WEBVTT - From the Vault: Carl Zimmer on Heredity's Power 0:00:05.760 --> 0:00:07.560 Hey, you welcome to Stuff to Blow your mind. My 0:00:07.640 --> 0:00:10.480 name is Robert Lamb and I'm Joe McCormick, and it's Saturday. 0:00:10.520 --> 0:00:12.960 Time to go into the Old Vault. This time we're 0:00:12.960 --> 0:00:15.520 going in for an interview. I want to say that 0:00:15.640 --> 0:00:18.400 this was a really interesting interview. I really liked it. 0:00:18.440 --> 0:00:21.239 This is the interview we had with the science writer 0:00:21.400 --> 0:00:26.760 Carl Zimmer, originally published in June of about his book 0:00:26.760 --> 0:00:29.920 on heredity called She Has Her Mother's Laugh The Powers, 0:00:30.000 --> 0:00:32.960 Perversions and Potential of Heredity. And I thought this was 0:00:33.000 --> 0:00:35.200 a really good talk. Yeah, this was a lot of fun. 0:00:35.520 --> 0:00:37.800 You know, I just got him chatting about, you know, 0:00:37.840 --> 0:00:40.920 his experiences writing the book, uh, you know, some of 0:00:40.960 --> 0:00:46.000 the real you know, high points regarding like what heredity is, 0:00:46.040 --> 0:00:48.519 how it works, and and also I remember we got 0:00:48.600 --> 0:00:50.519 him talking a little bit about like okay, what if 0:00:50.760 --> 0:00:53.120 what if you were to write your name and someone's genes, 0:00:53.360 --> 0:00:56.760 Like how long would that signature last? Uh So, yeah, 0:00:56.800 --> 0:00:59.160 it's a fun conversation and uh, you know it was 0:00:59.200 --> 0:01:01.080 and it was on honor to get to talk to 0:01:01.200 --> 0:01:03.480 Carl Zimmer, who's, you know, such a big name in 0:01:03.520 --> 0:01:06.280 science communication. He's been one of my favorite science writers 0:01:06.280 --> 0:01:08.920 for years and it was really cool. All right, let's 0:01:09.000 --> 0:01:14.840 jump right in. Welcome to Stuff to Blow your Mind 0:01:15.040 --> 0:01:23.360 from how Stuff Works dot com. Hey you, welcome to 0:01:23.360 --> 0:01:25.560 Stuff to Blow your Mind. My name is Robert Lamb 0:01:25.600 --> 0:01:27.440 and I'm Joe McCormick. And boy, do we have a 0:01:27.480 --> 0:01:30.600 treat for you today. That's right, we're we're chatting with 0:01:30.720 --> 0:01:34.759 Carl Zimmer about his new book, She Has Her Mother's Laugh, 0:01:35.120 --> 0:01:39.240 The Powers, Perversions and Potential of Heredity. This is a 0:01:39.319 --> 0:01:42.720 fantastic book. I was trying to finish it before we 0:01:42.760 --> 0:01:44.480 talked to him today, and I was up till two 0:01:44.520 --> 0:01:46.800 am last night and getting to the very last page. 0:01:47.240 --> 0:01:49.480 But it was worth it. It is a great book. 0:01:49.520 --> 0:01:52.760 I really highly recommended. It's a brick that's just full 0:01:52.840 --> 0:01:56.760 of weird, interesting delights and insights about how our views 0:01:56.800 --> 0:01:59.320 of heredity have changed over the years, all of the 0:01:59.400 --> 0:02:01.600 good and all of the evil to that knowledge has 0:02:01.640 --> 0:02:05.040 been used for and uh and also where it's going 0:02:05.080 --> 0:02:07.760 in the future. Yeah, yeah, this it's a fascinating book. 0:02:07.800 --> 0:02:10.760 I also I got to see him in conversation with 0:02:10.800 --> 0:02:14.160 the Maria Knakova at World Science Festival this year, in 0:02:14.200 --> 0:02:17.000 which he talked about the themes in the book as well, 0:02:17.240 --> 0:02:19.120 So it was a real it's a real delight to 0:02:19.160 --> 0:02:21.280 have him here on the show. And if you want 0:02:21.280 --> 0:02:23.720 to check out She Has Her Mother's Laugh. It is 0:02:23.760 --> 0:02:28.360 available in hardback, digital and as an audio book. So, uh, 0:02:28.560 --> 0:02:30.880 we hope you enjoy our interview with him, but certainly 0:02:31.400 --> 0:02:34.200 go check out his book as well for just an 0:02:34.240 --> 0:02:37.720 in depth, riveting journey through heredity. Now, wait a minute, 0:02:37.720 --> 0:02:39.639 we should say who he is. I don't think we've 0:02:39.639 --> 0:02:41.639 done that if you're if you're not familiar with Carl 0:02:41.720 --> 0:02:46.160 Zimmer and Carl Carl Zimmer is a prolific, excellent science writer. 0:02:46.280 --> 0:02:48.359 He writes for the New York Times. I think I've 0:02:48.360 --> 0:02:51.639 also seen these articles in the Atlantic and National Geographic 0:02:51.680 --> 0:02:53.839 all over the place. Uh. He's written a lot about 0:02:53.880 --> 0:02:57.240 parasites and uh, some of the most interesting stuff in 0:02:57.280 --> 0:03:01.560 biology is is Karl's territory. And uh, and I really 0:03:01.560 --> 0:03:03.359 had a good time talking to him today. Yes, some 0:03:03.400 --> 0:03:06.920 of his past books include Parasite rex Evolution, The Triumph 0:03:06.960 --> 0:03:10.720 of an Idea, and Microcosm. So, without further ado, here's 0:03:10.760 --> 0:03:16.080 our conversation with Carl Zimmer. So, Carl, what led you 0:03:16.120 --> 0:03:19.080 to write a book about heredity. I guess in a way, 0:03:19.120 --> 0:03:24.320 I've been thinking about heredity for forever. Really. I mean, 0:03:25.200 --> 0:03:27.400 I when I was a kid, you know, I would 0:03:27.480 --> 0:03:31.440 uh think back on my ancestors that my parents told 0:03:31.440 --> 0:03:34.200 me about, and you know, I wonder like, oh wow, 0:03:34.240 --> 0:03:38.320 if if you know, Roger Goodspeed had not sailed from 0:03:38.360 --> 0:03:42.960 England to Massachusetts in the sixteen thirties, would I ever exist? 0:03:43.120 --> 0:03:46.960 You know, those sorts of things. And then when I 0:03:47.000 --> 0:03:50.160 became a father, I've got two teenage girls now, and 0:03:50.280 --> 0:03:56.680 you know that immediately brought to bear just how urgent 0:03:56.800 --> 0:04:01.000 and mysterious heredity can be. Because now they these two 0:04:01.000 --> 0:04:04.840 people walking around who have inherited a lot of my genes, 0:04:04.880 --> 0:04:07.120 and you know what, what is it that I'm giving 0:04:07.160 --> 0:04:12.800 them that that suddenly becomes a very pressing issue. And 0:04:12.840 --> 0:04:16.160 I guess what really then kind of crystallize it all 0:04:16.200 --> 0:04:18.000 for me, was that in the past few years, I've 0:04:18.040 --> 0:04:19.920 been doing a lot of reporting from the New York 0:04:19.960 --> 0:04:24.400 Times and elsewhere about the real revolution happening in biology, 0:04:25.279 --> 0:04:31.400 allowing scientists to sequenced DNA, to rewrite DNA, and to 0:04:31.600 --> 0:04:36.080 also look at other kinds of biology that might help 0:04:36.839 --> 0:04:40.159 uh create this thing that we call heredity. Uh, and 0:04:41.080 --> 0:04:42.840 so it just it all kind of came together, and 0:04:42.920 --> 0:04:45.520 I realized that this would be something that I really 0:04:45.560 --> 0:04:48.400 wanted to spend a couple of years really exploring deeply. 0:04:48.960 --> 0:04:51.760 So you mentioned the idea of the sort of personal 0:04:51.839 --> 0:04:54.880 curiosity about our ancestors, and you talk in the book 0:04:54.920 --> 0:04:57.800 about how we often do family genealogies to sort of 0:04:58.240 --> 0:05:01.480 learn something about ourselves, as if the seeds of who 0:05:01.520 --> 0:05:05.640 we are are somehow present in our really distant ancestors. 0:05:06.200 --> 0:05:08.560 But how many generations back do you have to go 0:05:08.760 --> 0:05:13.640 before those relationships with our ancestors really don't matter all 0:05:13.680 --> 0:05:17.800 that much in terms of genetic closeness. You know, you 0:05:17.800 --> 0:05:19.719 don't have to go back that far. And that just 0:05:19.800 --> 0:05:24.400 has to do with how parents passed down their DNA 0:05:24.560 --> 0:05:27.400 to their kids. You know, we each have two copies 0:05:27.480 --> 0:05:31.320 of each gene for the most part, but you know, 0:05:31.400 --> 0:05:34.760 parents only passed down one copy of a given gene 0:05:35.760 --> 0:05:39.839 to each child. And so if you repeat that process 0:05:39.880 --> 0:05:43.359 generation after generation, there's a sort of a kind of 0:05:43.360 --> 0:05:46.919 a stochastic, kind of random process that will basically lead 0:05:47.720 --> 0:05:51.640 to you know, uh, some descendants not having any DNA 0:05:52.000 --> 0:05:55.880 at all from a particular ancestor. Um, there's only so 0:05:55.960 --> 0:05:58.960 much room in your genome and you can't pack in 0:05:58.960 --> 0:06:02.760 all the DNA for all your ancestors basically, and so 0:06:02.880 --> 0:06:05.640 geneticis have done some back of the envelope calculations and 0:06:05.839 --> 0:06:10.159 if you go back let's say ten generations, um, that 0:06:10.200 --> 0:06:14.120 would be like your ancestors in the sixt dreds. Uh, 0:06:14.360 --> 0:06:17.360 maybe only about half of them have a genetic link 0:06:17.400 --> 0:06:21.279 to you. The rest they're still your ancestors. But you 0:06:21.320 --> 0:06:23.640 cannot point to any piece of DNA in your genome 0:06:23.640 --> 0:06:27.120 and say, oh, I got that from from this particular 0:06:27.200 --> 0:06:30.760 person you know. So Um, So I think that actually 0:06:30.800 --> 0:06:34.760 like really shows how we have to, um think think 0:06:34.800 --> 0:06:38.280 bigger when it comes to heredity. It's not just some 0:06:38.360 --> 0:06:43.440 particular bit of DNA that that gives heredity its meaning. Well, 0:06:43.480 --> 0:06:45.880 on the other side of that coin, UM, could you 0:06:45.880 --> 0:06:49.000 talk a little bit about what the Yale mathematician Joseph 0:06:49.080 --> 0:06:51.760 Chang discovered about human ancestry. It seems sort of like 0:06:51.800 --> 0:06:54.480 the flip side of what you're just talking about. Yeah, 0:06:54.520 --> 0:06:58.440 I mean, so you know, so much about heredity is 0:06:58.640 --> 0:07:03.560 counterintuitive and almost you know, it seems to contradict itself. 0:07:03.560 --> 0:07:05.600 And that's in a way what makes it so fascinating. 0:07:05.839 --> 0:07:07.479 So I just told you about how if you go 0:07:07.560 --> 0:07:10.640 back a certain number of generations, you're gonna encounter ancestors 0:07:11.120 --> 0:07:14.880 from whom you've inherited no DNA at all. Um. But 0:07:15.800 --> 0:07:21.800 there's an interesting feature of human ancestry, which is that, um, 0:07:21.840 --> 0:07:27.880 you know people uh, everybody today, Uh, you know, it 0:07:28.400 --> 0:07:32.720 shares a common ancestor with some people who lived about 0:07:32.720 --> 0:07:37.800 five thousand years ago, roughly speaking in other words, UM, 0:07:37.880 --> 0:07:40.120 if you, if you, it's just a you can and 0:07:40.160 --> 0:07:43.600 you can figure this out as just changed just by 0:07:43.640 --> 0:07:47.520 looking at Genealogy is a mathematical problem. Um, just think 0:07:47.520 --> 0:07:49.600 of think of our genealogy is a kind of a 0:07:49.640 --> 0:07:54.960 branching network. Um. The thing is though that uh you 0:07:55.000 --> 0:07:59.160 know are if you think about your family tree, um, 0:07:59.200 --> 0:08:01.400 and you think while as me, and then you branch 0:08:01.480 --> 0:08:03.520 off to your parents, and then they branch off to 0:08:03.600 --> 0:08:06.440 their parents and so on and so forth. Um. If 0:08:06.480 --> 0:08:09.600 you just keep branching in that simple way, you're gonna 0:08:09.680 --> 0:08:11.800 end up, you know, a few thousand years back with 0:08:11.960 --> 0:08:15.480 more ancestors than there are people who have ever lived. 0:08:15.600 --> 0:08:17.800 You know, we're talking chillions of people. And that's absurd. 0:08:18.120 --> 0:08:23.280 So so that's actually not a realistic model of your ancestry. 0:08:23.400 --> 0:08:28.000 The fact is that your aunt all of you know, 0:08:28.960 --> 0:08:33.520 your parents are cousins. Now either that you know, in 0:08:33.559 --> 0:08:35.960 some cases first cousins get married, but in other cases 0:08:35.960 --> 0:08:38.400 they're very distant cousins. Another what that means is that 0:08:39.400 --> 0:08:42.720 your parents share an ancestor, a common ancestor somewhere in 0:08:42.720 --> 0:08:46.200 the past. It could be hundreds of thousands of years ago, 0:08:46.360 --> 0:08:49.320 but it doesn't matter. They have an ancestor. So what 0:08:49.400 --> 0:08:54.160 that does is it folds the family tree back in 0:08:54.240 --> 0:08:58.240 on itself. And what Joseph Chang realized was that that 0:08:58.400 --> 0:09:02.160 actually does something very interesting to human ancestry. What it 0:09:02.200 --> 0:09:03.720 means is that you do not have to go back 0:09:03.840 --> 0:09:07.400 very far to find somebody who is the common ancestor 0:09:07.880 --> 0:09:11.960 of literally everyone on earth. Uh And it's just in 0:09:12.000 --> 0:09:14.480 the past few thousand years that you could find people 0:09:14.520 --> 0:09:19.400 like that. Um. Now, of course you know those common ancestors, 0:09:19.440 --> 0:09:23.480 you know they for each of us that that that's 0:09:23.559 --> 0:09:26.880 one person or a few people out of thousands upon 0:09:27.000 --> 0:09:31.280 thousands of ancestors. But it's something that ties us all together. 0:09:31.480 --> 0:09:34.640 And the irony is that you know, people are really 0:09:34.800 --> 0:09:39.679 uh uh, really love to connect themselves to someone famous. 0:09:40.160 --> 0:09:41.800 You know, like, oh, did you know that I am 0:09:41.840 --> 0:09:45.200 descended from William the Conqueror? And the fact is that 0:09:45.320 --> 0:09:51.200 probably probably everybody of European descent is and is a 0:09:51.240 --> 0:09:56.000 descendant of William the Conqueror. Probably everybody of European descent 0:09:56.280 --> 0:10:01.439 is a descendant of Charlemagne Um. And you know, it's 0:10:01.440 --> 0:10:04.880 possible that everybody on earth is a descendant of you know, 0:10:04.920 --> 0:10:10.079 maybe Cleopatra. It's like, that's just the nature of human 0:10:10.120 --> 0:10:15.640 genealogy is that it's we're all descended from kings. That 0:10:15.679 --> 0:10:20.120 doesn't make anybody special. Well as as long as we're 0:10:20.160 --> 0:10:23.240 gazing backwards in time, here, can you tell us how 0:10:23.320 --> 0:10:28.000 ancient thinkers contemplated heredity? The weird thing is that they 0:10:28.040 --> 0:10:31.199 really didn't. And they at least they didn't think about 0:10:31.200 --> 0:10:34.400 heredity in the way that we do. Uh. You know, 0:10:35.040 --> 0:10:37.760 if you go back and you you look at what 0:10:37.880 --> 0:10:42.440 Hippocrates would say or Aristottle would say, Uh, this, this 0:10:42.480 --> 0:10:47.199 whole model of how we inherit something you know, microscopic 0:10:47.240 --> 0:10:51.320 and biological that that determines how we ended up the 0:10:51.320 --> 0:10:55.960 way we are just would not compute for them. And so, 0:10:56.280 --> 0:10:59.199 you know, you know, someone like Aristotle would say like, well, 0:10:59.520 --> 0:11:01.319 you know, the thing that one generation looks like the 0:11:01.320 --> 0:11:04.560 previous one is just because it's the same chemistry. Um, 0:11:04.600 --> 0:11:07.080 you know, of course you're going to be the uh, 0:11:07.360 --> 0:11:09.800 you're going to be the same because you know, it's 0:11:09.840 --> 0:11:14.600 the same set of processes that produced a person that 0:11:14.640 --> 0:11:17.480 produced you. So what's the big deal? And you know 0:11:17.520 --> 0:11:20.240 the word heredity, You know, it's a very old word, 0:11:20.280 --> 0:11:24.880 but it only referred to basically inheriting stuff. Um, you know, 0:11:25.000 --> 0:11:28.840 and I'm talking not talking about jeanes, I'm talking about houses, uh, 0:11:28.880 --> 0:11:31.480 you know, farmland things like that. You know, So in 0:11:31.520 --> 0:11:33.680 the Roman Empire there are lots of rules about you know, 0:11:33.720 --> 0:11:35.920 who got to be an heir, and that's what the 0:11:35.920 --> 0:11:40.480 word meant at that point. And it's really fascinating, Like 0:11:40.720 --> 0:11:42.240 you have to you have to wait a long time 0:11:42.320 --> 0:11:44.840 before you start to even see the first glimmers of 0:11:44.880 --> 0:11:48.400 how we think about heredity today. Um. My favorite example 0:11:48.480 --> 0:11:53.120 is in the fifteen fifteen, around fifteen eighty, uh, Montana 0:11:53.200 --> 0:11:59.199 this this famous essays. He writes an essay about his 0:11:59.280 --> 0:12:03.080 father because Mathenniel now is starting to get older and 0:12:03.120 --> 0:12:06.120 he's developing kidney stones, and it occurs to him that 0:12:06.160 --> 0:12:09.800 his father had kidney stones and around the same age, 0:12:10.880 --> 0:12:13.280 and he basically writes success saying, well, what is up 0:12:13.280 --> 0:12:17.080 with that? Now? Did I get these kid stones from 0:12:17.160 --> 0:12:21.360 my father? And like, if so, how because you know, 0:12:21.400 --> 0:12:23.160 when I was born, my father was young and he 0:12:23.200 --> 0:12:27.880 didn't have kidney stones, So what exactly went from him 0:12:27.880 --> 0:12:31.200 to me? Um? And you want to just you know, 0:12:31.280 --> 0:12:33.880 shout at the page like it's it's jeans, it's jeans. 0:12:34.000 --> 0:12:36.880 But you know he can't hear you, you know, like 0:12:37.040 --> 0:12:42.760 he his question went fundamentally unanswered for centuries. Um And 0:12:42.840 --> 0:12:46.320 so yeah, so so uh, it's really need to look 0:12:46.360 --> 0:12:49.480 back and and see how. You know, the way we 0:12:49.520 --> 0:12:53.160 think is not how everyone always thought. You know, the 0:12:53.160 --> 0:12:57.040 way we think about heredity is is a product of 0:12:57.440 --> 0:13:00.520 really the modern age. So did the select the breeding 0:13:00.520 --> 0:13:03.800 of animals and plants inform classical and medieval thinkers at 0:13:03.840 --> 0:13:06.360 all about the possible nature of heredity, because it seems 0:13:06.720 --> 0:13:08.920 it's I mean, it's kind of seems like people such 0:13:08.960 --> 0:13:12.080 as Aristotle or Albertus Magnus would have would have looked 0:13:12.120 --> 0:13:14.880 at how we bred flowers, crops and farm animals more 0:13:15.200 --> 0:13:17.840 were at least in addition to the influence of geography 0:13:17.960 --> 0:13:21.560 or experience, you would think so, I would I would 0:13:21.600 --> 0:13:23.640 have thought so. But I think that's because we are 0:13:24.000 --> 0:13:26.360 in the century and we look back and say, well, 0:13:26.360 --> 0:13:29.200 everyone must have thought the way we did. But there 0:13:29.200 --> 0:13:32.400 are actually, you know, whole books written, uh you know 0:13:32.440 --> 0:13:36.719 by Roman writers about farming for example, UM, and you 0:13:36.760 --> 0:13:39.200 can search them as I mean, I have sat down 0:13:39.200 --> 0:13:42.840 and look through these books for anything resembling what you're 0:13:42.840 --> 0:13:45.760 talking about, and it's just not there. They do not 0:13:45.880 --> 0:13:49.760 talk about, oh, well, there's some you know quality in 0:13:49.760 --> 0:13:54.120 this particular variety of olives that you know, if you 0:13:54.240 --> 0:13:57.440 if you, if you breed it, it will pass it 0:13:57.520 --> 0:14:02.280 down to two future generations of olive trees. That this 0:14:02.480 --> 0:14:05.880 isn't there. Instead, they'll say like, well, make sure that 0:14:05.960 --> 0:14:08.600 you know you're you're growing it on good soil, make 0:14:08.640 --> 0:14:13.079 sure your your farm gets a good supply rain. It's 0:14:13.080 --> 0:14:18.000 all about the environment. And it isn't really until I 0:14:18.000 --> 0:14:21.720 would argue, it's not really until the seventeen hundreds that uh, 0:14:21.800 --> 0:14:25.520 you start to see these farmers, these livestock breeders really 0:14:25.520 --> 0:14:31.000 take interest in this um. And part of it is 0:14:31.640 --> 0:14:37.520 that these European countries are all um looking for ways 0:14:37.600 --> 0:14:44.480 to use science to uh make their countries wealthier. And 0:14:45.000 --> 0:14:46.600 you know they're thinking, well, if we can we can, 0:14:46.600 --> 0:14:51.160 if we can produce new varieties of animals implants, um, 0:14:51.280 --> 0:14:54.440 then we we will enrich ourselves. Uh. And there's this 0:14:54.520 --> 0:14:59.720 one breeder named Robert Bakewell who produces an entirely new 0:15:00.000 --> 0:15:05.520 eat of sheep just by starting to think about heredity, 0:15:05.560 --> 0:15:08.280 to think about which individuals those sheep is he gonna 0:15:08.440 --> 0:15:11.720 mate together? Is he gonna just only mate within his flock? 0:15:11.800 --> 0:15:14.120 Is he gonna go pick out other ones from other 0:15:14.240 --> 0:15:17.480 flocks to mate? Um? And lo and behold he produces 0:15:17.520 --> 0:15:19.800 this this very successful new breed. And you know, people 0:15:19.840 --> 0:15:23.560 like Charles Darwin look at that and say, what has happened? 0:15:23.600 --> 0:15:26.960 How did they do that? Um? And in Germany and 0:15:27.040 --> 0:15:31.080 in Central Europe there's a big push to do the 0:15:31.160 --> 0:15:34.520 same thing with sheep, to do that with crops as well, 0:15:34.760 --> 0:15:38.120 and uh and to try to understand what are these rules. 0:15:38.160 --> 0:15:40.280 And one of those people who's trying to understand those 0:15:40.360 --> 0:15:43.760 rules is none other than Gregor mendel Um. So his 0:15:43.760 --> 0:15:48.560 his breeding experiments. You know, the foundation of genetics comes 0:15:48.600 --> 0:15:53.480 out of this new push to try to use heredity 0:15:53.600 --> 0:15:58.280 to enrich nations. All Right, we're gonna take a quick 0:15:58.280 --> 0:16:00.040 break and then we're gonna jump right back in to 0:16:00.120 --> 0:16:05.680 the interview and we're back. So at what point does 0:16:06.000 --> 0:16:09.080 the modern idea of heredity really emerge. Well, I'd say 0:16:09.080 --> 0:16:13.720 in the late eighteen hundreds, UM, people start to talk 0:16:13.760 --> 0:16:18.240 about heredity as a scientific question. And Charles Darwin is 0:16:18.280 --> 0:16:21.080 really important in all of this because, you know, he 0:16:21.600 --> 0:16:24.200 comes up with this theory of evolution and it depends 0:16:24.240 --> 0:16:28.280 on heredity. In other words, Um, you know, the only 0:16:28.320 --> 0:16:31.720 way for natural selection to work is so if parents 0:16:31.720 --> 0:16:35.440 can pass down traits to their offspring to give them 0:16:35.440 --> 0:16:39.080 some advantage and surviving and reproducing. And so it's very 0:16:39.080 --> 0:16:43.640 obvious to Darwin that, you know that that heredity is 0:16:43.680 --> 0:16:46.560 this huge glaring question in the middle of his theory, 0:16:46.600 --> 0:16:48.680 and he and he works really hard to try to 0:16:48.760 --> 0:16:53.280 find out for himself how heredity works. And he's very 0:16:53.320 --> 0:16:55.560 aware of a lot of the research that's going on 0:16:55.600 --> 0:16:58.640 at the time looking to the discovery of cells and 0:16:58.680 --> 0:17:01.200 the discovery that there are a little things inside of cells, 0:17:01.280 --> 0:17:03.920 but no one's quite sure what they are, UM. And 0:17:04.000 --> 0:17:07.520 so he developed a theory that there are particles in 0:17:07.560 --> 0:17:10.879 the cells throughout our body that they somehow stream into 0:17:10.960 --> 0:17:16.280 the eggs and sperm and uh then become something like 0:17:16.280 --> 0:17:20.080 we the way we think of genes um. That doesn't 0:17:20.080 --> 0:17:23.800 pan out. You know, his cousin Francis Galton, tries to 0:17:23.960 --> 0:17:28.160 test it by injecting blood from uh, you know, black 0:17:28.240 --> 0:17:30.879 rabbits into white rabbits, you know, different colored rabbits, and 0:17:30.880 --> 0:17:34.159 seeing if that changes the color of their offspring. Doesn't happen. 0:17:34.800 --> 0:17:39.440 Uh and uh So it's not really until after Darwin 0:17:39.800 --> 0:17:46.919 is dead that scientists start to really understand chromosomes and 0:17:46.960 --> 0:17:50.800 then rediscover mental and it all clicks together, and the 0:17:50.920 --> 0:17:53.960 science that they that they call genetics is born in 0:17:54.160 --> 0:17:59.720 nineteen uh and and you know, the it's really you 0:17:59.720 --> 0:18:01.760 can see how exciting it is for the scientists at 0:18:01.800 --> 0:18:04.119 the time. William Bateson, who coined the term genetics, he 0:18:04.480 --> 0:18:08.159 writes at the time that you know, the science of 0:18:08.240 --> 0:18:12.160 heredity has been revolutionized. You know that finally they feel 0:18:12.200 --> 0:18:16.280 like they can they can understand heredity um in its 0:18:16.440 --> 0:18:19.159 fundamental basis. So so how do we go from this 0:18:19.240 --> 0:18:22.040 point of of of just excitement and discovery and just 0:18:22.080 --> 0:18:26.640 fall so steeply into eugenics and then ultimately the horrors 0:18:26.720 --> 0:18:30.760 of the Third Reich. Well, if you look back, the 0:18:30.880 --> 0:18:36.760 roots of eugenics UM go back pretty far. Um. You 0:18:36.800 --> 0:18:41.800 know so Uh. On the one hand, Uh, so our 0:18:41.840 --> 0:18:46.920 modern conception of race UH starts to develop as early 0:18:46.960 --> 0:18:50.600 as really the fifteen hundreds are the fourteen hundreds, even 0:18:50.680 --> 0:18:55.960 where in Spain, uh, Jews are are being considered a 0:18:56.040 --> 0:19:02.199 separate race of people, and and and noble families have 0:19:02.320 --> 0:19:05.960 to do have to draw out genealogies to prove that 0:19:06.040 --> 0:19:09.480 they don't have any Jews in their in their ancestry. Um. 0:19:09.520 --> 0:19:11.600 Otherwise they you know, they won't be able to get 0:19:11.640 --> 0:19:15.240 that good job in government or so on. And so 0:19:15.280 --> 0:19:18.159 that starts to develop this idea that that groups of 0:19:18.160 --> 0:19:21.639 people are fundamentally different in some way that is carried 0:19:21.640 --> 0:19:25.960 on from one generation to the next. Um. Then Uh, 0:19:25.960 --> 0:19:29.920 in the in the eighteen hundreds, you start to see, 0:19:30.359 --> 0:19:36.400 you know, a real concern about UM poverty and crime, 0:19:37.040 --> 0:19:41.400 and and a lot of people start to to make 0:19:41.480 --> 0:19:45.240 claims that these are being carried down in certain families. 0:19:45.280 --> 0:19:47.359 You know, there are these bad families and why is 0:19:47.400 --> 0:19:49.439 it that one generation is just as bad as the 0:19:49.480 --> 0:19:52.840 previous one. And you know, people talk about some sort 0:19:52.880 --> 0:19:56.040 of hereditary curse that they must have. And and then 0:19:56.119 --> 0:20:00.359 you know, how do we keep that curse from being propagated? Okay? 0:20:00.920 --> 0:20:04.800 And so then when genetics gets discovered, um, a lot 0:20:04.840 --> 0:20:10.600 of actual genesis themselves and uh and other and others 0:20:10.640 --> 0:20:13.920 say well, aha, like here's here's the basis for what 0:20:13.960 --> 0:20:17.320 we've been talking about for decades now. Um. And you know, 0:20:17.359 --> 0:20:20.600 the word eugenics had actually been coined in eighteen eighties 0:20:20.640 --> 0:20:25.680 by Francis Coulton, Uh, Darwin's cousin, and he just thought, well, 0:20:25.720 --> 0:20:28.879 you know, if intelligence is inherited, then why don't we 0:20:28.920 --> 0:20:32.600 just essentially breed people away we breed sheep, So you 0:20:32.720 --> 0:20:36.000 just pick out the individuals who seemed to have, you know, 0:20:36.040 --> 0:20:39.280 the most genius he would call it, and then encourage 0:20:39.320 --> 0:20:42.080 them to have lots of kids. And and he had 0:20:42.119 --> 0:20:45.520 these dreams that to produced what he called the galaxy 0:20:45.560 --> 0:20:49.560 of genius in the future. Um. But by the time 0:20:49.680 --> 0:20:54.000 that eugenics arrives in the United States and genetics emerges, 0:20:54.320 --> 0:20:57.280 it takes on a much darker cast because people say, well, 0:20:57.840 --> 0:21:00.960 what we really need to focus on is as these 0:21:00.960 --> 0:21:04.119 people who have who we believe have genes that we 0:21:04.160 --> 0:21:06.840 don't like, and we want to prevent them from reproducing, 0:21:07.119 --> 0:21:09.359 because that's going to drag down our country, and so 0:21:09.440 --> 0:21:11.600 what are we going to do to keep them from reproducing? 0:21:12.200 --> 0:21:17.480 And um, that leads to sterilization and much worse. So, 0:21:17.560 --> 0:21:21.200 in reading your chapter about Henry Goddard and the origins 0:21:21.240 --> 0:21:25.080 of the American eugenics movement, I'm struck that this is 0:21:25.280 --> 0:21:29.080 a potential example of the dangers of bad research. Like 0:21:29.119 --> 0:21:33.120 you draw a really disturbing picture of how but like 0:21:33.240 --> 0:21:37.240 sloppy or fraudulent work that became the basis of Henry 0:21:37.240 --> 0:21:40.560 Goddard's published writings on heredity can be viewed in some 0:21:40.600 --> 0:21:43.919 ways is contributing directly to real world consequences, like the 0:21:43.960 --> 0:21:47.440 horrors of for sterilization in the United States or mass 0:21:47.520 --> 0:21:50.240 murder in Europe. Do you ever think, when you see 0:21:50.320 --> 0:21:55.040 bad science or pseudoscience being being publicized today that it 0:21:55.440 --> 0:21:58.560 could ever lead to such nightmares that even its authors 0:21:58.640 --> 0:22:02.520 might not have imagined? Uh, you know, I don't. I 0:22:02.560 --> 0:22:07.080 think that we can't uh rule out those kinds of possibilities. 0:22:07.119 --> 0:22:09.840 I mean, it might be very, very unlikely, but I mean, 0:22:10.240 --> 0:22:14.639 if you look at history, you can see how bad 0:22:14.760 --> 0:22:20.280 science combined with existing prejudices led to really horrific outcomes. 0:22:22.240 --> 0:22:26.520 And it wasn't that the science was somehow appropriated by 0:22:28.760 --> 0:22:35.480 pseudo scientists or something. Uh. Eugenics was embraced by most 0:22:35.520 --> 0:22:41.920 of the leading um biologists of the time. Uh and Uh, 0:22:41.960 --> 0:22:44.440 there were different forms of eugenics, you know. So some 0:22:44.480 --> 0:22:48.480 people were very much sort of concerned. We were quite 0:22:48.600 --> 0:22:51.800 racist and you know, concerned about uh, you know, the 0:22:51.840 --> 0:22:57.600 white quote unquote race being you know, polluted by other races. Um. 0:22:58.240 --> 0:23:02.199 But then there were progressives who thought that this was 0:23:02.200 --> 0:23:04.760 going to be part of their grand plan for making 0:23:04.920 --> 0:23:09.800 society a better, fairer place. Um. And I think it's 0:23:09.800 --> 0:23:13.600 really important to look at these episodes in history to 0:23:13.760 --> 0:23:17.560 see how things go bad. Um. And I think it's 0:23:17.600 --> 0:23:21.240 I think it's arrogant for any of us to say, well, 0:23:21.560 --> 0:23:23.879 things like this could never happen again, you know, and 0:23:24.040 --> 0:23:27.639 somehow we're vaccinated from from these sorts of things. But 0:23:27.720 --> 0:23:29.840 we can draw lessons from the past, and we can 0:23:29.880 --> 0:23:33.879 see how, um, how humble we need to be in 0:23:33.920 --> 0:23:39.600 the face of complexity in in our own biology. You know. 0:23:39.680 --> 0:23:42.719 We you know, I think we're in like in another revolution, 0:23:42.880 --> 0:23:44.840 the way we were a hundred years ago, you know, 0:23:44.840 --> 0:23:47.720 a hundred years ago, genetics itself was profoundly new. That 0:23:47.800 --> 0:23:50.840 gene was a new thing. Uh. Now we're at the 0:23:50.880 --> 0:23:54.520 point where we're looking at genomes, in other words, all 0:23:54.680 --> 0:23:56.920 the genes in our in our selves, and we can 0:23:57.040 --> 0:24:01.040 we can see them down to the atomic detail. UM, 0:24:01.080 --> 0:24:03.440 but there's still a vast amount we do not understand 0:24:03.440 --> 0:24:07.200 about it, and UM, you know, we we cannot let 0:24:07.280 --> 0:24:13.080 that be an opportunity to uh, you know, card out 0:24:13.080 --> 0:24:17.280 our old biases and prejudices and say, oh, I see 0:24:17.320 --> 0:24:20.399 now science backs up what I was saying all along 0:24:20.440 --> 0:24:25.040 about those other people. UM, we can't. We just we 0:24:25.080 --> 0:24:27.680 cannot let that happen again. I think that's a really 0:24:27.720 --> 0:24:30.560 good point. And I also think you can even look 0:24:30.600 --> 0:24:33.359 at it as there's a flip side to it where 0:24:34.080 --> 0:24:37.640 modern discoveries of genomics really complicate or in some sense 0:24:37.760 --> 0:24:41.679 is undermine what many people have traditionally understood as the 0:24:41.720 --> 0:24:46.240 concept of race within humans. Right. Yeah, So the scientific 0:24:46.600 --> 0:24:52.040 concept of race UH developed in in the seventeen hundreds, 0:24:52.240 --> 0:24:56.000 and it was really UM very much spurred on by 0:24:56.680 --> 0:25:00.560 UH by what Europe was doing at the time. So 0:25:01.040 --> 0:25:04.560 Europe was in the midst of building up huge colonies 0:25:05.080 --> 0:25:09.480 UM and enslaving many many people. There was a need 0:25:09.600 --> 0:25:12.560 for sort of legal and moral justifications for doing this, 0:25:13.160 --> 0:25:17.000 and a lot of it, uh was based on these 0:25:17.040 --> 0:25:21.359 concepts of race, so that for example, you know, Africans 0:25:21.440 --> 0:25:25.719 were were claimed to be a completely separate race, uh 0:25:25.760 --> 0:25:31.400 that you know, had inherent uh inferiority to the white race. 0:25:31.600 --> 0:25:35.200 And so therefore slavery is okay. And you can see 0:25:35.240 --> 0:25:38.199 this again and again in in lots of lots of 0:25:38.240 --> 0:25:44.639 writing at the time. Uh. Now, even in the early 0:25:44.720 --> 0:25:49.080 nineteen hundreds, Um, there were there were indications that this 0:25:49.240 --> 0:25:53.800 kind that genetics was not aligning with these these uh 0:25:54.680 --> 0:26:00.400 old ideas about race. They just weren't fitting neatly. Um. 0:26:00.440 --> 0:26:03.000 You it was very it was it was becoming harder 0:26:03.040 --> 0:26:06.919 and harder to sort of draw any particularly bright line 0:26:07.000 --> 0:26:11.000 between groups of people. I mean, obviously people are different, uh. 0:26:11.040 --> 0:26:13.119 You know, there are lots of differences and people in 0:26:13.200 --> 0:26:16.160 terms of skin color and height and shapes of faces 0:26:16.240 --> 0:26:19.359 and culture and all the rest of it. But the 0:26:19.440 --> 0:26:23.959 genes were not supporting these old ideas about race. And 0:26:23.960 --> 0:26:26.679 by the midnighteteen hundreds of people, a lot of anthropologists 0:26:26.720 --> 0:26:30.040 and geneticisis we're saying, you know, the word race is 0:26:31.280 --> 0:26:35.639 so burdened with so much that's terrible and immoral and 0:26:35.760 --> 0:26:38.800 has so little connection with the way we're starting to 0:26:38.880 --> 0:26:44.960 understand populations. Let's just get abandoned it. Um, that really 0:26:44.960 --> 0:26:49.560 hasn't that really didn't happen. But nevertheless, like now where 0:26:49.600 --> 0:26:53.480 we can look at whole genomes. Um. Yeah, the whole 0:26:53.520 --> 0:26:57.280 thing with race now is is it just is it's 0:26:57.320 --> 0:26:59.399 a bit one. The way one Jenet has put it 0:26:59.440 --> 0:27:02.600 to me is, well, you know, like talking for us, 0:27:02.640 --> 0:27:05.840 like talking about races, like the way Greeks talked about 0:27:05.880 --> 0:27:09.639 the you know, the four elements, air, fire, water, earth, 0:27:09.880 --> 0:27:13.879 like you know it. You know, Aristotle could explain all 0:27:13.880 --> 0:27:17.720 sorts of things, uh that way, and they seemed good 0:27:17.720 --> 0:27:20.320 to him. But you know, we know that there's things 0:27:20.320 --> 0:27:23.760 are much more complex than the four elements, and if 0:27:23.800 --> 0:27:26.359 you forced physicists to go back to the four elements, 0:27:26.400 --> 0:27:29.320 they'd be very unhappy. So genets are saying, like, please 0:27:29.320 --> 0:27:31.520 don't make us go back to you know, the genetic 0:27:31.600 --> 0:27:34.080 equivalent of the four elements. You know, we're you know, 0:27:34.160 --> 0:27:37.480 they're very interested in ancestry and how populations mixed together, 0:27:37.600 --> 0:27:39.600 how they become isolated, and all the rest of it. 0:27:40.119 --> 0:27:42.320 But these old ideas about race and on all the 0:27:42.359 --> 0:27:45.800 connotations of race, they don't map onto it at all, 0:27:46.000 --> 0:27:48.160 so they just don't want to use it now. Of course, 0:27:48.200 --> 0:27:52.120 in addition to just the passing on of genetic information, UH, 0:27:52.400 --> 0:27:57.119 we also have epigenetics. And even as you explore the 0:27:57.119 --> 0:27:59.600 effects of the microbiome, can can you talk about how 0:27:59.640 --> 0:28:02.200 these if changed our definition of heredity. So in the 0:28:02.320 --> 0:28:06.920 eight hundreds, heredity becomes a scientific question. You know, what 0:28:07.160 --> 0:28:11.399 is it that makes one generation connected to the past? 0:28:11.520 --> 0:28:15.919 Why is it that generations resemble their forerunners? Um? What 0:28:16.119 --> 0:28:21.399 what are these connections? And uh, genetics provided a huge 0:28:21.440 --> 0:28:24.200 part of that answer, which is that well, genes get 0:28:24.200 --> 0:28:29.120 copied and then transmitted through eggs and sperm and uh. 0:28:29.200 --> 0:28:31.720 And so that was a huge revolution and understanding. But 0:28:33.160 --> 0:28:39.240 that doesn't mean that that is all that heredity can be. 0:28:39.600 --> 0:28:42.920 I mean there's still the at least the logical possibility 0:28:43.000 --> 0:28:46.560 that there are other ways that each generation be can 0:28:46.600 --> 0:28:50.040 be connected to the to the previous ones. And so 0:28:50.080 --> 0:28:55.040 in my book I talk about different forms of heredity 0:28:55.120 --> 0:28:58.680 that scientists are exploring. Um. And so you know, one 0:28:58.840 --> 0:29:02.239 one very sighting possibility is what you referred to as 0:29:02.280 --> 0:29:06.040 epigenetics and epigenetics is kind of a broad term, but 0:29:07.120 --> 0:29:11.560 roughly speaking, what it refers to is the molecules inside 0:29:11.560 --> 0:29:16.160 our cells that control our genes. That that allows some 0:29:16.400 --> 0:29:19.920 genes to be switched on and to produce proteins and 0:29:20.000 --> 0:29:23.680 others that are kept silent um. And you know, it's 0:29:23.720 --> 0:29:27.280 it's very clear that this is incredibly important to our existence. 0:29:27.560 --> 0:29:30.560 You know, it's what makes your skin cells be skin cells, 0:29:30.600 --> 0:29:33.840 and you're you know, brain cells be brain cells, like 0:29:33.880 --> 0:29:36.840 they are using different genes in the same genome. And 0:29:37.880 --> 0:29:41.480 when these cells divide um, the you know, a skin 0:29:41.520 --> 0:29:46.400 cell does not normally instantly become a neuron or or 0:29:46.440 --> 0:29:48.520 you know it doesn't you don't grow a tooth on 0:29:48.560 --> 0:29:52.480 your back of your hand um. And that has to 0:29:52.480 --> 0:29:55.920 do with epigenetics um. And so what does this have 0:29:55.960 --> 0:29:59.280 to do with heredity, Well, you know, when the cells divide, 0:29:59.280 --> 0:30:03.560 there are basically inheriting the genes and the epigenetics of 0:30:03.680 --> 0:30:07.720 their mother's cell. But you know that the possibility rises, well, 0:30:07.720 --> 0:30:10.840 what if you pass those down to the next generation altogether, 0:30:10.960 --> 0:30:14.080 you know, through eggs and sperm um. And there's some 0:30:14.160 --> 0:30:17.520 evidence that that that can happen. And what makes us 0:30:18.000 --> 0:30:23.000 especially exciting is that you know, through our lives, experiences 0:30:23.240 --> 0:30:28.760 can change the epigenetic makeup of ourselves. You know, so 0:30:28.800 --> 0:30:31.440 if you if you get sick, if you smoke, if 0:30:31.480 --> 0:30:35.360 you experience stress, those all seemed to have an influence. 0:30:35.720 --> 0:30:39.160 And so the open question is, well, how much can 0:30:39.240 --> 0:30:44.120 those experiences we have in our lives then influence future generations. 0:30:45.000 --> 0:30:47.480 I think that the jury is still very much out 0:30:47.480 --> 0:30:50.920 when it comes to people, um, but in other species, 0:30:51.040 --> 0:30:53.960 especially plants, there's lots of it, and that that really 0:30:54.000 --> 0:30:55.760 is something that happens. You know, a plant goes through 0:30:55.800 --> 0:30:59.640 a drought and generations later there's still an epigenetic mark 0:30:59.800 --> 0:31:03.680 on its descendants. So yeah, epigenetics is in a really 0:31:03.720 --> 0:31:06.200 exciting area. So you just alluded to some of the 0:31:06.240 --> 0:31:09.640 controversy about epigenetics, and I guess there are other forms 0:31:09.680 --> 0:31:14.320 of ideas of non genetic inheritance, but epigenetics in some 0:31:14.400 --> 0:31:18.360 ways still remains controversial, especially in humans. Like you're talking about, 0:31:19.680 --> 0:31:22.520 if you're comfortable speculating and if you had to guess, 0:31:22.600 --> 0:31:26.120 how would you imagine our picture of non genetic inheritance 0:31:26.240 --> 0:31:28.560 might change over the next fifty years or so? What's 0:31:28.560 --> 0:31:31.680 your sense? You know? I think that it is actually 0:31:31.720 --> 0:31:36.160 possible that we'll just find that, um, human epigenetics is 0:31:36.200 --> 0:31:39.800 just not really that important. I mean, I'm actually I 0:31:39.800 --> 0:31:42.560 think there's a reason to be kind of pessimistic. Um 0:31:42.800 --> 0:31:45.320 that you know, there are these very cantalizing studies, but 0:31:45.360 --> 0:31:48.280 they're small, and they could just be the result of 0:31:48.360 --> 0:31:51.239 noise and so on, and and yet you know, we 0:31:51.280 --> 0:31:56.560 really want epigenetics to be real. Um. I mean, epigenetics 0:31:56.600 --> 0:32:01.040 has totally taken hold of the popular consciousness. And you know, 0:32:01.680 --> 0:32:05.720 I was astonished to learn not long ago that you 0:32:05.760 --> 0:32:10.320 can take classes and epigenetic yoga, which is not kidding, 0:32:10.360 --> 0:32:13.479 you can google it. And the thinking is, the claim 0:32:13.600 --> 0:32:16.600 is that you know that by doing this yoga you 0:32:16.680 --> 0:32:20.400 change the epigenetic profile of yourselves. And you know I 0:32:20.400 --> 0:32:23.720 and you know there are psych psychiatrists who will offer 0:32:23.760 --> 0:32:28.760 you epigenetic analysis to basically undo the trauma that you 0:32:28.840 --> 0:32:32.920 inherited from past generations. Um. It really speaks to us 0:32:32.920 --> 0:32:35.760 in a very profound way. But I actually don't think 0:32:35.800 --> 0:32:39.719 the science is going to really hold up very well. Um, 0:32:39.960 --> 0:32:42.600 because are but I don't think it looks like our 0:32:42.640 --> 0:32:45.600 biology just doesn't really allow that to make much of 0:32:45.640 --> 0:32:48.600 a difference. But you know, the flip side is that 0:32:50.080 --> 0:32:54.520 culture UM is actually, I I would argue, an incredibly 0:32:54.560 --> 0:32:59.160 important form of forredity, especially for our species. We we 0:32:59.280 --> 0:33:02.840 passed down not just our genes to the next generation, 0:33:02.920 --> 0:33:07.480 but all of our knowledge and and beliefs and customs 0:33:07.480 --> 0:33:10.760 and so on, and those those get propelled down through 0:33:10.760 --> 0:33:16.960 the generations UM in a very hereditary way and UM, 0:33:17.000 --> 0:33:20.320 and that's actually very different from other species. And I 0:33:20.320 --> 0:33:23.560 would and you know in the book, I talk about 0:33:23.560 --> 0:33:28.120 how you could argue that civilization itself is the product 0:33:28.240 --> 0:33:31.680 of our very special form of cultural inheritance. So in 0:33:31.760 --> 0:33:35.560 talking about non genetic inheritance, you've got potentially epigenetics, though 0:33:35.720 --> 0:33:38.960 the juries out on that, you've got, you've got culture. 0:33:39.200 --> 0:33:42.400 But we should talk a little bit about microbiology. Can 0:33:42.440 --> 0:33:44.680 you tell the story of how you found out that 0:33:44.680 --> 0:33:47.920 your belly button contained bacteria only known to exist in 0:33:47.960 --> 0:33:55.000 the Mariana Trench? Absolutely? Yeah. So I've been incredibly fascinated 0:33:55.040 --> 0:33:57.800 by the microbiome, you know, all the bacteria that live 0:33:57.960 --> 0:34:00.200 on us and in us. For quite some time, him 0:34:00.200 --> 0:34:03.760 In and I have been doing some reporting on it 0:34:03.840 --> 0:34:08.759 as scientists have found new ways to to explore our microbiome. 0:34:09.320 --> 0:34:13.200 And it used to be that you just have to 0:34:13.239 --> 0:34:16.960 scrape you know some you know, a little bit of 0:34:17.320 --> 0:34:20.840 skin or take a stool sample and taken into a 0:34:20.920 --> 0:34:24.759 lab and try to grow bacteria. And the fact is 0:34:24.800 --> 0:34:27.120 that very few of the bacteria that live on us 0:34:27.320 --> 0:34:31.680 uh or in us enjoy being in a petri dish 0:34:31.719 --> 0:34:33.920 on their own. It just it makes them miserable and 0:34:33.960 --> 0:34:38.080 they don't grow. So we had a very impoverished view 0:34:38.400 --> 0:34:44.600 of this inner world until scientists were able to just say, okay, 0:34:44.760 --> 0:34:47.560 we're going to grow into this sample and just grab 0:34:47.600 --> 0:34:49.560 out all the DNA and we're gonna sequence all the 0:34:49.640 --> 0:34:52.040 DNA and from that we're going to figure out what 0:34:52.160 --> 0:34:55.520 is in there. And that totally revolution I studied the 0:34:55.560 --> 0:34:58.400 microbiome because now you didn't have to grow these critters. 0:34:58.440 --> 0:35:01.879 You could just fish out there DNA and look at that. 0:35:02.800 --> 0:35:05.200 So it turns out we have hundreds, maybe thousands of 0:35:05.239 --> 0:35:08.000 species in our guts and on their skin and so 0:35:08.120 --> 0:35:11.279 on and um and so you know, one day at 0:35:11.280 --> 0:35:14.759 a meeting, UM I was walking past a scientist who 0:35:14.800 --> 0:35:17.799 was holding out a qute tip and he said, I'm 0:35:17.800 --> 0:35:20.839 doing a study on people's belly buttons. Would you mind 0:35:20.880 --> 0:35:23.439 giving me some of your belly button lint. Belly button lint, 0:35:23.680 --> 0:35:27.000 and I want to see what's in there, you know, 0:35:27.080 --> 0:35:29.560 and for someone like me, you don't have to ask 0:35:29.600 --> 0:35:31.520 me twice. I'm like, give me that cute tip. So 0:35:31.680 --> 0:35:33.560 you know, I go off into the bathroom and I, 0:35:33.680 --> 0:35:36.080 you know, fiddle around and dunt get in a little tube. 0:35:36.120 --> 0:35:38.759 But they gave me and handed it back. And then 0:35:38.800 --> 0:35:41.160 they went off and they looked at all the DNA 0:35:41.400 --> 0:35:44.440 there was on that cute tip, and you know, a 0:35:44.520 --> 0:35:46.440 lot of it was my own skin cells, but then 0:35:46.480 --> 0:35:48.840 a whole lot of it was not um. And actually 0:35:48.880 --> 0:35:54.120 they identified fifty three species as I recall, of bacteria 0:35:54.600 --> 0:35:59.160 just in my belly button, and uh, it was amazing 0:35:59.320 --> 0:36:03.480 to to look at, uh the information about each of 0:36:03.520 --> 0:36:08.479 those species. And so one of them it had only 0:36:09.200 --> 0:36:12.120 it's only known from a sample at the bottom of 0:36:12.120 --> 0:36:15.120 the ocean. They marry on a trench um. And there's 0:36:15.120 --> 0:36:18.319 another one that I have that's only been found in 0:36:18.960 --> 0:36:25.040 soil in Japan. I've never been to Japan, so um. 0:36:25.080 --> 0:36:27.800 But you know, this was entirely unsurprising to this scientist, 0:36:27.960 --> 0:36:31.600 because you know, he was looking at lots of people 0:36:31.680 --> 0:36:34.080 and was finding people with you know, over a hundred 0:36:34.120 --> 0:36:36.799 species just in their belly button alone and from all 0:36:36.800 --> 0:36:39.279 sorts of different places. UM. So what does this have 0:36:39.360 --> 0:36:43.040 to do with heredity? Well, you know, I I did 0:36:43.040 --> 0:36:49.160 not inherit that marry on a trench bacteria from my parents. UM. 0:36:49.200 --> 0:36:51.600 It's just you know, we have all of this, these 0:36:51.640 --> 0:36:55.319 these bacteria in the environment, um, and some of them 0:36:55.320 --> 0:37:00.440 have become very well adapted to living on our body um, 0:37:00.480 --> 0:37:03.920 and we just pick them up um through our life. 0:37:04.120 --> 0:37:08.440 But it does seem that the microbiome that there is 0:37:08.480 --> 0:37:13.160 some heredity to it. UM. The best examples come from 0:37:13.160 --> 0:37:18.520 certain animals like that passed down bacteria to their offspring. 0:37:18.960 --> 0:37:22.200 Then these bacteria can only live inside these animals, and 0:37:22.360 --> 0:37:25.720 without those bacteria, these animals die. The cockroaches are actually 0:37:25.760 --> 0:37:28.400 a great example of this. So you know, one reason 0:37:28.400 --> 0:37:31.520 the cockroaches are so successful is because they harbor one 0:37:31.560 --> 0:37:35.399 species of bacteria in a special little organ um where 0:37:35.400 --> 0:37:39.000 it breaks down some of their food and gives them nutrients. Um. 0:37:39.040 --> 0:37:42.000 And these bacteria never live outside of the cockroaches, and 0:37:42.160 --> 0:37:46.799 actually they're they're sitting inside of cockroach cells and then 0:37:46.800 --> 0:37:50.920 in the female cockroaches, those cells crawl over to an 0:37:50.920 --> 0:37:54.960 egg and rip open, and then the bacteria infect the eggs, 0:37:55.040 --> 0:37:59.640 so that cockroaches are born completely infected with these bacteria. 0:38:00.480 --> 0:38:03.480 That's that to me, just seems that's heredity. I mean, 0:38:03.920 --> 0:38:06.760 these bacteria are being passed down from millions of years 0:38:06.800 --> 0:38:10.920 from parents to offspring. Um. So the question now is, well, 0:38:10.920 --> 0:38:15.640 are is that true for humans? Um? Maybe not, uh, 0:38:15.840 --> 0:38:18.560 you know, in that particular way, but um, you know, 0:38:18.600 --> 0:38:20.840 it is possible that there are a lot of species 0:38:20.840 --> 0:38:23.960 that are very much adapted to us. You know, maybe 0:38:23.960 --> 0:38:26.719 mothers are passing down certain kinds of bacteria and the 0:38:26.840 --> 0:38:31.319 birth canal or during breastfeeding. Um. And maybe the most 0:38:31.400 --> 0:38:34.239 dramatic example of all is that in all of ourselves 0:38:34.800 --> 0:38:38.439 we generate fuel with these little blobs called mitochondria, which 0:38:38.480 --> 0:38:41.640 have their own DNA in them. And the reason they 0:38:41.680 --> 0:38:44.319 have their own DNA is because they started out as 0:38:44.400 --> 0:38:48.560 bacteria and about two billion years ago and our single 0:38:48.600 --> 0:38:53.160 celled ancestors, those bacteria infected our ancestors and then took 0:38:53.239 --> 0:38:56.799 up permanent residence in there and we cannot live without 0:38:56.840 --> 0:39:01.400 them today. So um so, so MicroB is gonna have 0:39:01.440 --> 0:39:05.120 a very powerful part in heredity. Do you think our 0:39:05.440 --> 0:39:09.440 expanding consciousness about the full scope of heredity, from like 0:39:09.600 --> 0:39:15.120 cross generation into symbionts or even to camerism, should force 0:39:15.280 --> 0:39:18.720 us to re examine our ideas about what it means 0:39:18.760 --> 0:39:22.040 to be an individual and individual animal and what the 0:39:22.080 --> 0:39:27.480 biological and categorical boundaries of the self really are. Absolutely, uh, 0:39:27.520 --> 0:39:32.200 you know, I think that uh, you know, heredity does 0:39:32.280 --> 0:39:36.440 not actually follow a lot of the simple rules that 0:39:36.520 --> 0:39:40.040 we assume it does, uh, and it and it does 0:39:40.280 --> 0:39:43.400 bring into question what it means to be an individual 0:39:43.640 --> 0:39:50.399 because you know, we think of he started out with 0:39:50.880 --> 0:39:54.400 some original genome in a fertilized egg, so we inherited 0:39:54.560 --> 0:39:57.000 half of that genome for me to our parents. It 0:39:57.080 --> 0:40:01.520 came together in this new combination and that's us. But 0:40:02.120 --> 0:40:06.400 you know that is not actually us. Um and in 0:40:06.520 --> 0:40:09.440 lots of different ways. So in one way, I mean, 0:40:09.440 --> 0:40:13.160 if you actually follow the cells that divide in an embryo, 0:40:14.440 --> 0:40:18.319 those cells can mutate and then you tate again and 0:40:18.360 --> 0:40:21.880 youtate again, so that if you were to look at, say, 0:40:21.960 --> 0:40:24.680 any two neurons in your brain, they would be different 0:40:24.719 --> 0:40:29.959 from each other because they have acquired different mutations as 0:40:30.040 --> 0:40:34.160 we developed. UM. So there is no one genome in 0:40:34.200 --> 0:40:37.680 our body because we are what scientists say call us 0:40:37.680 --> 0:40:43.719 our mosaics. UM. But then that's not the not the 0:40:43.800 --> 0:40:46.320 end of it. Um. So you know, we think of 0:40:46.400 --> 0:40:50.040 heredity is going down through the generations, but heredity can 0:40:50.080 --> 0:40:56.000 also come back up in reverse. Uh. And so one 0:40:56.040 --> 0:41:01.800 example of this is um when when and become pregnant, uh, 0:41:02.320 --> 0:41:05.480 cells from their fetus will circulate around in their blood. 0:41:06.560 --> 0:41:09.640 You can actually you can actually draw blood from a 0:41:09.640 --> 0:41:14.600 pregnant woman and sequence the genome of the fetus. Uh. 0:41:14.880 --> 0:41:18.920 We that is done in a regular basis. Now uh 0:41:19.160 --> 0:41:24.160 after pregnancy, Uh, those fetal cells may go away because 0:41:24.160 --> 0:41:27.040 of the mother's immune system is clearing them out. But 0:41:28.200 --> 0:41:32.719 surprisingly often UH those cells can establish them cells in 0:41:32.880 --> 0:41:37.440 a mother's liver or thyroid gland, even her brain. And 0:41:37.760 --> 0:41:42.919 scientists refer to uh such people as chimeras. Um. It's 0:41:43.080 --> 0:41:47.400 after the you know, the beast of Greek mythology. And 0:41:47.440 --> 0:41:51.400 you can get chimeras also from twins in the womb 0:41:51.640 --> 0:41:57.160 who are sharing DNA sharing cells uh. And so you 0:41:57.200 --> 0:42:01.080 can literally like have um. You know that one of 0:42:01.120 --> 0:42:05.200 the first discoveries of this was a woman who gave 0:42:05.239 --> 0:42:10.720 blood in the nineteen fifties and totally baffled the blood 0:42:10.719 --> 0:42:13.080 bank because she was giving two types of blood at 0:42:13.080 --> 0:42:16.160 the same time. And he said, this is not possible. 0:42:16.320 --> 0:42:19.080 You know, there must be some contamination somewhere. But it 0:42:19.120 --> 0:42:23.200 turned out that her blood was made up from two individuals, 0:42:23.239 --> 0:42:25.920 herself and a twin who had died when he was 0:42:27.400 --> 0:42:30.840 in infancy. Uh. And so you know, and this is 0:42:30.840 --> 0:42:34.920 not something that's rare. Timerism is probably quite common among humans, 0:42:34.920 --> 0:42:38.719 and it really challenges these these ideas that we we 0:42:38.800 --> 0:42:42.840 tell ourselves about heredity and individuality. One of the weirdest 0:42:42.880 --> 0:42:45.440 and most interesting types of heredity you discussed in the 0:42:45.440 --> 0:42:47.560 book is that I think you said it's eight or 0:42:47.680 --> 0:42:52.319 so lines of contagious cancer found in nature so far. 0:42:52.440 --> 0:42:55.719 Can you talk a little bit about contagious cancer and 0:42:55.800 --> 0:42:58.640 does it make sense to think of this cancer as 0:42:58.680 --> 0:43:01.920 an independent animal or organism of its own type, or 0:43:02.000 --> 0:43:06.839 as sort of an infection from an original animals genome. Yeah, 0:43:06.960 --> 0:43:11.200 this is where credity gets really weird, because you know, 0:43:11.640 --> 0:43:18.040 when when cancer arises in our bodies, it's a it's 0:43:18.040 --> 0:43:22.560 another one of these cases of mosaicism. In other words, Uh, 0:43:22.560 --> 0:43:25.719 these cancer cells are gaining mutations that the rest of 0:43:25.760 --> 0:43:29.799 the body doesn't have, and those mutations allow them to 0:43:29.880 --> 0:43:35.760 reproduce quickly and to be very aggressive and destructive. Now, 0:43:36.080 --> 0:43:42.120 UM cancer usually UH, you know, either is wiped out 0:43:42.640 --> 0:43:47.400 by the body or is lethal. In either case, you 0:43:47.440 --> 0:43:51.839 don't have cancer surviving beyond the life of its host. 0:43:52.920 --> 0:43:56.440 We we think of that as being weird, but it 0:43:56.560 --> 0:44:01.919 turns out that in fact cancer can endure UM. And 0:44:02.000 --> 0:44:07.880 this was really first discovered UM in in a uh 0:44:07.920 --> 0:44:12.400 in a case with dogs where dogs would be uh 0:44:12.560 --> 0:44:17.080 developing UM these these tumors UH, and it was very 0:44:17.120 --> 0:44:21.120 odd that they the cancer seemed to spread like an 0:44:21.120 --> 0:44:24.839 infectious disease, and so people scratching their head over this, 0:44:24.920 --> 0:44:27.719 and then they realized that actually what had happened was 0:44:27.760 --> 0:44:32.040 that the cancer cells themselves were spreading from one dog 0:44:32.080 --> 0:44:35.120 to another to another UM and so that the cancer 0:44:35.160 --> 0:44:37.360 cells were not in fact related to the dogs that 0:44:37.400 --> 0:44:40.960 they were in. And if you look at the DNA 0:44:41.080 --> 0:44:45.120 of this cancer, it goes back to some dog that 0:44:45.200 --> 0:44:49.040 lived maybe ten thousand years ago, and it has just 0:44:49.080 --> 0:44:52.440 been spreading from dog to dog ever since, and it's 0:44:52.480 --> 0:44:56.239 been mutating along the way. And it's and so it's 0:44:56.320 --> 0:44:59.520 the thing that you know, it's it's what you call it. 0:44:59.600 --> 0:45:01.400 I mean I don't know what we could call it, 0:45:01.440 --> 0:45:04.600 but you know, some have argued that it should be 0:45:04.680 --> 0:45:08.360 just given its own species name, because it's it's this, 0:45:09.360 --> 0:45:12.080 it's this lineage of animal cells that has its own 0:45:12.120 --> 0:45:14.640 genome UM, and has its own way of getting around 0:45:14.680 --> 0:45:18.040 in the world. It's it's doing just flying UM. So 0:45:18.680 --> 0:45:21.359 surely it deserves a name. UM. And then it turns 0:45:21.360 --> 0:45:23.680 out that in a few other cases, scientists have founded 0:45:23.680 --> 0:45:27.880 another species, so Tasmanian devils in Tasmania, they get a 0:45:27.880 --> 0:45:32.400 facial tumor because they bite each other when they're fighting, 0:45:32.880 --> 0:45:35.799 and they spread this cancer to each other. UM. And 0:45:36.200 --> 0:45:38.719 this this cancer has actually arisen a couple of times 0:45:38.719 --> 0:45:42.560 in Tasmania just in recent decades, so it isn't something 0:45:42.680 --> 0:45:47.319 that only happened once a long time ago. And what's 0:45:47.719 --> 0:45:50.440 most mind blowing is that some scientists stumbles across this 0:45:50.600 --> 0:45:54.480 yet again, just in the past few years, UH in clams, 0:45:54.480 --> 0:45:59.440 in shellfish UH and have discovered that there there's contagious 0:45:59.440 --> 0:46:03.319 cancer in the ocean. UM. So you're swimming. As you're 0:46:03.360 --> 0:46:06.200 swimming in the ocean, you're swimming around cancer cells that 0:46:06.239 --> 0:46:09.759 are moving from host to host. An infectious cancer as 0:46:09.800 --> 0:46:12.080 its own type of organism. What kingdom of life would 0:46:12.120 --> 0:46:16.440 that be? Would it be an animal? I yes, it 0:46:16.480 --> 0:46:19.520 would be an animal simply because it's descended from animals. Yeah, 0:46:19.719 --> 0:46:22.120 I mean I would say they would have to be given, 0:46:22.360 --> 0:46:25.040 you know, a place in the animal kingdom. But and 0:46:25.160 --> 0:46:27.360 you know, maybe you should just still call it like 0:46:27.400 --> 0:46:30.160 a species of you know, maybe the dog cancer should 0:46:30.200 --> 0:46:35.080 be a species of dog. Maybe you know, canus canus 0:46:35.120 --> 0:46:37.680 cancer or something. I don't know, I don't know, um, 0:46:38.400 --> 0:46:42.640 but you know it's and you know, when when and 0:46:42.680 --> 0:46:45.120 when you talk about or what makes up an animal, 0:46:45.320 --> 0:46:48.440 you know, like, uh, what makes up up us? You know, 0:46:48.520 --> 0:46:50.880 like we think of cancer cells as being part of ourselves. 0:46:50.920 --> 0:46:54.920 They they originate from our own cells. But um, imagine 0:46:54.960 --> 0:46:57.839 if your body was actually made up of your own 0:46:57.840 --> 0:47:02.040 cells and then cells that came from someone ten years ago, 0:47:02.680 --> 0:47:06.560 that that would be weird. Yeah. Alright, time for a 0:47:06.600 --> 0:47:09.200 quick break. Then we will be right back for more 0:47:09.360 --> 0:47:13.960 of our conversation with Carl zimmer Than. All right, we're 0:47:14.000 --> 0:47:17.520 back now. We can't talk about the future of heredity 0:47:17.560 --> 0:47:21.800 without touching on crisper. How is this technology affecting the 0:47:22.120 --> 0:47:25.520 future of human redity? Well, you know, we're going to 0:47:25.640 --> 0:47:30.560 have to wait and see exactly what happens, but certainly 0:47:30.760 --> 0:47:35.839 the potential is profound. UM Crisper is just a few 0:47:35.920 --> 0:47:39.480 years old, and it's this is this technology essentially to 0:47:40.239 --> 0:47:43.480 zero in on any particular bit of DNA, cut it out, 0:47:44.239 --> 0:47:48.400 and if you want, insert a different little stretch of 0:47:48.440 --> 0:47:52.719 DNA in there. So um, this raises the possibility of 0:47:52.760 --> 0:47:57.680 being able to cure hereditary diseases by rewriting uh, the 0:47:57.760 --> 0:48:01.000 DNA in cells, you know, to repair or a faulty gene. 0:48:02.480 --> 0:48:05.520 But what some scientists have been already exploring is, well, 0:48:05.560 --> 0:48:09.400 what if you take human embryonic cells. What if you 0:48:09.440 --> 0:48:11.919 take you know, human embryos are just a tiny little 0:48:11.960 --> 0:48:16.480 cluster just you know, seven or eight cells, and you 0:48:16.600 --> 0:48:20.960 use Crisper to rewrite their DNA. UM, let's say you 0:48:21.000 --> 0:48:24.520 fix a hereditary disease in just this handful of just 0:48:24.640 --> 0:48:28.440 as few cells. Well that if if you if that 0:48:28.680 --> 0:48:31.680 if a person were to develop from those cells, they 0:48:31.719 --> 0:48:35.520 they would have Crisper altered genes throughout their whole body, 0:48:35.880 --> 0:48:38.400 and if they were to have children, they would pass 0:48:38.440 --> 0:48:44.239 on those Crisper altered genes as well. And so you 0:48:44.280 --> 0:48:50.680 know that that that these experiments have already begun on 0:48:50.680 --> 0:48:54.640 on these tiny little human embryos, and so really, you 0:48:54.640 --> 0:48:57.799 know what what needs to happen now is for us 0:48:57.840 --> 0:49:03.720 to have a really a kind of global conversation about 0:49:04.160 --> 0:49:07.120 whether we want to use this or not, whether it's safe, 0:49:07.160 --> 0:49:11.640 whether it's ethical, UM, how do we feel about who 0:49:11.680 --> 0:49:14.759 should have access to this? UM? Do we have the 0:49:14.840 --> 0:49:21.080 right to alter future generations? Um? And you know we 0:49:21.840 --> 0:49:26.759 and maybe we'll feel comfortable with, say, you know, eradicating 0:49:26.800 --> 0:49:30.640 hunting news disease. But what if somebody says, well, yeah, 0:49:30.719 --> 0:49:32.719 but I want I'm using IVF and I want to 0:49:32.800 --> 0:49:36.120 just give my kids, Uh, this mutation that we know 0:49:36.239 --> 0:49:39.040 reduces your odds of getting Alzheimer's? Could I do that 0:49:39.120 --> 0:49:42.399 as well? And then you know what if you add 0:49:42.400 --> 0:49:44.160 on other things? What if you add on things that 0:49:44.160 --> 0:49:47.640 are not don't have to do with immediately treating some 0:49:47.800 --> 0:49:52.759 pready disorder, but you know, change a trait, change, hair color, change, height, change, 0:49:52.760 --> 0:49:55.440 all these things are people who are going to be 0:49:55.480 --> 0:49:59.200 comfortable with that, UM and this all you know this 0:50:00.000 --> 0:50:04.040 science fiction writers have had a monopoly on this conversation 0:50:04.120 --> 0:50:06.800 until now, but I think that everybody else needs to 0:50:06.840 --> 0:50:09.840 be talking about it too now as far as crisper 0:50:09.920 --> 0:50:15.399 altered genes go, given like a near future scenario, would 0:50:15.440 --> 0:50:17.680 they be detectable? What would somebody be able to say 0:50:18.200 --> 0:50:20.640 to to look at individual's genome and say, oh, well 0:50:20.760 --> 0:50:23.880 you've had there's gene altering evidence here. Or would a 0:50:24.280 --> 0:50:27.800 future civilization be able to look back at our genetic 0:50:27.800 --> 0:50:30.279 information and say, oh, well look here in this particular 0:50:30.320 --> 0:50:34.360 family line, we see evidence of of of of crisper alteration. 0:50:34.920 --> 0:50:39.040 That's an interesting question. Um, I I think you would. 0:50:39.080 --> 0:50:43.680 I think that it would be possible if the people 0:50:43.760 --> 0:50:49.160 doing the crisper changing um left behind, you know, a 0:50:49.360 --> 0:50:51.600 mark of what they were doing, you know, a little 0:50:51.719 --> 0:50:54.160 water mark. Think of it that way. You know, some 0:50:54.360 --> 0:50:59.960 distinctive sequence of non coding DNA nearby that basically says hello, 0:51:00.280 --> 0:51:04.719 you know this is this, this crisper alteration has brought 0:51:04.760 --> 0:51:08.840 to you courtesy of such and such hospital. You know, UM, 0:51:08.880 --> 0:51:11.800 you could totally encode a message in DNA people. You know, 0:51:11.840 --> 0:51:15.400 people have enquoded entire books in DNA now, so you 0:51:15.440 --> 0:51:20.080 could do that. Um, But if you if somebody decided 0:51:20.120 --> 0:51:22.560 not to leave a water mark, then no, actually, I 0:51:22.880 --> 0:51:27.399 think it might be very difficult to um to say, oh, well, 0:51:27.400 --> 0:51:33.360 this person descends from a crispered ancestor knowing knowing tech companies. 0:51:33.400 --> 0:51:35.200 I know we'd end up with like thirty page el 0:51:35.320 --> 0:51:38.760 agreements in there, sure absolutely, But you know the problem 0:51:38.840 --> 0:51:40.879 is that you know that over the generations that would 0:51:40.880 --> 0:51:45.759 get that agreement would mutate and uh, you know, the 0:51:45.840 --> 0:51:48.760 legal language would would change into things that the lawyers 0:51:48.760 --> 0:51:53.680 didn't have in mind. So given the great power that 0:51:53.800 --> 0:51:57.600 crisper has to to allow us to alter our chenes, 0:51:58.080 --> 0:52:00.560 what what do you think are the best is you've 0:52:00.600 --> 0:52:05.000 heard about how to guide it in a way that's 0:52:05.000 --> 0:52:08.880 that's fair, that's uh going to have good outcomes and 0:52:08.920 --> 0:52:12.360 not bad that uh you know the people have access 0:52:12.440 --> 0:52:16.240 to in in equitable ways. I mean, have you encountered 0:52:16.280 --> 0:52:19.320 anybody who has done the best what you would consider 0:52:19.360 --> 0:52:22.680 the best thinking so far on the ethics of gene alteration? 0:52:23.000 --> 0:52:25.680 You know, I I in the United States, the government 0:52:25.719 --> 0:52:31.760 is really just being very uh emphatic and not wanting 0:52:31.800 --> 0:52:35.720 to really talk about these issues at all. So uh, 0:52:35.760 --> 0:52:39.160 you know, not only is it not allowed to do 0:52:39.360 --> 0:52:42.440 germ line modification, but you can't do any research that 0:52:42.520 --> 0:52:47.200 might lead to that, and so um, we're not really 0:52:47.239 --> 0:52:50.799 having a meaningful conversation in the United States. Yet I 0:52:50.840 --> 0:52:56.239 think UM and UH. Unfortunately, what that means is that 0:52:56.400 --> 0:52:59.719 people are going to want to go to other countries 0:53:00.520 --> 0:53:04.719 where there is no particular regulation one or the other 0:53:04.880 --> 0:53:09.319 and do that in you know, in UM, in you know, 0:53:09.360 --> 0:53:13.080 clinics or that are hidden from view. UM. And in 0:53:13.120 --> 0:53:15.480 my book I talk about one case where actually this 0:53:15.560 --> 0:53:19.640 has already happened. UM. A couple went to Mexico and 0:53:19.640 --> 0:53:24.840 an American doctor joined them there to uh to basically 0:53:25.239 --> 0:53:29.799 replace the mitochondria in this woman's eggs with with healthy, 0:53:29.840 --> 0:53:33.920 healthy ones. UM. So you know, there are some genetically 0:53:33.960 --> 0:53:38.600 modified people alive today. UM. There there are a few, UM, 0:53:38.719 --> 0:53:44.880 but they're they're already here. UM. But they I think 0:53:45.000 --> 0:53:47.919 that it's a better, better way to deal with this 0:53:48.080 --> 0:53:52.760 is what England is doing. So in England this treatment 0:53:52.800 --> 0:53:57.279 called mitochondrial replacement therapy. UM. There was there was a 0:53:57.280 --> 0:54:00.279 lot of research that was done on it, um uh 0:54:01.239 --> 0:54:05.279 using animals, using using you know, eggs, human eggs, and 0:54:05.280 --> 0:54:09.560 so on and then UM and then Parliament actually had 0:54:09.560 --> 0:54:13.640 a big, full debate about it and you know, the 0:54:13.680 --> 0:54:16.920 advantages and the possible risks and the ethics and so on, 0:54:17.480 --> 0:54:19.759 and then they decided, well, we're going to allow this 0:54:19.840 --> 0:54:22.880 to happen, but it's going to happen under these rules. 0:54:23.920 --> 0:54:26.919 So you know, you can't just like walk into any 0:54:27.000 --> 0:54:29.560 doctor's office and get this therapy like that. You know, 0:54:29.560 --> 0:54:33.520 we're gonna really make really uh take We're gonna take 0:54:33.560 --> 0:54:36.480 real care to make sure that this has done safely 0:54:36.680 --> 0:54:40.560 and responsibly and under the right circumstances. And so now 0:54:40.600 --> 0:54:43.600 there is a university that has actually you know, gotten 0:54:43.640 --> 0:54:47.680 permission to basically open their doors for business UM. And 0:54:47.760 --> 0:54:51.280 I think that's the way to go UM, because then 0:54:51.400 --> 0:54:53.719 you can you can have these discussions and say, like, 0:54:53.760 --> 0:54:57.960 you know what, as a society, we don't want uh 0:54:58.320 --> 0:55:01.440 people to be trying to make their kids more intelligent 0:55:01.440 --> 0:55:04.080 by altering their genes. We think that's a that's bad 0:55:04.200 --> 0:55:06.480 for individuals and bad for society. We're not going to 0:55:06.560 --> 0:55:10.680 allow it. Um, and that will actually happen rather than 0:55:10.760 --> 0:55:14.160 sending people to other countries to have you know, possibly 0:55:14.280 --> 0:55:18.439 dangerous treatments. UM. That's the way I think uh things 0:55:18.440 --> 0:55:21.640 should go. UM. And you can see an example of 0:55:21.680 --> 0:55:24.279 it in England. And it would be great if if 0:55:24.320 --> 0:55:27.080 the United States could follow suit, you know, on this 0:55:27.120 --> 0:55:30.160 show a lot we talk about how often like science 0:55:30.200 --> 0:55:33.120 fiction is sort of the playground for people working out 0:55:33.160 --> 0:55:36.280 these problems before they're dealt with in the real world. 0:55:36.400 --> 0:55:40.160 Have you encountered any any science fiction or fiction in 0:55:40.200 --> 0:55:43.560 general that you thought did a good job of dealing 0:55:43.640 --> 0:55:47.680 with you know, raised the interesting questions, had intelligent things 0:55:47.719 --> 0:55:51.240 to say about the implications of genetic engineering and humans. 0:55:51.480 --> 0:55:55.400 Oh yeah, I think that there's a long tradition of 0:55:56.600 --> 0:56:01.960 genetic engineering in science fiction. Um and uh and even 0:56:02.000 --> 0:56:05.080 before people really knew what genetic engineering was. You know, 0:56:05.080 --> 0:56:08.640 A Brave New World is a fascinating book even now. 0:56:08.800 --> 0:56:13.000 I mean, and it's amazing when you think how um, 0:56:13.120 --> 0:56:19.440 how much uh uh was just only discovered after the 0:56:19.480 --> 0:56:25.600 publication of the book. Um and I I find that 0:56:25.640 --> 0:56:28.800 one quite quite prophetic. I think the problem with science 0:56:28.800 --> 0:56:33.719 fiction comes when people think that anything can happen. That 0:56:34.080 --> 0:56:39.240 when people think that biology allows anything you can imagine 0:56:39.320 --> 0:56:43.439 to be a possibility. Um and the fact is that 0:56:44.040 --> 0:56:47.160 biology doesn't work that way. And so you know, when 0:56:47.160 --> 0:56:51.400 when we're actually talking, you know, today about well, what 0:56:51.480 --> 0:56:58.600 are the real possibilities that Crisper could create? I think 0:56:58.640 --> 0:57:00.840 we need to sort of I think we need to 0:57:00.880 --> 0:57:03.560 make sure that we're not um, just letting our fantasies 0:57:03.640 --> 0:57:06.040 run wild. You know. Some people have said, like, oh, 0:57:06.080 --> 0:57:09.480 well you'll just be able to um Christoper your kid 0:57:09.600 --> 0:57:13.200 and and turn them into a genius. UM. And that 0:57:14.560 --> 0:57:19.400 it's not what science indicates. I mean, you know, intelligence 0:57:19.560 --> 0:57:24.800 is this incredibly complex phenomenon that is, you know, influenced 0:57:24.840 --> 0:57:28.160 by genes, it's influenced by the environment. It's partly a 0:57:28.240 --> 0:57:30.640 social thing, you know, in terms of like you know, 0:57:30.680 --> 0:57:34.120 intelligence really sort of gaining its meaning in you know, 0:57:34.160 --> 0:57:39.320 in a society. UM. And you can't just zoom in 0:57:39.360 --> 0:57:41.080 on a on a few genes and make a tweak 0:57:41.120 --> 0:57:43.240 here and there and say ah ha, like now my 0:57:43.400 --> 0:57:46.040 child is going to you know, get into the very 0:57:46.080 --> 0:57:49.120 best colleges. It just does not work that way. UM. 0:57:49.600 --> 0:57:55.439 And and I think that if people just go ahead 0:57:55.480 --> 0:58:00.000 with it anyway, UM, those children are going to be born, um, 0:58:00.080 --> 0:58:03.360 not just with these odd little changes to their genes, 0:58:03.400 --> 0:58:07.080 but with a whole huge set of expectations um from 0:58:07.120 --> 0:58:10.040 their parents. You know, I spent a hundred thousand dollars 0:58:10.040 --> 0:58:12.080 to change your genes to make you a genius. And 0:58:12.600 --> 0:58:16.400 why are you getting these grades in math? What's what's 0:58:16.400 --> 0:58:20.000 wrong with you? I just see a That's where I 0:58:20.040 --> 0:58:24.320 see the real dystopia emerging. Is just expecting heredity to 0:58:24.400 --> 0:58:28.080 do much more than it can possibly do, uh to 0:58:28.080 --> 0:58:31.360 to alter ourselves. That's really interesting and it raises another 0:58:31.440 --> 0:58:34.440 question that definitely comes up in the book, which is 0:58:34.480 --> 0:58:37.520 that even when we're talking about traits that are to 0:58:37.760 --> 0:58:41.280 some large extent heritable, what are some of the reasons 0:58:41.320 --> 0:58:44.040 that it can create misunderstandings for us to talk about 0:58:44.080 --> 0:58:47.959 there being quote a gene for a certain trait. Yeah, 0:58:48.080 --> 0:58:51.800 we really have come to look at genes as being 0:58:51.840 --> 0:58:56.520 all powerful and and that is a real mistake and 0:58:56.640 --> 0:59:00.920 it's but it's hard to really um get your head 0:59:00.960 --> 0:59:06.560 around the paradox of heredity in this regard um. And 0:59:06.600 --> 0:59:08.720 one of the examples I like to talk about is height. 0:59:09.480 --> 0:59:11.480 You know, height seems like it's simple, like it's just 0:59:12.520 --> 0:59:14.760 it's just a number that you get off a tape measure, 0:59:14.960 --> 0:59:18.200 Like how hard could that be to understand? But you know, 0:59:18.280 --> 0:59:23.080 in in fact, um, you know, heredity is this very 0:59:23.120 --> 0:59:27.520 weird mix of genes in the environment. Um, you know 0:59:27.640 --> 0:59:31.960 gene so height is is very what scientist say, very heritable, 0:59:32.320 --> 0:59:36.520 meaning that if you look at the variation among people 0:59:37.600 --> 0:59:40.120 in a particular population. Why are they tall, why are 0:59:40.120 --> 0:59:43.480 they're short? Uh, you can explain a lot of that 0:59:43.560 --> 0:59:46.880 because of the genes that they inherited from their parents. 0:59:46.880 --> 0:59:50.400 So tall parents tend to have tall children, short parents 0:59:50.400 --> 0:59:53.040 tend to have short children. And it's so that means 0:59:53.040 --> 0:59:56.680 it's very heritable. UM. But that does not mean that, 0:59:57.200 --> 1:00:00.600 you know, height is somehow um law sped in and 1:00:00.720 --> 1:00:03.360 fixed that. It does not mean that you can actually, 1:00:04.000 --> 1:00:07.960 you know, finally predict um the you know how tall 1:00:07.960 --> 1:00:11.000 it could will be, just based on their genes. In fact, 1:00:11.040 --> 1:00:13.200 we didn't even know about any of these genes until 1:00:13.800 --> 1:00:17.240 the past decade or so. Uh. And now scientists are 1:00:17.240 --> 1:00:21.120 discovering literally thousands of genes that influence height, each one 1:00:21.160 --> 1:00:23.600 in a tiny little bit. You know, I got my 1:00:23.640 --> 1:00:27.240 genome sequence and discovered you know that I had. It's 1:00:27.320 --> 1:00:29.960 very interested to find that a one particular gene. It 1:00:30.040 --> 1:00:32.120 was the first gene that was ever linked to height 1:00:32.640 --> 1:00:37.680 in population. And uh, I'm I'm about an eighth of 1:00:37.680 --> 1:00:39.720 an inch taller than it would be otherwise because of 1:00:39.720 --> 1:00:43.480 the variant that I have, So you know, it's it's 1:00:43.480 --> 1:00:47.520 almost invisible. UM. But you know, the genetic influence just 1:00:47.920 --> 1:00:51.480 is the some of all of these different variants. UM. 1:00:51.640 --> 1:00:54.960 And yet on top of all of that, UM, you know, 1:00:55.040 --> 1:00:57.520 you can have, you know, all the tall genes you want, 1:00:57.640 --> 1:01:00.640 but if you're not getting a good diet when you're 1:01:00.640 --> 1:01:04.920 a kid, and if you're facing dysentery on a regular basis, 1:01:04.960 --> 1:01:06.920 you're just not going to grow that tall because your 1:01:06.920 --> 1:01:11.440 body is going to be basically channeling all those resources 1:01:11.520 --> 1:01:16.280 to fighting disease and to you know, fight defend against starvation. 1:01:17.400 --> 1:01:20.080 And you know, on top of that, even more amazing 1:01:20.120 --> 1:01:22.320 to me is that in the whole world has actually 1:01:22.320 --> 1:01:26.160 gotten several inches taller over the past century because life 1:01:26.200 --> 1:01:29.320 overall is better. You know, there's more people have a 1:01:29.320 --> 1:01:34.840 better nutrition, better medicine. Education probably plays a role in this. Uh. 1:01:34.840 --> 1:01:39.760 And so it's not that people inherited you know, quote 1:01:39.800 --> 1:01:43.880 unquote tall genes, it's that they inherited a world that 1:01:44.120 --> 1:01:47.800 favors greater height. So I've got one last question that 1:01:47.880 --> 1:01:50.440 might be kind of weird, but we'll see what you 1:01:50.480 --> 1:01:53.920 think of it. I often hear hear people talking about 1:01:54.720 --> 1:01:58.440 their relationship with their own genome, um with their own 1:01:58.480 --> 1:02:03.360 genes into basic ways. One is self identification, you know, 1:02:03.400 --> 1:02:06.440 it's like, my genes are why I am like X, 1:02:06.480 --> 1:02:09.040 and so there there's a sort of I identify with 1:02:09.080 --> 1:02:12.600 my genes mentality. And then there's a kind of antagonistic 1:02:13.840 --> 1:02:15.680 kind of thing people think about with their genes, like 1:02:15.920 --> 1:02:20.240 the genes are this other disembodied force that made them 1:02:20.920 --> 1:02:23.040 and it's almost like another person that they have to 1:02:23.040 --> 1:02:26.280 negotiate with in some way. To what extent do you, 1:02:27.600 --> 1:02:30.120 given all of the research you've done and after having 1:02:30.120 --> 1:02:33.280 written this book, to what extent do you feel you 1:02:33.360 --> 1:02:36.600 are your genes or that your genes are this separate 1:02:36.680 --> 1:02:40.680 other force from you as a person. That's interesting. I yeah, 1:02:40.720 --> 1:02:44.000 I've heard that kind of language too, you know. And 1:02:44.120 --> 1:02:47.320 people will get their DNA sequenced and they'll discover they 1:02:47.360 --> 1:02:51.440 have a particular variant linked to some train and say, ah, 1:02:51.480 --> 1:02:55.200 well that's why I do X, Y Z, or or 1:02:55.240 --> 1:02:59.120 they'll discover they have ancestry from a particular place and say, ah, 1:02:59.360 --> 1:03:02.600 well that's why I that's why I like to tell stories, 1:03:02.680 --> 1:03:05.360 or that's why I like to run or what have you. 1:03:05.560 --> 1:03:07.960 Um And you know, you see ads on TV for 1:03:08.040 --> 1:03:10.760 these companies like ancestry dot com that play on that 1:03:11.000 --> 1:03:15.680 exact attitude towards our genes that somehow, you know, what 1:03:15.720 --> 1:03:18.360 we do in our lives is encapsulated in these genes 1:03:18.360 --> 1:03:21.880 that we inherit from our ancestors. Um. And then yeah, 1:03:21.920 --> 1:03:24.600 then there are people who just want to fight against it, um, 1:03:24.640 --> 1:03:27.480 you know, and part of that sometimes feels like, you know, 1:03:27.560 --> 1:03:29.560 it's it's sort of a displaced fight they're having with 1:03:29.600 --> 1:03:32.400 their parents, you know, like I'm not gonna be like 1:03:32.480 --> 1:03:34.720 you were, you know, and I don't care if I 1:03:34.720 --> 1:03:38.440 inherited gens from you. I'm going to be my own person, um, 1:03:38.520 --> 1:03:41.560 I would say, in my own experience. UM. You know, 1:03:41.920 --> 1:03:44.640 I got my genome sequenced and part of the research 1:03:44.680 --> 1:03:47.480 for this book, and I really looked at it very deeply. 1:03:47.520 --> 1:03:51.360 It's been a fascinating experience. But I can't find anything 1:03:51.360 --> 1:03:57.400 in there that is quote unquote me. I think that 1:03:58.400 --> 1:04:01.640 it's just not there, you know. I I was able 1:04:01.680 --> 1:04:04.200 to look at the genes that I inherited from Neandertal, 1:04:04.440 --> 1:04:07.120 you know, tens of thousands of years ago, and you know, 1:04:07.200 --> 1:04:10.200 which is fascinating. But then I say to these scientists, like, Okay, 1:04:10.280 --> 1:04:12.360 you've given me this catalog, got the indertal genes, let's 1:04:12.360 --> 1:04:14.240 talk about them. Like, what what does it mean that 1:04:14.280 --> 1:04:17.240 I inherit this particular Like, here's one gene, Tell me 1:04:17.320 --> 1:04:21.240 about it, and the scientists be like, well, it looks 1:04:21.240 --> 1:04:24.240 like no one actually knows what this gene does at all, 1:04:24.880 --> 1:04:27.040 you know, and then that you're just left there. But 1:04:27.160 --> 1:04:29.800 with the state of the science, you know, maybe I 1:04:29.920 --> 1:04:32.760 found that I have a neandertal gene that UM is 1:04:33.320 --> 1:04:38.520 linked to an increased risk of nose bleeds. I don't know. 1:04:38.840 --> 1:04:40.480 I don't know what to do with that, you know, 1:04:40.840 --> 1:04:43.920 And it also makes me wonder why neandertals might have nosebleeds. 1:04:43.920 --> 1:04:47.120 But that's a whole separate issue. But you know, I 1:04:47.920 --> 1:04:51.360 I don't I I can't say that anything I've done 1:04:51.920 --> 1:04:54.280 looking at my own d d n A has given 1:04:54.280 --> 1:04:58.440 me some deep insight about my inner self as a person, 1:04:58.720 --> 1:05:02.400 you know, as it's much more relevant to me to 1:05:02.440 --> 1:05:06.800 think about, you know, how my parents raised me and 1:05:06.840 --> 1:05:09.360 what my experiences were as a kid, and what it 1:05:09.360 --> 1:05:12.200 has been like, you know, being married and and and 1:05:12.360 --> 1:05:16.400 being a father, Like the lived experience matters much more 1:05:16.440 --> 1:05:20.400 to me than UM than the details of the genome 1:05:20.400 --> 1:05:25.000 I inherited from my parents. UM. And that's that's kind 1:05:25.000 --> 1:05:29.320 of where it stands for me now, all right, yeah, well, well, 1:05:29.320 --> 1:05:31.320 thank you so much, Carl. It's been a real pleasure 1:05:31.320 --> 1:05:34.000 talking to you today, and we appreciate you taking time 1:05:34.040 --> 1:05:36.480 to speak with us. My pleasure, my pleasure. I really 1:05:36.560 --> 1:05:38.760 enjoyed the conversation and I'm I'm glad you enjoyed the book. 1:05:42.360 --> 1:05:44.800 So there you have it. Thanks once again to Carl 1:05:44.880 --> 1:05:48.160 Zimmer for coming on the show and having this wonderful 1:05:48.240 --> 1:05:51.120 chat with us about his new book, She Has Her 1:05:51.160 --> 1:05:54.680 Mother's Laugh, The Powers, Perversions and Potential of Heredity Again. 1:05:54.680 --> 1:05:57.360 That's available in hardback, as a digital and as an 1:05:57.360 --> 1:05:59.920 audiobook right now, and you can check out Carl's website 1:06:00.280 --> 1:06:03.480 Carl Zimmer dot com for even more about him and 1:06:03.560 --> 1:06:07.160 his projects. That's right, go to that website. And hey, 1:06:07.320 --> 1:06:09.520 be sure to check out our website as well. It's 1:06:09.520 --> 1:06:11.440 Stuff to Blow your Mind dot com. That's who you'll 1:06:11.480 --> 1:06:14.680 find all of our episodes. You'll also find links out 1:06:14.720 --> 1:06:16.960 to our various social media accounts, so you can check 1:06:17.000 --> 1:06:19.160 those out as well. I want to remind everybody if 1:06:19.160 --> 1:06:21.320 you want to support the show, one of the best 1:06:21.360 --> 1:06:24.720 things you can do is rate and review us wherever 1:06:24.880 --> 1:06:27.760 you get your podcasts. Big thanks as always to our 1:06:27.800 --> 1:06:31.320 wonderful audio producers Alex Williams and Tarry Harrison. 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