Joe Rogan - William Von Hippel on How We Became Humans

what it looked like, but from all we can tell it was awfully close to today's chimps. And so if you look at chimps today, you can get a pretty good sense of what life was like then. And chimps today are really interesting. They're basically at the top of the food chain in the rainfall. Because they travel in groups, even amazing tree climbers like leopards won't try to attack them in trees. They're too dangerous, too fast. But if you look at a chimp on the ground, it can't even lock its knees. It's this kind of cute little stumbled-in-a-long thing. And then the question is, why would an animal that runs a show in the canopy leave the rainforest for the savanna? And then how would it survive once it did that? And that's the story of this book, and then how that manifests itself to where we are today. So really my goal, I'm a psychologist, I want to understand why we are the way we are. And so in trying to figure that out, I said, well, let's take a look back all the way to our common ancestors and see some of the key events and how they might have had an influence on how we are today. So the first question is, why would we leave the trees? Right? Here we are, we're dominant position, we're food on the ground, why would we ever take that risk? And the basic story there is the Great African Rift Valley. I'm not sure if you're familiar with it at all, but basically it runs down from up at the Red Sea, down to the coast of Mozambique. And you can think of it like a geographic zipper. You know, all the world sits on these tectonic plates, and sometimes they crash into each other, like how India is smashing into Asia and creates the Himalayas. Sometimes they literally tear apart, and Africa is tearing apart at the Great African Rift Valley. So that plate that has Somalia and Ethiopia, Tanzania, Kenya, that's moving off to the lower right, the rest of Africa is moving off to the upper left. And I got no idea why, it's been going on for quite a while. But one of the consequences of that is that the East Africa is starting to rise up slowly bit by bit. And when it rises up, the rainforest dry out. And so basically what you have is a situation where our ancestors were on the east side of that Rift Valley, and it started to dry out. And now they're in a situation where they've got this great lifestyle, they're dominant position, but now they're pushed, they're forced out onto the ground increasingly more and more because there's more and more ground and less and less rainforest. And so how do they survive that? What do they do in order to make that work? And this is a what, what period of time is this? How many millions of years ago? Six or seven. Six or seven. Does this coincide with the, when was the jump of the human brain size where it doubled? Oh, we'll get to that. So it's a super interesting question about why that happened as well. So basically, if you track us across the next three million years, how did our ancestors survive when they're basically chimpanzees on the open savanna? And you can get a hint of how they did it, because there's one chimpanzee group that does live on the savanna in Senegal. And they, they show some differences between themselves and other chimps that travel in slightly larger groups, they share more nicely with each other, which is interesting, that's kind of a human trait as well. And they also avoid open space, like they're just kind of trying to stay near the trees as much as possible. And so, and if you look at other eight, they're not eight, but other primates that are on the savanna, like savanna baboons, they're only monkeys, so they're not as sharp as chimpanzees are, but they have a similar strategy, large groups to try to protect themselves and lots of eyes to look out for predators. And they do fine on the savanna. And so what I suspect happened is for the first few million years, basically what you've got is this chimp-like animal that's kind of skirting the edges of savanna nowhere near the top dominant position they used to be, and just kind of noodle it around. And that takes, I suspect that takes us for about the first three, three and a half million years. And if you look at who we are then, we're Australopithecus afarensis. So it's, if you looked at one of them, you'd think it belongs in a zoo. It looks almost like a chimpanzee. And so a chimp brain, in answer to the first part of your question, is about 380 grams. And Australopithecus brain is about 450 grams. So three million years of evolution and all we've got for it is 70 grams. So why do we get so smart? Why do we take off in the next few million years? And what is it that Australopithecus did that helped us survive? And why do I call that the social leap? That's all kind of tied together. And the basic story is that by this point Australopithecus has become bipedal. And we can talk about how that happened if you'd like. And so because they're bipedal, their waist is now stretched out. They're musculature, like if you look at chimpanzee pecs, they aim upward because of course chimps climb in all the time. Australopithecus is more lateral, like we are, we're basically completely lateral because things are side to side as far as we're concerned. It's harder to climb a tree, but it's a whole lot easier to do a lot of other things. And we have much more limber shoulder, we have much more limber wrist, all that sort of thing. And a lot of that was in place by Australopithecus. So once they became bipedal, they gained a lot of these qualities. And then the question is, why do those qualities matter? Well, if you watch a chimpanzee throw, it's terrible at it, even though they're stronger than you and I are pound for pound by a sizable margin. When they throw their inept, they can't aim very well. And they typically use two hands, because they're not lined up well to throw. If you watch a really good thrower like you know, a gridiron, a football player, a baseball player, or hunt to gather a throw, you know, it's a full body motion, you step forward with the other leg, there's this rotation in the very last minute you bring your wrist through. Well, what that does is it creates an enormous amount of elastic energy across your muscles, tendons and ligaments. And the end of that throw for a human is like the snapping of her rubber band. So chimps can't do that. They're not lined up properly. But Australopithecus got to the point where they could probably do that pretty well. And so now, and this purely a byproduct of bipedalism, because it stretched out their whole body, and they don't, they're not climbing as much anymore. So their musculature is more lateral, which would have been helped them for throwing. So now you get to a point where they have access to the single most important military invention in history, which is the capacity to kill at a distance. So if you and I are running around the Savannah and a lion attacks us, and we got 50 of our best friends, we could kill it with our bare hands. But a lot of us are going to die in the process, right? Because you think 50 of us could kill a lion? Let's make it 100. Somebody think even a hundred of us could kill a lion? It would, you know, with a bunch of knives and shit. If I was a lion, I'd be super confident. Yeah, you wouldn't worry. You wouldn't worry very much. But, but even if we could, so we knew what we're doing, we're all armed with knives, whoever goes in first is screwed. And so the capacity to kill at a distance, though, allows a larger force of weaker individuals to easily defeat a stronger individual. And so once they gain this capacity to throw, if they were attacked by lions or something like that, whereas in the past, they'd have just scattered for the trees. Now they could throw stones at it and defend themselves. Now, an Australopithecus throwing rocks at a lion is going to be in the belly of a slightly annoyed lion in about three minutes, right? But 50 Australopithecines throwing rocks at lions is a totally different story. And so it's the, this is the idea here is the throwing hypothesis that what changed everything was throwing. And the reason it changed everything is that it caused us, it was the first reason why we should have any effective collective action. Because it's not a good strategy when you're on your own. It's not a good strategy if I do it and the rest of the group heads for the trees. But it's a great strategy if we all do it together. And so for the first time in history, the group's goals in our history, in our line, the primate line, the group's goals aligned with the individual goals, which is let's cooperate and work together to try to drive away these predators. Now, if you look at a lion and you look at someone throwing rocks, it still seems like a really big ask, right? To drive that thing away or kill it throwing rocks. And so, but Barbara Isaac was one of the first anthropologists to propose this hypothesis quite a while ago, went back and looked at the historical record. And these are extraordinary stories of how effective people are throwing rocks. And so when the Portuguese went to the Canary Islands to try to subjugate it, they rock up with armor, guns, crossbows, and this is in the 14 something, and all the locals were on with was stones. And despite the fact that the Portuguese are there in army, trained, ready to shoot, and in their armor, they were just decimated by the locals throwing rocks at them. And this story has happened over and over again. And when you read these accounts, they're extraordinary. I can read you some examples from here. They just happened in Australia. It happened in the Canary Islands. It happened elsewhere. They just saw rocks incredibly, accurately, incredibly hard and really fast. Hmm. So and there's, you know, accounts in Africa, basically killing a zebra with one blow of a rock to the head. Hmm. So like a pitcher, a major league pitcher. Yeah, exactly. Good rock. Who gets very accurate at it. Yeah. So do you think they they must have practiced constantly? Yeah. And so what I suspect is that we evolved to like to throw rocks. And so if I look at if you look at my son as a for example, when he was 18 months old, we would be walking back toward that. So if he saw a rock on the street, he'd pick it up and start trying to throw it. And my wife said, No, don't let him throw rocks. It's only going to cause trouble. First of all, I'm thinking, well, maybe he'll develop a good arm. So I'm gonna go ahead and let him anyway. But secondly, he frickin wants to this is like something inherently fun. Right. And I think all humans enjoy throwing. And it's, it's stunning how good you can get it with practice. So we were at the Ohio State Fair, this before my son was born, and I was walking by one of these stalls where you can throw in a radar gun. And so I thought, here's, I was just starting to date my wife and I thought, Oh, here's a perfect chance to impress her right now. How much I am. So I said, Hey, why don't I stop and I'll throw some balls here in this net? Because I had never thrown I didn't know how fast I could. So she's like, sure. And I was I played like little league, right? So I throw the ball. And it's like 50 miles an hour. And she's pretty impressed because that's sounds fast, right? And then this like kid shows up next to me, he's got to be 12 years old, probably weighs 85 pounds, this total gangl, not a muscle in his body. And he just starts frickin throwing ball after ball at like 65 miles an hour. And I'm like, fuck, I mean, she's not gonna be impressed with this like human twig next to me is kicking my ass, right. And so I pick up the last ball, I frickin throw it as hard as I can hurts my shoulder flies off at an odd angle doesn't hit anything. And it's like 57 miles an hour. And that little guy who's like literally the size of an Australopithecus was thrown at 65 and hitting the target every time. And so it's obvious that it's skill, it's practice that would have made you good at this. And if your life depends on it, you're going to do it. Well, that makes sense. Coming from a martial arts background, like, like coordinated movement, where at the end of it, you snap, it does make sense that this technique is so critical, even you're a larger person, someone with better technique could have more of an impact with that. So the throwing arm, I had read this, that was one of the hypothesis, there's several hypothesis why the human brain doubled over a period of 2 million years. Another one was cooked meat, right? Yeah, they figured out a way to get more nutrients out of meat. That's right. Right. So that's a little bit down the road. So here we are three and a half million years ago. And so for the first time, we put some pressure on ourselves to have an advantage to be smarter. So imagine you're a zebra, you know, what the hell good is it to you to be Einstein? You got hooves. What are you going to do with that brain, right? But it's a big, it's a big cost. Our brains are 20% of our metabolic energy, whether we're doing math or watching TV, it's constant drain. And so what are our ancestors, why would they pay for that drain? Now, just recently, there was a paper that came out maybe three months ago now on a new brain expansion gene they found, or they think that's what it is called, MATCH2NL. And it turns out, I don't know, 12, 15 million years ago, there was an accidental duplication of that gene on our genome. And it, but it was ineffective. And it just sat there doing nothing. Now, that's a great way that evolution works where it accidentally doubles a gene because then you don't, you can mess with it. And the old gene is still doing the job, right? So it sat there for about 9 million years in our line till about 3 million years ago around Australopithecus. And then it duplicated itself and it came online again. And what that gene seems to do is it makes our brain remain as stem cells for longer, which means a lot more duplication before they run away and start becoming neurons. And so if I had to guess, I'd say that that probably, that gene coming online probably happened many times in the past. And every time it happened in the past, it was more cost than it was worth. And so what's the chimp going to do with a little bit more brain and just means more calories and what does he gain from it? But now that we're working together, now that we have collective action, all sorts of things open up, we could, we could devise division of labor. I'll say, hey man, you do this and I'll do that. Because Australopithecus, they've got 70 more grams than a chimp. They can't do things like that. They can't all throw rocks at the same time. That's not rocket science. But all the kinds of things that came next probably were enabled by that process of us coming together and deciding to work together and cooperate. So if you look at chimpanzees, they don't cooperate very well. For example, one of the activities where they sort of cooperate is when they hunt monkeys. And so they'll all gather around and they'll see some monkeys in the trees and they come in from every angle. It's not very coordinated. It's kind of a wild free for all. But what's interesting about it is that when the hunt's over, let's say you just sat there the whole time and watched and I'm working my ass off chasing these monkeys. I got one. You come up and bug me for it. And I don't, I don't willingly handle it. You like keep nudging me till I share. But I'm just as likely to share with you if you helped as if you didn't. I don't make any distinction. And you'll never establish effective groups if you can't reward those who participate compared to those who don't. Even little kids, four year old kids, when you give them games to play and they earn stickers, if you didn't play, you don't, when you come up and ask, you don't get it. You played, even if you didn't do your job right, but you tried, boom, you can have a sticker. So humans immediately get that, that you get rewarded for your activities as part of the group. Chimps don't seem to have that.