WEBVTT - Ghost in the Genetic Machine: Animals 0:00:03.840 --> 0:00:06.720 Welcome to Stuff to Blow Your Mind from how Stuff 0:00:06.720 --> 0:00:13.800 Works dot com. Hey, welcome to Stuff to Blow your Mind. 0:00:13.840 --> 0:00:16.800 My name is Robert Lamb and I'm Julie Douglas. We're 0:00:16.800 --> 0:00:19.080 doing a couple of episodes here where we're really getting 0:00:19.079 --> 0:00:23.920 into the idea of genetic memory, which is the snazzier 0:00:23.920 --> 0:00:25.560 way of looking at if you want to get really technical, 0:00:25.600 --> 0:00:28.479 we are going to be talking about epigenetics. Don't be 0:00:28.520 --> 0:00:31.240 scared off by that. UM. I understand the temptation to 0:00:31.320 --> 0:00:34.040 be scared off by it because I've written about epigenetics 0:00:34.120 --> 0:00:37.360 before and uh. And it can be in a way 0:00:37.400 --> 0:00:41.280 a very dense topic because you are getting down to um, 0:00:41.360 --> 0:00:45.919 how the genome corresponds to the phenotype, how the contents 0:00:45.920 --> 0:00:49.120 of our genes is expressed, the phenotype is the expression 0:00:49.320 --> 0:00:52.000 of our genes. Um. So we can get a bit 0:00:52.040 --> 0:00:54.480 technical when you get into that, but ultimately we are 0:00:54.520 --> 0:01:00.600 talking about how the secrets written in ourselves, how thoseterialized 0:01:00.600 --> 0:01:03.040 as the person we are, both in terms of our 0:01:04.080 --> 0:01:08.280 our our body and in terms of our mind. Uh. 0:01:08.319 --> 0:01:11.760 And we ultimately really get into the conversation about nature 0:01:11.760 --> 0:01:15.360 and nurture concerning animals and humans. So we're splitting it up, 0:01:15.360 --> 0:01:18.240 we have this first episode about the animals. It's often 0:01:18.280 --> 0:01:21.160 a little easier to to look at the that something 0:01:21.200 --> 0:01:24.679 as uh as complex as this with the animals first, 0:01:24.720 --> 0:01:27.640 and certainly that's where most of the experiments are gonna 0:01:27.800 --> 0:01:30.600 taking place. And then after that we'll get into the 0:01:30.680 --> 0:01:34.280 human realm and the various human ramifications when we complicate 0:01:34.360 --> 0:01:36.800 things with all of our human baggage. Yeah, the idea 0:01:36.840 --> 0:01:40.160 here is we want to recast our ideas about evolution 0:01:40.360 --> 0:01:43.840 and also disease and how we can gain phenotypes the 0:01:43.880 --> 0:01:47.640 expression of these genes, uh, for for the better really. 0:01:48.120 --> 0:01:50.600 And in order to really get into this discussion, we 0:01:50.640 --> 0:01:54.480 have to talk about this guy named Gene Baptiste Lamarck 0:01:54.840 --> 0:02:00.720 or Gene eighteenth century French scientists and naturalists and and uh. 0:02:00.800 --> 0:02:04.919 He had some some very interesting ideas about how animals 0:02:05.120 --> 0:02:08.920 change over time, essentially about evolution, and he's most cited 0:02:09.639 --> 0:02:13.160 example is that of the giraffes. He argued that, okay, 0:02:13.280 --> 0:02:14.800 you look at the draft wanted to draft of a 0:02:14.840 --> 0:02:17.880 long neck. Well, Darwin's answer would be that they're all 0:02:17.919 --> 0:02:21.639 these various mutations over time, and some of those mutations 0:02:21.680 --> 0:02:25.080 involved longer necks. And since the longer necks were a 0:02:25.080 --> 0:02:28.240 better survival adaptation. Those are the ones that survived and 0:02:28.240 --> 0:02:32.160 flourished wanted on. The mutations with the shorter necks didn't 0:02:32.160 --> 0:02:34.800 pan out so well. Right, So longer neck naturally selected 0:02:34.840 --> 0:02:38.160 for taking a long time to be selected. Right. We're 0:02:38.160 --> 0:02:41.600 not just talking about one or two generations. Lamark's idea, though, 0:02:41.720 --> 0:02:44.239 is that you have this giraffe, imagine the short neck giraffe, 0:02:44.280 --> 0:02:47.680 and he looks up or she looks up at the call. 0:02:47.800 --> 0:02:51.120 Cindy looks up at the at the fruit in the tree. Yeah, 0:02:51.760 --> 0:02:54.840 Cindy's and Cindy's and her cohorts have already eaten all 0:02:54.880 --> 0:02:57.079 the low hanging fruit. They want the high hanging fruit, right, 0:02:57.240 --> 0:03:00.000 They want to reach up higher. So she's straining her 0:03:00.840 --> 0:03:03.680 she's looking up there. I want to eat those top fruit. 0:03:04.639 --> 0:03:09.640 And then Cindy's offspring have the same desire, and the 0:03:09.680 --> 0:03:12.760 offspring after that. There's this there's this need to reach 0:03:13.440 --> 0:03:16.639 the higher hanging fruit from generation to generation, and from 0:03:16.639 --> 0:03:25.600 generation to generation. The neck longands enough coffee this morning. Long, 0:03:25.880 --> 0:03:29.280 So already I'm thinking about Cindy from Brady Punch, whispering 0:03:29.360 --> 0:03:33.440 her desires to to reach the foliage length right, and 0:03:33.480 --> 0:03:36.520 then her offspring all lispening their desire to reach the 0:03:36.520 --> 0:03:40.040 foliage too and getting there. Because here's the Lamark deal. 0:03:40.480 --> 0:03:43.080 In his view, some giraffes managed to stretch their necks 0:03:43.200 --> 0:03:45.040 over out over the course of their lifetime, giving them 0:03:45.080 --> 0:03:47.720 an advantage of other giraffes, which then what we're talking 0:03:47.720 --> 0:03:49.440 about is passing on to their children. This is a 0:03:49.560 --> 0:03:55.080 really quick acquisition of traits here, and this is really 0:03:55.080 --> 0:03:59.400 what the story comes down to, acquiring traits versus genetic mutations. 0:03:59.760 --> 0:04:03.080 Now out with Lamarck right when he was talking about 0:04:03.080 --> 0:04:07.200 these droffs, well for a while, no, for he was 0:04:07.240 --> 0:04:09.600 dead wrong in this example. Yeah, I mean he was 0:04:09.640 --> 0:04:13.800 pretty much. This was considered the archaic idea, and we're 0:04:13.840 --> 0:04:16.599 not archaic, but an outdated idea that was that was 0:04:17.200 --> 0:04:21.400 it was far outperformed by Darwin's theory of evolution. So 0:04:21.520 --> 0:04:24.880 Darwin's theory becomes the predominant way that we make sense 0:04:25.040 --> 0:04:29.360 of these changes over time. But it does turn out 0:04:29.480 --> 0:04:33.160 that Lamarck was onto something um and his you know, 0:04:33.200 --> 0:04:36.080 his theory was dismissed for a long time as malarkey, Like, 0:04:36.080 --> 0:04:40.400 how I did that? Lamar Malarkey Lamarca malarkey. Yeah. But 0:04:40.600 --> 0:04:44.400 when epigenetics really came onto the scene in the seventies 0:04:44.440 --> 0:04:47.039 and more lately in the last ten years, people have 0:04:47.160 --> 0:04:50.760 been looking at Lamarky and evolution again because our better 0:04:50.839 --> 0:04:55.240 understanding of epigenetics makes what he was talking about possible. 0:04:55.320 --> 0:05:00.839 So epigenetics, Okay, you have genetics with the geno, and 0:05:00.839 --> 0:05:03.520 then you have this thing called epigenetic, which literally means 0:05:03.839 --> 0:05:08.120 in addition to genetics. Um, and this exists, and these 0:05:08.160 --> 0:05:11.520 changes exist between the genome and the phenotype. Now I 0:05:11.600 --> 0:05:13.679 like to think of this in terms of video games. 0:05:13.960 --> 0:05:16.560 It works for me, it'll work for some of you guys. Um, 0:05:16.760 --> 0:05:21.160 think of a flight simulator. Okay, you you put a 0:05:21.279 --> 0:05:23.720 load of flights that simulator up on the computer, right 0:05:24.040 --> 0:05:25.760 and uh, and you can go in there and you 0:05:25.800 --> 0:05:28.560 pretend to fly this airplane. Now, if you go in there, 0:05:28.600 --> 0:05:32.000 you go into the settings for this particular game, you 0:05:32.080 --> 0:05:37.680 can alter the realism of the flight experience. Okay, So 0:05:37.920 --> 0:05:39.839 think of it. Think of this way. The game engine, 0:05:40.960 --> 0:05:46.479 the game itself, This is the genome. Your actual game 0:05:46.520 --> 0:05:50.640 playing experience is the phenotype the expression right, and in 0:05:50.720 --> 0:05:54.279 between there you have epigenetics. You have the settings menu 0:05:54.520 --> 0:05:56.400 where you can where you can click on or click 0:05:56.440 --> 0:05:58.240 off all these little things like, oh, you don't want 0:05:58.279 --> 0:06:00.960 planes to be able to collide and there you don't 0:06:01.040 --> 0:06:03.359 want to ever run out of fuel. You want you know, 0:06:03.440 --> 0:06:06.440 unlimited uh, emma whatever. You can adjust those settings to 0:06:06.520 --> 0:06:10.200 have any anywhere between a highly realistic flight simulation and 0:06:10.240 --> 0:06:13.200 an arcade shoot them up, depending on how those settings 0:06:13.240 --> 0:06:17.240 are gamed. And so with an organism, you see a 0:06:17.360 --> 0:06:20.160 very similar thing. You have the you have the genome, 0:06:20.760 --> 0:06:23.680 which says this is what the organism is going to 0:06:23.760 --> 0:06:25.440 be like, this is what the phenotype is going to be, 0:06:25.560 --> 0:06:28.159 this is what the experience, the game experience that we 0:06:28.200 --> 0:06:30.440 live every day is going to consist of. And then 0:06:30.440 --> 0:06:33.400 you have all these various settings in between, these ways, 0:06:33.640 --> 0:06:36.960 these epigenetic changes that affect the way that the genes 0:06:37.000 --> 0:06:40.200 are expressed. That's right, because at the heart of epigenetics 0:06:40.320 --> 0:06:43.160 is really the study of these changes in gene activity 0:06:43.200 --> 0:06:47.000 that don't involve alterations to the genetic code, right, but 0:06:47.080 --> 0:06:50.359 they still get passed down to at least one successive generation. 0:06:50.880 --> 0:06:53.039 So again, think about the flight simulator that you just 0:06:53.040 --> 0:06:57.520 talked about, and think about um let me see it. 0:06:57.600 --> 0:07:00.920 Let's think about the genome is the hardware, and epigenome 0:07:01.080 --> 0:07:04.000 as the software. Okay, so you can load Windows if 0:07:04.000 --> 0:07:06.040 you want on your Mac. Okay, I think about it 0:07:06.080 --> 0:07:10.360 that way. So I think now about this epigenome, that 0:07:10.560 --> 0:07:13.920 extracellular material that is sitting on top of the genome, 0:07:14.560 --> 0:07:18.560 and it's these epigenetic marks or proteins that tell your 0:07:18.600 --> 0:07:22.320 genes to switch on or off. And it's through epigenetic 0:07:22.360 --> 0:07:26.520 marks that environmental factors like diet, stress and prenatal nutrition 0:07:26.600 --> 0:07:29.360 can make an imprint on those genes that are passed 0:07:29.360 --> 0:07:31.920 on from one generation to the next. So we're we're 0:07:31.920 --> 0:07:34.680 talking about this because this is really amazing stuff because 0:07:34.720 --> 0:07:37.360 what you can do is you could you can impact 0:07:37.680 --> 0:07:42.000 your your future offspring in a very significant way without 0:07:42.120 --> 0:07:47.040 changing your own DNA. And we essentially see Lamarckian evolution 0:07:47.160 --> 0:07:50.360 return in this or some semblance of the idea, only 0:07:51.040 --> 0:07:56.440 we call it transgenerational epigenetic inheritance. So it's the settings 0:07:56.480 --> 0:07:59.240 that to end up being put in place in one 0:07:59.280 --> 0:08:03.800 generation passing on to subsequent generations. UM. So it's like 0:08:03.880 --> 0:08:05.880 you know, a father had the realism settings on his 0:08:06.360 --> 0:08:10.320 flight simulator set to about and then that same those 0:08:10.360 --> 0:08:13.000 same settings pass on to the offspring, even if you 0:08:13.040 --> 0:08:14.800 know they're in a more arcade culture. I'm kind of 0:08:14.800 --> 0:08:17.160 stretching the metaphor, but I think you get what I'm saying, 0:08:17.160 --> 0:08:18.920 all right. So you're probably saying, well, how in the 0:08:18.920 --> 0:08:21.480 world does this happen? Anyway, what is the mechanism for 0:08:21.600 --> 0:08:26.440 delivering these changes? And that is something called DNA methylation. Okay, 0:08:26.440 --> 0:08:30.200 So that's how you game gene expression, the phenotype, how 0:08:30.200 --> 0:08:32.320 a gene is expressed turned on or off in an 0:08:32.320 --> 0:08:35.480 epig genome. So it takes only the addition of a 0:08:35.520 --> 0:08:38.280 methyl group to change an epigenome. And a methyl group 0:08:38.400 --> 0:08:41.319 is a basic unit in organic chemistry. We're talking one 0:08:41.360 --> 0:08:45.720 carbon atom attached to three hydrogen atoms. And when a 0:08:45.800 --> 0:08:48.520 methyl group attached to a specific spot on a gene, 0:08:48.880 --> 0:08:52.000 this is what we call DNA methyl ish methylation, and 0:08:52.080 --> 0:08:54.400 it changes that genes expression, turning it on and off, 0:08:54.520 --> 0:08:57.959 dampening it, making it louder. The choices are all there, right, 0:08:58.880 --> 0:09:02.680 So think of methylate and as chemical bundles that enzions 0:09:02.760 --> 0:09:05.480 hitch a ride to DNA on and then they have 0:09:05.600 --> 0:09:10.560 the ability to manipulate jeans. You with me here, all right, 0:09:10.800 --> 0:09:14.199 You guys out there with us UM in the methylization 0:09:14.240 --> 0:09:17.679 patterns can be affected by again external environment and then 0:09:17.720 --> 0:09:20.520 get passed on to offspring because they are maintained through 0:09:20.600 --> 0:09:23.240 cell division. Yeah, they can change drastically in the course 0:09:23.280 --> 0:09:25.640 of a lifetime, but they can also as well discussed 0:09:25.679 --> 0:09:28.640 they can be said permanently during embryo development. So it 0:09:28.840 --> 0:09:32.720 depends on various factors and that affect the distribution of 0:09:32.760 --> 0:09:36.839 methyl groups. So we have an example here of um 0:09:37.120 --> 0:09:41.680 one sort of DNA methyl methylation in process in nature, 0:09:41.720 --> 0:09:43.960 and this is with mice. This is in a two 0:09:43.960 --> 0:09:48.200 thousand and three Duke University study by oncologist Randy Jurtle 0:09:48.720 --> 0:09:51.920 in one of his postdoc students, Robert Waderland. They tinkered 0:09:51.960 --> 0:09:57.080 with genetics using mice with a uniquely regulated a Goudy gene. Okay, 0:09:57.080 --> 0:10:00.400 so this a Goudy gene gives mice yellow coat and 0:10:00.640 --> 0:10:05.040 propensity for obesity and diabetes when expressed continuously. So what 0:10:05.080 --> 0:10:07.640 did they do to to these mice, Well, they gave 0:10:07.720 --> 0:10:11.480 them a one group of them a diet rich envitamin B, 0:10:11.640 --> 0:10:15.440 so we're talking about folic acid and B twelve. Another 0:10:15.480 --> 0:10:18.280 group they did nothing to. What they found is that 0:10:18.320 --> 0:10:22.240 the vitamin B acted as methyl donors. They caused methyl 0:10:22.240 --> 0:10:26.600 groups to attach more frequently to that Goudy gene, essentially 0:10:26.720 --> 0:10:31.760 dampening it, turning it off, altering its expression. So without 0:10:31.800 --> 0:10:34.880 even messing with the d NA, what happened is that 0:10:34.960 --> 0:10:39.760 those mice with the gouty gene produced healthy offspring that 0:10:39.920 --> 0:10:42.760 had brown coats. They were normal weight, and they were 0:10:42.760 --> 0:10:47.280 not prone to diabetes. Just with this one aspect of nutrition. 0:10:48.320 --> 0:10:51.280 There's another really cool example that is often sided involving 0:10:51.280 --> 0:10:55.560 water fleas in a predator heavy environment. The creatures developed 0:10:55.559 --> 0:10:58.679 these large defensive spines on their bodies, all right, because 0:10:58.720 --> 0:11:02.080 the world has become danger so they they load up, 0:11:02.160 --> 0:11:04.720 you know, they develop these spikes. It's a harsh world, 0:11:04.760 --> 0:11:07.679 so they they grow the weapons they need to defend themselves, 0:11:07.960 --> 0:11:10.559 and then the trait will pass on to the offspring, 0:11:11.080 --> 0:11:14.160 even if those offspring are raised in a predator free setting. 0:11:14.440 --> 0:11:18.440 So it's another example of to personify evolution a bit 0:11:18.840 --> 0:11:23.160 here and and personify genetic expression. The fleet, the water 0:11:23.160 --> 0:11:25.520 fleet body is saying, all right, it's a it's a 0:11:25.600 --> 0:11:29.120 bad world. Let's grow these spines, and then the offspring 0:11:29.160 --> 0:11:31.360 is gonna be born into what can only be presumed 0:11:31.360 --> 0:11:33.320 to be a bad environment as well, so it better 0:11:33.320 --> 0:11:35.400 have the spines right out of the gate. Yeah. So, 0:11:35.440 --> 0:11:38.199 I mean if La Mark was alive today, he would say, 0:11:38.200 --> 0:11:41.079 who's laughing? Now? Right? You know it's correct in some sense. 0:11:41.320 --> 0:11:42.880 All Right, we're gonna take a quick break, and when 0:11:42.880 --> 0:11:44.600 we get back, we're going to talk about some very 0:11:44.640 --> 0:11:49.040 cool examples of this in round worms and uh, mice 0:11:49.240 --> 0:11:58.679 and wrap Okay, we're back. Uh. We're talking about genetics. 0:11:58.720 --> 0:12:02.959 We're talking about an expression in a large sense. We're 0:12:02.960 --> 0:12:06.120 talking about nature and nurture and how these these different 0:12:07.080 --> 0:12:10.880 genetic factors in different environmental factors effect who and what 0:12:11.400 --> 0:12:14.720 an organism happens to be in life. So we're looking 0:12:14.720 --> 0:12:16.800 at animals in this episode. In the next episode we'll 0:12:16.800 --> 0:12:18.839 get into humans. We're talking about a lot of the 0:12:18.840 --> 0:12:22.079 different organisms that we experiment on and then we analyze 0:12:22.120 --> 0:12:25.080 and attempt to understand the genetics better. And this brings us, 0:12:25.080 --> 0:12:28.280 of course to the roundworm. Yeah. This, Uh, These roundworms 0:12:28.320 --> 0:12:31.320 are of great interest to researchers because it turns out 0:12:31.400 --> 0:12:35.000 that they have a built in immunity to viruses or 0:12:35.040 --> 0:12:38.880 whether they can cultivate this built in immunity. So researchers 0:12:39.080 --> 0:12:43.000 at Columbia University found that these roundworms were able to 0:12:43.040 --> 0:12:46.000 develop a resistance to a virus and then they were 0:12:46.040 --> 0:12:50.200 able to pass along that immunity for successive generations UM. 0:12:50.360 --> 0:12:54.080 According to an ION nine article, they do this through 0:12:54.400 --> 0:12:58.480 r in a interference or are in a I. And 0:12:58.600 --> 0:13:01.400 this process is used by cell to mute certain genes 0:13:01.520 --> 0:13:04.120 and is often used to beat back viruses and other 0:13:04.240 --> 0:13:06.680 threats to the genome. This is really cool. This is 0:13:06.720 --> 0:13:09.680 like a defense system right here, sitting outside your your genome. 0:13:10.320 --> 0:13:15.160 UM RNA I destroys messenger RNA or mr rna, which 0:13:15.200 --> 0:13:17.960 is really important here because that's what's needed to communicate 0:13:17.960 --> 0:13:22.640 with various genes. So without their mr NA, genes basically 0:13:22.679 --> 0:13:26.200 shut down and become inactive. Yeah. And it was particularly 0:13:26.200 --> 0:13:30.079 interesting with study UH two thousand eleven Columbia University study 0:13:30.840 --> 0:13:33.840 because they set it up so that the roundworms couldn't 0:13:33.840 --> 0:13:37.520 gain immunity in the Darwinian fashion like they had they 0:13:37.559 --> 0:13:40.720 had to do. It was it was Lamarck or nothing 0:13:41.480 --> 0:13:42.840 if this is gonna happen, and they did and they 0:13:42.880 --> 0:13:47.240 actually observed this transgenerational process. So what's really cool here 0:13:47.360 --> 0:13:50.600 is that the researchers found that even a hundred generations 0:13:50.679 --> 0:13:53.839 at the initial effects infection, the round worms still carried 0:13:53.880 --> 0:13:57.920 the immunity acquired by their distant ancestor. Yeah, hud. Now, 0:13:57.920 --> 0:14:00.640 granted a hundred generations is a little different and around 0:14:01.080 --> 0:14:03.640 than in a human but still you can definitely see 0:14:03.679 --> 0:14:08.400 the survival advantage in ensuring that subsequent generations benefit from 0:14:08.400 --> 0:14:13.559 the same protection against a viral enemy that's still out there. Well, 0:14:13.600 --> 0:14:16.319 and you can also see why researchers would be chumping 0:14:16.320 --> 0:14:17.960 at the bit to study this more because how could 0:14:17.960 --> 0:14:20.800 you gain this for humans? Right? What what sort of 0:14:20.800 --> 0:14:25.120 defense system could we UH create for ourselves if possible? 0:14:25.680 --> 0:14:28.480 So of course it leads to more tinkering there. Um. 0:14:28.680 --> 0:14:34.160 And speaking of tinkering and UH studies experiments, we will 0:14:34.200 --> 0:14:36.120 have to of course go back to mice. So, yeah, 0:14:36.160 --> 0:14:39.360 there was a tough University School of Medicine UH study 0:14:39.400 --> 0:14:41.200 in two thousand nine. And what they did is they 0:14:41.240 --> 0:14:44.560 took some mice that they genetically engineered to have memory problems, 0:14:45.120 --> 0:14:48.240 and then they raised them in U an enriched environment. 0:14:48.280 --> 0:14:53.120 So there's an environment full of toys and exercise social interaction. Um, 0:14:53.160 --> 0:14:55.120 you know, so like working at Google or something. For 0:14:55.160 --> 0:14:57.960 these four mice, UH and they did this for two 0:14:58.000 --> 0:15:01.280 weeks during the adolescence for the for these animals, and 0:15:01.280 --> 0:15:04.840 they found that the animal's memory improved. Uh. And granted 0:15:04.880 --> 0:15:07.360 this is expected to a certain degree because we know 0:15:07.480 --> 0:15:11.160 that enrichment has been shown to boost brain function. That's 0:15:11.160 --> 0:15:13.880 why you you want to enrich young children, you want 0:15:13.920 --> 0:15:16.840 to enrich the lives of indoor pats. I mean, it's 0:15:16.840 --> 0:15:19.640 it's it's what enrichment is about. That's why we seek 0:15:19.640 --> 0:15:22.640 out knowledge as we're doing right now, right um. But 0:15:22.800 --> 0:15:27.160 what they found specifically is that the memory gene here 0:15:27.560 --> 0:15:30.040 that carried the mutation is called r A, S, g 0:15:30.400 --> 0:15:33.440 r F are the genes that regulate a signaling pathway 0:15:33.640 --> 0:15:37.600 that's involved in brain cell communication. So that's what was 0:15:38.040 --> 0:15:41.800 improved here. But the coolest thing is that the next generation, 0:15:42.600 --> 0:15:44.920 even though they had this gene, they had this mutated gene, 0:15:45.040 --> 0:15:47.640 they had better memories. So again, what we saw here 0:15:47.680 --> 0:15:52.520 is that DNA methylation process occurring, dampening the gene for 0:15:52.560 --> 0:15:55.280 the next generation. So we're not going to keep a 0:15:55.360 --> 0:15:59.000 running score for the nature versus nurture battle, but this 0:15:59.040 --> 0:16:01.960 one would certainly be victory for for nurture. So yeah, 0:16:02.000 --> 0:16:05.760 TuS University neuroscientists. Larry five had said that a striking 0:16:05.800 --> 0:16:08.400 feature of the study is that enrichment took place during 0:16:08.560 --> 0:16:13.040 pre adolescents, months before the mice were even fertile, yet 0:16:13.160 --> 0:16:16.720 the effect reached into the next generation. So that was surprising. 0:16:16.760 --> 0:16:18.880 And we'll talk a little a bit about that more 0:16:19.080 --> 0:16:23.280 with humans. UM, but we know that when UM, when 0:16:23.320 --> 0:16:28.080 an organism is going through its prenatal period, that what 0:16:28.160 --> 0:16:30.680 the mother does can't affect it. But what this is 0:16:30.680 --> 0:16:34.400 telling us here is that even before the mice were 0:16:34.440 --> 0:16:37.680 able to reproduce, that was affecting the genes of their 0:16:37.720 --> 0:16:40.720 eventual offspring. Yeah. I mean it makes sense again when 0:16:40.720 --> 0:16:44.040 you've stripped down all of our human expectations of life 0:16:44.080 --> 0:16:46.360 and get down to the basic genetic mission of any 0:16:46.440 --> 0:16:49.360 organism to spread its genes and pass it onto offspring, 0:16:49.520 --> 0:16:51.440 like right out of the gate. That is what it 0:16:51.520 --> 0:16:53.880 is here on earth to do. So we look at 0:16:53.920 --> 0:16:57.320 another aspect here of memory, and this is called long 0:16:57.440 --> 0:16:59.520 term potential ation, and again we look at it in 0:16:59.560 --> 0:17:03.400 mice and Larry Fogg's team did a secondary study on this. 0:17:03.520 --> 0:17:06.199 The same research group looked at this. They wanted to 0:17:06.240 --> 0:17:10.840 look at LPT, long term potential ation LPT strengthens communication 0:17:10.880 --> 0:17:14.880 between neurons and it increases memory. So again they had 0:17:14.920 --> 0:17:20.320 mice with a genetically faulty LPT expression and these, uh, 0:17:20.359 --> 0:17:23.240 this LPT was essentially fixed again when they were put 0:17:23.359 --> 0:17:27.879 in an enriched environment. So of course, what do we 0:17:27.920 --> 0:17:31.639 see happen with offspring? They turned out better even and 0:17:31.680 --> 0:17:35.120 this is the crazy part. The puffs demonstrated this improved 0:17:35.160 --> 0:17:38.720 the same improvemental process even when they were raised by 0:17:38.920 --> 0:17:41.919 memory deficient mice that had never had any of the 0:17:42.000 --> 0:17:45.320 or these are rich enrichment benefits. So in this you 0:17:45.400 --> 0:17:47.840 kind of see a little bit of the like the 0:17:47.960 --> 0:17:51.919 victory maybe not of nature but of nurtured nature, so 0:17:52.000 --> 0:17:55.119 a little bit of both. Yeah, you're right, both of 0:17:55.200 --> 0:17:59.159 them are definitely entangled here. But again, the big news 0:17:59.200 --> 0:18:02.680 here is that, um that this gene was switched off 0:18:02.760 --> 0:18:06.080 and game fixed it in one generation through enrichment and 0:18:06.119 --> 0:18:09.960 then bad parenting in the next generation didn't just automatically 0:18:10.080 --> 0:18:12.680 turn it off. So it's it shows that it's a 0:18:12.680 --> 0:18:15.040 little more complicated than that and also a little more 0:18:15.080 --> 0:18:19.439 fool proof. Now yeah, now these are all touchy feely examples, right, 0:18:19.440 --> 0:18:22.680 because we're improving things. What what if you're a researcher, 0:18:22.760 --> 0:18:24.600 and you want to see the opposite. You want to 0:18:25.359 --> 0:18:29.480 see what happens when you have rats that are abused, UM, 0:18:29.640 --> 0:18:32.960 that are raised by stressed mothers that neglect and physically 0:18:32.960 --> 0:18:37.240 abuse their offspring. UM. What will those offspring show in 0:18:37.359 --> 0:18:43.000 their epigenetic modifications. Well, sadly showed that the the abused 0:18:43.000 --> 0:18:45.080 my screw to be poor mothers as well and appear 0:18:45.119 --> 0:18:47.840 to pass down the same epigenetic changes to their offspring, 0:18:48.359 --> 0:18:52.240 which you know closely mirrors sort of the expected cycles 0:18:52.280 --> 0:18:55.960 that one sees, you know, even in humans. Yeah, and 0:18:56.000 --> 0:19:00.000 the twist here too is that the offspring of the 0:19:00.080 --> 0:19:05.040 use of mothers was then raised by healthy mothers, and 0:19:05.160 --> 0:19:08.440 although that did help with some of some of their behavior, 0:19:09.040 --> 0:19:13.639 it didn't It did not dampen um the expression of 0:19:13.640 --> 0:19:18.199 that behavior as the other DNA effylation did and the 0:19:18.200 --> 0:19:21.600 other scene that we saw with mice. So it helped, 0:19:21.680 --> 0:19:24.200 but it did not fix it. Yeah, and it again 0:19:24.280 --> 0:19:28.240 underlines that we're talking about a complex interaction of nurture 0:19:28.240 --> 0:19:31.640 and nature. That it's it's not just oh well, nature 0:19:31.720 --> 0:19:32.959 is gonna went out in this case and they're just 0:19:32.960 --> 0:19:35.720 gonna went out in the other. It's epigenetics is is 0:19:35.760 --> 0:19:38.239 a little more involved, and I think that you know 0:19:38.359 --> 0:19:40.520 that's that's the idea that you carry away from this 0:19:40.640 --> 0:19:42.320 is that it's not just one or the other. It's 0:19:42.359 --> 0:19:46.280 not just nature versus nurture. It is definitely a nuance 0:19:46.320 --> 0:19:50.760 of both. But it's also not just Darwinian evolution versus 0:19:51.080 --> 0:19:55.640 Lamarchian evolution. These also work in tandem, because we're still 0:19:55.680 --> 0:19:59.920 living in a Darwinian world. We just have some Wamarki 0:20:00.040 --> 0:20:02.960 in expression. Yeah, there are various ways that our genes 0:20:03.000 --> 0:20:05.480 can be expressed in the final phenotype, and a lot 0:20:05.480 --> 0:20:08.359 of that is determined by environment, by the way we're 0:20:08.400 --> 0:20:11.520 brought up, by just whatever kind of situation that our 0:20:11.520 --> 0:20:15.000 bodies are and ourselves are put into. But of course this, 0:20:15.000 --> 0:20:17.719 this UH is all very exciting because what does this 0:20:17.840 --> 0:20:20.879 mean for humans When you have such stark examples in 0:20:21.040 --> 0:20:25.960 nature of the epigenome um and its ability to to 0:20:26.080 --> 0:20:29.960 be expressed differently in subsequent generations, what does that mean 0:20:30.000 --> 0:20:32.040 to us? Well, there are two ways to look at 0:20:32.080 --> 0:20:33.720 and we'll get into more of this in the next podcast. 0:20:33.760 --> 0:20:35.480 But on one hand, it does give you the option 0:20:35.520 --> 0:20:38.520 to freak out about every little thing in life in 0:20:38.840 --> 0:20:41.880 concerning your own upbringing. That you know that your your children, 0:20:42.520 --> 0:20:45.600 your children's children, you can really begin to to over 0:20:45.640 --> 0:20:48.480 analyze every little detail. Also, as we continue to map 0:20:48.520 --> 0:20:51.960 out the epigenome, it gives us an increased ability to 0:20:52.000 --> 0:20:55.439 potentially go in there and and adjust these settings uh 0:20:55.680 --> 0:20:59.359 as one potentially as one would the realism settings and 0:20:59.480 --> 0:21:03.840 flights and later instead of leaving it purely to environmental changes. Yeah, 0:21:03.920 --> 0:21:07.120 it's really cool is that the Human Epigenome Project UM 0:21:07.400 --> 0:21:10.040 just like the Human Genome Project. They are trying to 0:21:10.119 --> 0:21:13.280 map it UM. Now that the Genome Project has done 0:21:13.359 --> 0:21:17.080 in the and the ability to do that is is 0:21:17.280 --> 0:21:21.560 um much more within grasp. The epigenome should be done 0:21:21.720 --> 0:21:24.760 fairly soon, and the kinds of stories that will come 0:21:24.760 --> 0:21:27.680 out of that will be I think of a mind 0:21:27.760 --> 0:21:31.159 blowing quality once they sort of passed through everything that 0:21:31.240 --> 0:21:34.520 they can unravel and everything that unfolds, and begin to 0:21:34.600 --> 0:21:37.359 apply it to us. Yeah, and and figure out what 0:21:37.400 --> 0:21:39.000 they can turn on and what they can't turn off. 0:21:39.040 --> 0:21:41.280 I mean, who knows what's in there because I've I've 0:21:41.280 --> 0:21:46.600 read the examples of being able to um. It's it's 0:21:46.680 --> 0:21:48.479 like toy with chickens, so that they're a little more 0:21:48.560 --> 0:21:52.480 like dinosaurs just by tinkering around, what's various epigenetic changes? Um, 0:21:52.520 --> 0:21:55.280 you know, granted they're they're probably would not be able 0:21:55.320 --> 0:21:57.360 to go in and just suddenly make spines growing grow 0:21:57.400 --> 0:22:00.440 out of our backs. But but we have spoken a 0:22:00.520 --> 0:22:05.160 good bit about some of the the various physiological things 0:22:05.240 --> 0:22:09.160 that that humans have left behind in their evolution, and uh, 0:22:09.280 --> 0:22:11.080 and I can't help but wonder, like which of them 0:22:11.080 --> 0:22:13.440 are still there, like the whole um, like the spiny 0:22:13.440 --> 0:22:16.800 penis thing that we discussed, Yeah, is that still on 0:22:16.840 --> 0:22:19.879 the table? I don't know, have genetics answer the question? 0:22:19.920 --> 0:22:22.480 I hope. So now I'm just thinking of urban chicken 0:22:22.640 --> 0:22:27.080 chicken coops and cities with with different phenotypes express and 0:22:27.119 --> 0:22:29.119 it's sort of like dinosaur chickens running around. You have 0:22:29.160 --> 0:22:32.600 a little velocity raptor chickens. Yeah, that's the future, folks, 0:22:33.080 --> 0:22:36.800 wrap it up right there. Yeah, So definitely tune into 0:22:36.800 --> 0:22:38.840 the next episode because that's gonna be the one where 0:22:38.840 --> 0:22:42.600 we're gonna talk about some of the findings involving experiments 0:22:42.800 --> 0:22:47.520 about humans, about human epigenetics, how these various how these 0:22:47.560 --> 0:22:52.080 various environmental changes affect uh, the expression of of our 0:22:52.119 --> 0:22:54.960 of our genomes in the final phenotype. And we'll also 0:22:55.080 --> 0:22:57.879 do a little pondering to a little more a little 0:22:57.880 --> 0:23:00.800 more philosophical stuff there at the end of that pticular episode. 0:23:00.840 --> 0:23:03.120 So let's call the robot over here and uh get 0:23:03.160 --> 0:23:08.320