it's your brain at work, and
Speaker 1: in that case is filling a specific niche. But that's
Speaker 1: a tool that was also used to kill the animal
Speaker 1: or chop the wood. Yeah, and that really supports what
Speaker 1: we were talking about a few minutes ago that once evolution,
Speaker 1: once a brain is evolved to a certain amount of intellect,
Speaker 1: the brain can take care of the organism and natural
Speaker 1: selection and genetics can kind of take a step back
Speaker 1: and not have to say, like, um, you know, uh,
Speaker 1: select for a thicker harrier chest. Because we're living in
Speaker 1: a colder time now because the brain can come up
Speaker 1: with a way to create a coat, right, So it
Speaker 1: just kind of takes over evolution from evolution by doing that,
Speaker 1: and that's that cognitive niche. And one of the consequences
Speaker 1: of it is that there seems to be as as
Speaker 1: things change in our environment, we figure out new ways
Speaker 1: to to solve those, and then those those solutions are
Speaker 1: inevitably going to create other problems or changes, So then
Speaker 1: we have to we have to evolve even further intelligence
Speaker 1: to figure out how to solve these new problems. You
Speaker 1: can actually see it still going on today, Chuck, Like,
Speaker 1: we've evolved a level of intelligence where we can extract
Speaker 1: petroleum from the earth, we can build machines that run
Speaker 1: on that petroleum, and we can develop science that figures
Speaker 1: out that burning those the that petroleum is really really
Speaker 1: bad for the climate. So now we've we've altered our
Speaker 1: ecosystem enough that we have to evolve intelligence enough to
Speaker 1: figure out how to get out of this new conundrum
Speaker 1: that we've created for ourselves based on our previous intellect.
Speaker 1: So intellect builds on intellect through environmental pressures that we
Speaker 1: often bring on ourselves. That seems like the case, Yeah,
Speaker 1: I mean, I think a lot of people seem to
Speaker 1: think of intelligence is only solving problems, but it also
Speaker 1: creates a lot as well. It's interesting, Yeah, it really is. Um.
Speaker 1: I know we were gonna skip this section entirely, but
Speaker 1: I think just for frenzies, we should very quickly mention one,
Speaker 1: uh the ideas from someone called Terence McKenna who describes
Speaker 1: as a post modern Timothy Leary type, one of these
Speaker 1: people that that advocates for psychedelic drug use, and just
Speaker 1: very quickly the idea is that, uh, the cavemen were
Speaker 1: tripping on mushrooms and that's how intelligence evolved. And I
Speaker 1: just like mention it because I feel like there's almost nothing,
Speaker 1: no leap in history that some person hasn't said, like
Speaker 1: the Enlightenment or whatever, like, oh man, they were just tripping, right,
Speaker 1: they were just super I don't think it's pretty funny.
Speaker 1: It is funny, but it does. I mean, like if
Speaker 1: you apply it exclusively to the Upper Paleolithic Revolution, where
Speaker 1: all of a sudden there's like art and jewelry and
Speaker 1: dancing that stuff, it's possible that it was based at
Speaker 1: least in part you know, yeah, you never know, alright,
Speaker 1: So I say, we take a break and we come
Speaker 1: back and get down to the nitty gritty of how
Speaker 1: food might have brought intelligence along. How about that? Mm hmm.
Speaker 1: By the way, Chuck, I have a theory real quick
Speaker 1: that the more you say uh or um, the more
Speaker 1: intelligent you um are. Oh boy, I must be a
Speaker 1: smarty pan. You know, other more intelligent podcasts cut all
Speaker 1: that stuff out. Yeah, I guess do they? Yeah? I mean,
Speaker 1: what did I mispronounced in the Row episode? I couldn't
Speaker 1: even substantive Oh yeah, yeah, it's true. Other podcasts would
Speaker 1: not have left that in. But that's because dummy leaves
Speaker 1: that they're not as brave. We're courageous podcasters. Okay, I'll
Speaker 1: buy that. Um. This next theory I think is super
Speaker 1: cool because anytime each tie in um, not just food,
Speaker 1: but sort of a an appreciation for a creature comfort,
Speaker 1: it really like turns turns me on and not you know,
Speaker 1: in certain ways intellectually turns me on. And in this case,
Speaker 1: we're talking about the fact that we used fire obviously
Speaker 1: and then started cooking food, and people that cooked food said, wow,
Speaker 1: this is really good, and this taste a whole lot
Speaker 1: better than that raw meat. We've been eating this charred
Speaker 1: meat is delicious, and let's let's try and do more
Speaker 1: of this around here. Yeah, And so that would have
Speaker 1: just them being um, responding to like a taste preference,
Speaker 1: and that's it. But it just so happened that that
Speaker 1: taste preference would have had a really big benefit and
Speaker 1: a big contribution to the development of intelligence. Because if
Speaker 1: you cook me eat um, you unlock a bunch of
Speaker 1: nutrients and calories that are otherwise unavailable to you if
Speaker 1: you just eat it raw. So over time, the people
Speaker 1: who ate meat would have had more energy and more
Speaker 1: calories to contribute to a growing brain, which could have
Speaker 1: helped the process along if not sped it up. And
Speaker 1: if you consider the fact that we've definitely seen that
Speaker 1: that taste and smell has responded to evolutionary pressures in
Speaker 1: that we at some point learned not to eat poop,
Speaker 1: and we learned not to eat rotten food and stuff. Um,
Speaker 1: And that's you know, taste and smell it can have
Speaker 1: the you know, it looks like it can have the
Speaker 1: opposite effect to where all of a sudden you have
Speaker 1: a preference for the good. And that just happens to
Speaker 1: work out in your favor. Yeah, and this is another
Speaker 1: example of one thing leading to another, where like you know,
Speaker 1: mothers developed an awareness of landmarks and wayfinding, and then
Speaker 1: that led to um being able to follow game, which
Speaker 1: expanded our diet, which led to us eating meat, which
Speaker 1: eventually led to applying controlled fire to that meat, which
Speaker 1: led to more calories and nutrients available, which led to
Speaker 1: bigger brain growth, which helped found uh, the growth of
Speaker 1: intelligence and humans. Just one thing, one totally random, unconnected thing,
Speaker 1: or even connected but seemingly unconnected, uh, just creating us today.
Speaker 1: It's just so nuts. So to me, I love it. Yeah,
Speaker 1: me too. And the fact that, like, think about this,
Speaker 1: not only the preference for a charred meat, but the
Speaker 1: preference for a specific charred meat because you know, different
Speaker 1: stuff tastes different. It's not like everything tastes like chicken.
Speaker 1: I know that's a joke, but all of a sudden
Speaker 1: took took his out there and and says, boy, that
Speaker 1: one thing that we killed yesterday. You guys, I don't
Speaker 1: know about you, but that was really really delicious. And
Speaker 1: we know that that is we saw that thing three
Speaker 1: days ago, about fifty miles away. Everyone said, what's a
Speaker 1: mile and he well, that doesn't matter right now, but
Speaker 1: the point that it was really far away. So all
Speaker 1: of a sudden, other things are introduced, like cooperation, not
Speaker 1: just wayfinding, but hey, let's let's all get together because
Speaker 1: this is like a three day journey and this thing
Speaker 1: is really big. That tastes so delicious, So it's gonna
Speaker 1: take a few of us to bring this thing down
Speaker 1: and to process this animal and get this meat ready
Speaker 1: for cooking. So it just introduces like a cascade and this,
Speaker 1: and it could have all just come from Hey, that
Speaker 1: tastes really great. Yeah, and so that that you know,
Speaker 1: these all that hunting and coordinating all that takes like
Speaker 1: a lot of intelligence. And not only does it take
Speaker 1: intelligence to to coordinate, it takes intelligence to explain what
Speaker 1: you're talking about. And it takes intelligence to come up
Speaker 1: with that plan in the first place, you know. So
Speaker 1: all of those factors combining are just making humans more
Speaker 1: and more intelligent with every every step. And again, it's
Speaker 1: not like it's just following this perfect linear progression. Yeah,
Speaker 1: it's just like it's just kind of randomly. And the
Speaker 1: the reason that we're intelligent today is because the attempts
Speaker 1: that didn't work out, got selected out, the fact got
Speaker 1: trimmed along the way. Is it kind of a ruthless
Speaker 1: way to put it, but you know it makes sense. Uh.
Speaker 1: And that sort of ties into this other theory of
Speaker 1: um smaller prey, like when they were hunting um large
Speaker 1: prey species that you know, they eventually uh, they were
Speaker 1: hunting and track of these these large animals and eventually
Speaker 1: they were driven to extinction. So humans had to start
Speaker 1: going after smaller things or I guess, uh, hominem's had
Speaker 1: to start going after smaller things, and the fossil record
Speaker 1: indicates this. It sort of worked in lockstep with the
Speaker 1: evolution of human intelligence. So all of a sudden, if
Speaker 1: you're hunting smaller things, you probably have to be a
Speaker 1: little bit smarter. You have to be a little bit
Speaker 1: more coordinated, you have to cooperate a little more, you
Speaker 1: have to maybe invent new tools, and like obviously using
Speaker 1: a big thing to smash a large thing isn't the
Speaker 1: same thing smashing a small thing. Uh. And just simply
Speaker 1: the fact that they had to do a lot more
Speaker 1: of it. You know, if you're eating a squirrel uh
Speaker 1: as your diet, you're you're eating a lot of squirrel
Speaker 1: every day, whereas if you eat a wooly mammoth, that's
Speaker 1: your food for the month or whatever exactly. And that's
Speaker 1: a really good example of what I was talking about earlier,
Speaker 1: that cognitive niche where the more sophisticated we get, the
Speaker 1: more problems we actually generate for ourselves, the more challenges,
Speaker 1: the more intelligent we have to become. That's right. And
Speaker 1: what about this last notion? And then I think this
Speaker 1: is kind of where it all comes together, right, Yeah,
Speaker 1: so you know, we have like a real urge and
Speaker 1: a desire to to wrap everything up in a neat
Speaker 1: little package, and we just haven't reached that point yet
Speaker 1: with human intelligence. But if you step back and look
Speaker 1: at some of the theories, um and see how they
Speaker 1: all kind of fit together, it seems like most are.
Speaker 1: All of them with the exception of stone date probably
Speaker 1: could be right. But they all have to work together
Speaker 1: and work with one another, um, which is great because
Speaker 1: that level of organization requires intelligence, that's right. But the
Speaker 1: key to all of this, and I think, um, we
Speaker 1: we talked about the evolution of language on a whole show,
Speaker 1: right yeah, uh, we we still don't quite know exactly
Speaker 1: how that evolve, but we have some ideas, like we
Speaker 1: talked about with the uh, what'd you call it? Mother
Speaker 1: ins No, mother ease, mother ease. But all of this
Speaker 1: became possible because of language. All of this, like you
Speaker 1: were saying, all of this coordination, all this cooperation, anything
Speaker 1: that would eventually lead to writing down human history, all
Speaker 1: of that had to have language. So it seems that
Speaker 1: all of these sort of theories coalescing around the beginnings
Speaker 1: of language, and eventually the written word is like the
Speaker 1: key to it all. Yeah, totally. And one of the
Speaker 1: other things. Um, because we are so aware that we're
Speaker 1: intellectually superior, not only to all the other animals, at
Speaker 1: the very least, we're intellect really different from the other
Speaker 1: smart ones. Um, we tend to think of ourselves as
Speaker 1: the most intellectually evolved or the most successful humans ever,
Speaker 1: and that's absolutely not the case. Um. I think Homo
Speaker 1: erectus was around for one and a half million years
Speaker 1: and modern humans have only been around for about three
Speaker 1: hundred thousand years. So we're definitely not necessarily the pinnacle
Speaker 1: of evolution just in the amount of time and success
Speaker 1: we've had so far. But also, um, we have a
Speaker 1: tendency to think like we're we're the top and there's
Speaker 1: nothing coming. And that's not necessarily true either. Like if
Speaker 1: you look at that acceleration and technology, like um, some
Speaker 1: of our ancestors used the same tool for a million
Speaker 1: and a half years without innovating upon it. They just
Speaker 1: made that same tool over and over and over again.
Speaker 1: And then somebody came along who was born and figured
Speaker 1: out a way to make it better, and that kicked
Speaker 1: off more and more technology, and you can see it's
Speaker 1: picking up faster and faster. But the fact that evolution
Speaker 1: has jumped from the external old for us to our
Speaker 1: brains and in turn to our culture, you can make
Speaker 1: a really good case that we're not necessarily going to
Speaker 1: physically evolve any longer. We're going to mentally evolve. So
Speaker 1: it's not it's not certain what humanity is going to
Speaker 1: look like in the future, but it's probably going to happen.
Speaker 1: The changes are going to happen a lot faster soon
Speaker 1: than they have been before, and we'll all just end
Speaker 1: up brains and jars right probably or uploaded. That's right.
Speaker 1: Oh boy, good luck with that. Everybody that had a
Speaker 1: very so long sucker bring to you, got anything else?
Speaker 1: I got nothing else. I love these, uh that types
Speaker 1: of episodes. Stuff me too. Since Chuck and I agreed
Speaker 1: we'd love this episode, it's time for listener mail. So
Speaker 1: this is another Appalachian trail probably the last one I'll
Speaker 1: read because, Um, Sophie here a k A tough cookie,
Speaker 1: which a Sophie's trail name. It's just a lovely human
Speaker 1: and we we had a nice back and forth Sophie
Speaker 1: and Sophie's sister did a nobo through hike inven and
Speaker 1: just had some kind of fun things to point out. Um.
Speaker 1: One of the general rules of trail names is someone
Speaker 1: else has to give it to you. So I think
Speaker 1: that's kind of like, uh, if you're a pilot in
Speaker 1: the military, you're like a Maverick and Goose. I think
Speaker 1: people think they name themselves cool names. But my brother
Speaker 1: in law was like, no, no no, no, no, no, you'd
Speaker 1: get a name, and it's usually not something super cool
Speaker 1: like Maverick. Yeah, if you name yourself, I'm sure that
Speaker 1: people are going to be way harder on you in
Speaker 1: the name they actually select for you. Yeah. I don't
Speaker 1: even know if you're allowed to. I'm not sure. Uh.
Speaker 1: Sophie says that my sister and I cheated a little
Speaker 1: bit because we gave names to each other a few
Speaker 1: days in. I don't think that's cheating. You're still naming
Speaker 1: someone else. Sure, that's called getting ahead of the curve. Uh.
Speaker 1: We We did have some unofficial trail names though, that
Speaker 1: other people would refer to the pair of us as.
Speaker 1: My favorite was a sixty year old Kentucky hiker from
Speaker 1: Maine who told us, uh, he referred to us as
Speaker 1: the Kentucky Wonders, which is pretty fun. And one thing
Speaker 1: I realized after reading all these A t emails is
Speaker 1: that it's it's really kind of fun. Like people get
Speaker 1: together and like they start off alone and all of
Speaker 1: a sudden there's a group of like twelve people hiking
Speaker 1: together for weeks at a time. That is the very
Speaker 1: reason why I will never hike they that sounds like
Speaker 1: a nightmare to me. You would be the uh, the
Speaker 1: loner hiker totally. Maybe, like, don't turn your back on
Speaker 1: that one. I think your trail name might be Jed Bundy. Um.
Speaker 1: The trail through West Virginia is actually less than four
Speaker 1: miles and I heard this from other people to um,
Speaker 1: not eighteen. So I think we screwed that up. It's
Speaker 1: an amazing feeling to go through so quickly after psychologically,
Speaker 1: after completing Virginia, which is five hundred miles and a
Speaker 1: quarter of the whole entire trail. Uh. And there is
Speaker 1: a four state challenge that some hikers will attempt to
Speaker 1: do a forty five mile day to go through the
Speaker 1: end of Virginia, West Virginia, Maryland, and into Pennsylvania in
Speaker 1: two hours. Her family hosts a trail magic spot because
Speaker 1: they live near the trail in Tennessee, So they will
Speaker 1: go out on the weekends and they pack up a
Speaker 1: bunch of hiker food and they grill burgers and stuff
Speaker 1: or make pancakes and just feed people on the trail
Speaker 1: and then we'll go back home. I think you could
Speaker 1: be down with that part, right. Sure, I'd need a
Speaker 1: free hamburger, Like can I take it to go? I'd
Speaker 1: be like why, I'd be like why is there mustard
Speaker 1: on here? But not catch up? Uh. And then finally,
Speaker 1: during the hike, we would treat ourselves to podcast for
Speaker 1: a couple of hours when hiking was getting monotonous and
Speaker 1: wanted to get out of our heads some and your
Speaker 1: voices were a frequent, frequent companion listening to stuff that
Speaker 1: you should know. Selects these days often have the weird
Speaker 1: sensation of remembering exactly where I was hiking in the
Speaker 1: woods when I listened to that episode. Uh, come to
Speaker 1: Kentucky sometime, check out the Bourbon distilleries and the Red
Speaker 1: River Gorge and do a show here Lexington. I know
Speaker 1: you'd probably rather go to Louisville or Cincinnati, but Lexington
Speaker 1: is definitely worth a visit. And Sophie sent along a
Speaker 1: bunch of cool pictures of Sophie and her sister before
Speaker 1: and after, and it's just looked like a really great time.
Speaker 1: That's awesome. Thanks a lot for that email, Sophie, that
Speaker 1: was a great one. And agreed Chuck that one had
Speaker 1: to be right for sure. Just stay away from Josh
Speaker 1: if you see him in the woods. No, I'm harmless.
Speaker 1: I just don't want to be spoken to. That's all.
Speaker 1: I want to be left alone. It's too awkward. Otherwise,
Speaker 1: you could just hike with a big giant like nineteen
Speaker 1: seventies headphones as if you're listening to right with my
Speaker 1: head down, sunglasses on in a bag over my head.
Speaker 1: I love it. If you want to be like Sophie
Speaker 1: and get in touch with us. You can send us
Speaker 1: an email and send it off heart Radio. For more
Speaker 1: podcasts my heart Radio, visit the heart radio app. Apple
Speaker 1: podcasts are ever you listen to your favorite shows. H