So, in this lecture, Ape Self-Domestication, we're actually gonna try to apply what we've learned about dogs to a very different species, and try to understand the evolution of one of our closest relatives, based on what we've learned about dogs. So, for this lecture, the Genius of Dogs, it's gonna be chapter five that's gonna be most relevant. There's really no lab activity from Dognition here. So I wanna introduce the concept of convergent evolution. We talked about the ecological approach to cognition. And this is purely one of the most important implications of this ecological approach, which is that you can see that similar ecologies can shape distantly related organisms in analogous ways. So if you look at how species are related, phenotypically, you can find cases where very distantly related species are similar in surprising ways. So if you take the case of marsupials that only live in Australia, and then you look at animals that live in North America, like the carnivores, you see that there are very similar species, even though they are completely different from one another. So, in the case of the familiar, in North America, we have wolves as a carnivore and then obviously we have different types of deer like elk and white tailed deer, et cetera. But when you travel to Australia, where there are no wolves and where there are no deer and there are only marsupial, we see the same types of animals filling the same types of roles in that special ecology. Within human history there was a wolf-like species of marsupial known as the Tasmanian wolf or Tasmanian tiger, also known as a the Thylacine. Unfortunately, they went extinct as far as we know. It would be really cool if there were any left. Obviously they're herbivores. But of course they're in the form of kangaroos. So there's been convergent evolution where basically you have very similar species evolve, even though they're very, very distantly related on the tree of life represented on the left. And so that is what we think may be going on. And this is the reason why we think learning about dogs could help us understand about not only ourselves, but other species. Because we may see that the same evolutionary process that led to dogs, or certainly is illustrated by the foxes, at least, it may be playing out in other species that are distantly related from canids. So that brings me to talking to you about Bonobos. Bonobos are one of your two closest relatives, but they're a puzzle to explain how they evolved and their behavior is fascinating. So what I want to do to introduce you to Bonobos is to show you a video of an experiment we did, where we asked Bonobos a very simple question, which is, would you prefer to share with somebody that you were really good friends with or somebody that you've never met before. And usually, when I ask people this question, and imagine I give you the example, that you went to Vegas and you won some money, it's some discretionary money and you can do whatever you want with it, do you send that money in an envelope to a friend or do you send that money to, in an envelope, to somebody you've never met before? And most people what they respond is, I'm gonna send that to family and friend. Or I'm gonna do something together with my family and friend with that extra money. I'm not gonna give it to somebody I've never met before. Well, when we ask that question of Bonobos we get a very different answer. So, here is how we ask them. We place food in a room and the food is a relatively small amount of food for Bonobos. And we place it there before Bonobo breakfast. So all the Bonobos, that we're gonna be talking about, are very hungry. And this is some of their favorite fruit treats. And then what we did is, we had one bonobo that was in an adjacent room, who was good friends of the Bonobo who's gonna be let into this room with food, and we had another Bonobo that, they actually had never met. And you can see there is a one-way key in the door. And there is no way for the Bonobo in the adjacent room to open the door. Only the Bonobo coming into the room here in the video could potentially open the door. So they have the choice of either eating all the food, or sharing with somebody whose a friend or somebody they have never seen before. And what we found the Bonobos did, is not only do they open the door and share food. But they prefer to share with someone they have never met before. They prefer to voluntarily share with a stranger. So their sorta like, [LAUGH] and they obviously have a good time doing it. They're sorta like the original good Samaritans, helping strangers in a way that even probably humans wouldn't. And we got really interested in what is it internally, what's the internal process, we've observed the phenomenon now, now can we explain it? Is it the case that somehow Bonobos have a level of empathy that we don't see in other species? And what you see in the picture here is a Bonobo yawning. And, it ends up that yawning has been used in people and in lots of different animals to measure empathy. And, the reason is that contagious yawning, or yawning in response to somebody else yawning, develops in children as they start to develop theory of mind, or the ability to think about the thoughts of others. And those children that don't contagiously yawn tend to have developmental delays in their social skills, and often are in the autism spectrum. So we know that contagious yawning is actually related to the level of empathy you feel for others. And in fact, in studies of Bonobos and lots of their species, the closer the relationship you have with somebody the more likely you are to contagiously yawn when you see them yawn. So you can watch in your classrooms or your board meetings or whatever and see who actually feels empathy for one another. But we went and did it on a study of Bonobo contagious yawning. But we varied who they watched yawning. And we looked at did they yawn when they saw a groupmate yawn? Did they yawn when they saw a stranger yawn? And the answer was that they yawned for both. And in fact they yawned a little bit more for strangers than they did their own groupmates. And that is a lot like their sharing behavior. That suggested to us that Bonobos may be feeling a very basic form of empathy for strangers that we don't see in their close relative, the chimpanzee, where you see, when other researchers have done the similar research, but with chimpanzees. You do see chimpanzees contagiously yawn for group mates, but they don't contagiously yawn for strangers. We took to be really interesting evidence that Bonobos, together with their sharing behavior and their yawning behavior, seemed to be attracted to strangers. The technical term for that is they're xenophilic. They really like people, or I should say, like other Bonobos they haven't met before, and that's very different from chimpanzees and probably very different from humans.
