WEBVTT - How Natural Selection Works 0:00:01.040 --> 0:00:11.120 Welcome to Stuff you Should Know from House Stuffworks dot com. Hey, 0:00:11.119 --> 0:00:14.000 and welcome to the podcast. I'm Josh Clark, There's Charles W. 0:00:14.160 --> 0:00:17.760 Chuck Bryant, and there's no which makes us a very 0:00:17.760 --> 0:00:21.759 special edition of Stuff you Should Know, harrier than Jerry. Yeah, 0:00:22.079 --> 0:00:26.880 edition much harrier. No, let's see your hair man that 0:00:26.960 --> 0:00:30.200 has a lot of hair hairsuite. He's like the original 0:00:30.320 --> 0:00:35.800 Kings of Leon. I used to love those guys back 0:00:35.840 --> 0:00:38.279 when they were like Tennessee hill Billy's. Yeah, and then 0:00:38.320 --> 0:00:40.760 they got their glam makeover and I was like, it's 0:00:40.760 --> 0:00:46.040 like Metallica after the Black album. Yeah, what happened? What 0:00:46.120 --> 0:00:50.280 happened Metallica Lars. I think they enjoyed making loads of money, 0:00:50.320 --> 0:00:53.680 truckloads of money. Didn't think more than being like heavy 0:00:53.680 --> 0:00:57.280 metal parking lot guys. Yeah exactly. Um, hey Chuck. Before 0:00:57.280 --> 0:00:58.960 we get started, we want to tell everybody you can 0:00:58.960 --> 0:01:01.360 follow us on Twitter. That's why sk podcast. You can 0:01:01.400 --> 0:01:03.920 hang out with us on Facebook, dot com, slash stuff. 0:01:03.960 --> 0:01:06.640 You should know our YouTube channel search Josh and Chuck. 0:01:06.760 --> 0:01:10.520 It's pretty awesome, and as always we have a wonderful website. 0:01:10.680 --> 0:01:13.120 Stuff you Should Know dot com. That's right, you can 0:01:13.160 --> 0:01:15.360 hang out with us outside of the podcast if you want, 0:01:15.400 --> 0:01:21.640 if you want, no pressure. So how are you doing? 0:01:21.760 --> 0:01:24.520 I'm great. I'm super excited about this topic because A 0:01:24.800 --> 0:01:27.600 we're pairing it with our Charles Darwin show, Yeah, which 0:01:27.600 --> 0:01:30.840 I guess came out last episode, right, aren't we pairing 0:01:30.840 --> 0:01:33.920 the two? Yeah? I think we're doing Darwin first. Let's 0:01:33.920 --> 0:01:36.720 do Darwin first, because I think in the Darwin episode 0:01:36.760 --> 0:01:39.960 we say we should do natural selection. It's here we are. 0:01:40.280 --> 0:01:43.119 But I'm just excited because to me, and I gushed 0:01:43.160 --> 0:01:48.000 a little at Darwin's feet, this is my own personal statement. 0:01:48.560 --> 0:01:51.960 I think natural selection is the most exciting and like 0:01:52.120 --> 0:01:57.880 beautiful thing that exists. It's it's just it really turns 0:01:57.960 --> 0:02:03.880 my crank. You know, you're like an old timey car. Yeah, yeah, 0:02:04.560 --> 0:02:07.040 you know. I grew up this is again my personal story. 0:02:07.240 --> 0:02:11.560 I grew up in churches most listeners now, uh, which 0:02:11.720 --> 0:02:15.320 was heavy doses of of creation, the creation story. And 0:02:15.480 --> 0:02:19.960 I remember, as a kid, even fully involved in in church, 0:02:20.200 --> 0:02:22.680 thinking like I just this doesn't make sense to me. 0:02:23.040 --> 0:02:26.040 I just it didn't add up. So natural selection it 0:02:26.160 --> 0:02:29.080 just makes sense to you. Yeah. When I finally learned 0:02:29.080 --> 0:02:32.600 about natural selection, like really really understood and learned it. 0:02:32.600 --> 0:02:35.880 It just it made total sense because I can like 0:02:36.080 --> 0:02:38.960 see it, it was tangible. I could make sense of it. 0:02:39.400 --> 0:02:44.200 And again that's my own story. We don't poo poo 0:02:44.240 --> 0:02:48.400 anyone or saying anyone should feel anyway, but we just 0:02:48.520 --> 0:02:51.280 explain how things work exactly. You know. But I have 0:02:51.400 --> 0:02:53.120 a personal attachment to this just because I think it's 0:02:53.120 --> 0:02:55.200 like the grooviest thing going. Yeah, no, I know what 0:02:55.240 --> 0:02:58.160 you mean. Like it it makes uttering complete sense. It's 0:02:58.160 --> 0:03:03.600 almost um in capable of being appropriated to serve some agenda. 0:03:03.680 --> 0:03:06.760 It just is what it is, you know, It's just there. 0:03:07.200 --> 0:03:10.320 It's beautiful. I agree with you entirely. It's an elegant theory. 0:03:10.320 --> 0:03:13.520 Its just super neat. Yeah. Um. And the wonderful thing 0:03:13.600 --> 0:03:16.800 is is like there's even squabbles in the scientific community 0:03:16.840 --> 0:03:23.200 over exactly how evolution works and processes, and regardless, everyone's 0:03:23.200 --> 0:03:28.000 still like, yep, natural selection pretty much perfect. Yeah, it 0:03:28.120 --> 0:03:30.679 just makes sense. I'm gonna have a t shirt natural selection. 0:03:31.040 --> 0:03:33.920 It just makes sense. I have a feeling we'll be 0:03:33.919 --> 0:03:37.080 getting an email with something like that eventually, So let's 0:03:37.080 --> 0:03:39.200 talk about natural selection. I think a lot of people, 0:03:39.320 --> 0:03:42.480 including myself, um, kind of had an idea of what 0:03:42.520 --> 0:03:45.920 it was, pretty good idea, but not necessarily understanding the 0:03:45.920 --> 0:03:48.400 ins and outs of it. And well, that's what we're 0:03:48.400 --> 0:03:50.200 here for, is to explain the ins and outs of 0:03:50.400 --> 0:03:56.600 natural selection. So, um, basically, a lot of people interchange 0:03:56.760 --> 0:04:02.360 evolution and natural selection. That's incorrect. Um. Evolution is this 0:04:02.800 --> 0:04:08.960 huge process by which species adapt and change to survive 0:04:09.240 --> 0:04:12.760 in their environments, and the way that that moves along. 0:04:12.800 --> 0:04:16.599 The mechanism that drives that is natural selection. So they're 0:04:16.600 --> 0:04:20.520 not one and the same. Natural selection drives evolution. Yeah, 0:04:20.560 --> 0:04:24.400 and who wrote this one? Was this? Uh? Grabowski? The 0:04:24.400 --> 0:04:28.240 grabster I should have known. Uh, just very simply puts 0:04:28.240 --> 0:04:31.240 it very early on the article. Organisms best suited to 0:04:31.240 --> 0:04:35.040 survive in their particular circumstance have a greater chance of 0:04:35.040 --> 0:04:37.919 passing their traits onto the next generation. That's right, it 0:04:38.040 --> 0:04:40.880 just makes sense. I'm gonna try not to say that 0:04:40.920 --> 0:04:43.919 every ten minutes, but just now that that's going on 0:04:43.960 --> 0:04:47.000 in my head. Yeah, and and and um do you 0:04:47.000 --> 0:04:50.240 want that on a T shirt? And natural selection is 0:04:50.279 --> 0:04:54.680 like it's this ongoing, basically never ending process even when 0:04:54.800 --> 0:04:58.480 organisms really kind of seemingly stopped developing, like they figured 0:04:58.520 --> 0:05:02.720 it out. Yeah, but it's it isn't. It doesn't have 0:05:02.880 --> 0:05:06.120 its own sentience. It isn't its own thing. Like you can't. 0:05:06.480 --> 0:05:09.320 You can't attribute it to some sort of creator or 0:05:09.320 --> 0:05:12.479 creation necessarily unless you believe that kind of thing. But 0:05:12.560 --> 0:05:14.720 like if you're if you, it's very easy to give 0:05:14.720 --> 0:05:18.080 it a personality, but it's not. It's the byproduct of 0:05:18.160 --> 0:05:23.800 how organisms exist, and we exist by our genes and 0:05:23.839 --> 0:05:26.839 by the fact that those genes change frequently within the 0:05:26.880 --> 0:05:29.880 lifetime of a person thanks to what we understand now 0:05:30.000 --> 0:05:34.080 is of the genetics, but also through reproduction. And from 0:05:34.240 --> 0:05:38.479 these these moments, these periods where genes are up for 0:05:38.680 --> 0:05:43.599 a change, they can completely or even just partially change 0:05:43.839 --> 0:05:46.480 part of an organism, and that change may or may 0:05:46.560 --> 0:05:49.680 not help the organism survive in the environment, like you 0:05:49.800 --> 0:05:52.680 just quoted Grabanowski. And if it does, bay a natural 0:05:52.680 --> 0:05:56.239 selection will root that out and it will propagate that. Yeah, 0:05:56.279 --> 0:05:59.680 and uh. It also points out Darwin um he did 0:05:59.720 --> 0:06:03.400 coin term natural selection and survival of the fittest. And 0:06:03.480 --> 0:06:05.520 I do think that many people hear survival of the 0:06:05.560 --> 0:06:09.080 fittest and they think of the lion eating the gazelle. 0:06:09.320 --> 0:06:12.280 But it's also, like he says, the tree that can 0:06:12.279 --> 0:06:15.680 disperse its seed where it needs to for those seeds 0:06:15.720 --> 0:06:19.640 to grow or the bacteria that uh survives. It's not 0:06:19.720 --> 0:06:22.479 you know, animal eating animal, although it can, right, And 0:06:22.560 --> 0:06:26.080 so since we're on it, Chuck, fitness is basically um 0:06:26.279 --> 0:06:29.560 like you say, like a tree's ability to spread seeds 0:06:29.880 --> 0:06:32.960 and for those seeds to take rud because its grabs. 0:06:32.960 --> 0:06:35.039 Her points out, it's not enough for a tree to 0:06:35.120 --> 0:06:39.040 produce a bunch of seeds, which is its ability to reproduce, Yeah, 0:06:39.040 --> 0:06:41.520 and its ability to survive long enough to even get 0:06:41.560 --> 0:06:43.920 to the point to it where it reproduces. Right. That's 0:06:43.960 --> 0:06:46.440 step one is to live long enough to be able 0:06:46.520 --> 0:06:49.880 to reproduce. Step two, or the second part of it 0:06:50.040 --> 0:06:54.600 is that that reproduction is as successful as it possibly 0:06:54.640 --> 0:06:57.440 can be. Yeah, Like it says, not only you gotta 0:06:57.480 --> 0:06:59.880 do it, you gotta do it well. So that tree, 0:07:00.040 --> 0:07:03.080 it spreads tons and tons of seeds. If those seeds 0:07:03.640 --> 0:07:08.240 um happen to um catch fire and sunlight, that's not 0:07:08.279 --> 0:07:10.840 going to be a very good trait. But if they 0:07:10.880 --> 0:07:14.520 have like a really hard husk that can survive the 0:07:14.600 --> 0:07:18.720 elements but then disintegrates when it's digested by a raccoon 0:07:18.880 --> 0:07:21.640 and then pooped out. You know, then all of a 0:07:21.680 --> 0:07:24.400 sudden you've got that step two covered. Yeah, or if 0:07:24.400 --> 0:07:26.480 it you know, if it's just dumb luck, if that 0:07:26.560 --> 0:07:29.160 tree exists in a place where it's super windy and 0:07:29.200 --> 0:07:33.160 can disperse the seeds better, uh, then it will propagate. 0:07:33.240 --> 0:07:35.480 If not, then you may not even know that that 0:07:35.520 --> 0:07:41.400 tree existed exactly unless you consult the fossil record. That's right. Um, Okay, 0:07:41.440 --> 0:07:46.560 So I guess the whole point to natural selection is 0:07:46.640 --> 0:07:49.600 that it is an agent of change, but it's also 0:07:49.680 --> 0:07:52.800 a byproduct of change, and we kind of have to 0:07:52.840 --> 0:07:57.160 take a step backward to figure out where this change 0:07:57.200 --> 0:07:59.040 is happening. I already said it a little bit, but 0:07:59.080 --> 0:08:02.560 it's in it's our DNA. It's in the DNA of 0:08:02.600 --> 0:08:08.360 all living things to change. Yeah, well, traits were all 0:08:08.360 --> 0:08:11.600 born with traits, and we inherent those traits from you 0:08:11.640 --> 0:08:17.600 know who who made us our folks and um. But 0:08:17.640 --> 0:08:20.560 it's not necessarily that's not necessarily natural selection at work 0:08:20.640 --> 0:08:23.520 over like one generation to the next. Right, there can 0:08:23.600 --> 0:08:26.320 be differences in traits. Like Darwin, as we'll see, points 0:08:26.320 --> 0:08:28.200 that out himself. He's like, let's just get it out 0:08:28.200 --> 0:08:30.240 of the way, Like just because you have brown eyes 0:08:30.280 --> 0:08:33.200 and somebody else has blue eyes, that's not evolution. No, 0:08:33.520 --> 0:08:35.959 and he uses a good example here of tall versus 0:08:35.960 --> 0:08:40.160 short folks. Uh, tall people might be basketball players, people 0:08:40.200 --> 0:08:44.440 might be jockeyscus the grabs are not Darwin. Yeah yeah, yeah, 0:08:44.760 --> 0:08:47.440 Um did they have basketball? When was that advented? When 0:08:47.440 --> 0:08:49.520 did the name sent in mid basketball? I want to 0:08:49.520 --> 0:08:53.400 say eighteen forty eight, but it's probably eighteen seventy, not 0:08:53.480 --> 0:08:55.679 too far off. So he makes the point that you know, 0:08:56.480 --> 0:09:01.760 if something happened to where like jockeys could reproduce better 0:09:01.880 --> 0:09:04.439 or basketball players could not reproduce anymore. Yeah, I was 0:09:04.480 --> 0:09:09.320 trying to imagine, just make up anything, I know, I 0:09:09.360 --> 0:09:12.120 was trying to and like I couldn't come up with it. Well, 0:09:12.160 --> 0:09:15.479 just make make up something like being able to uh 0:09:15.960 --> 0:09:19.280 dribble and dunk lowers your sperm count. Oh that's a 0:09:19.280 --> 0:09:21.480 good one. See, that's what I'm saying. I think my 0:09:21.559 --> 0:09:25.120 brain was in understand natural selection modes of my My 0:09:25.520 --> 0:09:31.079 imagination grew less fertile, so it didn't survive, No, it didn't. Um, 0:09:31.160 --> 0:09:34.240 And over time, basically basketball players don't reproduce as much 0:09:34.400 --> 0:09:37.839 jockey's do, and over several generations, people are going to 0:09:37.920 --> 0:09:42.480 be shorter on average. It sounds almost dumb, it's so simple, 0:09:42.520 --> 0:09:44.160 but that's really the basis of it. It is, and 0:09:44.240 --> 0:09:46.720 it's one of those things. It's like economics where it's 0:09:46.760 --> 0:09:49.320 so simple that it's hard to wrap your mind around 0:09:49.360 --> 0:09:52.440 it because you make it more complex necessarily than it is. 0:09:53.120 --> 0:09:57.080 It's it's very similar for me. Um. And with that 0:09:57.120 --> 0:10:01.880 basketball example which just happened, was humanity evolved to be shorter. 0:10:02.120 --> 0:10:07.000 That was the end result. And that evolution took place 0:10:07.200 --> 0:10:12.040 because there was a shift in the distribution of traits. 0:10:12.679 --> 0:10:16.720 So before lots of basketball players, lots of jockeys, tallness 0:10:16.760 --> 0:10:20.920 and shortness, which are traits or variations on the trade 0:10:20.920 --> 0:10:23.560 of height in humans, Like we have height, we're not 0:10:23.600 --> 0:10:28.440 too dimensional inherited by who bore you, right, not us, 0:10:28.520 --> 0:10:32.760 your parents. We bore you in a different way. Um. 0:10:33.120 --> 0:10:36.679 So the variations on the trade eventually gave rise to evolution. 0:10:36.800 --> 0:10:40.080 So within just like our generation or even a couple 0:10:40.080 --> 0:10:43.920 of generations, the differences in eye color, height or something 0:10:43.960 --> 0:10:47.480 like that, it doesn't represent evolution, but changes like that 0:10:48.240 --> 0:10:51.960 can lead to evolution over time. Yeah, if they are 0:10:52.080 --> 0:10:56.320 changes that either aid or prevent your survival, right, Like 0:10:56.400 --> 0:10:58.920 if something happens and all of a sudden human women 0:10:58.960 --> 0:11:01.560 were all like, we're not gonna mate with anybody but 0:11:01.640 --> 0:11:04.640 blue eyes. You can bet your bippy that within two 0:11:04.679 --> 0:11:08.240 generations there's gonna be nothing but blue eyed kids. Yeah, 0:11:08.400 --> 0:11:12.720 or grown adults getting blue contacts. That's a good idea 0:11:12.920 --> 0:11:16.559 because they're tired of not having sex. But then maybe 0:11:16.559 --> 0:11:19.760 our eyes would adapt to um the context and just 0:11:19.840 --> 0:11:25.440 absorb them. Something has to happen. Your imagination is plenty fertill, 0:11:25.480 --> 0:11:28.280 my friend, I guess so. Uh, and this all goes 0:11:28.280 --> 0:11:29.800 back if we can go back a little further to 0:11:29.920 --> 0:11:34.960 something called DNA um that is a chemical structure that 0:11:35.080 --> 0:11:37.960 is the basis for everything that is. Is that a 0:11:37.960 --> 0:11:41.720 good way to say it? And Uh? Within DNA are 0:11:42.240 --> 0:11:46.320 sequences of traits, sets of traits, and those are the genes. 0:11:46.960 --> 0:11:50.079 And then there's something called the LLL, which is really 0:11:50.120 --> 0:11:52.480 where it all comes together. Is it all? Or allele? 0:11:53.240 --> 0:12:01.160 Does I say ll adele? No? Adele allele? Okay? So 0:12:01.240 --> 0:12:04.280 it's like a gene is like a specific sequence of 0:12:04.400 --> 0:12:09.480 DNA that produces some trade. So height, like you have 0:12:09.520 --> 0:12:12.240 a height gene like and when that gene is working 0:12:12.280 --> 0:12:14.760 like you will grow. Yeah, the expression of the gene 0:12:14.760 --> 0:12:17.880 is the allele. Yeah, that's the variation of that trait. 0:12:18.000 --> 0:12:21.800 So imagine like as just a stretch of genes is 0:12:21.840 --> 0:12:25.839 like a few boxes, say five of them, and three 0:12:25.840 --> 0:12:29.920 are off the three that will encode to make brown eyes, uh, 0:12:29.960 --> 0:12:33.000 and two are on the two that will encode to 0:12:33.120 --> 0:12:37.240 make blue eyes. So each one's an allele, but the 0:12:37.280 --> 0:12:40.840 one that's functioning gives you blue eyes. So in allal 0:12:41.000 --> 0:12:43.280 is just a variation on a trade. And a trade 0:12:43.360 --> 0:12:46.679 is produced by a gene, which is a sequence of DNA. 0:12:46.920 --> 0:12:49.360 That variation is produced by an allele, which is a 0:12:49.679 --> 0:12:53.320 sequence of the gene. And how often that allele shows 0:12:53.440 --> 0:12:57.600 up in a population is the allele frequency. And it's 0:12:57.640 --> 0:12:59.840 really simple. You hear alleal frequency and it sounds like, 0:13:00.000 --> 0:13:02.800 oh that's science, but it's really pretty easy. That's what 0:13:02.880 --> 0:13:05.199 they go to school force to learn the jargon. Yeah, 0:13:05.280 --> 0:13:08.960 and uh, we did a really good episode on population 0:13:09.760 --> 0:13:12.439 and uh, we're gonna be talking about here again though, 0:13:12.480 --> 0:13:15.400 So we should just say that a population is a 0:13:15.440 --> 0:13:21.480 group uh in one place that have sex with each other. Yeah. Um, 0:13:21.520 --> 0:13:25.480 so like a zebra in Africa. He makes up he 0:13:25.480 --> 0:13:28.720 should have used real examples because he said, let's say 0:13:28.720 --> 0:13:31.280 there were zebras in South America. But I see his point, 0:13:31.360 --> 0:13:33.679 that would be a different population because they can't have 0:13:33.720 --> 0:13:36.360 sex with the zebras in Africa, because zebras can't swim 0:13:36.400 --> 0:13:39.120 across the ocean. And a lion in Africa is in 0:13:39.160 --> 0:13:41.520 a different population than a zebra in Africa because they 0:13:41.760 --> 0:13:46.880 don't do it right. They can't. It's an abomination. It is. 0:13:47.880 --> 0:13:50.520 You come up with a zion, that'd be kind of cool. 0:13:51.200 --> 0:13:56.400 I guess, sort of like a tiger. Probably maybe that's 0:13:56.400 --> 0:14:00.920 what a tiger. I think. It's So you were talking 0:14:00.960 --> 0:14:05.840 about populations and you're in a little frequency. So, um, 0:14:06.000 --> 0:14:10.920 you could conceivably quantify the alleal frequency of blue eyes 0:14:10.960 --> 0:14:15.360 and the human population because we transcended, like the difference 0:14:15.360 --> 0:14:18.080 between Africa and South America. Like we have planes now, 0:14:18.559 --> 0:14:21.440 so we we all have access to sex with one 0:14:21.440 --> 0:14:23.800 another as a population, as long as you have a 0:14:23.800 --> 0:14:28.760 passport and some money for a plane ticket. Um. So 0:14:29.040 --> 0:14:32.800 speaking about a lieal frequency, Um, the point of that 0:14:32.880 --> 0:14:37.240 whole thing is that with evolution, I guess another way 0:14:37.240 --> 0:14:39.080 to put it, the way it grabs or puts it 0:14:39.200 --> 0:14:42.600 is evolution is just a shift or a change in 0:14:42.640 --> 0:14:46.720 alleal frequency. And the reason that that change takes places 0:14:46.800 --> 0:14:51.640 because those alleles that become more and more widespread and 0:14:51.680 --> 0:14:58.160 distributed it across the population, UM have made that organism 0:14:58.200 --> 0:15:02.320 more likely to survive, to reproduce, and more likely to 0:15:02.400 --> 0:15:06.000 successfully reproduce. Yeah, that's it. That's it. That's the evolution 0:15:06.120 --> 0:15:09.880 driven by natural selection. Do you want to quit? I 0:15:09.920 --> 0:15:12.680 don't think we could top at this point. Now it 0:15:12.720 --> 0:15:17.000 does get more interesting. Um Alile's create are created in 0:15:17.040 --> 0:15:19.920 a few different ways. UM. One is called a mutation, 0:15:20.320 --> 0:15:25.160 which you probably heard of. Uh. These are random changes. Uh. 0:15:25.400 --> 0:15:29.320 They are pretty rare, like the X men. Yeah, very rare, 0:15:29.680 --> 0:15:31.840 very rare mutants are. That's why they got to hang 0:15:31.840 --> 0:15:34.680 out with the president a lot. Yeah, but the president 0:15:34.680 --> 0:15:39.520 was also a mutant, wouldn't he. Oh yeah, eventually Kelsey Grammer. No, no, no, 0:15:39.600 --> 0:15:43.280 the president was the guy with the son with the wings. 0:15:44.080 --> 0:15:46.800 I thought, ye, his son was the mutant and the 0:15:46.840 --> 0:15:50.920 president the president. But I think Kelsey Grammer eventually was 0:15:50.960 --> 0:15:56.840 elected president Blue president, Blue Harry President. So to me, 0:15:57.200 --> 0:16:00.640 the cool thing about mutations is is they can be 0:16:01.200 --> 0:16:05.160 completely new traits that are introduced that are completely different 0:16:05.160 --> 0:16:08.320 than anything you've ever seen in that species, which is 0:16:08.320 --> 0:16:12.560 pretty radical. Another way is just like we've been talking 0:16:12.560 --> 0:16:17.320 about sex a lot reproduction just with animals humans. That 0:16:17.520 --> 0:16:20.760 is the way that an aile can express itself. Right. 0:16:20.800 --> 0:16:23.960 It's the mixing together when when your mom and your 0:16:24.000 --> 0:16:28.080 dad love each other very much and they copulate. Um, 0:16:28.120 --> 0:16:32.520 there sperm and egg mixed together, break down their DNA 0:16:32.880 --> 0:16:37.640 and it's glorious, fantastic um little mini explosion inside the 0:16:37.680 --> 0:16:42.560 womb and uh, and then it really it recombines into 0:16:42.640 --> 0:16:46.640 a totally new form that shares part of the dad's 0:16:46.680 --> 0:16:48.800 DNA and part of the mom's UNICH to make a 0:16:48.800 --> 0:16:51.320 new human. Yeah, and you get all the bad traits 0:16:51.360 --> 0:16:54.440 from each of them, right, hopefully you get all the 0:16:54.480 --> 0:16:59.600 best traits. But that's the point of sexual reproduction, which 0:16:59.680 --> 0:17:04.080 was itself naturally selected, because it increases the potential that 0:17:04.119 --> 0:17:07.639 you're going to inherit uh, good traits that will let 0:17:07.640 --> 0:17:10.880 you survive. That's right, there's just more traits out there. 0:17:10.880 --> 0:17:13.560 It's like um. I think it was the Sense of 0:17:13.680 --> 0:17:17.320 Smell episode we did where we talked about pheromones, the 0:17:17.400 --> 0:17:21.600 idea that pheromones among humans, we we can still detect 0:17:21.640 --> 0:17:23.760 them even though we don't know it. And the whole 0:17:23.760 --> 0:17:27.040 reason we can is to smell out other people's immune 0:17:27.040 --> 0:17:30.399 system and we want somebody with an opposite immune system 0:17:30.400 --> 0:17:32.600 of RS. So when you put the two together, it 0:17:32.680 --> 0:17:35.840 produces a little mini superhuman who can't be killed. There 0:17:35.920 --> 0:17:37.720 was an interesting study I think where they just had 0:17:37.720 --> 0:17:41.480 people smelling things, but the gauging attraction levels right. But 0:17:41.520 --> 0:17:44.439 it's based on the premise of sexual reproduction, which is 0:17:44.800 --> 0:17:49.240 the combining as many good traits as possible make somebody 0:17:49.280 --> 0:17:52.960 with a lot of them. Uh. And then the final 0:17:53.000 --> 0:17:57.240 way that um alile's are created is um genetic recombination, 0:17:57.760 --> 0:17:59.080 and that would be in the case of like a 0:17:59.119 --> 0:18:02.280 bacteria who obviously don't go out and have sex with 0:18:02.320 --> 0:18:06.520 each other um, but they do absorb DNA that they 0:18:06.760 --> 0:18:11.680 get from other bacteria and basically make it part of them. Yeah, 0:18:11.920 --> 0:18:15.199 they think that's where the ukaryotes came from. Yeah, the 0:18:15.240 --> 0:18:18.679 mitochondria was its own thing and it became absorbed by 0:18:18.720 --> 0:18:22.760 some ancient cell to serve as like the power center 0:18:23.600 --> 0:18:27.040 of the of the cell, and from that like gave 0:18:27.119 --> 0:18:29.520 rise to everything with the backbone, everything that's not a 0:18:29.520 --> 0:18:34.720 bacteria basically, so fish at first, I guess yeah, but eventually, 0:18:34.760 --> 0:18:36.600 like it all, it all just came to that and 0:18:36.640 --> 0:18:40.119 it's still going on today. It's just two organisms in 0:18:40.240 --> 0:18:44.160 one neat yeah that's super neat, and then one other thing. 0:18:44.240 --> 0:18:46.679 Like there are three ways that this could happen. That 0:18:46.880 --> 0:18:51.199 um that new alliles could be introduced. But um, I 0:18:51.240 --> 0:18:56.760 wonder if epigenetics will eventually be added to that. Yeah, 0:18:56.760 --> 0:18:58.439 because think about it. I mean, it's a change in 0:18:58.520 --> 0:19:03.280 gene expression, right, So yeah, I could see that leading 0:19:03.320 --> 0:19:06.280 to I guess I guess it could be classified as 0:19:06.280 --> 0:19:11.760 a spontaneous mutation. I guess it would fall under that umbrella. Yeah, 0:19:11.800 --> 0:19:13.240 but so much leads up to it. I don't know. 0:19:14.200 --> 0:19:16.320 I'm with you. What's out of fourth? Okay, et the 0:19:16.400 --> 0:19:21.320 genetics is officially added as a change to Allele's I'm 0:19:21.320 --> 0:19:23.680 sure we'll get an email from someone that's super smart 0:19:23.760 --> 0:19:26.159 that will explain exactly why that won't happen there. Like, 0:19:26.240 --> 0:19:32.480 first of all, Chuck was right, it's allows so Chuck 0:19:32.600 --> 0:19:34.399 we um. You know we said that all of this 0:19:34.520 --> 0:19:37.639 starts at DNA and the fact that it changes, we 0:19:37.760 --> 0:19:43.399 actually should go back even further, um than that, uh, 0:19:43.600 --> 0:19:47.480 into the backdrop of nature, the environment, the reason that 0:19:47.680 --> 0:19:52.879 DNA changes, that traits change over time is because of 0:19:52.920 --> 0:19:57.840 a little thing called death. Yeah, we all die and 0:19:57.840 --> 0:20:01.040 how to avoid it exactly. It's it's the combination of 0:20:01.040 --> 0:20:04.000 the two things. We're all going to die, and all 0:20:04.160 --> 0:20:07.360 organisms appear to be driven by a desire to put 0:20:07.400 --> 0:20:10.199 off that moment as long as possible, So we have 0:20:10.280 --> 0:20:15.760 an instinct to survive. Right. The problem is is the 0:20:15.800 --> 0:20:18.640 processes of nature are trying to put us down all 0:20:18.680 --> 0:20:23.520 the time, so there is a inherent struggle to survive. 0:20:24.080 --> 0:20:28.320 So when you combine our desire to live with nature 0:20:28.359 --> 0:20:31.200 trying to kill us all the time, it forms that struggle. 0:20:31.280 --> 0:20:34.480 The struggles have survived gives rise to the changes in genes, 0:20:34.720 --> 0:20:39.960 which eventually are selected and convert to evolution. So it 0:20:40.000 --> 0:20:43.760 all begins with the struggle to survive and the desire 0:20:43.840 --> 0:20:50.440 to survive. Right, And this is spelled out by Darwin himself. Yeah, 0:20:50.440 --> 0:20:53.479 should we read some of his quotes, Uh this is 0:20:53.600 --> 0:20:55.800 These are from the on the Origin of the Species, 0:20:55.840 --> 0:20:58.000 which if you just listen to the Charles Starwin, you know, 0:20:58.040 --> 0:21:01.240 that was his most famous work that he put up, 0:21:02.320 --> 0:21:05.800 one of many, but that's his uh you know, warrant Peace. 0:21:06.440 --> 0:21:10.359 It's close second was my travels with Timmy about his 0:21:10.400 --> 0:21:14.360 pet rabbit and he going around the county bothering neighbors. 0:21:14.480 --> 0:21:19.359 So he here are you with the Here a few 0:21:19.400 --> 0:21:21.639 of the basic tenants in on the origin of the 0:21:21.680 --> 0:21:25.399 species and with some quotes from Darwin himself. One is 0:21:25.440 --> 0:21:29.359 the organisms show variations of a variation of traits. Yeah, 0:21:29.359 --> 0:21:30.919 that's him just getting it out of the way, like, 0:21:31.000 --> 0:21:34.480 don't be dumb. If you think that your your dad's 0:21:34.480 --> 0:21:37.240 blue eyes and your brow and eyes are revolution, you're wrong. Okay, 0:21:37.480 --> 0:21:40.280 I like that better than his quote. Actually, let's do that. 0:21:40.359 --> 0:21:43.320 Let's do Josh's take on his quote. I'll do what 0:21:43.359 --> 0:21:46.480 I can, all right. Uh. Number two is more organisms 0:21:46.480 --> 0:21:50.359 are born that could ever possibly be supported by the 0:21:50.440 --> 0:21:55.200 resources here on the planet. That's right. Uh, stop being 0:21:55.200 --> 0:21:57.960 such an idiot. There's such a thing as scarcity, don't 0:21:57.960 --> 0:22:01.359 you know that. I mean this is great. Um, I 0:22:01.400 --> 0:22:05.280 feel the birth of the new podcast coming. Number three. Therefore, 0:22:05.400 --> 0:22:08.320 in conclusion, all organisms must struggle to live. You already 0:22:08.400 --> 0:22:13.480 kind of covered that, okay. Um. Number four, some traits 0:22:13.720 --> 0:22:19.399 offer advantages in the struggle. That's right. Uh, those are mutations, 0:22:20.640 --> 0:22:25.320 and as Josh will eventually predict, epigenetics, not always mutations 0:22:25.320 --> 0:22:31.000 though right changes to Allele's um. Organisms that have those 0:22:31.040 --> 0:22:33.160 traits are the ones that will help you survive, are 0:22:33.160 --> 0:22:36.159 more likely to be successful and reproduce and pass them on. 0:22:37.359 --> 0:22:40.800 And then finally successful variations the ones that we have 0:22:40.840 --> 0:22:43.440 just talked about that allow you to survive and reproduce more. 0:22:43.880 --> 0:22:47.639 They accumulate over the years and the generations as they 0:22:47.680 --> 0:22:49.399 are exposed to something we'll talk about in a minute 0:22:49.400 --> 0:22:53.320 called population pressure. Right. And he points out too that 0:22:53.400 --> 0:22:58.720 this is essentially specific and local. Like UM, if humans 0:22:58.840 --> 0:23:04.439 had a right where you cooled extremely easily all the time, UM, 0:23:04.520 --> 0:23:08.440 under under all conditions, it wouldn't play very well. When 0:23:08.440 --> 0:23:11.560 you move to the northern latitudes, you die, so it 0:23:11.600 --> 0:23:14.800 would be selected out of populations in the northern latitudes. 0:23:15.040 --> 0:23:18.040 But if you lived in the tropics, it would probably 0:23:18.080 --> 0:23:22.960 be selected um and propagated over time because you probably 0:23:22.960 --> 0:23:24.600 have a lot more energy. You wouldn't just be laying 0:23:24.640 --> 0:23:27.880 around fanning yourself with palm fronds. Well you do that too, 0:23:27.920 --> 0:23:31.000 but you wouldn't need to. Yeah, but it's just it's 0:23:31.000 --> 0:23:35.439 a nice experience. UM. So I mentioned population pressure, and 0:23:35.520 --> 0:23:40.399 that's a key here to understanding this whole bowl of soup. 0:23:40.720 --> 0:23:46.240 And we'll talk about that right after this message. All right, 0:23:46.720 --> 0:23:48.720 So here we are in the stew I called it soup. 0:23:48.760 --> 0:23:53.239 It's really a stew of evolution and that section. So 0:23:53.280 --> 0:23:57.359 we need to talk about population pressure, which is basically 0:23:57.440 --> 0:24:02.280 anything in a population that makes it tough for your species. 0:24:02.359 --> 0:24:06.919 Are you, as an individual plant or animal to survive it? Yeah? Again, 0:24:06.960 --> 0:24:09.800 because there's such things scarcity that means you compete with 0:24:09.920 --> 0:24:14.040 people in your species or people outside of your species, right, 0:24:14.119 --> 0:24:17.080 like a lion wants to eat you. Yeah, there's always 0:24:17.080 --> 0:24:20.760 it's always going on, yes, um. And then even if 0:24:20.800 --> 0:24:23.639 you lived in total harmony with all the plants and 0:24:23.680 --> 0:24:27.359 animals around you and vice versa, nature is still shooting 0:24:27.480 --> 0:24:31.960 lightning bolts at you, train your floods, droughts, famine, all 0:24:32.000 --> 0:24:35.400 that stuff there is always in and is Darwin put 0:24:35.400 --> 0:24:40.720 it like every organism struggles to survive one way or another. Yeah, 0:24:40.720 --> 0:24:43.000