Where Did Human Intelligence Come From?

That's uh, that's how appropriate. It totally Chuck, because we are talking today about human intelligence in the origin of human intelligence, and it just seems super stuff you should know me for us to not be able to come up with a decent joke, you know, well Ed did that for us, actually, because I did want to shut out. We usually don't mention like section titles and stuff like that that's actually in our notes, but Ed drops because

it's you know, it's for our eyes. But Ed dropped to Simpson's reference in his section title one of the great Simpsons references chimpan A to Chimpanzee was so great. That was from the Planet of the Apes musical, right, that's right. And I just I like to think is

that as a little gift from Ed to us? Yeah, it definitely was, and it was well received too, So thanks ed Um and the reason Ed created a section called chimpaneze to chimpanzees because we're gonna talk about the lineage of humanity like where humans came from UM And despite that hilarious and clever um section title, we did not actually evolve from chimpanzees, but we do share a

common ancestor from chimpanzee. So chimps and humans split off from a shared ancestor about six to eight million years ago UM, and that really kicked off a long line, very long process um of evolution where intelligence started to develop fairly early on. It just was really slow to start, and then over time it kind of picked up speed. Yeah, you found this some kind of cool statistic. There's a researcher writer named Richard Leakey and H Richard, and I

think most people agree. They posit that there was what's called a big bang of human culture around the Upper Paleolithic time period where things were, like you said, slow going for so long, and things were measured in in eras before that, very very slowly over like hundreds of millennia, and then all of a sudden, like sixty two thirty thousand years ago or so, things started to really ramp

up in terms of innovation and intelligence. And uh, just really moving the ball forward to use a football metaphor, and we're talking about you know, clothing and uh, social structure and in art and creativity and stuff like that. So it's kind of cool to think, and you know, we're going to talk about why that might have happened, but uh, the fact that that did happen got us on the moon in short order over the last few

thousand years. It's kind of like if you look at the development of intelligence as a train that's starting from a stop, it starts out with kind of a chuck good chug good chug chug chugga chug a chuga, and then that um, that Upper Paleolithic Revolution, the big bang of culture. That's the cho choo part that really punctuates the whole thing. I was thinking more along the lines of it like a Japanese bullet train. But sure, I don't think we're OK. We still do some really stupid stuff.

So we can also create a bullet train. We can, but we just can't be the bullet train intellectual. Oh man, mind blown. So chuck. The fact that thirty to sixty thousand years ago there was that Upper Paleolithic Revolution where humanity just suddenly blossom into what we recognize today as humanity. It's really tempting to think that human intelligence just was suddenly born all of a sudden, like geologically speaking, overnight

at that time. But that's just not the case. Um. It seems like something definitely happened there, like some wire connected with another wire that really made a big difference. But instead, again, it was this part of this very long line of seemingly random and unconnected um developments in the in the history of humanity. And I guess our our genus Homo um that led to that point and actually led to that point today, because we're still evolving

and developing. Yeah, I guess uh. If you look at it on a timeline, it looks like a mechanic came along and said, well, here's your problem. You forgot to plug you forgot to plug it in. That's right, you gotta plug these two wires together and then you're all set totally. But we like to talk about Homo sapiens in in terms of human intelligence for good reason. Homo sapiens, that is to say, us a k a. Modern humans

evolved about three hundred thousand years ago, um. But we are just one of a collection of uh in in this big lovely family called the Hominem's yeah, cominens comin in Yeah, I think it's at ms. Yeah. So the hominins are everybody that um that started off branching from that common ancestor with chimps. That's the hominin line, and humans in our genus Homo that Homo sapiens are a

part of, is just part of that hominin. There are other entirely different genus or genie i that make up the hominin line, right, that's right, And we should point out that sapiens actually is taken from the Latin word for knowledge, so it kind of all makes sense. It does.

So the whole thing starts out it seems like as far back because we can tell um something again, like somewhere around six or so million years ago, there was a group of homonyms called Artipithecus um who basically walked upright. But that was essentially the big difference between them and chimpanzees.

But as we'll see, that was a really really big difference, right, Yeah, I mean we'll we'll get into this in more detail, but obviously if you're walking up right, then you have a very important thing at your disposal, which is use of your hands. Right, So then, um, you've got Australopithecus uh, and some a few other different kinds of branches that kind of branch off. It's a really tangled, convoluted family tree, um, where some kind of lead to blind alleys, others lead

to others. But um, they think that Australopithecus is was a really big, long lasting group that was a little more human, definitely more human than art Epithecus um, but not quite as human as the genus Homo um, which off all of these different species of human Because we're we're alive today, we're on you know, planet Earth, living here in two and every single human alive is a

member of the same species. So like there's different kinds of cats, there's different kinds of fish species, there's different kinds of bird species. Um, there's only one kind of human species. But that wasn't always the case. There are plenty of different human species, some living alongside one another for tens or hundreds of thousands of years, that's right.

And almost all the hominins used tools, it seems like, and make made tools, and for a long time we thought that that was sort of it, that only the Homo genus was the one who did use tools, which is and you know, we talk about things like being bipedal and using tools as sort of some of the building blocks of what would become human intelligence. But now we know that there are uh some older you know, we found evidence that they use tools before that. Uh

that's kind of fairly recently, right, Yeah. We we wanted to say that toolmaking started sometime after the Homo genus showed up of a couple million years ago, um, but we found even older tools. So it seems like austral Epithecus, which again their hominance, they're part of the branch that led to us humans, but they're not human in any way,

shape or form um. So the fact that they're using tools was kind of mind blowing, and it also really kind of undermined kind of like what you were saying, like our idea of using tools, like that's a big sign of intelligence, and and humans are intelligent, so it's weird to find out that non humans were using tools millions of years ago. That's right. Um, should we move on to the hardware software thing? Yeah, So if if tools and fire are not, um, because we found use

of fire dating back at least a million years. UM. So if if tools fire hanging out with one another collectively, if these aren't like the indicators that make human intelligence, we've got to like get a little more granular. Unfortunately for you and I sitting here today, chuck, UM, scientists have done that, and they've come up with some really interesting like ways of looking at this. Yeah, and UM, there's a bit more of a preamble before we get

actually to the intelligence. UM. And I like the way ed put this, sort of like talking about hardware versus software. Um, they were very intertwined and um, you know, sort of happening at the same time. So it's not like one couldn't happen without the other as far as the hardware

software thing goes. But Uh, if we're looking at hardware and we're talking about um changes that made us like better at walking up right, Like you can you all of a sudden just don't stand up and start walking like this happens over a long long period of time. Our hind legs got longer, Uh, the shape of our

pelvis changed. Um. There's something called the Foreman magnum, which is a hole in the base of the skull where the spinal cord and lots of nerves and things passed like sort of open up those neural pathways, and that changed its location. So these literal physical changes are happening over great periods of time in order just to be able to walk up right right and and bipedalism it's

like the defining characteristic of prominence. Right. There's there's not really, as far as I can tell, any other animals that that walk upright like by default. Um, so there had to be physiological changes, but they're not entirely certain why we started walking up right. But the fact that we did and it's lasted for this long means that there was some advantage to it because enough people walking upright

were able to pass along their genes. And they think one one big theory is that it helped us survive climate change where maybe things got colder and there were less trees. So since we weren't arboreal anymore, we didn't hang out and live and eating trees. We were able to kind of move around and find different like food sources in different shelters, whereas the like our cousins the chimps,

were in big trouble. They were up the proverbial creek. Yeah, and I love that you point out that we, uh, we're the only ones who walk upright by default, because I think we can all agree there's nothing more fun than YouTube videos of like a dog or a cat or something just walking on its hind legs for some reason. Definitely, and and it's the coolest and most fun thing ever. It totally is. And I mean, now I'll take like a Jesus lizard running across some water once in a

while too. There's nothing wrong with watching. Is that what those are called? Yeah? I think I saw one of those in Mexico, but that was surprising. Are they not there? I don't know. I'm just saying I've I've never seen one in real life, so I'm sure that was surprising to see. I saw a lizard that was walking, and it wasn't walking on water, but I think it was one of those kinds that can I just didn't know the name of it. Had you recently eaten the worm

from the bottom of the bottom of most cow? Very funny. Another thing we should point out is that walking upright is an energy saver. I mean, it's they've done studies and they found that um, you use about the energy um rather than you know, bounding around on all fours like a chimp mte right or like a chimp does. But to save that energy, to conserve it um, our pelvis has had to change shape. Like you mentioned, that

was just a consequence of walking upright. Um. And the reason to change shape is when you walk up right, if you're a chimp, your body swings side to side. You have to hold your arms up to balance yourself. That takes a lot of energy. UM. So we developed like gluteal muscles and other muscles that can cling to a specific shaped in size pelvis so that we don't have to spend all the energy. Our muscles are just

kind of keeping us much more balanced. But one of the consequences of that of walking upright and our pelvis changing means that the size of the birth canal afforded by the hole in the all of us the child passes through during birth. UM got smaller, a lot smaller. And it's really strange to think that this the the decreasing in size of the birth canal actually was one

of the factors that led to an increase in intelligence. Yeah, and you know, we should point out this is just the first of what will be a lovely cascade of theories that we're gonna lay lay on your brains today. Uh, and that, like you said earlier, there there is no one, single one. It's kind of when you put all of this stuff together. I think that's sort of the beauty of of human intelligence, is it took all of these

great things sort of coalescing um. But the whole thing with the brain is interesting because the size of the brain is is one of nature's kind of controversies. Like we know that as far as humans go, just because you have a bigger brain doesn't mean that you definitely will be smarter. But there are some correlations cross species in nature, uh, and in humans there can be, you know,

evidence that bigger brain means you're more intelligent. But it's not one of those things where it settles science where they just say, hey, if you've got a bigger brain, you're gonna be smarter. No, And in fact, like there's all sorts of evidence in nature that suggests that's not the case. Because our brain to body size ratio among humans is one to forty, So our brain makes up about our body mass, and that's the same ratio that a mouse has. My mice just I don't care how

you cut it. They're just not as intelligent as humans. But on the other hand, an elephants brain to body ratio is one to five hundred and sixty and elephants are super smart. So, um, you you can't really find much there that says, you know, there's no direct correlation where it's like the bigger the brain, the more intelligent the being. Um. But there does have to be some minimum amount of brain size because it seems like the connections of the brain is we'll see, are what really matter.

And the more brain tissue you have up to a certain point, the more connections that can be made. Right, So that brings us back to the birth canal situation. Like you mentioned you're walking upright, that changes in the shape of the pelvis, you have a much smaller birth

canal all of a sudden. So evolutionarily speaking, you might think, well, does that mean we're going to have to have babies with tiny, tiny little heads and therefore tiny tiny little brains that may not be able to grow very fast because it's enclosed in a skull that's sort of locked down,

but that didn't happen to us. What happened was we have Fontanell's and we have this delayed fusing of the skull kind of you know, closing for good, and so it allows and it's you know, it's remarkable still to think about this to me, but it allows that little baby head to squish down to get through the birth canal, and it through the vagina and out into the world

and stay that way for a while. And it's during that for a while period before that skull completely fuses that a human brain really really grows a lot, and chimps don't have that ability. No, a chimp, uh, their skull fuses mostly in the womb, and their brain, as a consequence, grows mostly to what size it's going to reach in the womb. So, on the one hand, a chimp baby, you could say, is much smarter and much

less helpless than a human baby. But given enough time, the human baby is going to start to exceed the chimp's abilities very quickly. And it's because our development is delayed. We do a lot of developing outside of the womb, and that's afforded by that skull that's not fused. For a couple of years after birth. And this was not there is no intelligent design, so there this was not like, um,

like a good solution or work around. This was just a natural selected, naturally selected trait, the skull not fusing. That was a solution to the smaller birth canal, not to not to increase intelligence, but the advent of babies being born that didn't have few skulls allowed for the advent of intelligence. Yeah, a solution to the problem of walking up right, which is really interesting to think about. Yeah, And it also just goes to show like it's like

nature is not always like elegantly simple. Sometimes it's really convoluted and organisms including us are held together by like duct tape and bubblegum, you know. And that's a good example of it. I think that's a good time for the break, yea, yea. And we'll come back and drop some plasticity on your brain right after this, So, Chuck, this is the point we're about to talk about brain plasticity.

This seems to be, uh, what if anything explains human intelligence, and certainly the burst of intelligence that happened thirty to sixty thou years ago. Yeah, And I think the opening statement to this whole thing is all you gotta do is look at the fact that we learn almost everything as humans, like from the moment we're born. There there is some maybe instinctive knowledge, but like you said, like

human babies are kind of helpless, little dumb dumbs. And from that point forward, our brains are are learning and they're growing, and they're capable of learning, and they're capable of adapting. And this all has to do with plasticity, right, So, just if you aren't familiar, plasticity is the brain's ability to um basically rewire and create new connections as new

experiences come along. Uh, And you can even take old experiences that you experience more than once and the second and third and fourth time, those neural connections are going to become more sophisticated and more connected than they were before. So our brains are plastic. They can be molded and shaped kind of like in the rhinoplastic um sense of the word. They're not made of plastic. They can be molded and they're molded by the connections that they make.

So it's not necessarily that you have a giant brain. It's that you human being have a brain that is really highly capable of creating new connections, and it's those connections that forms the basis of intellect. Yeah, and that really frees up, Like once you have a brain that's plastic and that can evolve, you know, to figure out a pro ablem rather than taking eons and eons to have like genetic to genetically adapt to a solution to

a problem. If all of a sudden you have a brain that can figure something out, you do it so much quicker, and that frees you up to do more and learn more, and it creates this feedback loop all of a sudden where the process really really speeds up. And that's you know, basically what we saw thirty sixty years ago. Yeah, and the reason and we're still seeing

it today, Chuck. I mean, like you know, a thirty to sixty thousand years ago, it was a huge burst of creativity and intelligence, but we're still talking about changes that took place over thousands of years. Now. We're seeing changes to the human condition in our society that takes place over like tens of years. So it still seems to be speeding up and we're still going through the

same process. But the I guess the best way to think about what you've just described as evolution, which typically you know, UM forces changes on us based on environmental conditions, goes into the brain, and now it's the brain that's able to change, and like you said, it changes much faster, and that leaves genetic evolution or genetic natural selection to focus on UM selecting for traits that create more and more intelligence. So it creates that positive feedback loop like

you said, and speeds things up. It's pretty brilliant. So there's been a lot of really interesting research, especially in that it seemed like the early to mid nineteen nineties about plasticity UM. There are a couple of researchers name to Be and Cosmides great names, and they had a theory basically that human intelligence UH evolved with all these UM encapsulated cognitive models, so they did not have the

ability to excess each other. Each each of these modules, and each one was very specialized for a very specialized problem or task that was trying to do our problem that was trying to solve, and that's like a language module, UH, spatial relation module. UH, here's how to make and use

a tool that kind of a module. And that all these modules are still around, uh and basically the same form that they were back then, because it's there on the timeline of you know, humanity, that that hasn't been a lot of time to undergo any kind of modifications basically, So I disagree with that. I think I think on a speaking about classic evolution natural selection, that's true, but brain based evolution and natural selection like cultural natural selection,

I think that that's false. You hear that to be. So. The the idea about all this is that these modules that we developed over time is like we came upon new problems in our environments and had to figure out new solutions to them. They started to kind of get cross referenced here there, Like you could say, um, you know, the same the same ability to UM to to follow the sunset, right, Yeah, I wish I would have come up with something better can also can also be used

to UM to follow herds of game, right. And so all of a sudden we now not only just know to to follow the sunset if we want to follow the sunset, we also know we can use that same ability to follow game around. And all of a sudden, our diet expands that kind of thing. So as these different modules started cross referencing themselves and and got more and more connected. We were able to apply these different things to more and more situations and got more and

more intelligent. All right, So that's UM. That's one sort of grand theory which I love. Another one that we're going to talk about is I think super interesting because some of this stuff is so kind of rudimentary in it when you just sort of look at it from a macro view, but when you really have to think about how important that ended up being, it's it's fascinating to me. And in this case, we're talking about the fact that UM. One of the sort of side and

again it's going back to bipedalism. One of the side effects bipedalism is that we lost our ability, UM, with our feet to be able to like hang onto things like chimpanzees do. They were these boots were all of a sudden made for walking, and they weren't made for grabbing. And if they weren't made for grabbing, then you couldn't hang on to mama like a chimp could with hands and feet. So mama had to hang on to human baby.

And mama can't hang on to human baby all the time because mama still has to get things done around the you know, savannah. So what you have to do then is leave that baby somewhere and go do stuff like go down to the river and uh and do things and uh. If you leave a baby somewhere, what you go down to the river and do and things? Two things you know unen uh and if you leave that baby And this is all leading to this statement, if you leave that baby somewhere, you want to be

able to go back and find that baby. And it seems so rudimentary and basic, but that is a huge thing in the development of the early human brain, is simply to spatially map and remember, like where I have left this child. It's important to go back and get that child, and I can do that. Yeah, and then um.

Consequently to that, another adaptation seems to have arisen from the same problem, the problem of not being able to cling to the mother anymore, and then also the problem of the baby being otherwise helpless, way more helpless than a baby chimp. Right, So they think that around the same time baby's cries developed, like you don't hear other things necessarily crying like a human baby, And they don't think that babies cried like that until around this time,

because there was that problem. So even if a mom couldn't remember where she put her baby, she could listen out for the baby crying. And they also think around this time that an urge or desire to soothe the baby from its crying would have developed, and that it's possible, Chuck, And this makes so much awesome sense that language actually developed out of what's called mother ease, that kind of soothing baby talk that calms the baby, that mothers know

how to do just naturally. They think that it's possible that that is what formed the basis of language. Yeah, and I'm gonna go beyond that even because what I noticed when I had a baby in the house was that, even beyond the soothing thing, if you are holding your baby and you have to put your baby down to go wash the dishes or whatever, generally, and I think I speak for most parents, you don't just go set your baby down, go in the other room and do stuff.

You're you're talking to that baby from the very beginning, and you're saying, all right, let's go over to our little place here. I'll be right back. I'm gonna be right here in the other whom that baby doesn't know what you're talking about, obviously, but there's there just seems to be this evolutionary instinct to to say things to

it right out of the gate. It's really interesting. It is interesting, and then wrapped up in this also there's a better example than following the stupid sunset that I came up with. I love sunsets. But if you can now all of a sudden like remember where landmarks are and then wayfind your your way back to you know, the starting point. Now you can start to use that to follow game further and further afield, and you're expanding

your range and you can expand your diet. So that's a really good example of one thing kind of leading to another, and all of it being um arising from environmental pressers brought on by changes to buy of us. Yeah, I love it me too. Um. This next one is kind of fits in a little bit with a plasticity I think. Uh. The idea of the cognitive niche um, which is, you know, typically figuring out like a solution

to a problem. But this theory is that maybe intelligence evolved as a universal adaptation to all kinds of uh, evolutionary pressures that we're bearing down. So um and ed has a pretty great example. If you've got a an island with a tree that has a certain um fruit seed that's really beneficial for your body, Um, but you can't crack into it. There's you know, it would take a bird, uh, you know, hundreds to thousands or millions of years to develop and evolved to have a beak

that can crack that thing open. But if all of a sudden, you know how to make a tool, you can just walk over and steal that thing from that dumb bird and just crack it open with the tool. So it's not filling, it's your brain at work, and in that case is filling a specific niche. But that's a tool that was also used to kill the animal

or chop the wood. Yeah, and that really supports what we were talking about a few minutes ago that once evolution, once a brain is evolved to a certain amount of intellect, the brain can take care of the organism and natural selection and genetics can kind of take a step back and not have to say, like, um, you know, uh,

select for a thicker harrier chest. Because we're living in a colder time now because the brain can come up with a way to create a coat, right, So it just kind of takes over evolution from evolution by doing that,

and that's that cognitive niche. And one of the consequences of it is that there seems to be as as things change in our environment, we figure out new ways to to solve those, and then those those solutions are inevitably going to create other problems or changes, So then we have to we have to evolve even further intelligence

to figure out how to solve these new problems. You can actually see it still going on today, Chuck, Like, we've evolved a level of intelligence where we can extract petroleum from the earth, we can build machines that run on that petroleum, and we can develop science that figures out that burning those the that petroleum is really really

bad for the climate. So now we've we've altered our ecosystem enough that we have to evolve intelligence enough to figure out how to get out of this new conundrum that we've created for ourselves based on our previous intellect. So intellect builds on intellect through environmental pressures that we often bring on ourselves. That seems like the case, Yeah, I mean, I think a lot of people seem to think of intelligence is only solving problems, but it also

creates a lot as well. It's interesting, Yeah, it really is. Um. I know we were gonna skip this section entirely, but I think just for frenzies, we should very quickly mention one, uh the ideas from someone called Terence McKenna who describes as a post modern Timothy Leary type, one of these people that that advocates for psychedelic drug use, and just very quickly the idea is that, uh, the cavemen were

tripping on mushrooms and that's how intelligence evolved. And I just like mention it because I feel like there's almost nothing, no leap in history that some person hasn't said, like the Enlightenment or whatever, like, oh man, they were just tripping, right, they were just super I don't think it's pretty funny.

It is funny, but it does. I mean, like if you apply it exclusively to the Upper Paleolithic Revolution, where all of a sudden there's like art and jewelry and dancing that stuff, it's possible that it was based at least in part you know, yeah, you never know, alright, So I say, we take a break and we come back and get down to the nitty gritty of how food might have brought intelligence along. How about that? Mm hmm.

By the way, Chuck, I have a theory real quick that the more you say uh or um, the more intelligent you um are. Oh boy, I must be a smarty pan. You know, other more intelligent podcasts cut all that stuff out. Yeah, I guess do they? Yeah? I mean, what did I mispronounced in the Row episode? I couldn't even substantive Oh yeah, yeah, it's true. Other podcasts would not have left that in. But that's because dummy leaves that they're not as brave. We're courageous podcasters. Okay, I'll

buy that. Um. This next theory I think is super cool because anytime each tie in um, not just food, but sort of a an appreciation for a creature comfort, it really like turns turns me on and not you know, in certain ways intellectually turns me on. And in this case, we're talking about the fact that we used fire obviously and then started cooking food, and people that cooked food said, wow, this is really good, and this taste a whole lot

better than that raw meat. We've been eating this charred meat is delicious, and let's let's try and do more of this around here. Yeah, And so that would have just them being um, responding to like a taste preference, and that's it. But it just so happened that that taste preference would have had a really big benefit and a big contribution to the development of intelligence. Because if you cook me eat um, you unlock a bunch of nutrients and calories that are otherwise unavailable to you if

you just eat it raw. So over time, the people who ate meat would have had more energy and more calories to contribute to a growing brain, which could have helped the process along if not sped it up. And if you consider the fact that we've definitely seen that that taste and smell has responded to evolutionary pressures in that we at some point learned not to eat poop,

and we learned not to eat rotten food and stuff. Um, And that's you know, taste and smell it can have the you know, it looks like it can have the opposite effect to where all of a sudden you have a preference for the good. And that just happens to

work out in your favor. Yeah, and this is another example of one thing leading to another, where like you know, mothers developed an awareness of landmarks and wayfinding, and then that led to um being able to follow game, which expanded our diet, which led to us eating meat, which eventually led to applying controlled fire to that meat, which led to more calories and nutrients available, which led to bigger brain growth, which helped found uh, the growth of

intelligence and humans. Just one thing, one totally random, unconnected thing, or even connected but seemingly unconnected, uh, just creating us today. It's just so nuts. So to me, I love it. Yeah, me too. And the fact that, like, think about this, not only the preference for a charred meat, but the preference for a specific charred meat because you know, different stuff tastes different. It's not like everything tastes like chicken.

I know that's a joke, but all of a sudden took took his out there and and says, boy, that one thing that we killed yesterday. You guys, I don't know about you, but that was really really delicious. And we know that that is we saw that thing three days ago, about fifty miles away. Everyone said, what's a mile and he well, that doesn't matter right now, but

the point that it was really far away. So all of a sudden, other things are introduced, like cooperation, not just wayfinding, but hey, let's let's all get together because this is like a three day journey and this thing is really big. That tastes so delicious, So it's gonna take a few of us to bring this thing down and to process this animal and get this meat ready for cooking. So it just introduces like a cascade and this, and it could have all just come from Hey, that

tastes really great. Yeah, and so that that you know, these all that hunting and coordinating all that takes like a lot of intelligence. And not only does it take intelligence to to coordinate, it takes intelligence to explain what you're talking about. And it takes intelligence to come up with that plan in the first place, you know. So all of those factors combining are just making humans more and more intelligent with every every step. And again, it's

not like it's just following this perfect linear progression. Yeah, it's just like it's just kind of randomly. And the the reason that we're intelligent today is because the attempts that didn't work out, got selected out, the fact got trimmed along the way. Is it kind of a ruthless

way to put it, but you know it makes sense. Uh. And that sort of ties into this other theory of um smaller prey, like when they were hunting um large prey species that you know, they eventually uh, they were hunting and track of these these large animals and eventually they were driven to extinction. So humans had to start going after smaller things or I guess, uh, hominem's had to start going after smaller things, and the fossil record indicates this. It sort of worked in lockstep with the

evolution of human intelligence. So all of a sudden, if you're hunting smaller things, you probably have to be a little bit smarter. You have to be a little bit more coordinated, you have to cooperate a little more, you have to maybe invent new tools, and like obviously using a big thing to smash a large thing isn't the same thing smashing a small thing. Uh. And just simply the fact that they had to do a lot more

of it. You know, if you're eating a squirrel uh as your diet, you're you're eating a lot of squirrel every day, whereas if you eat a wooly mammoth, that's your food for the month or whatever exactly. And that's a really good example of what I was talking about earlier, that cognitive niche where the more sophisticated we get, the more problems we actually generate for ourselves, the more challenges, the more intelligent we have to become. That's right. And

what about this last notion? And then I think this is kind of where it all comes together, right, Yeah, so you know, we have like a real urge and a desire to to wrap everything up in a neat little package, and we just haven't reached that point yet with human intelligence. But if you step back and look at some of the theories, um and see how they all kind of fit together, it seems like most are. All of them with the exception of stone date probably

could be right. But they all have to work together and work with one another, um, which is great because that level of organization requires intelligence, that's right. But the key to all of this, and I think, um, we we talked about the evolution of language on a whole show, right yeah, uh, we we still don't quite know exactly how that evolve, but we have some ideas, like we talked about with the uh, what'd you call it? Mother ins No, mother ease, mother ease. But all of this

became possible because of language. All of this, like you were saying, all of this coordination, all this cooperation, anything that would eventually lead to writing down human history, all of that had to have language. So it seems that all of these sort of theories coalescing around the beginnings of language, and eventually the written word is like the key to it all. Yeah, totally. And one of the

other things. Um, because we are so aware that we're intellectually superior, not only to all the other animals, at the very least, we're intellect really different from the other smart ones. Um, we tend to think of ourselves as the most intellectually evolved or the most successful humans ever, and that's absolutely not the case. Um. I think Homo erectus was around for one and a half million years and modern humans have only been around for about three

hundred thousand years. So we're definitely not necessarily the pinnacle of evolution just in the amount of time and success we've had so far. But also, um, we have a tendency to think like we're we're the top and there's nothing coming. And that's not necessarily true either. Like if you look at that acceleration and technology, like um, some of our ancestors used the same tool for a million and a half years without innovating upon it. They just made that same tool over and over and over again.

And then somebody came along who was born and figured out a way to make it better, and that kicked off more and more technology, and you can see it's picking up faster and faster. But the fact that evolution has jumped from the external old for us to our brains and in turn to our culture, you can make a really good case that we're not necessarily going to

physically evolve any longer. We're going to mentally evolve. So it's not it's not certain what humanity is going to look like in the future, but it's probably going to happen. The changes are going to happen a lot faster soon than they have been before, and we'll all just end up brains and jars right probably or uploaded. That's right. Oh boy, good luck with that. Everybody that had a very so long sucker bring to you, got anything else? I got nothing else. I love these, uh that types

of episodes. Stuff me too. Since Chuck and I agreed we'd love this episode, it's time for listener mail. So this is another Appalachian trail probably the last one I'll read because, Um, Sophie here a k A tough cookie, which a Sophie's trail name. It's just a lovely human and we we had a nice back and forth Sophie and Sophie's sister did a nobo through hike inven and just had some kind of fun things to point out. Um. One of the general rules of trail names is someone

else has to give it to you. So I think that's kind of like, uh, if you're a pilot in the military, you're like a Maverick and Goose. I think people think they name themselves cool names. But my brother in law was like, no, no no, no, no, no, you'd get a name, and it's usually not something super cool like Maverick. Yeah, if you name yourself, I'm sure that people are going to be way harder on you in the name they actually select for you. Yeah. I don't

even know if you're allowed to. I'm not sure. Uh. Sophie says that my sister and I cheated a little bit because we gave names to each other a few days in. I don't think that's cheating. You're still naming someone else. Sure, that's called getting ahead of the curve. Uh. We We did have some unofficial trail names though, that other people would refer to the pair of us as. My favorite was a sixty year old Kentucky hiker from Maine who told us, uh, he referred to us as

the Kentucky Wonders, which is pretty fun. And one thing I realized after reading all these A t emails is that it's it's really kind of fun. Like people get together and like they start off alone and all of a sudden there's a group of like twelve people hiking together for weeks at a time. That is the very reason why I will never hike they that sounds like a nightmare to me. You would be the uh, the loner hiker totally. Maybe, like, don't turn your back on

that one. I think your trail name might be Jed Bundy. Um. The trail through West Virginia is actually less than four miles and I heard this from other people to um, not eighteen. So I think we screwed that up. It's an amazing feeling to go through so quickly after psychologically, after completing Virginia, which is five hundred miles and a

quarter of the whole entire trail. Uh. And there is a four state challenge that some hikers will attempt to do a forty five mile day to go through the end of Virginia, West Virginia, Maryland, and into Pennsylvania in two hours. Her family hosts a trail magic spot because they live near the trail in Tennessee, So they will go out on the weekends and they pack up a bunch of hiker food and they grill burgers and stuff or make pancakes and just feed people on the trail

and then we'll go back home. I think you could be down with that part, right. Sure, I'd need a free hamburger, Like can I take it to go? I'd be like why, I'd be like why is there mustard on here? But not catch up? Uh. And then finally, during the hike, we would treat ourselves to podcast for a couple of hours when hiking was getting monotonous and wanted to get out of our heads some and your voices were a frequent, frequent companion listening to stuff that

you should know. Selects these days often have the weird sensation of remembering exactly where I was hiking in the woods when I listened to that episode. Uh, come to Kentucky sometime, check out the Bourbon distilleries and the Red River Gorge and do a show here Lexington. I know you'd probably rather go to Louisville or Cincinnati, but Lexington

is definitely worth a visit. And Sophie sent along a bunch of cool pictures of Sophie and her sister before and after, and it's just looked like a really great time. That's awesome. Thanks a lot for that email, Sophie, that was a great one. And agreed Chuck that one had to be right for sure. Just stay away from Josh if you see him in the woods. No, I'm harmless. I just don't want to be spoken to. That's all.

I want to be left alone. It's too awkward. Otherwise, you could just hike with a big giant like nineteen seventies headphones as if you're listening to right with my head down, sunglasses on in a bag over my head. I love it. If you want to be like Sophie and get in touch with us. You can send us an email and send it off heart Radio. For more podcasts my heart Radio, visit the heart radio app. Apple podcasts are ever you listen to your favorite shows. H