Science Friday - Undiscovered Presents: Planet Of The Killer Apes

Episode Date: November 27, 2019

In Apartheid-era South Africa, a scientist uncovered a cracked, proto-human jawbone. That humble fossil would go on to inspire one of the most blood-spattered theories in all of paleontology: the “Killer Ape” theory.  According to the Killer Ape theory, humans are killers—unique among the apes for our capacity for bloodthirsty murder and violence. And at a particularly violent moment in U.S. history, the idea stuck! It even made its way into one of the most iconic scenes in film history. Until a female chimp named Passion showed the world that we might not be so special after all. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Hey there again. I'm here to tell you that our podcast, Undiscovered, is back this week with one final episode. So without further ado, here are Annie and Ella with Planet of the Killer Apes. So, Ella, you have seen the opening to 2001 A Space Odyssey. A long time ago. Yes. Okay. Chimps gathered around an obelisk? Monolith? Monolith? Yeah. All right. So I'm going to refresh your memory. This movie starts on a kind of rocky desert landscape. We're watching an ape.

He is squatting in the dirt, kind of snuffling around next to this pile of animal bones. And then suddenly he pauses, cocks his head, looks at the pile of bones, and has a world-shattering idea. What if I used one of these bones as a weapon? And sure enough, in the very next scene, you see this confrontation between two groups of apes. And, ooh, our ape buddy wax one of those apes in the head with a bone. Wacking while they're down? They've been neutralized.

Stop. This was the flash of insight. Yep. The earth-shattering was, I can whack other apes with bones. Indeed. Okay. So this sequence is called the Don of Man. It has always made not a ton of sense to me.

But recently, I was talking to Erica. Erica Milam. I am a historian of science at Princeton University. And Erica told me what we're watching in those first nine minutes of 2001 a space odyssey is a dramatization of a scientific theory. The killer ape theory. The killer ape theory is the idea that in the long, deep human past, there has to have been some kind of driver that made the human lineage different from all other great ape species. And according to the killer ape theory, that key difference, the key moment in our evolution

that split us off forever from our ape cousins was when we humans figured out how to kill. I feel like there should be like a dun dun dun. Yes, absolutely. I'm Annie. And I'm Ella. and you're listening to Undiscovered. And today we present the killer ape theory. In the 1960s, a scientist in South Africa and a Hollywood scriptwriter

had a ton of people convinced that we humans are natural-born killers. That you, you are a murderer at your core. And then just as quickly as this theory rose, it all fell apart. Coming up, what killed the killer ape? So how does a scientific theory end up in one of the biggest movies of the 20th century? I think the answer to that question basically comes down to one guy. Robert Ardry. Robert Ardry is not actually a scientist.

He's a writer. He's this talkative guy from Chicago with bad posture and a flare for drama. And as a writer, he kind of does everything. He writes plays. For a while, carves out a really comfy niche for himself in Hollywood-turning novels. into screenplays, so he does stuff like Madam Bovary, the Three Musketeers. Dills are forbidden. In the name of Prime Minister Richelieu, I arrest you.

Do your best in the king's name. But in the mid-50s, Ardrey is writing magazine pieces. He's actually traveling around Africa, writing pieces about politics, and he gets a tip that is going to completely change his career. A friend tells him, if you want a good story, go down to South Africa. Africa and talk to this scientist named Raymond Dart. So Raymond Dart, a little bit controversial is kind of a maverick. Three decades earlier, he discovered what he claimed was our oldest human ancestor, this

kind of A.B. creature that he names Australopithecus Afrikanus. Dart also took a lot of flack for suggesting that humans evolved out of Africa, quite controversial at the time. Of course, he turns out to be totally right about this. And so Ardrey thinks, okay, I'm going to give this guy Dard a shot. So one stormy day, Ardry shows up at Darts' office in Johannesburg. Here's how Ardry wrote about that meeting later. A last rare storm of the rainy season darkened Darts' upper floor office at the medical school. Fossil bones of extinct animals piled up before me.

Then I found in my hand what seemed a human jaw. When Ardry first shows up in his office, Dart introduces him to a jawbone. This jawbone belonged to one of these proto-humans, Australopithecus Africanus, and it's pretty wrecked. Like there's a big crack running down the front of the jaw. The front four teeth are missing. And Dart, in the way that Ardrey relates it, Dart takes a very interesting approach, which is he says, I am going to leave you to your own reasoning as you examine this specimen. And so Ardry talks about sitting there with this jawbone and looking at it and reasoning through as a layperson,

what could possibly have led to the caved-in front part of the jaw and the four missing teeth. So here is Ardrey, the writer's reasoning. First, he wants to know, okay, When did this jawbone break? Is it possible that maybe it broke two million years after this australopithecine died? You have a bone, lying around in a cave. Someone steps on it. Boom, it's broken. But he figures that probably didn't happen.

For in that case, the fragments would have been scattered about. And they're not. Flesh must have held the fragments together to be fossilized as a single hole. Ardry also thinks... Nor could the blow have resulted in anything but death. He thinks this blow was fatal because the bones didn't knit back together. They didn't heal. And then finally, Arjee thinks that whatever socked this osteopithecine in the jaw and killed him was not an accident.

What? Wait, what? That's a bit of a leap. Like, wait, wait. He's like, who falls on their jaw at precisely this angle? Nobody. For Ardry, it is perfectly obvious. One needed nothing but the lay common sense of a jaw.

jurymen to return a verdict that at some terrible moment in ancient times, murder had been done. That being the voice of our coworker Charles as Ardrey. Nothing but the, what was it, the lay common sense? Yeah. And apparently this is the right answer because that murder has been done. Yes, yes. Because Dr. Dart then goes on to share with Ardry, his theory, the killer ape theory, and it goes like this. So way back in our history, when our ancestors were just small-brained Australopithecines, we learned how to kill.

And not only did we learn how to kill and maim and murder, but according to Dart, killing is what made us human. Killing is what separated us forever from our peaceable ape cousins and put us on this path to becoming what we are today. Killing was the key to our evolution, which made no sense to me. Why would it have been beneficial for our ancestor to have invented murder? Like, why is this good evolutionarily? It's generally not considered good evolutionarily. The concept of murder was deeply tied for artery, for dart, to the idea of hunting for meat. Hunting for meat is phenomenally useful.

For Dart, killing animals for meat, killing each other, even cannibalism, they're kind of all part of the same phenomenon. And Dart thinks he has really good evidence that Australopithecus was indeed killing other animals for meat. He and his students have been looking at these fossils from South African caves. And Dart notices there seem to be a whole lot of humorous bones in those caves. Okay. And to him, those humorous bones look a little bit like clubs? Sure. And then he notices some of these animal skulls have these cracks and dents in them, kind of like they've been bashed in by clubs.

Right. Yes. And it's like it's all coming together. Our ancestors grabbed some of these bone clubs, whacked each other, just like in the opening of 2001 of Space Odyssey. And they also whacked other animals and ate them. Or as Dart put this slightly more colorfully in a scientific paper. Osterlapithecus, quote, battered them to death, tore apart their broken bodies, dismembered them limb from limb, and how did he put this? Oh, yeah, slaked their ravenous thirst with the hot blood of victims.

So gross. It's not funny. Language like this did not win Raymond Dart a whole lot of scientific support. Yeah, no kidding. But Robert Ardrey, dramatist, script writer, he is very alive to the dramatic possibility. of the killer ape theory. Robert Ardrey writes four pop science books inspired by killer apes. A few of them are bona fide bestsellers.

Major newspapers review them, columnists debate them. On TV, NBC airs a primetime documentary featuring Dr. Raymond Dart talking about his killer ape theory. And then, of course, comes 2001. Stanley Kubrick had gotten a hold of Ardrey's first book, extensively underlines it. And he brings this theory to the big screen with a level of accuracy and attention to detail that is startling. Like, I'd always assumed those apes at the beginning of the movie were just some kind of generic human ancestor ape. I thought they were chimps.

No, they are actually recreations of what people really thought australopithecines would have looked like at the time. They are very specially created masks. Kubrick goes so far as to hire a paleoanthropologist to come on the set and to teach his actors how to move like they think Australopithecines would have moved. So we asked this question, how did the killer ape theory get so popular? And I think honestly, Robert Ardrey is a huge reason. But Arjory's timing is also just really good. Because it's the 1960s and people are thinking about violence a lot. Doctors are working feverishly over Senator Kennedy.

There are a whole series of high-profile assassinations. Gernie has just been brought in there, lifting Senator Kennedy onto the gurney now. The U.S. involvement in Vietnam is really communicating scenes of violence and destruction into American homes through flickering television scenes. violent acts that would never have been allowed on TV if they were not real. All right, give me some cover. The assassinations of John F. Kennedy, Martin Luther King Jr., Robert Kennedy, the Tet Offensive, the Miley Masker. Like, this is what is coming through your television screen in the 60s and early 70s.

And not that far off from World War II. Right. Yeah. And so it's really easy to imagine people watching this and thinking, like, what is the a deal with humans. Like, is this who we are? And then Robert Ardrey comes in with the killer ape theory, and he's like, you know what? Maybe. People are stunned.

They can't believe what's happened. One woman's crying. And then, it all fell apart. Coming up, we were wrong. The fall of the killer rape theory. By the late 1960s, the killer rape theory is really. really big. That doesn't mean that everyone is buying it. From the beginning, Dart and Ardrey's evidence seems shaky. There's a lot of assumption built on assumption, built on

assumption. And starting in the 60s, this paleontologist in South Africa named Bob Brain starts taking down those assumptions. So Dart and Ardry had read, as you will recall, a whole lot of murder into some dented and cracked fossils. Bob Brain looks at those same fossils and is like, Like, this is just fossil wear and tear. Like, this is what happens when piles of bones are crushed under sediment for thousands of years. And where Dart and Ardry had sold us this picture of ancient man as this, you know, bloodthirsty, bone-wielding predator, Bob Brains sees something a little bit more deflating. He says, maybe Australopithecines were prey.

Like, he finds this Australopithecine skull with two holes in it that perfectly line up with the spacing of a leopard's canines. So maybe it wasn't actually. man the hunter? Maybe it was manned the hunted. But this is a debate that's largely happening in the scientific press. None of this is reaching the public who's still like at the theater watching 2001. But then in the 1970s, Jane Goodall discovers something that makes everybody pay attention. So a decade earlier, Jane Goodall made us all fall in love with chimps. She's on TV in the 60s, playing with her chimp friends at the Gombay Stream Reserve in Tanzania. The chimps gradually came to realize that I was not dangerous after all.

And after about 15 months, I was allowed to approach a small group without attempting to hide. This is from a primetime 1965 documentary. And Ella. Oh my God. This is the cutest documentary I have ever seen. Baby Chimp. So tiny. It poked her, it booped her on the nose.

Yeah. Oh, no. She has made friends of wild animals, and in so doing, has been able to observe them at closer quarters and in more intimate detail and has ever been managed before. And all this chimp cuteness works amazing for the killer ape theory, because remember, chimps are supposed to be the path not taken. We are the killer apes. They are the peaceable, cuddly nose boopers. And then in the 1970s, Goodall pulls the rug out from under us. When Goodall first goes to Gombe, there's only a single group of chimpanzees.

And between 1960 and 1974, that single unitary group has actually split. And there's now two social entities, one in the north and one in the south. And in 1974, the male chimps in the southern group start getting murdered. So one of the first hits in this chimp war, as it comes to be described, is on one of Goodall's favorite chimps. It's an older chimp named Goliath. And he's cornered by a group of five chimps from the northern group. And he's savagely beaten so much that Goodall reports that he can no longer sit up. She later sent some of her assistants out to try to find him to see whether he'd survived, but they never found him again.

And the same thing happens to other males in the Southern group. So by 1978, there is no southern group of chimps anymore. So that's what's going on with the males. Circa, 1974 in Gombe. What's happening with the females is actually, in my opinion, more disturbing. The main culprit, if you want to use that word, is passion. So passion is a female chimp. She has two kids, a female chimp named POM and a male chimp named Pross.

And one day, Goodall gets a call over her radio from Gombe that Passion has been seen eating another chimps baby. Passion goes and kills the infant of Glicka and then brings that dead infant back to Palm and Proff and shares the meat as if it is normal prey. Passion ate another chimps baby? Yeah. Eight. Eight. And this keeps happening. Over the next year, Passion and her daughter, they kill and they eat two more baby chimps from their own group. Why is their group still hanging out with them? Good question. So you're saying something about Goodall. So Goodall describes being out in the field and watching Palm, the daughter chimp, and Passion, the mom. They're sitting next to this other mother from their group called Littleby. And Littleby is holding her baby. Oh, God. And Goodall describes seeing Palm, the daughter, turn to look at Little Bee's baby and reach out her hand towards the infant and then look back at her mom like, hey, what about this one?

And Goodall actually tries to stop it. She starts, you know, yelling, throwing things, trying to make a racket and distract Palm so that Little Bee and her baby can get away. And they do. But Goodall is horrified. One of the things that she says is that her vision of chimpanzee nature was never the same. That this fundamentally changed the way that she thought about chimpanzees as a species and the kinds of social behavior that they were capable of. Chimp violence is a problem for the killer ape theory.

Like if Dart and Ardry are saying that the key thing that separated us from all the other apes was our ability to kill, explain chimps. It can't be the thing that made the difference. So the killer ape theory died. And in the end, it wasn't one thing that killed it. There was a whole range of evidence from paleontology, anthropology, evidence from other primates. All of it came together to say, you know what, this theory doesn't really hold up. In fact, we're not even sure that Australopithecus Afrikanus was our direct ancestor. So obviously they were in the family.

And frankly, it's kind of a relief. Killer apes, along with whatever other problems it might have, was an incredibly cynical theory. And these days, it kind of seems like the pendulum is swinging the other way. Like scientists are looking at the fossil record, and they're not seeing a whole lot of evidence of violence. Instead, they find... We were really compassionate. That's Augustine Twentez. He's an anthropologist at Notre Dame. We developed not only the ability to hurt one another, but what seems like we spent more time feeding elderly.

who have lost all their teeth, or caring for, you know, five-year-old homorectus who had a congenital defect or helping individuals with broken legs or limbs. So there's really good evidence in the fossil record that we began to care for one another in ways that go way beyond what other organisms do well before there's good evidence for us whacking each other over the head on a regular basis. I mean, yeah. I mean, of course, this is a thing that we do really well, kindness. Not to discount our horrible violence, but sometimes people,

obviously do incredible things for each other. Like we literally give each other body parts. So if I was going to pick something that made us humans special among the apes, I would pick that. Yeah. So scientists are also thinking along these lines. They're thinking that actually what makes us special and different from other apes, it isn't murder. It's cooperation. But that can also cut both ways.

Cooperation allows us to build hospitals and save lives and change the world for the better and to do, you know, Awful things, genocides, atrocities, torture, economic inequality, racism. All of that needs cooperation. So I think what we've got to get away from is this idea that we're hardwired to be good or bad. We have the capacity to be the worst thing on the planet and the best thing on the planet simultaneously. So any last thing before we go, while you were researching this killer ape story, I got curious about who really is the murderiest of all the mammals? The murderiest? The most murderous.

Somebody has, in fact, studied this. Inevitably. They tried to. They ranked all these different mammal species. And at the very top, at nearly 20%, so one in five deaths in this species, they attributed to murder. Please tell me it's not us. Mere cats. No.

Not to moan. Yeah, according to this one study anyway, one in five mere cat deaths are the results of murder. That is ghastly. So if murder, as Dart proposed, is the path to world domination, thankfully you showed that it is not. Yeah. But if it were, this would not be Planet of the Apes. It would be Planet of the Mirkats. Oh, boy.

Undiscovered was reported and produced by me, Annie Minoff. And by me, Ella Fetter. Our senior editor was Christopher and Taliatta, and our composer was Daniel Petersmith. This free version of Also Sheprach Zarathustra is by Kevin McLeod. Erica Milam's new book about the killer ape theory is called Creatures of Cain. You can find a link to it, plus more info about this episode in our show notes. We are Undiscoveredpodcast.org. And that's a wrap for Undiscovered.

Thank you so much for listening these past few years. If you want more podcasts from Science Friday, we will have another one in your ears soon called Science Diction, a show that digs into the scientific origin stories behind our world. words and language. You can find out more by subscribing to the Science Diction newsletter at ScienceFriday.com slash sciencediction.