WEBVTT - Interview Interlude Playlist, Part 9: Carl Zimmer 0:00:03.040 --> 0:00:05.840 Welcome to Stuff to Blow your Mind from how Stuff 0:00:05.840 --> 0:00:14.120 Works dot com. Hey you welcome to Stuff to Blow 0:00:14.160 --> 0:00:16.920 your Mind. My name is Robert Lamb and I'm Joe McCormick. 0:00:16.960 --> 0:00:18.959 And boy do we have a treat for you today. 0:00:19.000 --> 0:00:22.279 That's right, we're we're chatting with Carl Zimmer about his 0:00:22.520 --> 0:00:26.840 new book, She Has Her Mother's Laugh, The Powers, Perversions 0:00:26.920 --> 0:00:30.840 and Potential of Heredity. This is a fantastic book. I 0:00:31.360 --> 0:00:33.280 I was trying to finish it before we talked to 0:00:33.360 --> 0:00:35.320 him today, and I was up till two am last 0:00:35.400 --> 0:00:37.640 night and getting to the very last page. But it 0:00:37.720 --> 0:00:40.080 was worth it. It is a great book. I really 0:00:40.159 --> 0:00:44.040 highly recommended. It's a brick that's just full of weird, 0:00:44.200 --> 0:00:47.559 interesting delights and insights about how our views of heredity 0:00:47.600 --> 0:00:50.000 have changed over the years, all of the good and 0:00:50.040 --> 0:00:52.680 all of the evil that that knowledge has been used for, 0:00:53.200 --> 0:00:56.680 and uh and also where it's going in the future. Yeah. Yeah, 0:00:56.720 --> 0:00:59.400 this it's a fascinating book. I also I got to 0:00:59.400 --> 0:01:02.800 see him in conversation with the Maria Knakova at World 0:01:02.800 --> 0:01:06.039 Science Festival this year, in which he talked about the 0:01:06.040 --> 0:01:08.119 themes in the book as well, so it was a 0:01:08.120 --> 0:01:10.200 real It's a real delight to have him here on 0:01:10.240 --> 0:01:12.280 the show. And if you want to check out She 0:01:12.360 --> 0:01:16.160 Has Her Mother's Laugh. It is available in hardback, digital 0:01:16.480 --> 0:01:19.160 and as an audio book. So, uh, we hope you 0:01:19.240 --> 0:01:22.280 enjoy our interview with him, but certainly go check out 0:01:22.319 --> 0:01:26.120 his book as well for just an in depth, riveting 0:01:26.200 --> 0:01:28.399 journey through heredity. Now, wait a minute, we should say 0:01:28.400 --> 0:01:30.319 who he is. I don't think we've done that if 0:01:30.319 --> 0:01:32.520 you're if you're not familiar with Carl Zimmer and Carl 0:01:32.880 --> 0:01:36.759 Carl Zimmer is a prolific, excellent science writer. He writes 0:01:36.760 --> 0:01:39.000 for the New York Times. I think I've also seen 0:01:39.000 --> 0:01:42.200 these articles in the Atlantic and National Geographic all over 0:01:42.240 --> 0:01:45.680 the place. Uh. He's written a lot about parasites and uh, 0:01:46.000 --> 0:01:48.600 some of the most interesting stuff in biology is is 0:01:48.680 --> 0:01:52.120 Karl's territory. And uh and I really had a good 0:01:52.160 --> 0:01:54.080 time talking to him today. Yeah. Some of his past 0:01:54.120 --> 0:01:57.720 books include Parasite, rex Evolution, The Triumph of an Idea, 0:01:57.840 --> 0:02:02.080 and Microcosm. So, without other ado, here's our conversation with 0:02:02.160 --> 0:02:06.800 Carl Zimmer. So, Carl, what led you to write a 0:02:06.800 --> 0:02:09.760 book about heredity? I guess in a way, I've been 0:02:09.800 --> 0:02:15.880 thinking about heredity for forever. Really. I mean, I when 0:02:15.880 --> 0:02:18.960 I was a kid, you know, I would uh think 0:02:19.000 --> 0:02:22.120 back on my ancestors that my parents told me about, 0:02:22.280 --> 0:02:25.120 and you know, I wonder, like, oh wow, if if 0:02:25.600 --> 0:02:29.040 you know, Roger Goodspeed had not sailed from England to 0:02:29.120 --> 0:02:33.520 Massachusetts in the sixteen thirties, would I ever exist? You know, 0:02:33.760 --> 0:02:38.120 those sorts of things. And then when I became a father, 0:02:38.600 --> 0:02:41.200 I've got two teenage girls now, and you know that 0:02:41.360 --> 0:02:48.120 immediately brought to bear just how urgent and mysterious heredity 0:02:48.200 --> 0:02:52.240 can be. Because now they're these two people walking around 0:02:52.280 --> 0:02:55.360 who have inherited a lot of my genes, and you 0:02:55.400 --> 0:02:58.560 know what, what is it that I'm giving them that 0:02:58.560 --> 0:03:03.320 that suddenly be the very pressing issue? And I guess 0:03:03.360 --> 0:03:06.600 what really then kind of crystallize it all for me 0:03:06.720 --> 0:03:08.440 was that in the past few years, I've been doing 0:03:08.520 --> 0:03:10.520 a lot of reporting from the New York Times and 0:03:10.600 --> 0:03:16.799 elsewhere about the real revolution happening in biology, allowing scientists 0:03:16.840 --> 0:03:22.560 to sequenced DNA, to rewrite DNA, and to also look 0:03:22.600 --> 0:03:27.880 at other kinds of biology that might help, uh create 0:03:27.960 --> 0:03:31.600 this thing that we call heredity. H And so it 0:03:31.720 --> 0:03:33.600 just it all kind of came together and I realized 0:03:33.639 --> 0:03:36.120 that this would be something that I really wanted to 0:03:36.120 --> 0:03:39.520 spend a couple of years really exploring deeply. So you 0:03:39.560 --> 0:03:43.160 mentioned the idea of the sort of personal curiosity about 0:03:43.160 --> 0:03:45.600 our ancestors, and you talk in the book about how 0:03:45.680 --> 0:03:49.240 we often do family genealogies to sort of learn something 0:03:49.280 --> 0:03:52.520 about ourselves, as if the seeds of who we are 0:03:52.560 --> 0:03:56.720 are somehow present in our really distant ancestors. But how 0:03:56.720 --> 0:03:59.840 many generations back do you have to go before those 0:04:00.120 --> 0:04:04.240 relationships with our ancestors really don't matter all that much 0:04:04.280 --> 0:04:08.280 in terms of genetic closeness. You know, you don't have 0:04:08.320 --> 0:04:10.280 to go back that far. And that just has to 0:04:10.320 --> 0:04:15.400 do with how parents passed down their DNA to their kids. 0:04:15.960 --> 0:04:18.800 You know, we each have two copies of each gene 0:04:18.839 --> 0:04:22.159 for the most part, but uh, you know, parents only 0:04:22.160 --> 0:04:26.840 passed down one copy of a given gene to each child, 0:04:27.640 --> 0:04:31.480 And so if you repeat that process generation after generation, 0:04:31.920 --> 0:04:34.760 there's a sort of a kind of a stochastic, kind 0:04:34.760 --> 0:04:39.559 of random process that will basically lead to you know, uh, 0:04:39.720 --> 0:04:43.200 some descendants not having any DNA at all from a 0:04:43.279 --> 0:04:46.840 particular ancestor. Um. There's only so much room in your 0:04:46.839 --> 0:04:50.200 genome and you can't pack in all the DNA from 0:04:50.240 --> 0:04:54.040 all your ancestors basically, and so geneticis have done some 0:04:54.120 --> 0:04:56.640 back of the envelope calculations and if you go back 0:04:56.720 --> 0:05:01.120 let's say ten generations, um, that would be like your 0:05:01.120 --> 0:05:05.640 ancestors in the sixteen hundreds. Uh, maybe only about half 0:05:05.680 --> 0:05:09.320 of them have a genetic link to you. The rest 0:05:09.440 --> 0:05:12.440 they're still your ancestors. But you cannot point to any 0:05:12.480 --> 0:05:14.400 piece of DNA in your genome and say, oh, I 0:05:14.480 --> 0:05:19.320 got that from from this particular person you know. So um, 0:05:19.440 --> 0:05:22.240 So I think that actually, like really shows how we 0:05:22.320 --> 0:05:26.920 have to, um think think bigger when it comes to heredity. 0:05:27.000 --> 0:05:31.320 It's not just some particular bit of DNA that that 0:05:31.760 --> 0:05:34.479 gives heredity its meaning. Well, on the other side of 0:05:34.520 --> 0:05:37.240 that coin, um, could you talk a little bit about 0:05:37.320 --> 0:05:41.200 what the Yale mathematician Joseph Chang discovered about human ancestry. 0:05:41.200 --> 0:05:42.800 It seems sort of like the flip side of what 0:05:42.839 --> 0:05:46.360 you're just talking about. Yeah, I mean, so, you know, 0:05:46.760 --> 0:05:51.080 so much about heredity is counterintuitive and almost you know, 0:05:52.200 --> 0:05:54.560 it seems to contradict itself, and that's in a way 0:05:54.600 --> 0:05:56.800 what makes it so fascinating. So I just told you 0:05:56.839 --> 0:05:59.240 about how if you go back a certain number of generations, 0:05:59.240 --> 0:06:02.520 you're gonna encounter their ancestors from whom you've inherited. No 0:06:02.760 --> 0:06:08.960 DNA at all. Um. But there's an interesting feature of 0:06:09.040 --> 0:06:15.240 human ancestry, which is that, um, you know, people uh, 0:06:15.360 --> 0:06:20.120 everybody today, Uh you know, it shares a common ancestor 0:06:20.240 --> 0:06:23.960 with some people who lived about five thousand years ago, 0:06:24.120 --> 0:06:28.640 roughly speaking in other words, UM, if you if you, 0:06:28.960 --> 0:06:31.040 it's just uh you can and you can figure this 0:06:31.080 --> 0:06:35.000 out as just Chang did, just by looking at genealogy 0:06:35.080 --> 0:06:38.440 is a mathematical problem. Um, just think of think of 0:06:38.520 --> 0:06:42.400 our genealogy is a kind of a branching network. Um. 0:06:42.600 --> 0:06:46.640 The thing is though that uh you know are if 0:06:46.680 --> 0:06:50.039 you think about your family tree, um, and you think, well, 0:06:50.120 --> 0:06:52.520 there's me, and then you branch off to your parents, 0:06:52.520 --> 0:06:54.840 and then they branch off to their parents and so 0:06:54.960 --> 0:06:57.520 on and so forth. Um. If you just keep branching 0:06:57.560 --> 0:07:00.839 in that simple way, you're gonna end, you know, a 0:07:00.880 --> 0:07:04.479 few thousand years back with more ancestors than there are 0:07:04.480 --> 0:07:06.920 people who have ever lived. You know, we're talking chillions 0:07:06.920 --> 0:07:10.400 of people. And that's absurd. So so that's actually not 0:07:10.520 --> 0:07:14.640 a realistic model of your ancestry. The fact is that 0:07:16.400 --> 0:07:22.480 your aunt all of you know, your parents are cousins 0:07:22.600 --> 0:07:25.000 now either that you know, in some cases first cousins 0:07:25.000 --> 0:07:27.280 get married, but in other cases they're very distant cousins. 0:07:27.320 --> 0:07:31.480 Another what that means is that your parents share an ancestor, 0:07:31.520 --> 0:07:34.760 a common ancestor somewhere in the past. It could be 0:07:34.920 --> 0:07:37.680 hundreds of thousands of years ago, but it doesn't matter. 0:07:37.720 --> 0:07:40.480 They have an ancestor. So what that does is it 0:07:40.680 --> 0:07:46.440 folds the family tree back in on itself. And what 0:07:46.560 --> 0:07:50.800 Joseph Chang realized was that that actually does something very 0:07:50.800 --> 0:07:52.960 interesting to human ancestry. What it means is that you 0:07:52.960 --> 0:07:55.480 do not have to go back very far to find 0:07:55.600 --> 0:07:59.960 somebody who is the common ancestor literally everyone on earth. 0:08:00.640 --> 0:08:03.040 Uh and uh, it's just in the past few thousand 0:08:03.120 --> 0:08:06.440 years that you could find people like that. Um. Now, 0:08:06.560 --> 0:08:10.960 of course you know those common ancestors, you know they 0:08:11.040 --> 0:08:14.800 for each of us that that's one person or a 0:08:14.800 --> 0:08:19.400 few people out of thousands upon thousands of ancestors. But 0:08:19.600 --> 0:08:22.240 it's something that ties us all together. And the irony 0:08:22.360 --> 0:08:26.960 is that you know, people are really uh uh really 0:08:26.960 --> 0:08:31.000 love to connect themselves to someone famous, you know, like, oh, 0:08:31.160 --> 0:08:33.400 did you know that I am descended from Lilliam the Conqueror. 0:08:34.559 --> 0:08:38.839 And the fact is that probably probably everybody of European 0:08:38.920 --> 0:08:43.160 descent is and is a descendant of William the Conqueror. 0:08:43.880 --> 0:08:50.240 Probably everybody of European descent is a descendant of Charlemagne Um. 0:08:50.559 --> 0:08:53.120 And you know, it's possible that everybody on earth is 0:08:53.160 --> 0:08:58.800 a descendant of you know, maybe Cleopatra. It's like, that's 0:08:58.840 --> 0:09:03.200 just the nature of human genealogy is that it's we're 0:09:03.240 --> 0:09:09.400 all descended from kings. That doesn't make anybody special. Well 0:09:09.400 --> 0:09:12.120 as as long as we're gazing backwards in time, here, 0:09:12.520 --> 0:09:16.760 can you tell us how ancient thinkers contemplated heredity? The 0:09:16.840 --> 0:09:20.120 weird thing is that they really didn't, and they at 0:09:20.160 --> 0:09:22.360 least they didn't think about heredity in the way that 0:09:22.480 --> 0:09:26.120 we do. Uh. You know that if you go back 0:09:26.160 --> 0:09:29.440 and you you look at what Hippocrates would say or 0:09:29.520 --> 0:09:33.960 Aristotle would say, Uh, this, this whole model of how 0:09:34.040 --> 0:09:39.040 we inherit something you know, microscopic and biological that that 0:09:39.160 --> 0:09:42.679 determines how we ended up the way we are just 0:09:42.760 --> 0:09:47.320 would not compute for them. And so you know, you know, 0:09:47.360 --> 0:09:50.000 someone like Aristotle would say, like, well, you know, the 0:09:50.040 --> 0:09:52.160 reason that one generation looks like the previous one is 0:09:52.200 --> 0:09:55.080 just because it's the same chemistry. Um, you know, of 0:09:55.120 --> 0:09:57.920 course you're going to be the uh, you're going to 0:09:58.000 --> 0:10:01.040 be the same because you know, it's the same set 0:10:01.040 --> 0:10:05.720 of processes that produced a person that produced you. So 0:10:05.800 --> 0:10:09.040 what's the big deal? And you know, the word heredity, 0:10:09.280 --> 0:10:11.040 you know, it's a very old word, but it only 0:10:11.080 --> 0:10:15.480 referred to basically inheriting stuff. Um, you know, and I'm 0:10:15.520 --> 0:10:19.040 talking not talking about jeans, I'm talking about houses. Uh, 0:10:19.080 --> 0:10:21.680 you know, farmland, things like that. You know, So in 0:10:21.679 --> 0:10:23.880 the Roman Empire, there are lots of rules about you know, 0:10:23.920 --> 0:10:26.079 who got to be an heir, and that's what the 0:10:26.120 --> 0:10:30.679 word meant at that point. And it's really fascinating, Like 0:10:30.920 --> 0:10:32.440 you have to you have to wait a long time 0:10:32.480 --> 0:10:35.040 before you start to even see the first glimmers of 0:10:35.040 --> 0:10:38.600 how we think about heredity today. Um. My favorite example 0:10:38.640 --> 0:10:43.280 is in the fifteen fifteen, around fifteen eighty, uh, Montana 0:10:43.400 --> 0:10:49.400 this this famous essays. He writes an essay about his 0:10:49.480 --> 0:10:53.200 father because Matennia now is is starting to get older 0:10:53.200 --> 0:10:56.160 and he's developing kidney stones, and it occurs to him 0:10:56.200 --> 0:10:59.640 that his father had kidney stones and around the same 0:10:59.679 --> 0:11:03.240 age and He basically writes Sussi saying, well, what is 0:11:03.320 --> 0:11:07.040 up with that? Now? Did I get these kids stones 0:11:07.120 --> 0:11:11.520 from my father? And like, if so, how because you know, 0:11:11.600 --> 0:11:13.360 when I was born, my father was young and he 0:11:13.360 --> 0:11:18.040 didn't have kidney stones, So what exactly went from him 0:11:18.080 --> 0:11:21.400 to me? Um? And you want to just you know, 0:11:21.440 --> 0:11:24.079 shout at the page like it's it's Janes, it's Jeans. 0:11:24.160 --> 0:11:27.040 But you know he can't hear you, you know, like 0:11:27.240 --> 0:11:32.959 he his question went fundamentally unanswered for centuries. Um And 0:11:33.000 --> 0:11:36.520 so yeah, so so uh, it's really need to look 0:11:36.559 --> 0:11:39.640 back and and see how. You know, the way we 0:11:39.720 --> 0:11:43.320 think is not how everyone always thought. You know, the 0:11:43.360 --> 0:11:47.200 way we think about heredity is is a product of 0:11:47.640 --> 0:11:50.800 really the modern age. So did the selective breeding of 0:11:50.840 --> 0:11:54.120 animals and plants inform classical and medieval thinkers at all 0:11:54.200 --> 0:11:57.080 about the possible nature of heredity, because it seems it's 0:11:57.160 --> 0:11:59.240 I mean, it's kind of seems like people such as 0:11:59.280 --> 0:12:02.400 Aristotle or Albertus Magnus would have would have looked at 0:12:02.400 --> 0:12:05.520 how we bred flowers, crops and farm animals more were, 0:12:05.520 --> 0:12:08.840 at least in addition to the influence of geography or experience, 0:12:09.640 --> 0:12:12.320 you would think, so I would I would have thought so. 0:12:12.440 --> 0:12:15.320 But I think that's because we are in the century 0:12:15.360 --> 0:12:17.320 and we look back and say, well, everyone must have 0:12:17.360 --> 0:12:20.559 thought the way we did. But there are actually, you know, 0:12:20.679 --> 0:12:23.960 whole books written, uh you know by Roman writers about 0:12:24.040 --> 0:12:27.920 farming for example, UM, and you can search them as 0:12:28.120 --> 0:12:30.319 I mean, I have sat down and look through these 0:12:30.360 --> 0:12:34.120 books for anything resembling what you're talking about, and it's 0:12:34.160 --> 0:12:37.360 just not there. They do not talk about, oh, well, 0:12:37.400 --> 0:12:41.960 there's some you know quality in this particular variety of 0:12:42.040 --> 0:12:45.800 olives that you know, if you if you if you 0:12:46.120 --> 0:12:49.880 bread it, it will pass it down to two future 0:12:49.880 --> 0:12:53.960 generations of olive trees. That this isn't there. Instead, they'll 0:12:53.960 --> 0:12:56.920 say like, well, make sure that you know you're you're 0:12:56.960 --> 0:12:59.880 growing it on good soil, make sure your your farm 0:13:00.120 --> 0:13:04.320 gets a good supply rain. It's all about the environment. 0:13:05.040 --> 0:13:09.000 And it isn't really until I would argue, it's not 0:13:09.080 --> 0:13:12.520 really until the seventeen hundreds that uh, you start to 0:13:12.559 --> 0:13:20.280 see these farmers, these livestock breeders really take interest in this, UM. 0:13:20.360 --> 0:13:24.920 And part of it is that these European countries are 0:13:24.960 --> 0:13:31.240 all um looking for ways to use science to uh 0:13:31.800 --> 0:13:36.000 make their countries wealthier. And you know, they're thinking, well, 0:13:36.040 --> 0:13:37.880 if we can, we can, if we can produce new 0:13:37.960 --> 0:13:44.080 varieties of animals implants, um, then we we will enrich ourselves. Uh. 0:13:44.120 --> 0:13:49.040 And there's this one breeder named Robert Bakewell who produces 0:13:49.080 --> 0:13:53.720 an entirely new breed of sheep just by starting to 0:13:53.760 --> 0:13:57.920 think about heredity, to think about which individuals those sheep 0:13:57.960 --> 0:14:00.880 is he gonna mate together? Is he gonna just only 0:14:00.920 --> 0:14:03.160 mate within his flock? Is he gonna go pick out 0:14:03.200 --> 0:14:06.480 other ones from other flocks to mate? Um? And lo 0:14:06.600 --> 0:14:09.320 and behold he produces this this very successful new breed. 0:14:09.360 --> 0:14:11.480 And you know, people like Charles Darwin look at that 0:14:11.559 --> 0:14:15.720 and say, what just happened? How did they do that? Um? 0:14:15.800 --> 0:14:19.840 And in Germany and in Central Europe there's a big 0:14:19.880 --> 0:14:22.960 push to do the same thing with sheep, to do 0:14:23.120 --> 0:14:26.240 that with crops as well, and uh and to try 0:14:26.280 --> 0:14:29.080 to understand what are these rules. And one of those 0:14:29.080 --> 0:14:31.520 people who's trying to understand those rules is none other 0:14:31.600 --> 0:14:36.200 than Gregor mendel Um. So his his breeding experiments, you know, 0:14:36.240 --> 0:14:40.360 the foundation of genetics comes out of this new push 0:14:40.480 --> 0:14:47.640 to try to use heredity to enrich nations. All Right, 0:14:47.680 --> 0:14:49.320 we're gonna take a quick break and then we're gonna 0:14:49.400 --> 0:14:54.960 jump right back into the interview and we're back. So 0:14:55.000 --> 0:14:58.880 at what point does the modern idea of heredity really emerge. Well, 0:14:58.880 --> 0:15:03.040 I'd say in the late eighteen hundreds, UM, people start 0:15:03.120 --> 0:15:07.840 to talk about heredity as a scientific question. And Charles 0:15:07.960 --> 0:15:11.160 Darwin is really important in all of this because, you know, 0:15:11.200 --> 0:15:13.560 he he comes up with the theory of evolution and 0:15:13.680 --> 0:15:17.680 it depends on heredity. In other words, Um, you know, 0:15:18.120 --> 0:15:20.920 the only way for natural selection to work is so 0:15:21.280 --> 0:15:25.240 if parents can pass down traits to their offspring to 0:15:25.280 --> 0:15:28.760 give them some advantage and surviving and reproducing. And so 0:15:28.840 --> 0:15:31.760 it's very obvious to Darwin that, you know that that 0:15:33.080 --> 0:15:36.280 heredity is this huge glaring question in the middle of 0:15:36.280 --> 0:15:38.480 his theory, and he and he works really hard to 0:15:38.520 --> 0:15:42.440 try to find out for himself how heredity works. And 0:15:42.520 --> 0:15:45.160 he's he's very aware of a lot of the research 0:15:45.240 --> 0:15:47.760 that's going on at the time, looking to the discovery 0:15:47.760 --> 0:15:50.360 of cells and the discovery that there are little things 0:15:50.400 --> 0:15:53.760 inside of cells, but no one's quite sure what they are. UM. 0:15:53.920 --> 0:15:57.600 And so he develops a theory that there are particles 0:15:57.600 --> 0:16:00.520 in the cells throughout our body that they somehow stream 0:16:00.760 --> 0:16:06.280 into the eggs and sperm and uh then become something 0:16:06.320 --> 0:16:09.880 like we the way we think of genes um. That 0:16:09.920 --> 0:16:13.680 doesn't pan out. You know, his cousin, Francis Galton, tries 0:16:13.920 --> 0:16:17.240 to test it by injecting blood from uh, you know, 0:16:18.080 --> 0:16:20.960 black rabbits into white rabbits, you know, different colored rabbits, 0:16:21.000 --> 0:16:23.400 and seeing if that changes the color of their offspring. 0:16:23.640 --> 0:16:28.040 Doesn't happen. Uh and uh So it's not really until 0:16:28.400 --> 0:16:35.680 after Darwin is dead that scientists start to really understand 0:16:35.800 --> 0:16:39.880 chromosomes and then rediscover mental and it all clicks together, 0:16:40.200 --> 0:16:43.680 and the science that they that they call genetics is 0:16:43.720 --> 0:16:49.400 born in nine uh and and you know, the it's 0:16:49.400 --> 0:16:51.400 really you can see how exciting it is for the 0:16:51.400 --> 0:16:54.200 scientists at the time. William Bateson, who coined the term genetics. 0:16:54.240 --> 0:16:57.320 He he writes at the time that you know, the 0:16:57.840 --> 0:17:01.120 science of heredity has been red illuctionized. You know that 0:17:01.440 --> 0:17:05.680 finally they feel like they can they can understand heredity 0:17:05.760 --> 0:17:08.879 um in its fundamental basis. So so how do we 0:17:08.920 --> 0:17:11.240 go from this point of of of just excitement and 0:17:11.280 --> 0:17:15.439 discovery and just fall so steeply into eugenics and then 0:17:15.520 --> 0:17:19.320 ultimately the horrors of the third Reich well, if you 0:17:20.200 --> 0:17:26.680 look back, the roots of eugenics UM go back pretty far. UM. 0:17:26.840 --> 0:17:31.480 You know. So Uh. On the one hand, uh, so 0:17:31.720 --> 0:17:36.800 our modern conception of race uh starts to develop as 0:17:36.840 --> 0:17:40.520 early as really the fifteen hundreds are the fourteen hundreds, 0:17:40.560 --> 0:17:46.040 even where in Spain, UH, Jews are are being considered 0:17:46.080 --> 0:17:52.240 a separate race of people, and and and noble families 0:17:52.320 --> 0:17:55.800 have to do have to draw out genealogies to prove 0:17:56.000 --> 0:17:59.560 that they don't have any Jews in their in their ancestry. Um. 0:17:59.680 --> 0:18:01.560 Other wise they you know, they won't be able to 0:18:01.600 --> 0:18:05.120 get that good job in government or so on. And 0:18:05.280 --> 0:18:08.240 so that starts to develop this idea that that groups 0:18:08.240 --> 0:18:11.439 of people are fundamentally different in some way that is 0:18:11.480 --> 0:18:16.120 carried on from one generation to the next. Um. Then uh, 0:18:16.160 --> 0:18:20.119 in the in the eighteen hundreds, you start to see, 0:18:20.520 --> 0:18:26.560 you know, a real concern about UM poverty and crime 0:18:27.240 --> 0:18:31.600 and and a lot of people start to to make 0:18:31.640 --> 0:18:35.400 claims that these are being carried down in certain families. 0:18:35.440 --> 0:18:37.560 You know, there are these bad families and why is 0:18:37.600 --> 0:18:39.639 it that one generation is just as bad as the 0:18:39.680 --> 0:18:43.040 previous one. And you know, people talk about some sort 0:18:43.080 --> 0:18:46.239 of hereditary curse that they must have and and then 0:18:46.320 --> 0:18:49.080 you know, how do we keep that curse from being propagated. 0:18:51.119 --> 0:18:54.960 And so then when genetics gets discovered, UM, a lot 0:18:55.040 --> 0:19:00.760 of actual genesis themselves and uh and other and others 0:19:00.800 --> 0:19:04.080 say well, aha, like here's here's the basis for what 0:19:04.119 --> 0:19:07.480 we've been talking about for decades now. UM. And you know, 0:19:07.520 --> 0:19:10.800 the word eugenics had actually been coined in eighteen eighties 0:19:10.840 --> 0:19:15.840 by Francis Coulton, Uh, Darwin's cousin, and he just thought, well, 0:19:15.880 --> 0:19:19.080 you know, if intelligence is inherited, then why don't we 0:19:19.119 --> 0:19:22.760 just essentially breed people away we breed sheep, So you 0:19:22.880 --> 0:19:26.199 just pick out the individuals who seemed to have you know, 0:19:26.240 --> 0:19:29.439 the most genius he would call it, and then encourage 0:19:29.480 --> 0:19:32.280 them to have lots of kids. And and he had 0:19:32.280 --> 0:19:35.720 these dreams that to produced what he called the galaxy 0:19:35.760 --> 0:19:39.760 of genius in the future. UM. But by the time 0:19:39.880 --> 0:19:44.200 that eugenics arrives in the United States and genetics emerges, 0:19:44.520 --> 0:19:47.480 it takes on a much darker cast because people say, well, 0:19:48.040 --> 0:19:51.480 what we really need to focus on is these people 0:19:51.560 --> 0:19:54.720 who have who we believe have genes that we don't like, 0:19:54.840 --> 0:19:57.800 and we want to prevent them from reproducing, because that's 0:19:57.800 --> 0:19:59.840 going to drag down our country, and so what are 0:19:59.840 --> 0:20:03.840 we to keep them from reproducing? And um that leads 0:20:03.920 --> 0:20:08.679 to sterilization and much worse. So in reading your chapter 0:20:08.720 --> 0:20:13.560 about Henry Goddard and the origins of the American eugenics movement, 0:20:14.240 --> 0:20:17.320 I'm struck that this is a potential example of the 0:20:17.400 --> 0:20:20.760 dangers of bad research, Like you draw a really disturbing 0:20:20.800 --> 0:20:25.600 picture of how but like sloppy or fraudulent work that 0:20:25.720 --> 0:20:29.720 became the basis of Henry Goddard's published writings on heredity 0:20:29.800 --> 0:20:32.440 can be viewed in some ways is contributing directly to 0:20:32.520 --> 0:20:35.760 real world consequences, like the horrors of for sterilization in 0:20:35.800 --> 0:20:39.159 the United States or mass murder in Europe. Do you 0:20:39.200 --> 0:20:43.200 ever think, when you see bad science or pseudoscience being 0:20:43.440 --> 0:20:46.800 being publicized today that it could ever lead to such 0:20:46.920 --> 0:20:51.400 nightmares that even its authors might not have imagined? Uh, 0:20:51.440 --> 0:20:55.160 you know, I don't. I think that we can't rule 0:20:55.240 --> 0:20:58.280 out those kinds of possibilities. I mean, it might be very, 0:20:58.359 --> 0:21:03.320 very unlikely, But if you look at history, you can 0:21:03.359 --> 0:21:08.840 see how bad science combined with existing prejudices lead to 0:21:09.040 --> 0:21:14.320 really horrific outcomes. And it wasn't that the science was 0:21:14.520 --> 0:21:23.160 somehow appropriated by the pseudo scientists or something. Uh. Eugenics 0:21:23.400 --> 0:21:28.680 was embraced by most of the leading um biologists of 0:21:28.760 --> 0:21:34.000 the time. UH and Uh, there were different forms of eugenics, 0:21:34.040 --> 0:21:37.000 you know. So some people were very much sort of concerned, 0:21:37.640 --> 0:21:41.800 were quite racist and you know, concerned about uh, you know, 0:21:41.840 --> 0:21:46.240 the white quote unquote race being you know, polluted by 0:21:46.359 --> 0:21:51.920 other races. Um. But then there were progressives who thought 0:21:51.960 --> 0:21:53.960 that this was going to be part of their grand 0:21:53.960 --> 0:21:59.399 plan for making society a better, fairer place. Um. And 0:21:59.440 --> 0:22:03.080 I think it's really important to look at these episodes 0:22:03.119 --> 0:22:07.159 in history to see how things go bad. Um. And 0:22:07.200 --> 0:22:10.399 I think it's I think it's arrogant for any of 0:22:10.480 --> 0:22:13.640 us to say, well, things like this could never happen again, 0:22:13.840 --> 0:22:16.960 you know, and somehow we're vaccinated from from these sorts 0:22:16.960 --> 0:22:19.520 of things. But we can draw lessons from the past, 0:22:19.560 --> 0:22:23.240 and we can see how, um, how humble we need 0:22:23.280 --> 0:22:28.000 to be in the face of complexity in in our 0:22:28.040 --> 0:22:31.520 own biology. You know. We you know, I think we're 0:22:31.520 --> 0:22:34.240 in like in another revolution, the way we were hundred 0:22:34.320 --> 0:22:36.879 years ago. You know, a hundred years ago, genetics itself 0:22:36.960 --> 0:22:40.280 was profoundly new, that gene was a new thing. Uh. 0:22:40.320 --> 0:22:43.600 Now we're at the point where we're looking at genomes, 0:22:43.680 --> 0:22:46.720 in other words, all the genes in our in our selves, 0:22:46.760 --> 0:22:49.040 and we can we can see them down to the 0:22:49.080 --> 0:22:52.760 atomic detail. Um, but there's still a vast amount we 0:22:52.760 --> 0:22:56.560 do not understand about it, and UM, you know, we 0:22:56.560 --> 0:23:01.720 we cannot let that be an opportunity to you. Uh 0:23:01.920 --> 0:23:07.040 you know, card out our old biases and prejudices and say, oh, 0:23:07.080 --> 0:23:09.800 I see now science backs up what I was saying 0:23:09.840 --> 0:23:14.639 all along about those other people. UM, we can't. We 0:23:14.680 --> 0:23:17.640 just we cannot let that happen. Again. I think that's 0:23:17.640 --> 0:23:20.280 a really good point. And I also think you can 0:23:20.320 --> 0:23:23.000 even look at it as there's a flip side to 0:23:23.040 --> 0:23:27.359 it where modern discoveries of genomics really complicated or in 0:23:27.440 --> 0:23:31.639 some sense is undermine what many people have traditionally understood 0:23:31.640 --> 0:23:35.000 as the concept of race within humans. Right. Yeah, So 0:23:35.240 --> 0:23:40.399 the scientific concept of race uh developed in the in 0:23:40.840 --> 0:23:44.880 the seventeen hundreds, and it was really um, very much 0:23:44.880 --> 0:23:49.719 spurred on by, uh by what Europe was doing at 0:23:49.760 --> 0:23:53.560 the time. So Europe was in the midst of building 0:23:53.600 --> 0:23:59.160 up huge colonies um and enslaving many many people. There 0:23:59.240 --> 0:24:02.240 was a need for serve legal and moral justifications for 0:24:02.359 --> 0:24:06.600 doing this, and a lot of it, uh was based 0:24:06.680 --> 0:24:10.879 on these concepts of race, so that for example, you know, 0:24:10.960 --> 0:24:15.160 Africans were were claimed to be a completely separate race 0:24:15.520 --> 0:24:21.000 uh that you know, had inherent uh inferiority to the 0:24:21.040 --> 0:24:24.879 white race. And so therefore slavery is okay. And you 0:24:24.920 --> 0:24:27.800 can see this again and again in in lots of 0:24:28.000 --> 0:24:32.919 lots of writing at the time. Uh. Now, even in 0:24:32.960 --> 0:24:38.280 the early nineteen hundreds, Um, there were there were indications 0:24:38.320 --> 0:24:43.040 that this kind that genetics was not aligning with these 0:24:43.080 --> 0:24:48.280 these uh old ideas about race, and they just weren't 0:24:48.359 --> 0:24:52.320 fitting neatly. Um. You it was very it was it 0:24:52.359 --> 0:24:56.720 was becoming harder and harder to draw any particularly bright 0:24:56.800 --> 0:25:01.159 line between groups of people. I mean, obviously people are different, uh. 0:25:01.240 --> 0:25:03.320 You know, there are lots of differences and people in 0:25:03.400 --> 0:25:06.320 terms of skin color and height and shapes of faces 0:25:06.400 --> 0:25:09.560 and culture and all the rest of it. But the 0:25:09.640 --> 0:25:14.119 genes were not supporting these old ideas about race. And 0:25:14.160 --> 0:25:16.879 by the midnighteteen hundreds of people, a lot of anthropologists 0:25:16.920 --> 0:25:20.240 and geneticisis were saying, you know, the word race is 0:25:21.480 --> 0:25:25.800 so burdened with so much that's terrible and immoral and 0:25:25.960 --> 0:25:29.000 has so little connection with the way we're starting to 0:25:29.040 --> 0:25:35.120 understand populations. Let's just get abandoned it. Um, that really 0:25:35.160 --> 0:25:39.760 hasn't that really didn't happen. But nevertheless, like now where 0:25:39.760 --> 0:25:43.159 we can look at the whole genomes. Um. Yeah, the 0:25:43.400 --> 0:25:46.520 whole thing with race now is is it just is 0:25:47.320 --> 0:25:49.520 it's a bit one. The way one genete has put 0:25:49.520 --> 0:25:52.320 it to me is like, well, you know, like talking 0:25:52.400 --> 0:25:54.880 for us, like talking about race is like the way 0:25:55.119 --> 0:25:59.800 Greeks talked about the you know, the four elements air, fire, water, earth, 0:26:00.119 --> 0:26:04.080 like you know it. You know, Aristotle could explain all 0:26:04.080 --> 0:26:07.920 sorts of things uh that way, and they seemed good 0:26:07.920 --> 0:26:10.480 to him. But you know, we know that there's things 0:26:10.520 --> 0:26:13.960 are much more complex than the four elements, and if 0:26:14.000 --> 0:26:16.560 you forced physicists to go back to the four elements, 0:26:16.560 --> 0:26:19.520 they'd be very unhappy. So Jenets they're saying like, please 0:26:19.520 --> 0:26:21.760 don't make us go back to you know, the genetic 0:26:21.800 --> 0:26:24.280 equivalent of the four elements. You know, we're you know, 0:26:24.320 --> 0:26:27.679 they're very interested in ancestry and how populations mixed together, 0:26:27.800 --> 0:26:29.800 how they become isolated, and all the rest of it. 0:26:30.280 --> 0:26:32.520 But these old ideas about race and on all the 0:26:32.520 --> 0:26:35.960 connotations of race they don't map onto it at all, 0:26:36.160 --> 0:26:38.360 so they just don't want to use it now. Of course, 0:26:38.400 --> 0:26:42.280 in addition to just the passing on of genetic information, UH, 0:26:42.560 --> 0:26:47.280 we also have epigenetics. And even as you explore the 0:26:47.320 --> 0:26:49.760 effects of the microbiome, can can you talk about how 0:26:49.800 --> 0:26:52.439 these have changed our definition of heredity? So in the 0:26:52.520 --> 0:26:57.119 eight hundreds, heredity becomes a scientific question. You know, what 0:26:57.359 --> 0:27:01.560 is it that makes one generation connected to the past? 0:27:01.680 --> 0:27:06.320 Why is it that generations resemble their forerunners? Um? What 0:27:06.320 --> 0:27:11.600 what are these connections? And Uh, genetics provided a huge 0:27:11.640 --> 0:27:14.280 part of that answer, which is that well, genes get 0:27:14.400 --> 0:27:19.320 copied and then transmitted through eggs and sperm and uh. 0:27:19.359 --> 0:27:21.919 And so that was a huge revolution and understanding. But 0:27:23.320 --> 0:27:29.439 that doesn't mean that that is all that heredity can be. 0:27:29.800 --> 0:27:33.080 I mean there's still the at least the logical possibility 0:27:33.200 --> 0:27:36.720 that there are other ways that each generation be can 0:27:36.760 --> 0:27:40.200 be connected to the to the previous ones. And so 0:27:40.280 --> 0:27:45.240 in my book I talk about different forms of heredity 0:27:45.320 --> 0:27:48.840 that scientists are exploring. UM and so you know, one 0:27:49.040 --> 0:27:53.200 one very exciting possibility is what you referred to as epigenetics. 0:27:53.880 --> 0:27:58.120 And epigenetics is kind of a broad term, but roughly speaking, 0:27:58.200 --> 0:28:02.520 what it refers to is the molecules inside our cells 0:28:02.560 --> 0:28:07.280 that control our genes. That that allows some genes to 0:28:07.560 --> 0:28:10.560 be switched on and to produce proteins and others that 0:28:10.600 --> 0:28:14.320 are kept silent um. And you know, it's it's very 0:28:14.320 --> 0:28:17.959 clear that this is incredibly important to our existence. You know, 0:28:18.000 --> 0:28:20.879 it's what makes your skin cells be skin cells, and 0:28:20.920 --> 0:28:24.240 you're you know, brain cells be brain cells, like they 0:28:24.240 --> 0:28:28.280 are using different genes in the same genome. And when 0:28:28.280 --> 0:28:31.960 these cells divide um the you know, a skin cell 0:28:32.000 --> 0:28:36.720 does not normally instantly become a neuron or or you 0:28:36.760 --> 0:28:38.920 know it doesn't you don't grow a tooth on your 0:28:38.960 --> 0:28:42.760 back of your hand um. And that has to do 0:28:42.800 --> 0:28:46.240 with epigenetics um. And so what does this have to 0:28:46.240 --> 0:28:49.440 do with heredity. Well, you know, when those cells divide, 0:28:49.480 --> 0:28:53.720 they are basically inheriting the genes and the epigenetics of 0:28:53.880 --> 0:28:57.920 their mother cell. But you know that the possibility arises, well, 0:28:57.920 --> 0:29:00.000 what if you pass those down to the next general 0:29:00.000 --> 0:29:03.760 ation altogether, you know, through eggs and sperm um. And 0:29:03.800 --> 0:29:06.840 there's some evidence that that that can happen. And what 0:29:07.320 --> 0:29:11.200 makes it especially exciting is that you know, through our lives, 0:29:11.760 --> 0:29:18.760 experiences can change the epigenetic makeup of ourselves. You know, 0:29:18.840 --> 0:29:21.240 so if you if you get sick, if you smoke, 0:29:21.440 --> 0:29:25.560 if you experience stress, those all seem to have an influence. 0:29:25.880 --> 0:29:29.360 And so the open question is, well, how much can 0:29:29.440 --> 0:29:35.040 those experiences we have in our lives then influence future generations? UM. 0:29:35.160 --> 0:29:37.640 I think that the jury is still very much out 0:29:37.680 --> 0:29:41.120 when it comes to people. UM, But in other species, 0:29:41.200 --> 0:29:44.280 especially plants, there's lots of evidence that that really is 0:29:44.280 --> 0:29:46.040 something that happens. You know, a plant goes through a 0:29:46.120 --> 0:29:50.080 drought and generations later there's still an epigenetic mark on 0:29:50.120 --> 0:29:54.640 its descendants. So yeah, epigenetics is in a really exciting area. 0:29:54.920 --> 0:29:58.240 So you just alluded to some of the controversy about epigenetics, 0:29:58.280 --> 0:30:00.480 and I guess there are other forms of ideas of 0:30:00.720 --> 0:30:06.600 non genetic inheritance, but epigenetics in some ways still remains controversial, 0:30:06.680 --> 0:30:10.760 especially in humans. Like you're talking about, if you're comfortable 0:30:10.760 --> 0:30:13.360 speculating and if you had to guess, how would you 0:30:13.400 --> 0:30:17.240 imagine our picture of non genetic inheritance might change over 0:30:17.240 --> 0:30:20.080 the next fifty years or so, what's your sense? You know, 0:30:20.200 --> 0:30:22.960 I think that it is actually possible that we'll just 0:30:23.040 --> 0:30:27.680 find that UM. Human epigenetics is just not really that important. 0:30:27.920 --> 0:30:30.959 I mean, I'm actually I think there's reason to be 0:30:31.040 --> 0:30:33.920 kind of pessimistic. Um that you know, there are these 0:30:34.040 --> 0:30:37.640 very cantalizing studies, but they're small and they could just 0:30:37.720 --> 0:30:40.680 be the result of noise and so on, and and 0:30:40.760 --> 0:30:45.280 yet you know, we really want epigenetics to be real. Um. 0:30:45.320 --> 0:30:50.120 I mean, epigenetics has totally taken hold of the popular consciousness. 0:30:50.280 --> 0:30:54.280 And you know, I was astonished to learn not long 0:30:54.280 --> 0:30:59.360 ago that you can take classes and epigenetic yoga, which 0:31:00.000 --> 0:31:03.000 not kidding, you can google it. And the thinking is, 0:31:03.120 --> 0:31:06.160 the claim is that you know that by doing this 0:31:06.240 --> 0:31:10.600 yoga you change the epigenetic profile of yourselves and I 0:31:10.600 --> 0:31:13.920 and you know there are psych psychiatrists who will offer 0:31:13.960 --> 0:31:18.920 you epigenetic analysis to basically undo the trauma that you 0:31:19.000 --> 0:31:23.080 inherited from past generations. Um. It really speaks to us 0:31:23.080 --> 0:31:25.960 in a very profound way. But I actually don't think 0:31:26.000 --> 0:31:30.080 that science is going to really hold up very well. Um, 0:31:30.120 --> 0:31:32.800 because are but I don't think it looks like our 0:31:32.800 --> 0:31:35.800 biology just doesn't really allow that to make much of 0:31:35.800 --> 0:31:40.680 a difference. But you know, the flip side is that culture, 0:31:41.160 --> 0:31:45.200 um is actually I I would argue an incredibly important 0:31:45.200 --> 0:31:49.760 form of fredity, especially for our species. We we pass 0:31:49.840 --> 0:31:53.240 down not just our genes to the next generation, but 0:31:54.040 --> 0:31:57.800 all of our knowledge and and beliefs and customs and 0:31:57.840 --> 0:32:01.040 so on, and those those get pell down through the 0:32:01.080 --> 0:32:07.280 generations UM in a very hereditary way and UM, and 0:32:07.320 --> 0:32:10.760 that's actually very different from other species. And I would 0:32:10.920 --> 0:32:14.000 and you know, in the book, I talked about how 0:32:15.360 --> 0:32:18.680 you could argue that civilization itself is the product of 0:32:18.680 --> 0:32:22.200 our very special form of cultural inheritance. So in talking 0:32:22.200 --> 0:32:25.960 about non genetic inheritance, you've got potentially epigenetics, though the 0:32:26.040 --> 0:32:29.560 juries out on that, You've got, you've got culture. But 0:32:30.040 --> 0:32:32.680 we should talk a little bit about microbiology. Can you 0:32:32.720 --> 0:32:35.040 tell the story of how you found out that your 0:32:35.040 --> 0:32:38.240 belly button contained bacteria only known to exist in the 0:32:38.240 --> 0:32:45.320 Mariana Trench? Absolutely? Yeah. So I've been incredibly fascinated by 0:32:45.320 --> 0:32:48.280 the microbiome, you know, all the bacteria that live on 0:32:48.400 --> 0:32:51.720 us and in us for quite some time and and 0:32:51.920 --> 0:32:54.720 I have been doing some reporting on it as scientists 0:32:54.760 --> 0:32:59.720 have found new ways to to explore our microbiome. And 0:33:00.400 --> 0:33:03.880 it used to be that you just have to scrape, 0:33:04.640 --> 0:33:07.800 you know some you know a little bit of skin, 0:33:08.080 --> 0:33:11.280 or take a stool sample and taken into a lab 0:33:11.320 --> 0:33:15.080 and try to grow bacteria. And the fact is that 0:33:15.200 --> 0:33:17.840 very few of the bacteria that live on us uh 0:33:18.160 --> 0:33:22.040 or in US enjoy being in a petri dish on 0:33:22.080 --> 0:33:24.239 their own. It just it makes them miserable and they 0:33:24.240 --> 0:33:29.120 don't grow. So we had a very impoverished view of 0:33:29.560 --> 0:33:34.760 this inner world until scientists were able to just say, Okay, 0:33:34.920 --> 0:33:37.760 we're going to grow into this sample and just grab 0:33:37.760 --> 0:33:39.760 out all the DNA and we're gonna sequence all the 0:33:39.840 --> 0:33:42.240 DNA and from that we're going to figure out what 0:33:42.360 --> 0:33:45.720 is in there. And that totally revolution. I studied the 0:33:45.760 --> 0:33:48.600 microbiome because now you didn't have to grow these critters. 0:33:48.600 --> 0:33:52.080 You could just fish out their DNA and look at that. 0:33:53.000 --> 0:33:55.400 So it turns out we have hundreds, maybe thousands of 0:33:55.440 --> 0:33:58.160 species in our guts and on our skin and so 0:33:58.320 --> 0:34:01.479 on and um and so you know, one day at 0:34:01.480 --> 0:34:04.920 a meeting, UM I was walking past a scientist who 0:34:05.000 --> 0:34:08.000 was holding out a qute tip and he said, I'm 0:34:08.000 --> 0:34:11.040 doing a study on people's belly buttons. Would you mind 0:34:11.040 --> 0:34:13.600 giving me some of your belly button lint? Belly button lint, 0:34:13.880 --> 0:34:17.200 and I want to see what's in there, you know, 0:34:17.280 --> 0:34:19.759 and for someone like me, you don't have to ask 0:34:19.760 --> 0:34:21.719 me twice. I'm like, give me that cute tip. So 0:34:21.840 --> 0:34:23.759 you know, I go off into the bathroom and I 0:34:23.840 --> 0:34:25.920 you know, fiddle around and don't get in a little 0:34:25.960 --> 0:34:28.799 tube that they gave me and handed it back, and 0:34:28.840 --> 0:34:30.920 then they went off and they looked at all the 0:34:31.040 --> 0:34:34.560 DNA there was on that cute tip, and you know, 0:34:34.600 --> 0:34:36.440 a lot of it was my own skin cells, but 0:34:36.480 --> 0:34:38.680 then a whole lot of it was not um. And 0:34:38.719 --> 0:34:43.400 actually they identified fifty three species as I recall of 0:34:43.640 --> 0:34:48.600 bacteria just in my belly button, and uh, it was 0:34:48.719 --> 0:34:53.560 amazing to to look at, uh, the information about each 0:34:53.600 --> 0:34:58.359 of those species. And so one of them it's had 0:34:58.400 --> 0:35:01.800 only there's only no own from a sample at the 0:35:01.840 --> 0:35:04.560 bottom of the ocean. They marry on a trench um. 0:35:04.680 --> 0:35:07.879 And there's another one that I have that's only been 0:35:07.920 --> 0:35:12.520 found in soil in Japan. I've never been to Japan, 0:35:12.800 --> 0:35:17.279 so um. But you know, this was entirely unsurprising to 0:35:17.320 --> 0:35:21.279 this scientist, because you know, he was looking at lots 0:35:21.320 --> 0:35:23.759 of people and was finding people with you know, over 0:35:23.800 --> 0:35:26.239 a hundred species just in their belly button alone, and 0:35:26.600 --> 0:35:29.239 from all sorts of different places. Um. So what does 0:35:29.280 --> 0:35:32.680 this have to do with heredity? Well, you know, I 0:35:32.880 --> 0:35:36.960 I did not inherit that marry on a trench bacteria 0:35:37.080 --> 0:35:40.319 from my parents. UM. It's just you know, we have 0:35:40.560 --> 0:35:44.160 all of this, these these bacteria in the environment um, 0:35:44.280 --> 0:35:47.319 and some of them have become very well adapted to 0:35:48.440 --> 0:35:51.480 living on our bodies. Um, and we just picked them 0:35:51.600 --> 0:35:56.239 up um through our life. But it does seem like 0:35:56.440 --> 0:36:01.200 that the microbiome UM, that there is some heredity to it. UM. 0:36:01.239 --> 0:36:05.960 The best examples come from certain animals like that passed 0:36:06.040 --> 0:36:10.279 down bacteria to their offspring. Then these bacteria can only 0:36:10.320 --> 0:36:14.200 live inside these animals, and without those bacteria, these animals die. 0:36:14.760 --> 0:36:17.080 The cockroaches are actually a great example of this. So 0:36:17.600 --> 0:36:20.239 you know, one reason that cockroaches are so successful is 0:36:20.239 --> 0:36:23.800 because they harbor one species of bacteria in a special 0:36:23.800 --> 0:36:26.759 little organ um where it breaks down some of their 0:36:26.800 --> 0:36:30.359 food and gives them nutrients. Um. And these bacteria never 0:36:30.440 --> 0:36:35.160 live outside of the cockroaches, and actually they're they're sitting 0:36:35.200 --> 0:36:38.400 inside of cockroach cells. And then in the female cockroaches, 0:36:38.480 --> 0:36:42.640 those cells crawl over to an egg and rip open, 0:36:42.680 --> 0:36:46.560 and then the bacteria infect the eggs so that cockroaches 0:36:46.600 --> 0:36:51.560 are born completely infected with these bacteria. That's that to 0:36:51.680 --> 0:36:54.960 me just seems that's heredity. I mean, these bacteria are 0:36:55.040 --> 0:36:58.520 being passed down from millions of years from parents to offspring. 0:36:58.960 --> 0:37:01.600 Um so the US and now as well. Are is 0:37:01.640 --> 0:37:06.239 that true for humans? Um? Maybe not, uh, you know, 0:37:06.360 --> 0:37:09.040 in that particular way, but um, you know, it is 0:37:09.080 --> 0:37:11.279 possible that there are a lot of species that are 0:37:11.400 --> 0:37:14.839 very much adapted to us. You know, maybe mothers are 0:37:14.840 --> 0:37:17.640 passing down certain kinds of bacteria in the birth canal 0:37:17.840 --> 0:37:22.480 or during breastfeeding. Um. And maybe the most dramatic example 0:37:22.520 --> 0:37:25.600 of all is that in all of ourselves we generate 0:37:25.640 --> 0:37:28.960 fuel with these little blobs called mitochondria, which have their 0:37:28.960 --> 0:37:32.080 own DNA in them. And the reason they have their 0:37:32.080 --> 0:37:36.399 own DNA is because they started out as bacteria and 0:37:36.960 --> 0:37:39.600 about two billion years ago and our single celled ancestors, 0:37:39.600 --> 0:37:43.960 those bacteria infected our ancestors and then took up permanent 0:37:44.000 --> 0:37:47.520 residence in there and we cannot live without them today. 0:37:48.200 --> 0:37:52.280 So um so, so MicroB is gonna have a very 0:37:52.320 --> 0:37:57.120 powerful part in heredity. Do you think our expanding consciousness 0:37:57.160 --> 0:38:00.879 about the full scope of heredity from like generation into 0:38:00.960 --> 0:38:06.600 symbiance or even to camerism should force us to re 0:38:06.760 --> 0:38:10.040 examine our ideas about what it means to be an individual, 0:38:10.080 --> 0:38:14.320 an individual animal, and what the biological and categorical boundaries 0:38:14.360 --> 0:38:18.120 of the self really are. Absolutely, uh, you know, I 0:38:18.160 --> 0:38:24.200 think that uh, you know, heredity does not actually follow 0:38:24.800 --> 0:38:28.400 a lot of the simple rules that we assume. It does, uh, 0:38:28.719 --> 0:38:32.239 and it and it does bring into question what it 0:38:32.320 --> 0:38:36.799 means to be an individual because you know, we think 0:38:36.840 --> 0:38:42.680 of he started out with some original genome in a 0:38:42.760 --> 0:38:45.800 fertilized egg, so we inherited half of that genome for 0:38:45.880 --> 0:38:48.319 me to our parents. It came together in this new 0:38:48.360 --> 0:38:54.160 combination and that's us. But you know that is not 0:38:54.320 --> 0:38:58.600 actually us um, and in lots of different ways. So 0:38:58.640 --> 0:39:00.840 in one way, I mean, if you actually follow the 0:39:01.600 --> 0:39:06.560 cells that divide in an embryo, those cells can mutate 0:39:07.480 --> 0:39:10.120 and then utate again and mutate again, so that if 0:39:10.160 --> 0:39:13.279 you were to look at, say, any two neurons in 0:39:13.280 --> 0:39:16.400 your brain, they would be different from each other because 0:39:16.480 --> 0:39:22.239 they have acquired different mutations as we developed. UM. So 0:39:22.400 --> 0:39:25.960 there is no one genome in our body because we 0:39:26.040 --> 0:39:30.920 are what scientists say call us our mosaics. UM. But 0:39:31.000 --> 0:39:34.960 then that's not the not the end of it. UM. 0:39:35.239 --> 0:39:37.800 So you know, we think of heredity is going down 0:39:38.239 --> 0:39:42.040 through the generations, but heredity can also come back up 0:39:42.200 --> 0:39:47.399 in reverse. Uh. And so one example of this is 0:39:48.040 --> 0:39:53.880 um when women become pregnant, UH, cells from their fetus 0:39:53.920 --> 0:39:58.160 will circulate around in their blood. You can actually you 0:39:58.160 --> 0:40:01.439 can actually draw blood from a pre new woman and 0:40:01.560 --> 0:40:06.080 sequence the genome of the fetus. Uh we that is 0:40:06.080 --> 0:40:12.120 done on a regular basis. Now uh after pregnancy, uh, 0:40:12.200 --> 0:40:15.239 those fetal cells may go away because of the mother's 0:40:15.280 --> 0:40:20.359 immune system is clearing them out. But surprisingly often uh 0:40:20.400 --> 0:40:25.400 those cells can establish themselves in a mother's liver, syroid, gland, 0:40:25.480 --> 0:40:30.920 even her brain. And scientists refer to uh such people 0:40:31.040 --> 0:40:35.000 as chimeras. Um it's after the you know, the beast 0:40:35.080 --> 0:40:39.799 of Greek mythology. And you can get chimeras also from 0:40:40.440 --> 0:40:46.399 twins in the womb who are sharing DNA sharing cells uh. 0:40:46.440 --> 0:40:50.560 And so you can literally like have um. You know 0:40:50.640 --> 0:40:52.759 that one of the first discoveries of this was a 0:40:52.800 --> 0:40:59.080 woman who gave blood in the nineteen fifties and totally 0:40:59.120 --> 0:41:02.439 baffled uh the blood bank because she was giving two 0:41:02.440 --> 0:41:04.959 types of blood at the same time. And he said, 0:41:05.200 --> 0:41:07.600 this is not possible, you know, there must be some 0:41:07.760 --> 0:41:11.040 contamination somewhere. But it turned out that her blood was 0:41:11.120 --> 0:41:15.080 made up from two individuals, herself and a twin who 0:41:15.120 --> 0:41:19.840 had died when he was in infancy. Uh. And so 0:41:20.200 --> 0:41:23.239 you know, and this is not something that's rare. Timerism 0:41:23.320 --> 0:41:26.120 is probably quite common among humans, and it really challenges 0:41:26.200 --> 0:41:30.240 these these ideas that we we tell ourselves about heredity 0:41:30.360 --> 0:41:34.239 and individuality. One of the weirdest and most interesting types 0:41:34.280 --> 0:41:36.320 of heredity you discussed in the book is that, I 0:41:36.360 --> 0:41:38.960 think you said of it's eight or so lines of 0:41:39.080 --> 0:41:43.120 contagious cancer found in nature so far. Can you talk 0:41:43.160 --> 0:41:46.520 a little bit about contagious cancer and does it make 0:41:46.560 --> 0:41:50.280 sense to think of this cancer as an independent animal 0:41:50.400 --> 0:41:52.600 or organism of its own type, or as sort of 0:41:52.640 --> 0:41:57.440 an infection from an original animals genome. Yeah, this is 0:41:57.440 --> 0:42:02.080 where heredity gets really weird because us, you know, when 0:42:03.840 --> 0:42:08.479 when cancer arises in our bodies, it's a it's another 0:42:08.520 --> 0:42:12.719 one of these cases of mosaicism. In other words, Uh, 0:42:12.760 --> 0:42:15.920 these cancer cells are gaining mutations that the rest of 0:42:16.040 --> 0:42:19.960 the body doesn't have, and those mutations allows them to 0:42:20.040 --> 0:42:27.839 reproduce quickly and to be very aggressive and destructive. Now, Um, 0:42:28.040 --> 0:42:33.520 cancer usually uh, you know, either is wiped out by 0:42:33.600 --> 0:42:37.839 the body or is lethal. In either case, you don't 0:42:37.840 --> 0:42:43.400 have cancer surviving beyond the life of its host. We 0:42:43.400 --> 0:42:47.080 we think of that as being weird, but it turns 0:42:47.080 --> 0:42:52.359 out that in fact cancer can endure um And this 0:42:52.640 --> 0:42:58.200 was really first discovered um in in a uh in 0:42:58.239 --> 0:43:03.360 a case with dogs where dogs would be uh developing 0:43:03.640 --> 0:43:07.640 um these these tumors uh. And it was very odd 0:43:07.719 --> 0:43:12.280 that they the cancer seemed to spread like an infectious disease, 0:43:12.320 --> 0:43:15.359 and so people scratching their head over this, and then 0:43:15.400 --> 0:43:19.000 they realized that actually what had happened was that the 0:43:19.120 --> 0:43:22.720 cancer cells themselves were spreading from one dog to another 0:43:22.760 --> 0:43:25.799 to another UM and so that the cancer cells were 0:43:25.840 --> 0:43:28.040 not in fact related to the dogs that they were in. 0:43:28.760 --> 0:43:33.080 And if you look at the DNA of this cancer, 0:43:34.040 --> 0:43:36.239 it goes back to some dog that lived maybe ten 0:43:36.280 --> 0:43:40.160 thousand years ago, and it has just been spreading from 0:43:40.200 --> 0:43:44.440 dog to dog ever since, and it's been mutating along 0:43:44.440 --> 0:43:47.439 the way. And it's and so it's the thing that 0:43:47.600 --> 0:43:50.040 you know, it's it's what do you call it? I mean, 0:43:50.080 --> 0:43:53.120 I don't know what we could call it, but you know, 0:43:53.160 --> 0:43:55.560 some have argued that it should be just given its 0:43:55.600 --> 0:44:00.520 own species name because it's it's this, it's this lineage 0:44:00.520 --> 0:44:03.400 of animal cells that has its own genome UM, and 0:44:03.480 --> 0:44:05.440 has its own way of getting around in the world. 0:44:05.600 --> 0:44:09.760 It's it's doing just fine. UM. So surely it deserves 0:44:09.800 --> 0:44:11.880 the name UM. And then it turns out that in 0:44:11.960 --> 0:44:14.719 a few other cases scientists have found another species, so 0:44:14.800 --> 0:44:20.120 Tasmanian devils in Tasmania, they get a facial tumor because 0:44:20.160 --> 0:44:23.800 they bite each other when they're fighting, and they spread 0:44:23.800 --> 0:44:27.440 this cancer to each other. UM. And this this cancer 0:44:27.440 --> 0:44:29.840 has actually arisen a couple of times in Tasmania just 0:44:29.880 --> 0:44:35.080 in recent decades, so it isn't something that only happened 0:44:35.120 --> 0:44:38.800 once a long time ago. And what's most mind blowing 0:44:38.880 --> 0:44:41.520 is that some scientists stumbles across this yet again, just 0:44:41.560 --> 0:44:46.240 in the past few years uh in clams, in shellfish UH, 0:44:46.280 --> 0:44:51.440 and have discovered that there there's contagious cancer in the ocean. UM. 0:44:51.680 --> 0:44:54.440 So you're swimming. As you're swimming in the ocean, you're 0:44:54.440 --> 0:44:58.000 swimming around cancer cells that are moving from host to host. 0:44:58.560 --> 0:45:01.279 An infectious cancer as its own type of organism. What 0:45:01.400 --> 0:45:06.560 kingdom of life would that be? Would it be an animal? I? Yes, 0:45:06.600 --> 0:45:09.840 it would be an animal simply because it's descended from animals. Yeah, 0:45:09.880 --> 0:45:12.320 I mean I would say they would have to be given, 0:45:12.520 --> 0:45:15.200 you know, a place in the animal kingdom. But and 0:45:15.360 --> 0:45:17.560 you know, maybe you should just still call it like 0:45:17.600 --> 0:45:20.360 a species of you know, maybe the dog cancer should 0:45:20.360 --> 0:45:25.239 be a species of dog. Maybe you know, cana is 0:45:25.320 --> 0:45:27.879 cancer or something. I don't know. I don't know, um, 0:45:28.600 --> 0:45:32.799 but you know it's and you know, when when and 0:45:32.880 --> 0:45:35.320 when you talk about or what makes up an animal, 0:45:35.520 --> 0:45:38.600 you know, like, uh, what makes up up us? You know, 0:45:38.719 --> 0:45:41.000 like we think of cancer cells as being part of ourselves. 0:45:41.080 --> 0:45:45.120 They they originate from our own selves. But um, imagine 0:45:45.120 --> 0:45:48.000 if your body was actually made up of your own 0:45:48.040 --> 0:45:51.760 cells and then cells that came from someone ten thousand 0:45:51.840 --> 0:45:56.560 years ago, that that would be weird. Yeah, alright, time 0:45:56.560 --> 0:45:58.760 for a quick break. Then we will be right back 0:45:58.960 --> 0:46:03.960 for more of our versation with Carl zimmer Than. All right, 0:46:04.000 --> 0:46:07.200 we're back now. We can't talk about the future of 0:46:07.200 --> 0:46:11.880 heredity without touching on Crisper. How is this technology affecting 0:46:11.920 --> 0:46:15.640 the future of human redity? Well, you know, we're going 0:46:15.680 --> 0:46:19.640 to have to wait and see exactly what happens, but 0:46:20.239 --> 0:46:25.839 certainly the potential is profound um. Crisper is just a 0:46:25.840 --> 0:46:29.600 few years old, and it's this is this technology essentially 0:46:29.640 --> 0:46:33.319 to zero in on any particular bit of DNA, cut 0:46:33.360 --> 0:46:38.200 it out, and if you want, insert a different little 0:46:38.200 --> 0:46:42.000 stretch of DNA in there. So um, this raises the 0:46:42.080 --> 0:46:47.560 possibility of being able to cure hereditary diseases by rewriting uh, 0:46:47.800 --> 0:46:51.200 the DNA in cells, you know, to repair a faulty gene. 0:46:52.680 --> 0:46:55.719 But what some scientists have been already exploring is, well, 0:46:55.719 --> 0:46:59.600 what if you take human embryonic cells. What if you 0:46:59.640 --> 0:47:02.120 take you know, human embryos are just a tiny little 0:47:02.160 --> 0:47:06.680 cluster just you know, seven or eight cells, and you 0:47:06.800 --> 0:47:11.160 use Crisper to rewrite their DNA. UM, let's say you 0:47:11.200 --> 0:47:14.719 fix a hereditary disease in just this handful of just 0:47:14.800 --> 0:47:18.560 as few cells. Well that if if you if that 0:47:18.840 --> 0:47:21.880 if a person were to develop from those cells, they 0:47:21.880 --> 0:47:25.680 they would have Crisper altered genes throughout their whole body, 0:47:26.080 --> 0:47:28.560 and if they were to have children, they would pass 0:47:28.640 --> 0:47:34.440 on those Crisper altered genes as well. And so you 0:47:34.480 --> 0:47:40.880 know that that that these experiments have already begun on 0:47:40.880 --> 0:47:44.799 on these tiny little human embryos, and so really, you 0:47:44.840 --> 0:47:48.000 know what what needs to happen now is for us 0:47:48.040 --> 0:47:53.920 to have a really a kind of global conversation about 0:47:54.320 --> 0:47:57.360 whether we want to use this or not, whether it's safe, 0:47:57.360 --> 0:48:01.879 whether it's ethical. UM, how do we feel about who 0:48:01.880 --> 0:48:04.920 should have access to this? UM? Do we have the 0:48:05.040 --> 0:48:11.279 right to alter future generations? Um? And you know we 0:48:12.000 --> 0:48:16.920 and maybe we'll feel comfortable with, say, you know, eradicating 0:48:17.000 --> 0:48:20.960 Huntings disease. But what if somebody says, well, yeah, but 0:48:21.040 --> 0:48:23.080 I want I'm using IVF and I want to just 0:48:23.320 --> 0:48:26.920 give my kids, Uh, this mutation that we know reduces 0:48:27.000 --> 0:48:29.760 your odds of getting Alzheimer's? Could I do that as well? 0:48:30.640 --> 0:48:33.280 And then you know what if you add on other things? 0:48:33.320 --> 0:48:35.319 What if you add on things that are not don't 0:48:35.320 --> 0:48:39.280 have to do with immediately treating some ready to disorder, 0:48:39.360 --> 0:48:42.960 but you know, change a trait, change, hair color, change, height, change, 0:48:42.960 --> 0:48:45.640 all these things are are people are going to be 0:48:45.680 --> 0:48:49.640 comfortable with that? UM? And this all you know this 0:48:50.040 --> 0:48:54.200 science fiction writers have had a monopoly on this conversation 0:48:54.320 --> 0:48:57.000 until now, but I think that everybody else needs to 0:48:57.000 --> 0:48:59.960 be talking about it too. Now. As far as crisper 0:49:00.120 --> 0:49:05.600 altered genes go, given like a near future scenario, would 0:49:05.640 --> 0:49:07.879 they be detectable. What would somebody be able to say 0:49:08.400 --> 0:49:10.839 to to look at individual's genome and say, oh, well 0:49:10.920 --> 0:49:14.040 you've had there's gene altering evidence here. Or would a 0:49:14.480 --> 0:49:17.960 future civilization be able to look back at our genetic 0:49:18.000 --> 0:49:20.440 information and say, oh, well look here in this particular 0:49:20.520 --> 0:49:24.560 family line, we see evidence of of of of crisper alteration. 0:49:25.120 --> 0:49:29.399 That's an interesting question. Um, I think you would. I 0:49:29.480 --> 0:49:34.240 think that it would be possible if the people doing 0:49:34.280 --> 0:49:39.840 the crisper changing um left behind, you know, a mark 0:49:40.120 --> 0:49:42.479 of what they were doing, you know, a little water mark. 0:49:42.719 --> 0:49:46.320 Think of it that way. You know, some distinctive sequence 0:49:46.400 --> 0:49:50.640 of non coding DNA nearby that basically says hello, you know, 0:49:50.920 --> 0:49:55.120 this is this, this crisper alteration has brought to you 0:49:55.200 --> 0:49:59.120 courtesy of such and such hospital. You know, Um, you 0:49:59.160 --> 0:50:02.000 could totally code a message in DNA people. You know, 0:50:02.000 --> 0:50:05.600 people have enquoted entire books in DNA. Now, so you 0:50:05.600 --> 0:50:10.280 could do that. Um, But if you if somebody decided 0:50:10.320 --> 0:50:12.759 not to leave a water mark, then no, Actually, I 0:50:13.040 --> 0:50:17.560 think it might be very difficult to UM to say, oh, well, 0:50:17.600 --> 0:50:23.040 this person descends from a crispered ancestor knowing knowing tech 0:50:23.120 --> 0:50:25.080 companies I know we'd end up with like thirty page 0:50:25.160 --> 0:50:28.520 ELA agreements in there. Sure, absolutely, But you know the 0:50:28.520 --> 0:50:30.840 problem is that you know that over the generations they 0:50:30.840 --> 0:50:34.640 would get that agreement would mutate, and uh, you know, 0:50:35.880 --> 0:50:38.520 the legal language would would change into things that the 0:50:38.560 --> 0:50:42.640 lawyers didn't have in mind. So, given the great power 0:50:42.920 --> 0:50:47.760 that Crisper has to to allow us to alter our genes, 0:50:48.239 --> 0:50:50.759 what what do you think are the best ideas you've 0:50:50.760 --> 0:50:55.160 heard about how to guide it in a way that's 0:50:55.200 --> 0:50:59.200 that's fair, that's going to have good outcomes and not 0:50:59.360 --> 0:51:02.680 bad it. Uh, you know, the people have access to 0:51:03.080 --> 0:51:06.920 in in equitable ways. I mean, have you encountered anybody 0:51:06.960 --> 0:51:09.640 who has done the best what you would consider the 0:51:09.680 --> 0:51:12.880 best thinking so far on the ethics of gene alteration? 0:51:13.200 --> 0:51:15.840 You know, I I in the United States, the government 0:51:15.920 --> 0:51:21.920 is really just being very uh emphatic and not wanting 0:51:21.960 --> 0:51:25.880 to really talk about these issues at all. So uh, 0:51:25.960 --> 0:51:29.359 you know, not only is it not allowed to do 0:51:29.560 --> 0:51:32.640 germ line modification, but you can't do any research that 0:51:32.719 --> 0:51:37.400 might lead to that, and so um, we're not really 0:51:37.440 --> 0:51:42.080 having a meaningful conversation in the United States yet, I think, um, 0:51:42.480 --> 0:51:47.439 and uh, Unfortunately, what that means is that people are 0:51:47.480 --> 0:51:51.439 going to want to go to other countries where there 0:51:51.600 --> 0:51:55.440 is no particular regulation one or the other and do 0:51:55.520 --> 0:51:59.920 that in you know, in um, in you know clinic 0:52:00.040 --> 0:52:03.120 sort of on that are hidden from view. UM. And 0:52:03.160 --> 0:52:05.440 in my book I talk about one case where actually 0:52:05.560 --> 0:52:09.080 this has already happened. UM. A couple went to Mexico 0:52:09.760 --> 0:52:14.400 and an American doctor joined them there to uh to 0:52:14.520 --> 0:52:20.000 basically replace the mitochondria in this woman's eggs with with healthy, 0:52:20.040 --> 0:52:24.120 healthy ones. UM. So you know there are some genetically 0:52:24.120 --> 0:52:28.799 modified people alive today. UM. There there are a few, UM, 0:52:28.920 --> 0:52:35.080 but they're they're already here. UM. But they I think 0:52:35.200 --> 0:52:38.120 that it's a better, better way to deal with this 0:52:38.280 --> 0:52:42.960 is what England is doing. So in England this treatment 0:52:42.960 --> 0:52:47.480 called mitochondrial replacement therapy. UM. There was there was a 0:52:47.480 --> 0:52:50.239 lot of research that was done on it, UM and 0:52:51.400 --> 0:52:55.440 using animals, using using you know eggs, human eggs and 0:52:55.480 --> 0:52:59.719 so on and then UM and then Parliament actually had 0:52:59.719 --> 0:53:03.840 a big full debate about it and you know, the 0:53:03.880 --> 0:53:07.080 advantages and the possible risks and the ethics and so on, 0:53:07.680 --> 0:53:09.960 and then they decided, well we're going to allow this 0:53:10.040 --> 0:53:13.080 to happen, but it's going to happen under these rules. 0:53:14.080 --> 0:53:17.120 So you know, you can't just like walk into any 0:53:17.200 --> 0:53:19.719 doctor's office and get this therapy like that. You know, 0:53:19.760 --> 0:53:23.719 we're gonna really make really uh take We're gonna take 0:53:23.760 --> 0:53:26.640 real care to make sure that this has done safely 0:53:26.840 --> 0:53:30.719 and responsibly and under the right circumstances. And so now 0:53:30.760 --> 0:53:33.800 there is a university that has actually you know, gotten 0:53:33.800 --> 0:53:37.880 permission to basically open their doors for business. UM. And 0:53:37.920 --> 0:53:41.480 I think that's the way to go UM, because then 0:53:41.600 --> 0:53:43.920 you can you can have these discussions and say, like, 0:53:43.960 --> 0:53:48.320 you know what, as a society, we don't want uh 0:53:48.520 --> 0:53:51.640 people to be trying to make their kids more intelligent 0:53:51.640 --> 0:53:54.280 by altering their genes. We think that's a that's bad 0:53:54.400 --> 0:53:56.680 for individuals and bad for society. We're not going to 0:53:56.719 --> 0:54:00.879 allow it. UM, And that will actually happen rather than 0:54:00.920 --> 0:54:04.360 sending people to other countries to have you know, possibly 0:54:04.440 --> 0:54:08.600 dangerous treatments. UM. That's the way I think UH things 0:54:08.600 --> 0:54:11.839 should go. UM. And you can see an example of 0:54:11.880 --> 0:54:14.480 it in England, And it would be great if if 0:54:14.520 --> 0:54:17.279 the United States could follow suit. You know, on this 0:54:17.320 --> 0:54:20.320 show a lot we talked about how often like science 0:54:20.360 --> 0:54:23.319 fiction is sort of the playground for people working out 0:54:23.360 --> 0:54:26.400 these problems before they're dealt with in the real world. 0:54:26.560 --> 0:54:30.359 Have you encountered any any science fiction or fiction in 0:54:30.400 --> 0:54:33.720 general that you thought did a good job of dealing 0:54:33.800 --> 0:54:37.879 with you know, raised the interesting questions, had intelligent things 0:54:37.920 --> 0:54:41.440 to say about the implications of genetic engineering and humans. 0:54:41.640 --> 0:54:45.600 Oh yeah, I think that there's a long tradition of 0:54:46.760 --> 0:54:52.120 genetic engineering in science fiction. Um and uh and even 0:54:52.160 --> 0:54:55.279 before people really knew what genetic engineering was. You know, 0:54:55.360 --> 0:54:59.239 Brave New World is a fascinating book even now. I mean, 0:54:59.280 --> 0:55:03.520 and it's amazing think when you think how um, how 0:55:03.640 --> 0:55:10.239 much uh uh was just only discovered after the publication 0:55:10.280 --> 0:55:15.759 of the book. Um and I it's I find that 0:55:15.800 --> 0:55:19.000 one quite quite prophetic. I think the problem with science 0:55:19.000 --> 0:55:23.880 fiction comes when people think that anything can happen. That 0:55:24.239 --> 0:55:29.400 when people think that biology allows anything you can imagine 0:55:29.480 --> 0:55:33.600 to be a possibility. Um and the fact is that 0:55:34.239 --> 0:55:37.320 biology doesn't work that way. And so you know, when 0:55:37.360 --> 0:55:41.600 when we're actually talking, you know, today about well, what 0:55:41.640 --> 0:55:48.799 are the real possibilities that Crisper could create, I think 0:55:48.800 --> 0:55:51.040 we need to sort of I think we need to 0:55:51.040 --> 0:55:53.719 make sure that we're not um, just letting our fantasies 0:55:53.800 --> 0:55:56.439 run wild. You know, some people have said like, oh, well, 0:55:56.480 --> 0:56:00.240 you'll just be able to um Cristoper your kid and 0:56:00.760 --> 0:56:05.320 turn them into a genius. Um, and that it's not 0:56:05.800 --> 0:56:09.920 what science indicates. I mean, you know, intelligence is this 0:56:10.200 --> 0:56:15.480 incredibly complex phenomenon that is, you know, influenced by genes, 0:56:15.560 --> 0:56:19.120 it's influenced by the environment. It's partly a social thing, 0:56:19.280 --> 0:56:22.040 you know, in terms of like you know, intelligence really 0:56:22.200 --> 0:56:26.000 sort of gaining its meaning in you know, in a society. UM. 0:56:26.280 --> 0:56:30.040 And you can't just zoom in on a on a 0:56:30.080 --> 0:56:32.080 few genes and make a tweak here and there and 0:56:32.120 --> 0:56:34.480 say ah ha, like now my child is going to 0:56:35.080 --> 0:56:37.400 you know, get into the very best colleges. It just 0:56:37.640 --> 0:56:41.239 does not work that way. Um. And and I think 0:56:41.360 --> 0:56:47.040 that if people just go ahead with it anyway, UM, 0:56:47.080 --> 0:56:50.600 those children are going to be born, um, not just 0:56:50.719 --> 0:56:53.960 with these odd little changes to their genes, but with 0:56:54.040 --> 0:56:57.960 a whole huge set of expectations um from their parents. 0:56:58.120 --> 0:57:00.279 You know, I spent a hundred thousand dollar. There's a 0:57:00.400 --> 0:57:03.200 change your genes to make you a genius? And why 0:57:03.239 --> 0:57:06.799 are you getting these grades and math? What's what's wrong 0:57:06.880 --> 0:57:10.399 with you? I just see a That's where I see 0:57:10.400 --> 0:57:14.719 the real dystopia emerging is just expecting heredity to do 0:57:14.840 --> 0:57:18.360 much more than it can possibly do, uh to to 0:57:18.480 --> 0:57:21.960 alter ourselves. That's really interesting and it raises another question 0:57:22.040 --> 0:57:24.760 that definitely comes up in the book, which is that 0:57:24.880 --> 0:57:28.160 even when we're talking about traits that are to some 0:57:28.360 --> 0:57:31.560 large extent heritable, what are some of the reasons that 0:57:31.640 --> 0:57:34.440 it can create misunderstandings for us to talk about there 0:57:34.480 --> 0:57:38.400 being quote a gene for a certain trait. Yeah, we 0:57:38.480 --> 0:57:42.280 really have come to look at genes as being all 0:57:42.320 --> 0:57:47.040 powerful and and that is a real mistake and it's 0:57:47.880 --> 0:57:51.440 but it's hard to really, um get your head around 0:57:51.480 --> 0:57:56.960 the paradox of heredity in this regard um. And one 0:57:56.960 --> 0:57:58.880 of the examples I like to talk about is height. 0:57:59.640 --> 0:58:01.600 You know how it seems like it's simple, like it's 0:58:01.640 --> 0:58:04.920 just just a number that you get off a tape measure, 0:58:05.160 --> 0:58:08.400 Like how hard could that be to understand? But you know, 0:58:08.480 --> 0:58:13.280 in in fact, um, you know, heredity is this very 0:58:13.320 --> 0:58:17.720 weird mix of genes in the environment. Um, you know 0:58:17.840 --> 0:58:21.080 gene so height is is very what scientists say are 0:58:21.360 --> 0:58:25.320 very heritable, meaning that if you look at the variation 0:58:25.960 --> 0:58:30.040 among people in a particular population, why are they tall? 0:58:30.080 --> 0:58:33.480 Why they're short. Uh. You can explain a lot of 0:58:33.480 --> 0:58:36.240 that because of the genes that they inherited from their parents. 0:58:37.040 --> 0:58:40.600 So tall parents tend to have tall children. Short parents 0:58:40.600 --> 0:58:43.200 tend to have short children. And it's so that means 0:58:43.200 --> 0:58:46.880 it's very heritable. UM. But that does not mean that, 0:58:47.400 --> 0:58:51.480 you know, height is somehow um locked in and fixed that. 0:58:51.760 --> 0:58:54.440 It does not mean that you can actually, you know, 0:58:54.640 --> 0:58:58.439 finally predict um the you know, how tall it could 0:58:58.440 --> 0:59:01.280 will be just based on their gene. In fact, we 0:59:01.280 --> 0:59:04.040 didn't even know about any of these genes until the 0:59:04.080 --> 0:59:08.000 past decade or so. Uh. And now scientists are discovering 0:59:08.240 --> 0:59:11.400 literally thousands of genes that influence height, each one in 0:59:11.440 --> 0:59:14.120 a tiny little bit. You know, I got my genome 0:59:14.160 --> 0:59:18.040 sequence and discovered you know that I had very interested 0:59:18.120 --> 0:59:20.640 to find that at one particular gene was the first 0:59:20.680 --> 0:59:25.520 gene that was ever linked to height in population. And 0:59:26.440 --> 0:59:28.680 I'm I'm about an eighth of an inch taller than 0:59:28.720 --> 0:59:30.800 it would be otherwise because of the variant that I have. 0:59:31.560 --> 0:59:36.280 So you know, it's it's almost invisible. UM. But you know, 0:59:36.360 --> 0:59:39.880 the genetic influence just is the sum of all of 0:59:39.920 --> 0:59:43.320 these different variants. Um. And yet on top of all 0:59:43.360 --> 0:59:46.160 of that. UM. You know, you can have, you know, 0:59:46.240 --> 0:59:49.400 all the tall genes you want, but if you're not 0:59:49.600 --> 0:59:51.960 getting a good diet when you're a kid, and if 0:59:52.000 --> 0:59:55.520 you're facing dysentery on a regular basis, you're just not 0:59:55.560 --> 0:59:57.600 going to grow that tall because your body is going 0:59:57.680 --> 1:00:03.480 to be basically channeling all those resources to fighting disease 1:00:03.560 --> 1:00:08.280 and to you know, fight defend against starvation. And you know, 1:00:08.320 --> 1:00:10.760 on top of that, even more amazing to me is 1:00:10.840 --> 1:00:13.520 that in the whole world has actually gotten several inches 1:00:13.600 --> 1:00:17.480 taller over the past century because life overall is better. 1:00:17.680 --> 1:00:21.480 You know, there's more people have a better nutrition, better medicine. 1:00:21.840 --> 1:00:25.400 UM education probably plays a role in this. Uh. And 1:00:25.600 --> 1:00:30.400 so it's not that people inherited you know, quote unquote 1:00:30.440 --> 1:00:34.880 tall genes, it's that they inherited a world that favors 1:00:35.320 --> 1:00:38.200 greater height. So I've got one last question that might 1:00:38.240 --> 1:00:40.800 be kind of weird, but we'll see what you think 1:00:40.840 --> 1:00:44.840 of it. I often hear hear people talking about UM 1:00:44.880 --> 1:00:48.640 their relationship with their own genome, UM with their own 1:00:48.680 --> 1:00:53.560 genes in two basic ways. One is self identification. You know, 1:00:53.600 --> 1:00:56.640 it's like my genes are why I am like X. 1:00:56.680 --> 1:00:59.200 And so there there's a sort of I identify with 1:00:59.240 --> 1:01:01.640 my genes and lady. And then there's a kind of 1:01:01.800 --> 1:01:05.680 antagonistic kind of thing people think about with their genes, 1:01:05.760 --> 1:01:10.120 like the genes are this other disembodied force that made 1:01:10.160 --> 1:01:13.080 them and it's almost like another person that they have 1:01:13.120 --> 1:01:16.480 to negotiate with in some way. To what extent do you, 1:01:17.800 --> 1:01:20.280 given all of the research you've done and after having 1:01:20.280 --> 1:01:23.479 written this book, to what extent do you feel you 1:01:23.520 --> 1:01:26.800 are your genes or that your genes are this separate 1:01:26.880 --> 1:01:30.840 other force from you as a person. That's interesting. I yeah, 1:01:30.920 --> 1:01:34.200 I've heard that kind of language too, you know. And 1:01:34.320 --> 1:01:37.520 people will get their DNA sequenced and they'll discover they 1:01:37.520 --> 1:01:41.640 have a particular variant linked to some trade and say, ah, 1:01:41.680 --> 1:01:45.400 well that's why I do X Y Z or or 1:01:45.440 --> 1:01:49.760 they'll discover they have ancestry from a particular place and say, ah, well, 1:01:49.800 --> 1:01:52.960 that's why that's why I like to tell stories, or 1:01:53.040 --> 1:01:55.520 that's why I like to run, or what have you. 1:01:55.760 --> 1:01:58.160 Um And you know, you see ads on TV for 1:01:58.240 --> 1:02:00.960 these companies like ancestry dot Com that play on that 1:02:01.160 --> 1:02:05.840 exact attitude towards our genes that somehow, you know, what 1:02:05.880 --> 1:02:08.560 we do in our lives is encapsulated in these genes 1:02:08.560 --> 1:02:12.120 that we inherit from our ancestors. Um. And then yeah, 1:02:12.120 --> 1:02:14.800 then there are people who just want to fight against it, um, 1:02:14.840 --> 1:02:17.680 you know, and part of that sometimes feels like, you know, 1:02:17.760 --> 1:02:19.760 it's it's sort of a displaced fight they're having with 1:02:19.800 --> 1:02:22.560 their parents, you know, Like I'm not gonna be like 1:02:22.640 --> 1:02:24.880 you were, you know, and I don't care if I 1:02:24.920 --> 1:02:28.600 inherited genes from you. I'm going to be my own person, um, 1:02:28.680 --> 1:02:31.720 I would say, in my own experience. UM. You know, 1:02:32.120 --> 1:02:34.840 I got my genome sequence and part of the research 1:02:34.880 --> 1:02:37.640 for this book, and I really looked at it very deeply. 1:02:37.680 --> 1:02:41.520 It's been a fascinating experience. But I can't find anything 1:02:41.560 --> 1:02:47.600 in there that is quote unquote me. I think that 1:02:48.600 --> 1:02:51.840 it's just not there, you know. I I was able 1:02:51.880 --> 1:02:54.440 to look at the genes that I inherited from neandertals, 1:02:54.640 --> 1:02:56.800 you know, tens of thousands of years ago, and you know, 1:02:57.400 --> 1:03:00.400 which is fascinating. But then I say to these scientists, Okay, 1:03:00.480 --> 1:03:02.520 you've given me this catalog, got the indertal genes, let's 1:03:02.560 --> 1:03:04.440 talk about them, Like, what what does it mean that 1:03:04.480 --> 1:03:07.480 I inherit this particult? Like, here's one gene tell me 1:03:07.520 --> 1:03:11.120 about it and the sciences to be like, well, it 1:03:11.160 --> 1:03:13.439 looks like no one actually knows what this gene does 1:03:14.080 --> 1:03:16.400 at all, you know, and then that you're just sort 1:03:16.440 --> 1:03:18.560 of left there. But with the state of the science, 1:03:18.680 --> 1:03:20.960 you know, maybe I found that I have in the 1:03:20.960 --> 1:03:25.120 andertal gene that UM is linked to an increased risk 1:03:25.160 --> 1:03:29.520 of nose bleeds. I don't know. I don't know what 1:03:29.600 --> 1:03:31.640 to do with that, you know, And I it also 1:03:31.640 --> 1:03:34.160 makes me wonder why the inertals might have nosebleeds. But 1:03:34.200 --> 1:03:38.120 that's a whole separate issue. But you know, I I 1:03:38.120 --> 1:03:41.520 I don't I. I can't say that anything I've done 1:03:42.080 --> 1:03:44.440 looking at my own d d n A has given 1:03:44.480 --> 1:03:48.640 me some deep insight about my inner self as a person, 1:03:48.880 --> 1:03:52.560 you know, as it's much more relevant to me to 1:03:52.640 --> 1:03:56.960 think about, you know, how my parents raised me and 1:03:57.040 --> 1:03:59.520 what my experiences were as a kid, and what it 1:03:59.520 --> 1:04:02.400 has been lie you know, being married and and and 1:04:02.520 --> 1:04:06.560 being a father, like, the lived experience matters much more 1:04:06.640 --> 1:04:10.560 to me than UM than the details of the genome 1:04:10.600 --> 1:04:15.160 I inherited from my parents. UM. And that's that's kind 1:04:15.200 --> 1:04:19.120 of where where it stands for me now, all right, Yeah, well, 1:04:19.280 --> 1:04:21.040 well thank you so much, Carl. It's been a real 1:04:21.120 --> 1:04:23.960 pleasure talking to you today and we appreciate you taking 1:04:23.960 --> 1:04:26.480 time to speak with us. My pleasure, my pleasure. I 1:04:26.520 --> 1:04:28.919 really enjoyed the conversation and I'm glad you enjoyed the book. 1:04:32.560 --> 1:04:34.959 So there you have it. Thanks once again to Carl 1:04:35.080 --> 1:04:38.360 Zimmer for coming on the show and having this wonderful 1:04:38.440 --> 1:04:41.320 chat with us about his new book, She Has Her 1:04:41.360 --> 1:04:44.880 Mother's Laugh, The Powers, Perversions and Potential of Heredity Again. 1:04:44.880 --> 1:04:47.520 That's available in hardback, as a digital and as an 1:04:47.520 --> 1:04:49.760 audio book right now, and you can check out Carl's 1:04:49.800 --> 1:04:53.600 website Carl Zimmer dot com for even more about him 1:04:53.600 --> 1:04:57.360 and his projects. That's right, go to that website, and hey, 1:04:57.480 --> 1:04:59.680 be sure to check out our website as well. It's 1:04:59.680 --> 1:05:01.640 Stuff to Blow your Mind dot com. That's who you'll 1:05:01.640 --> 1:05:04.840 find all of our episodes. You'll also find links out 1:05:04.880 --> 1:05:07.160 to our various social media account so you can check 1:05:07.160 --> 1:05:09.360 those out as well. I want to remind everybody if 1:05:09.360 --> 1:05:11.520 you want to support the show, one of the best 1:05:11.520 --> 1:05:14.920 things you can do is rate and review us wherever 1:05:15.040 --> 1:05:17.960 you get your podcasts. Big thanks as always to our 1:05:18.000 --> 1:05:21.520 wonderful audio producers Alex Williams and Torry Harrison. 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