WEBVTT - Green Beard Genes 0:00:00.040 --> 0:00:01.680 Are you a Stuff to Blow your Mind fan? Are 0:00:01.680 --> 0:00:03.880 you a New Yorker? Do you plan to attend this 0:00:03.960 --> 0:00:06.800 year's New York Comic Con. If so, then you've got 0:00:06.800 --> 0:00:10.600 to check out our exclusive live show NYCC presents Stuff 0:00:10.640 --> 0:00:14.000 to Blow Your Mind Live Stranger Science. Join all three 0:00:14.080 --> 0:00:16.880 of us as we record a live podcast about the 0:00:16.920 --> 0:00:21.640 exciting science and tantalizing pseudo science underlying the hit Netflix 0:00:21.640 --> 0:00:25.840 show Stranger Things. It all goes down Friday, October six 0:00:26.239 --> 0:00:29.240 from seven pm to eight thirty pm at the Hudson 0:00:29.280 --> 0:00:32.279 Mercantile in Manhattan. Stuff You missed in History class has 0:00:32.280 --> 0:00:34.920 a show right before us, so you can really double down, 0:00:35.080 --> 0:00:37.920 learn more and buy your tickets today at New York 0:00:37.920 --> 0:00:45.960 Comic Con dot com slash NYCC hyphen presents Welcome to 0:00:46.280 --> 0:00:55.440 Stuff to Blow Your Mind from How Stuffworks dot com. Hey, 0:00:55.480 --> 0:00:57.040 are you welcome to Stuff to Blow Your Mind? My 0:00:57.120 --> 0:00:59.720 name is Robert Lamb and I'm Joe McCormick and Robert 0:00:59.760 --> 0:01:02.240 I got a question. How often do you have this 0:01:02.360 --> 0:01:08.399 experience of finding out one subtle way that somebody is 0:01:08.520 --> 0:01:13.480 like you, and it's suddenly changing your whole attitude toward them. 0:01:14.040 --> 0:01:17.480 So you're talking to somebody new you haven't met before. 0:01:17.880 --> 0:01:20.720 You know, you're getting to know somebody who's been an 0:01:20.760 --> 0:01:24.520 acquaintance and you find out that they really like one 0:01:24.640 --> 0:01:28.600 movie that you like, or they really or they've traveled 0:01:28.640 --> 0:01:31.200 to one place you've traveled to, or something like this, 0:01:31.280 --> 0:01:35.840 and suddenly your brain just unlocks and you say, oh, okay, 0:01:36.040 --> 0:01:39.480 we're cool now. Yeah, I encountered this a lot. You know, 0:01:39.520 --> 0:01:41.480 they'll be I tend to be a little you know, 0:01:41.560 --> 0:01:45.480 distrusting of new people and uh. And then sometimes you know, 0:01:45.520 --> 0:01:47.000 you get to talk to them a little bit, or 0:01:47.080 --> 0:01:50.320 you check out their social media activity or something in 0:01:50.320 --> 0:01:53.120 your lies. Hey, they they really like this film, or 0:01:53.440 --> 0:01:56.760 they they really like this artist that not many of 0:01:56.840 --> 0:01:59.840 us are into, or they're into this h this other 0:02:00.000 --> 0:02:02.000 a kind of niche thing that I love and there 0:02:02.200 --> 0:02:04.280 and then you you you sort of give them the 0:02:04.280 --> 0:02:08.240 benefit of a doubt based on that information. You're like, well, 0:02:08.240 --> 0:02:10.839 they're they're probably pretty good, they're probably pretty cool, Like, babe, 0:02:10.840 --> 0:02:12.120 I should talk to them a little bit more. What 0:02:12.200 --> 0:02:14.840 else are they into that I like? But why why 0:02:15.000 --> 0:02:17.400 is that? I mean, why is it that just using 0:02:17.520 --> 0:02:21.919 like a shared favorite movie for example, Like what basis 0:02:21.960 --> 0:02:25.440 do you have for thinking that somebody who likes the 0:02:25.480 --> 0:02:28.560 same movie you like is a good person. Well, it 0:02:29.120 --> 0:02:33.160 falls apart under the scrutiny of other things, because, for instance, um, 0:02:33.440 --> 0:02:36.480 I'll use Tool as an example. Tool is one of 0:02:36.480 --> 0:02:39.360 my my my favorite bands and Uh and their band 0:02:39.400 --> 0:02:42.000 I loved in in high school and I've never I've 0:02:42.040 --> 0:02:44.800 never stopped loving. There's been a lot of bands that 0:02:45.120 --> 0:02:47.799 a lot of musical styles that have sort of come 0:02:47.840 --> 0:02:50.720 and gone that I'll rediscover and and or that I'll 0:02:50.720 --> 0:02:52.640 hate for a little home. But but but I've always liked Tool. 0:02:52.840 --> 0:02:55.600 So what you're saying is the best rubric for discovering 0:02:55.600 --> 0:02:57.720 whether a person is good or not is do they 0:02:57.760 --> 0:03:01.640 like Tool? Yes and no. So, for instance, here at work, 0:03:02.400 --> 0:03:06.840 Nathan our our our social media guru, uh, shortly after 0:03:06.919 --> 0:03:09.840 he started, he saw that I had some some Tool 0:03:09.919 --> 0:03:13.480 memorabilia at my desk, and we instantly struck up conversation 0:03:13.520 --> 0:03:16.160 about it, and that was like our initial uh uh, 0:03:16.200 --> 0:03:20.120 you know, bonding moment, or the fact that we both 0:03:20.200 --> 0:03:23.360 like this group. On the other hand, I've gone to 0:03:23.480 --> 0:03:27.920 enough Tool concerts to witness people that are also fans 0:03:28.000 --> 0:03:30.520 of Tool and sometimes interact with them where I end 0:03:30.560 --> 0:03:32.960 up getting a bit judge, and I think to myself, well, 0:03:32.960 --> 0:03:35.680 there's no there's no way that they are appreciating this 0:03:35.840 --> 0:03:40.200 music on the same level that I am. So it 0:03:40.240 --> 0:03:42.040 can kind of cut both ways. You can be very 0:03:42.120 --> 0:03:46.040 choosy about about how you feel regarding other people's appreciation 0:03:46.080 --> 0:03:50.000 of your stuff. But ideally it would mean that if 0:03:50.040 --> 0:03:53.000 if someone else is into something that that the that 0:03:53.080 --> 0:03:54.920 you dig, then they're they're going to be into some 0:03:54.960 --> 0:03:58.160 of the same ideas, some of the same values, some 0:03:58.240 --> 0:04:00.840 of the same you know, aesthetic quality days what have you, 0:04:01.240 --> 0:04:03.720 that that there's going to be more than just this 0:04:03.800 --> 0:04:06.800 one thing that lines up between the two of you, right, 0:04:06.880 --> 0:04:10.520 But you're using that one little detail, that one tiny 0:04:10.560 --> 0:04:13.520 thing is some kind of like totem. It's this one 0:04:13.600 --> 0:04:17.720 it's the signifier, this tiny flag flying above their head 0:04:18.240 --> 0:04:21.520 that you have decided, for whatever reason, is good enough 0:04:21.560 --> 0:04:25.679 evidence to open yourself up to this person and essentially 0:04:25.720 --> 0:04:28.120 give them a fair shake that you might not give 0:04:28.200 --> 0:04:32.120 to any other stranger. I've caught myself doing the same 0:04:32.160 --> 0:04:35.280 thing too, even though I realized it makes no sense. 0:04:35.360 --> 0:04:39.200 I mean, I think generally that you might be able 0:04:39.320 --> 0:04:42.920 to make some kind of case that in some cases 0:04:43.000 --> 0:04:47.360 shared aesthetics or shared values. Uh, you know that if 0:04:47.440 --> 0:04:49.920 you like the same movie as somebody, it might embody 0:04:50.080 --> 0:04:54.960 some kinds of values or intellectual predispositions that you would 0:04:54.960 --> 0:04:57.359 find in common with other people who tend to like it. 0:04:57.400 --> 0:04:59.360 But a lot of times that's not the case. I 0:04:59.400 --> 0:05:01.479 don't know. I mean, I love Blade Runner, but there's 0:05:01.480 --> 0:05:03.560 probably a lot of people who love Blade Runner who 0:05:03.600 --> 0:05:07.560 are just absolute vampire. You saying they don't appreciate it 0:05:07.560 --> 0:05:11.240 on the same level as you. Maybe that's it. I 0:05:11.240 --> 0:05:13.560 wonder if you don't appreciate it on the same level 0:05:13.600 --> 0:05:16.680 I do. I don't know. I've I've actually spoken about 0:05:16.680 --> 0:05:18.400 this a little bit, but my thoughts on Blade Run 0:05:18.400 --> 0:05:20.520 are mixed. But I do I do. I do love 0:05:20.600 --> 0:05:24.480 Blade Runner. So today we're gonna be talking about a 0:05:24.560 --> 0:05:29.840 hypothesis in genetics and genomics that is going to be 0:05:29.880 --> 0:05:33.680 a kind of weird analogy to the personality tests that 0:05:33.720 --> 0:05:37.640 we've just been discussing, and it's the concept of green 0:05:37.920 --> 0:05:42.039 beard genes or the green beard effect. Now that the 0:05:42.080 --> 0:05:45.760 sad news is that this episode does not really deal 0:05:45.880 --> 0:05:49.320 with actual green beards. If you're looking for if you go, 0:05:49.440 --> 0:05:51.599 if you're coming into this expecting an episode and a 0:05:51.640 --> 0:05:55.960 weird genetic anomaly that makes people grow green beards, or 0:05:56.000 --> 0:05:59.080 say a famous pirate with a green beard. Um, you're 0:05:59.120 --> 0:06:01.080 gonna be disappointed on those counts. But the but the 0:06:01.120 --> 0:06:03.560 underlying science we're going to discuss here in the genetics 0:06:03.680 --> 0:06:06.520 is pretty amazing and pretty fascinating. Now I wanted to 0:06:06.560 --> 0:06:09.159 come up with the backstory of the pirate green beard. 0:06:09.400 --> 0:06:11.279 I couldn't think of what it is. What it's like 0:06:11.320 --> 0:06:13.839 he's got algae in there or something. He just never 0:06:13.920 --> 0:06:16.840 cleans his beard. Yeah, you're just um, I'm guessing you 0:06:16.920 --> 0:06:19.160 probably have like really green teeth as well, you know, 0:06:19.240 --> 0:06:21.720 and just maybe he eats a lot of plant matter 0:06:21.760 --> 0:06:24.159 and it just kind of drolls down in his unwashed beard. 0:06:24.520 --> 0:06:27.000 But you know, this does bring if there was if 0:06:27.000 --> 0:06:29.480 there was a pirate with a green beard and he 0:06:29.560 --> 0:06:32.280 met another pirate with a green beard, perhaps he would 0:06:32.279 --> 0:06:34.760 have this effect. He would say, look, there is another 0:06:34.800 --> 0:06:39.200 pirate who shares my esthetic qualities, perhaps my diet. Maybe 0:06:39.279 --> 0:06:44.200 we have more thoughts on hygiene. Yeah. So the name 0:06:44.360 --> 0:06:47.800 of the green beard hypothesis, which we will explain, comes 0:06:47.839 --> 0:06:51.039 to us from Richard Dawkins, based on an example he 0:06:51.160 --> 0:06:54.200 used to illustrate the concept in his nineteen seventy six 0:06:54.240 --> 0:06:57.320 book The Selfish Gene. But the idea goes back to 0:06:57.560 --> 0:07:02.359 the influential English biologists of the twentieth century W. D. 0:07:02.480 --> 0:07:07.200 Hamilton's um And so the idea arises in the context 0:07:07.279 --> 0:07:12.920 of a question about explaining how biology creates social behavior. Now, 0:07:12.920 --> 0:07:18.040 this is one of the biggest, most difficult questions in biology, right, 0:07:18.120 --> 0:07:22.320 So humans and other animals display these complex things like culture, 0:07:23.200 --> 0:07:29.480 like aesthetic preferences, taste, uh, social behavior, all these things 0:07:29.520 --> 0:07:34.720 that are complicated and have all these weird semi coded rules, 0:07:34.800 --> 0:07:37.720 and we know at some level must be at least 0:07:37.880 --> 0:07:41.520 semi dictated by genetic predispositions. But it's hard to know 0:07:42.080 --> 0:07:45.560 what parts of culture and behavior are genetic and what 0:07:45.720 --> 0:07:49.360 parts are just happenstances that you know that that arise 0:07:49.520 --> 0:07:52.720 naturally and somewhat randomly. Well, we have all these levels 0:07:52.760 --> 0:07:56.920 of cognition and culture that are kind of an illusion 0:07:57.560 --> 0:08:00.960 and and and they're they're overriding the biology. But since 0:08:01.200 --> 0:08:03.640 we are the illusion, it's hard to it's it's often 0:08:03.680 --> 0:08:06.280 hard for us to really think about and in terms 0:08:06.320 --> 0:08:09.600 of underlying biological properties. Yeah, so let's let's explore this 0:08:09.680 --> 0:08:14.440 question that this problem with explaining social behavior through biology. 0:08:14.480 --> 0:08:17.600 So we all know that species arise from the propagation 0:08:17.720 --> 0:08:22.600 of self replicating molecules like DNA, the fundamental units of 0:08:22.680 --> 0:08:26.040 heredity and DNA or genes. These are the parts of 0:08:26.040 --> 0:08:30.239 your DNA that do something that are inherited from your parents. 0:08:30.240 --> 0:08:34.040 And because genes make copies of themselves, we find some 0:08:34.120 --> 0:08:37.199 of the same genes spread out across many different organisms 0:08:37.200 --> 0:08:40.360 in the same gene pool. Now, obviously, genes that cause 0:08:40.400 --> 0:08:44.000 an organism to die immediately at birth become less numerous 0:08:44.000 --> 0:08:47.800 and eventually disappear. Genes that help an organism survive and 0:08:47.840 --> 0:08:50.880 produce more offspring become more numerous in the gene pool. 0:08:51.200 --> 0:08:54.800 These are the fundamentals of evolution by natural selection. This 0:08:54.840 --> 0:08:57.079 is basic stuff. We we know it up to this point. 0:08:57.120 --> 0:09:01.360 But here's a question. Why would an organism produced by 0:09:01.400 --> 0:09:04.800 this process, that arises out of evolution by natural selection 0:09:05.360 --> 0:09:10.880 ever displayed behaviors that we would call selfless or generous 0:09:11.000 --> 0:09:15.840 or altruistic, for example, things like sharing food with another 0:09:15.960 --> 0:09:20.760 organism or defending another organism in a fight. Now, I 0:09:21.040 --> 0:09:23.319 do want to heavily qualify that by saying I think 0:09:23.360 --> 0:09:28.480 It's probably not hard to explain why humans in particular altruistic, because, 0:09:28.520 --> 0:09:31.000 after all, there appear to be a lot of ways 0:09:31.040 --> 0:09:34.839 in which our complex brains can generate motivation for behaviors 0:09:34.840 --> 0:09:38.680 that run contrary to our genetic fitness, and the simplest 0:09:38.720 --> 0:09:43.240 example one of thousands would be celibacy. Whether for religious 0:09:43.320 --> 0:09:46.920 reasons or philosophical reasons, or simply out of personal preference, 0:09:47.240 --> 0:09:52.800 some people voluntarily choose never to have sexual relationships. This 0:09:52.880 --> 0:09:57.000 runs absolutely counter to our genetic programming. Another more common 0:09:57.040 --> 0:09:59.680 example would be the use of contraception. Many people who 0:09:59.720 --> 0:10:03.560 are sexually active still choose to have no children, or 0:10:03.640 --> 0:10:06.480 choose to have far fewer children than they technically could, 0:10:06.679 --> 0:10:10.000 for a variety of reasons. So obviously there are some 0:10:10.040 --> 0:10:12.720 ways in which the complex human brain has acquired the 0:10:12.760 --> 0:10:16.319 capacity to override the genes that programmed it well, I think. 0:10:16.400 --> 0:10:18.920 One one example that comes to mind is say, for instance, 0:10:18.960 --> 0:10:21.760 my own son UH has adopted and so he is 0:10:21.800 --> 0:10:27.319 not my biological offspring, but he he fulfills all the 0:10:28.040 --> 0:10:30.640 needs and desires that that I had that I have 0:10:30.760 --> 0:10:34.400 as a human for for offspring, for a son, right, 0:10:34.520 --> 0:10:37.840 your genes don't care about him, but you do. Uh, 0:10:37.880 --> 0:10:39.720 it's it's there in your brain, it is there in 0:10:39.720 --> 0:10:43.840 your personality. So if you were only wondering about humans, 0:10:43.880 --> 0:10:46.080 it might not be so hard to explain why we 0:10:46.080 --> 0:10:49.560 would share scarce resources with a stranger, or risk our 0:10:49.600 --> 0:10:53.080 own safety to intervene in somebody else's defense, or any 0:10:53.120 --> 0:10:56.520 number of other selfless acts. We're smart enough to recognize, 0:10:56.559 --> 0:11:00.199 maybe philosophical or religious reasons why we think we should 0:11:00.080 --> 0:11:03.480 to help other people and override those selfish instincts to 0:11:03.520 --> 0:11:06.080 act on those reasons. Or if you look at it 0:11:06.080 --> 0:11:09.240 from another angle, maybe the more cynical person would say, well, 0:11:09.280 --> 0:11:13.480 our complex, language obsessed brains are highly vulnerable to memes 0:11:13.520 --> 0:11:16.120 that have the power to override the optimization of our 0:11:16.160 --> 0:11:19.679 genetic fitness. Either way, human mentality appears to be fairly 0:11:19.760 --> 0:11:22.000 unique on Earth, and it can account for behavior that 0:11:22.080 --> 0:11:27.319 you wouldn't expect to find in other animals. But altruism 0:11:27.520 --> 0:11:30.960 isn't only present in human beings with their religions and 0:11:31.000 --> 0:11:36.000 moral philosophy and complex cognition. Altruism seems to be robustly 0:11:36.040 --> 0:11:39.280 observed in other animals, from like complex mammals all the 0:11:39.320 --> 0:11:42.240 way down to insects. Right, yeah, yeah, we have. We 0:11:42.280 --> 0:11:45.400 have a few I think very illustrative examples here to 0:11:45.480 --> 0:11:50.360 run through. Here's a crazy one. Vampire bats will regurgitate 0:11:50.600 --> 0:11:53.959 blood for other bats who were unable to find a meal, 0:11:54.200 --> 0:11:58.040 sacrificing their own immediate nutrition to keep another bat in 0:11:58.040 --> 0:12:01.240 their community from starving. And this has been documented since 0:12:01.280 --> 0:12:04.160 it was discovered in the nineteen eighties by a biologist 0:12:04.280 --> 0:12:08.600 named Gerald Wilkinson. And that that's no small feat because 0:12:08.640 --> 0:12:12.040 these bats are sort of operating constantly near the edge 0:12:12.040 --> 0:12:14.440 of starvation. As we've talked about before. You know, if 0:12:14.440 --> 0:12:17.319 a vampire bat goes a few days without food, it's 0:12:17.320 --> 0:12:20.960 in a bad place. It can it can starve um. 0:12:21.120 --> 0:12:24.600 And so sharing food like this is a significant sacrifice 0:12:24.679 --> 0:12:28.280 for the good of another uh not necessarily related bat. 0:12:28.400 --> 0:12:31.120 And you have to ask yourself, would your friends and 0:12:31.160 --> 0:12:34.120 coworkers be selfless enough to vomit up blood in your 0:12:34.200 --> 0:12:36.200 mouth if you've missed a meal. None of them have 0:12:36.320 --> 0:12:40.800 ever offered, And it makes me feel rather sour. But 0:12:40.880 --> 0:12:43.720 it's not even just the mammals, right, We see classic 0:12:43.840 --> 0:12:48.240 altruistic behaviors in in uh animals that are thought of 0:12:48.280 --> 0:12:51.280 as less complex. Right, Oh yeah, I mean bees are 0:12:51.320 --> 0:12:54.199 a prime example of altruism, and I mean you social 0:12:54.280 --> 0:12:59.319 insects in general have pretty much perfected altruism in many respects. 0:12:59.720 --> 0:13:03.400 So worker bee works for the benefit of the queen's 0:13:03.440 --> 0:13:08.280 offspring while for going reproduction herself. Genetically speaking, she is 0:13:08.320 --> 0:13:11.480 not the genetic future the hive. The queen is, the 0:13:11.559 --> 0:13:14.080 drones are, but the workers do all the work. In 0:13:14.080 --> 0:13:16.800 a weird way, you can almost think about the insects 0:13:16.840 --> 0:13:20.280 like this, being that the queen is the organism and 0:13:20.320 --> 0:13:23.840 the worker bees are like fingers or appendages of the 0:13:23.880 --> 0:13:28.800 major organism. Yeah, exactly, and it's just completely completely selfless 0:13:28.880 --> 0:13:30.760 if you look at it from the right angle. Yeah, 0:13:31.120 --> 0:13:34.840 but how about birds too, well, ravens who we've talked 0:13:34.880 --> 0:13:37.679 about ravens a bit when we talked about bird intelligence. Uh, 0:13:38.280 --> 0:13:41.280 Ravens have been observed to call in additional ravens when 0:13:41.280 --> 0:13:45.000 they happen upon food, so like a mouse or something, 0:13:45.520 --> 0:13:48.000 which doesn't make any sense that they have it, but 0:13:48.040 --> 0:13:50.800 they have apparently have a special call that they use, 0:13:51.200 --> 0:13:54.320 so they raise the alarm and say, hey, other ravens 0:13:54.320 --> 0:13:57.000 that are not me or my children, come in here 0:13:57.000 --> 0:13:58.960 and get part of this mouse. Why would you do that? 0:13:59.040 --> 0:14:03.240 It doesn't seem to make sense. But some ravens even 0:14:03.280 --> 0:14:06.520 return to their roost and recruit more eaters to come 0:14:06.559 --> 0:14:10.160 and share in the feast. Yet again, so your friends 0:14:10.160 --> 0:14:12.400 and co workers, they've never offered to vomit blood in 0:14:12.440 --> 0:14:14.600 your mouth. They've also probably never offered to share a 0:14:14.600 --> 0:14:17.960 dead mouse with you. Well, no, but on the rare, 0:14:18.280 --> 0:14:22.200 on the on the instances where we've had catered dead mouse, Uh, 0:14:22.840 --> 0:14:25.120 then it certainly people will come around and say, hey, 0:14:25.160 --> 0:14:29.080 there's food on the question mark table, come and eat 0:14:29.160 --> 0:14:32.360 with us. So, well, that's just their moral philosophy or 0:14:32.360 --> 0:14:36.080 their religion or whatever. Alright, Well we have some some 0:14:36.120 --> 0:14:39.080 other just quick examples throughout. Dolphins and elephants are fairly 0:14:39.120 --> 0:14:43.680 complex social animals and display uh various forms of altruism. 0:14:44.200 --> 0:14:46.560 They form social bonds, and then then they seem to 0:14:46.560 --> 0:14:49.840 make conscious decisions to help members of their group. Yeah, 0:14:49.920 --> 0:14:51.960 and so we have all these examples of these are 0:14:52.000 --> 0:14:55.320 by far not the only examples. There are just tons 0:14:55.400 --> 0:14:59.760 of documented examples of animals in the wild or in 0:15:00.000 --> 0:15:03.720 a conditions seeming to help other animals who are not 0:15:03.800 --> 0:15:07.240 their direct offspring at their own at their own expense. 0:15:08.080 --> 0:15:10.560 And obviously we can see why evolution would select for 0:15:10.640 --> 0:15:14.520 genes that cause organisms to be altruistic towards their own children. Right, 0:15:14.560 --> 0:15:17.000 that's kind of the whole point. Your genes optimize your 0:15:17.040 --> 0:15:19.800 body to have lots of children that can carry as 0:15:19.800 --> 0:15:22.440 many copies of those genes into the future as possible. 0:15:23.480 --> 0:15:27.400 But why would evolution produce creatures that sacrifice some of 0:15:27.440 --> 0:15:31.240 their own safety or resources to help save another creature 0:15:31.320 --> 0:15:34.600 that wasn't their direct offspring? I mean, wouldn't wouldn't genes 0:15:34.640 --> 0:15:41.000 that promoted selfishness and cowardice produce the most grandchildren on average? Well? 0:15:41.040 --> 0:15:43.800 I mean one obvious answer here is that there's an 0:15:43.880 --> 0:15:47.960 individual survival advantage in groups, right, Right, The group kind 0:15:47.960 --> 0:15:51.720 of becomes the meta organism, and natural selection encourages the 0:15:51.800 --> 0:15:55.480 pro group members of the metal organism and not and 0:15:55.560 --> 0:15:58.440 not the lone wolves. Now, this is attempting direction to 0:15:58.480 --> 0:16:01.120 go in, but there are critic of this type of thinking, 0:16:01.200 --> 0:16:03.800 So lots of scientists have tried to go in this direction, 0:16:03.840 --> 0:16:06.840 including EO. Wilson in later years. Uh. And this is 0:16:06.880 --> 0:16:10.120 sort of related to the concept known as group selection. Right. 0:16:10.440 --> 0:16:14.240 The idea that natural selection can select for not just 0:16:14.400 --> 0:16:19.200 the survival of individual genes or the survival of individual organisms, 0:16:19.200 --> 0:16:22.080 but groups of organisms together. This is also known as 0:16:22.160 --> 0:16:25.800 multi level selection. But, like I mentioned, this idea has 0:16:25.840 --> 0:16:29.800 a lot of harsh critics, including Dawkins. I mean, he's 0:16:29.800 --> 0:16:33.760 criticized this idea. And here's one potential snag. It's true 0:16:33.800 --> 0:16:37.000 that teamwork pays off, right, But you know what pays 0:16:37.040 --> 0:16:40.560 off even more than teamwork? Letting other people do the 0:16:40.560 --> 0:16:44.040 team Ah. This is the This is the classic um 0:16:44.360 --> 0:16:48.080 A classroom situation where you've been assigned to groups and 0:16:48.080 --> 0:16:50.160 you're gonna have somebody in the group who's a real 0:16:50.240 --> 0:16:52.960 hard work, are very dedicated. You have some other individuals, 0:16:52.960 --> 0:16:54.920 and you can have at least one person who's just 0:16:55.000 --> 0:16:57.920 gonna coast right right, Yeah, So you let the rest 0:16:57.920 --> 0:17:00.280 of the team do the work while you sand bag 0:17:00.320 --> 0:17:02.520 and reap the rewards. So if you imagine if you've 0:17:02.520 --> 0:17:06.440 got wild dogs that have a gene that causes cooperative 0:17:06.440 --> 0:17:10.080 pack hunting behavior where every dog chips in and does 0:17:10.119 --> 0:17:12.399 their share of work in the hunt, and in turn, 0:17:12.480 --> 0:17:15.600 this increases the group's chances of catching prey and then 0:17:15.600 --> 0:17:18.960 they all share the benefits. That would be great. Everything's 0:17:18.960 --> 0:17:21.480 going great if you've got dogs with those genes, But 0:17:21.680 --> 0:17:24.359 then one of the dogs in the pack acquires a 0:17:24.480 --> 0:17:28.199 mutation that says, actually, don't help with the hunt, just 0:17:28.320 --> 0:17:31.560 hang around until your pack mates catch something, and then 0:17:31.680 --> 0:17:34.639 show up and plunge your face into that delicious viscera. 0:17:35.920 --> 0:17:38.840 A dog with this trait would spend less energy hunting, 0:17:39.280 --> 0:17:41.920 and it would risk less injury, and it would still 0:17:42.000 --> 0:17:44.480 get the rewards of the hunt, so it would ultimately 0:17:45.080 --> 0:17:48.199 benefit more than any of the team players, and on 0:17:48.320 --> 0:17:52.320 average that that freeloader dog would have more offspring, meaning 0:17:52.359 --> 0:17:55.880 that over time the freeloader gene would become more common 0:17:55.920 --> 0:17:58.359 than the team player gene, and the pack hunting system 0:17:58.359 --> 0:18:01.639 would sort of fall apart. So systems that rely on 0:18:01.800 --> 0:18:05.040 benefits of group cooperation for the sake of the group 0:18:05.080 --> 0:18:09.199 as a whole are sort of pervasively undermined by the 0:18:09.280 --> 0:18:13.480 interests of individual organisms and individual genes within the group, 0:18:13.800 --> 0:18:17.280 which will sort of inevitably find ways to run counter 0:18:17.440 --> 0:18:20.400 to the success of the group as a whole. So 0:18:20.480 --> 0:18:22.760 to sum up, we can show that in general, natural 0:18:22.800 --> 0:18:25.920 selection will tend to push organisms to favor their own 0:18:26.000 --> 0:18:28.640 success at the expense of others and at the expense 0:18:28.680 --> 0:18:31.840 of their groups. And yet at the same time, group 0:18:31.880 --> 0:18:36.160 cooperation and selflessness is present in nature, so there must 0:18:36.160 --> 0:18:39.560 be some way to reconcile these observations, right, yes, and 0:18:39.600 --> 0:18:42.040 I imagine this is where the green beard comes in. Well, 0:18:42.080 --> 0:18:44.320 the green beard is going to be one weird way 0:18:44.320 --> 0:18:47.359 of branching off of this question. Actually, the main answers 0:18:47.560 --> 0:18:50.280 to this question are not going to be the focus 0:18:50.280 --> 0:18:52.600 of today's episode, but we should mention them. So two 0:18:52.600 --> 0:18:55.280 of the main answers that emerged in the twentieth century 0:18:55.320 --> 0:18:58.280 to answer this question, or what's known as kin selection 0:18:58.520 --> 0:19:03.119 and what's known as reciprocal altruism. So reciprocal altruism is 0:19:03.160 --> 0:19:06.200 basically another way of summing it up, is just the 0:19:06.240 --> 0:19:09.080 phrase tip for tat. And while in many cases it 0:19:09.080 --> 0:19:11.720 can be hard to verify outside of lab conditions, you 0:19:11.760 --> 0:19:15.080 can sort of build models of organisms that behave on 0:19:15.119 --> 0:19:18.800 this principle and it does appear to be stable if 0:19:19.119 --> 0:19:21.000 and the way this works is like this, So if 0:19:21.000 --> 0:19:23.639 a member of the pack is mean to you, or 0:19:23.680 --> 0:19:26.600 if they try to cheat and be selfish, you repay 0:19:26.640 --> 0:19:28.879 them back the same way you're mean to them back 0:19:29.359 --> 0:19:32.560 you you don't share with them. But if another member 0:19:32.560 --> 0:19:34.960 of the pack is nice to you, you're nice back. 0:19:35.280 --> 0:19:38.480 So essentially you just mirror. You start with the basis 0:19:38.520 --> 0:19:42.240 of being nice, and then you mirror the you mirror 0:19:42.280 --> 0:19:45.720 the behavior that people display towards you. Okay, well that 0:19:45.720 --> 0:19:48.680 that makes sense. I think everybody can fall fall behind that. Yeah. 0:19:48.680 --> 0:19:51.680 And if you run models like this, it is mathematically stable. 0:19:51.760 --> 0:19:55.040 Genes that encourage this type of behavior don't tend to 0:19:55.080 --> 0:19:57.640 get eliminated from the gene pool, but they can reach 0:19:57.680 --> 0:20:01.320 a kind of stable equilibrium. But the other main idea 0:20:01.400 --> 0:20:04.240 is what's known as kin selection, and this was explored 0:20:04.240 --> 0:20:08.919 in the nineteen sixties by the English biologist we mentioned earlier, W. D. Hamilton's. 0:20:09.359 --> 0:20:13.439 Now Hamilton's used these quantitative genetics modeling methods, which is 0:20:13.480 --> 0:20:17.000 like math about how genes are inherited and distributed to 0:20:17.080 --> 0:20:21.679 show something interesting, It makes mathematical sense for genes to 0:20:21.880 --> 0:20:27.240 optimize for altruism toward blood relatives other than our own offspring. 0:20:28.240 --> 0:20:31.440 So it turns out that for a sexually reproducing species 0:20:31.480 --> 0:20:34.920 like us, you share the same percent of your genes 0:20:34.920 --> 0:20:37.679 with each of your children that you do with your 0:20:37.720 --> 0:20:41.320 full brothers and sisters and with your parents. In each case, 0:20:41.359 --> 0:20:44.480 you share fifty percent of your genes with them, and 0:20:44.520 --> 0:20:47.000 to a lesser extent, the same goes for other members 0:20:47.000 --> 0:20:49.800 of your family. Further removed, you'll share more genes with 0:20:49.840 --> 0:20:52.679 your aunts and uncles and nieces and nephews than you 0:20:52.760 --> 0:20:55.800 do with the general population and so forth. And given 0:20:55.800 --> 0:20:58.880 this calculus, you can work out how genes that direct 0:20:59.040 --> 0:21:03.399 organisms to be generous and altruistic toward family members become 0:21:03.480 --> 0:21:06.520 more numerous in the gene pool than genes that direct 0:21:06.640 --> 0:21:10.920 organisms to be exclusively selfish and unhelpful to anybody. So 0:21:11.040 --> 0:21:14.480 if I have a cousin that appears on America's Got Talent, 0:21:15.160 --> 0:21:19.879 I'm going to root for them in part because they 0:21:19.960 --> 0:21:23.800 share more of my genes than anybody else that's contestant 0:21:23.800 --> 0:21:26.040 on that show. I mean, on average, they probably do. 0:21:26.160 --> 0:21:28.520 You might have like a secret unknown brother or sister, 0:21:29.000 --> 0:21:32.320 but yeah, yeah, on average, that's going to be the case. Now. 0:21:32.320 --> 0:21:34.320 And of course, there are lots of weird ways that 0:21:34.359 --> 0:21:39.080 maybe things like kin selection or reciprocal altruism uh could 0:21:39.080 --> 0:21:42.639 be could be sort of modified in various circumstances to 0:21:42.840 --> 0:21:46.679 generate the mechanisms that create altruism that get applied in 0:21:46.720 --> 0:21:50.760 other ways. But it is in the context of discussing 0:21:50.760 --> 0:21:54.679 this this whole question about altruism and biology in the 0:21:54.680 --> 0:21:58.399 Selfish Gene that Dawkins also came up with this weird 0:21:58.520 --> 0:22:03.760 hypothetical idea for one weird type of selective altruism, the 0:22:03.840 --> 0:22:06.720 green Beard. All Right, we're gonna take a quick break 0:22:06.760 --> 0:22:09.560 and when we come back we will join back up 0:22:09.600 --> 0:22:14.160 with Captain green Beard and discuss the details of of 0:22:14.160 --> 0:22:21.600 of this idea. Alright, we're back. So we were mentioning 0:22:21.640 --> 0:22:24.679 how the name of the green Beard gene comes from 0:22:24.720 --> 0:22:27.480 an example given by Richard Dawkins in The Selfish Gene 0:22:27.480 --> 0:22:31.480 in n So, Dawkins is pointing out how any arbitrary 0:22:31.560 --> 0:22:34.960 gene will become more numerous if it makes carriers of 0:22:35.000 --> 0:22:39.280 that gene friendly and helpful toward other carriers, right, and 0:22:39.320 --> 0:22:41.560 that sort of makes sense. It says like, if you've 0:22:41.560 --> 0:22:45.080 got gene A in your body, gene A does especially 0:22:45.080 --> 0:22:49.360 well if it makes your body give food and night, 0:22:49.520 --> 0:22:52.720 you know, nice behavior toward other carriers of gene A. Right, 0:22:53.040 --> 0:22:55.919 it's just a boost for gene A across the board. 0:22:57.280 --> 0:23:00.439 So he starts talking about the example of the gene 0:23:00.440 --> 0:23:03.280