Speaker 1: Welcome to the Psychology Podcast, where we give you insights
Speaker 1: into the mind, brained behavior and creativity. I'm doctor Scott
Speaker 1: Barry Kaufman, and in each episode I have a conversation
Speaker 1: with a guest. He will stimulate your mind and give
Speaker 1: you a greater understanding of yourself, others, and the world
Speaker 1: to live in. Hopefully we will also provide a glimpse
Speaker 1: into human possibility. Thanks for listening and enjoy the podcast.
Speaker 1: So today we have Karl Zimmer on the podcast. Zimmer
Speaker 1: reports from the frontiers of biology, where scientists are expanding
Speaker 1: our understanding of life. Since two thousand and four, he
Speaker 1: has written about science for The New York Times, whereas
Speaker 1: column Matter has appeared weekly since twenty thirteen. Zimmer has
Speaker 1: won many awards for his work, including the Stephen J. Goldprize,
Speaker 1: awarded by the Society for the Study of Evolution to
Speaker 1: recognize individuals whose sustained efforts have advanced public understanding of
Speaker 1: evolutionary science. Zimmer is the author of thirteen books about science,
Speaker 1: and his latest book is She Has Her Mother's Laugh
Speaker 1: The Power, Perversions and Potential of Heredity. Thanks for chatting
Speaker 1: with me today, Carl. Thanks for having me. I remember
Speaker 1: when I was a wee grad student at Yale and
Speaker 1: you came to do I was so excited that I
Speaker 1: got selected to be in this little group of people
Speaker 1: to talk to the great Carl Zimmer about public science communication.
Speaker 1: Do you remember that? Like it was like we're talking
Speaker 1: like a decade ago. Yeah. I've been doing it every
Speaker 1: spring since with some Bale graduate students. Just you know,
Speaker 1: the the interest is just getting stronger and stronger. I
Speaker 1: think grad students who are looking at a future in science,
Speaker 1: you know, realize that, you know, part of it is
Speaker 1: connecting with everybody else. They don't look at science purely
Speaker 1: as just collecting data. That's right. And I remember listening
Speaker 1: to you talk and thinking to myself, I want to
Speaker 1: do what that guy does someday, you know. So I see,
Speaker 1: really we're in an inspiration You're the way that you write,
Speaker 1: The way that you write is balanced, and I think
Speaker 1: that's what we need more of in the science communication world,
Speaker 1: is balance. Right, So this book. Let's talk about this
Speaker 1: book because it's an interesting sort of hybrid model because
Speaker 1: it's kind of reads like a novel in a way.
Speaker 1: You know, it's kind of like a page turn and
Speaker 1: I want to start off with the word heredity, which
Speaker 1: is in your title, because you know, a lot of
Speaker 1: people think heredity and they think genetics, and could you
Speaker 1: please explain about why they're not synonymous in this book
Speaker 1: that you've written, genetics and heredity. Right, So the word genetics,
Speaker 1: you know, is actually a pretty young word. It's a
Speaker 1: little over one hundred years old, whereas the word heredity
Speaker 1: is thousands of years old. The oldest route that we
Speaker 1: can trace it to is hereditass from Latin. And so
Speaker 1: we've been thinking about heredity in lots of different ways
Speaker 1: for a long time, long before the science of genetics
Speaker 1: came on the scene. And heredity means a lot of
Speaker 1: things to us. It means incredibly important things to us.
Speaker 1: It is how we connect ourselves to the past and
Speaker 1: to the future, and also how we define ourselves. You know,
Speaker 1: what is our blood? You know that in a way
Speaker 1: that kind of says who we are. And genetics as
Speaker 1: a science came about as an attempt to answer the
Speaker 1: question of what is heredity, but a very particular version
Speaker 1: of heredity. In other words, in the eighteen hundreds, people
Speaker 1: like Charles Darwin's really started to conceptualize heritity as being
Speaker 1: some sort of physical substance on a microscopic scale that
Speaker 1: was being passed down from one generation to the next.
Speaker 1: And I'd argue that, you know, genetics is a hugely
Speaker 1: important answer to what is heredity, but actually heredity is
Speaker 1: even bigger than that. It's not simply saying genes does
Speaker 1: real disservice to heredity itself. It's a much bigger than that,
Speaker 1: and it really defines our intuitions about what connects us
Speaker 1: to the future in the past great and there's a
Speaker 1: lot of weirdness to heredity that stick to the standard
Speaker 1: story that a lot of people weren't even in like
Speaker 1: eighth grade biology class, right, you know, there's more of
Speaker 1: the story that whether you inherited your mother's lies, for instance. Right. Yeah.
Speaker 1: I mean, I think that we're in this situation in
Speaker 1: the twenty first century where most people learn about genetics
Speaker 1: in grade school or high school and then that's about it,
Speaker 1: and they get about as far as mental and so
Speaker 1: we tend to think about heredity not just in terms
Speaker 1: of genes, but as single genes, as genes that are
Speaker 1: you know, totally dominant and recessive. And you know, if
Speaker 1: there's some trait, well you must have the gene for
Speaker 1: that trait. And actually, you know, mental is a great
Speaker 1: place to start to understand redity, but it's a terrible
Speaker 1: place to stop because you know, if you take a
Speaker 1: trait like height, for example, there's no height gene. There
Speaker 1: are thousands of genes that make proteins that are involved
Speaker 1: in lots of different things going on in our cells
Speaker 1: and between ourselves, and mutations to those thousands of genes
Speaker 1: can alter our height on average, so that you know,
Speaker 1: if you have a variant for one gene, you know
Speaker 1: that might on average, you know, increase people's height, you know,
Speaker 1: maybe a millimeter. And so you know, to look at
Speaker 1: your parents or your grandparents and say like, oh, I'm
Speaker 1: you know, short because they're short, Well, yes, but they're
Speaker 1: actually you're actually talking about thousands of different genes and
Speaker 1: all these complex interactions between them just to talk about height,
Speaker 1: And that's really like the low hanging fruit when it
Speaker 1: comes to talking about who we are. If you want
Speaker 1: to talk about things like personality or intelligence things like that, yeah,
Speaker 1: well then it's just you got to to step back
Speaker 1: and take a bigger view of reddity. And what's exciting
Speaker 1: is that actually, you know, scientists right now are starting
Speaker 1: to really grapple with heredity on that scale. You know,
Speaker 1: they can actually look at entire genomes and actually look
Speaker 1: at them at this a huge scale, using incredibly powerful
Speaker 1: computers to get out these basic questions. So I wanted
Speaker 1: to share the excitement of the scientific progress that's happening
Speaker 1: right now. But in order to do that, you have
Speaker 1: to sort of sort of break out of that kind
Speaker 1: of high school genetics that is really was irrelevant. It
Speaker 1: was relevant one hundred years ago, it's not so relevant now.
Speaker 1: Good Good, And you argue that we need a new
Speaker 1: definition of redity that takes into account some of the
Speaker 1: exciting recent discoveries such as Crisper and CAST nine gene editing,
Speaker 1: so as well as other technologists, and I'd like to
Speaker 1: just cover some of these new emerging techniquessnologies. Could you
Speaker 1: please explain some of the upcoming or what we currently
Speaker 1: have in the technology terms of gene editing. Crisper is
Speaker 1: a gene editing technology which basically is a way to
Speaker 1: design molecules that are able to zero in on some
Speaker 1: particular spot in a genome, cut out a little section
Speaker 1: of DNA, and in some cases insert another stretch of
Speaker 1: DNA in the place of what was taken out. So
Speaker 1: you can think of it a bit like you know,
Speaker 1: searching through a Microsoft word document, highlighting a passage and
Speaker 1: then deleting it or pasting in something else. And where
Speaker 1: are we at in that technology right now? How expensive
Speaker 1: is this technology? What do you sort of predict how
Speaker 1: many years till this becomes more widespread maybe even available
Speaker 1: to the general public. Well, you know, if you go
Speaker 1: to biology labs, it's in widespread use. I mean everybody's
Speaker 1: using it, okay, and you know they will use it
Speaker 1: for all sorts of different things. So, like, let's say
Speaker 1: you want to do an experiment to figure out which
Speaker 1: genes are essential for a cancer cell to grow aggressively
Speaker 1: to be a cancer cell. You can just create a
Speaker 1: bunch of cell colonies and Petrie dishes and use crisper
Speaker 1: in each one of those to cut out a different
Speaker 1: gene and then you just see how well they grow
Speaker 1: after that. And so scientists have actually done this, you know,
Speaker 1: they've gone through and like, you know, twenty thousand or
Speaker 1: so genes and cut out everyone, and they've made up
Speaker 1: this list, this much shorter list of essential cancer genes
Speaker 1: and that is going to be a huge that's huge.
Speaker 1: It's huge because then you know they're actually drug companies
Speaker 1: right now who are using these catalogs to say like, okay,
Speaker 1: like we're going to now look for cancer drugs that
Speaker 1: go after this particular gene. You know, nobody knew that
Speaker 1: this gene was essential for cancer. Now we know now
Speaker 1: we're going to go for it. So that's just one
Speaker 1: example of what people using crisper for. I think where
Speaker 1: crisper gets its real excitement and maybe some anxiety for
Speaker 1: some people is the ability to use Crisper to make permanent,
Speaker 1: inherited changes in an organism. And so right now there's
Speaker 1: a lot of work going on with plants to use
Speaker 1: Crisper to tinker with the DNA of crops, for example,
Speaker 1: to make tomatoes that can grow in a shorter growing season.
Speaker 1: For example, it turns out if you just cut out
Speaker 1: a tiny piece of DNA, which is just acts like
Speaker 1: a little sort of control switch to one gene, you
Speaker 1: can actually get them to grow better in more northern climates.
Speaker 1: So there's a case where you know, once you created
Speaker 1: that change with crisper, that can get passed down from
Speaker 1: generation to generation, and so you know, the possibility arises
Speaker 1: that you could do the same thing in animals, which
Speaker 1: some people are experimenting with. The real controversy, of course,
Speaker 1: is what if you use this on humans exactly, and
Speaker 1: we build up to psychological traits and discuss those implications,
Speaker 1: would we be able to headit thousands of genes at
Speaker 1: the same time. Well, it's hard to look into the
Speaker 1: future and say exactly what gene editing will allow us
Speaker 1: to do in the future right now, No way, right
Speaker 1: right right now, Like single genes at this point, right yeah, yeah,
Speaker 1: it's very hard to do more than just one gene.
Speaker 1: I mean, there have been some experiments where people have
Speaker 1: you know, altered a few genes at the same time,
Speaker 1: and there have been cases actually where people have been
Speaker 1: able to cut out, you know, many dozens of pieces
Speaker 1: of DNA at once. But that's I won't say it's cheating,
Speaker 1: but what they're doing in a case like that is
Speaker 1: that they're actually looking for almost identical sequences of DNA
Speaker 1: and cutting them all out. This is actually a study
Speaker 1: where researchers wanted to make a breed of pigs that
Speaker 1: would be safer for using for possible growing organs for transplantation,
Speaker 1: and the problem with pigs is that they have certain
Speaker 1: stretches of DNA in their genome that are actually viruses
Speaker 1: that got embedded in their genome. Lots of species have this,
Speaker 1: but you don't want to get a pig transplant and
Speaker 1: then suddenly have it producing viruses inside of you that
Speaker 1: that would be bad. But with Crisper, it looks like
Speaker 1: you can actually go in and just edit all of
Speaker 1: those out at once, and so it might be possible
Speaker 1: to produce a breed of pigs that was free of
Speaker 1: these what are called hodogenous retroviruses. That's so fascinating. We're
Speaker 1: like long way off from like psychiatrists, instead of prescribing SSRIs,
Speaker 1: prescribing CRISPER. Yeah, no, I that will. I don't want
Speaker 1: to say never, you never know, But I mean one
Speaker 1: thing I hope my book gets across is just what
Speaker 1: an insanely complicated proposal that would be. Because when you
Speaker 1: talk about traits like intelligence or personality, you're talking about
Speaker 1: things that are certainly influenced by genes, but they are
Speaker 1: influenced again by thousands of genes. In each gene is
Speaker 1: playing a part that we don't understand at all, and
Speaker 1: you know, maybe one makes a protein that makes some
Speaker 1: particular connection between neurons, maybe another one is involved with
Speaker 1: the molecules that act as signals between neurons. But how
Speaker 1: that translates to, you know, depression is we just do
Speaker 1: not know. We nowhere near making those sorts of connections
Speaker 1: from the genetic level to the level of how we
Speaker 1: experience life. And not only that, but these genes are
Speaker 1: working in an environment, and so you know, you may
Speaker 1: it's possible, you may have genes that may put you
Speaker 1: at risk for certain conditions as an adult, but only
Speaker 1: like if you grow up in a very stressful environment.
Speaker 1: If you don't, then they're not a risk factor at all.
Speaker 1: So to say like, oh well, if we just change
Speaker 1: this spelling, then everything's fine totally misses the point when
Speaker 1: it comes to our psychology. Yeah, it's an excellent point.
Speaker 1: So you talk about some examples that Stephen J. Gould
Speaker 1: talked about similar examples in The Mismeasure of Man, so
Speaker 1: like the Calikak family story. I mean, you also talk
Speaker 1: about cirl Bert's fraud. You know, I would be gray
Speaker 1: if you could just briefly summarize that. But my real
Speaker 1: question is that you know, the truth of the matter is,
Speaker 1: even though some of their work was really shoddy, I mean,
Speaker 1: modern science does confirm some of their hypotheses nevertheless, in
Speaker 1: the sense that there is a genetic contribution not deterministic,
Speaker 1: but probabilistic to intelligence and IQ right, it's kind of
Speaker 1: a baby in bathwater situation. I focus a lot in
Speaker 1: the book on as you mentioned, this book called the
Speaker 1: Calikak Family. This was actually and I organized that chapter
Speaker 1: actually around a woman who was the subject of this
Speaker 1: book and was sort of involuntarily turned in kind of
Speaker 1: a poster child for eugenics. Her name was Emma Wolverton,
Speaker 1: and she was institutionalized in a home for the quote
Speaker 1: unquote feeble minded, not because she was feeble minded, but
Speaker 1: because she basically got in the way her mother wanted
Speaker 1: to get rid of her so she could get remarried.
Speaker 1: And this happened all the time, and as she would
Speaker 1: end up spending her entire life in institutions, even though
Speaker 1: she could very well have survived as fine on her
Speaker 1: own in the outside world. When she was a teenager,
Speaker 1: she met a man named Henry Goddard who was a
Speaker 1: psychologist who was hired at her school. The violand training school,
Speaker 1: and he discovered intelligence testing in Europe, which was just
Speaker 1: a way of trying to decide whether children were sort
Speaker 1: of kind of had an average mental age for their age,
Speaker 1: or were a little slow or little ahead. And he
Speaker 1: started testing the students and then got so excited by
Speaker 1: the results he was getting that he started to think
Speaker 1: that he could come up with a whole science of intelligence.
Speaker 1: And around this time he discovers genetics, which is very
Speaker 1: new at the time, and decides to go off and
Speaker 1: find the families of his students. And what he does
Speaker 1: is he draws pedigrees for all his students, and he
Speaker 1: will mark, you know, people who lived fifty one hundred,
Speaker 1: one hundred and fifty years earlier as feeble minded, just
Speaker 1: from the stories that his field workers would hear. And
Speaker 1: then he would then use this as evidence that feeble
Speaker 1: mindedness was a simple genetic trait, maybe carried by one gene.
Speaker 1: So he publishes this book called the Klikak Family, about
Speaker 1: his discovery, and you know, and this he and others
Speaker 1: used this as evidence for a really aggressive eugenics program
Speaker 1: because they feel like, well, there are so many feeble
Speaker 1: minded people and we have to stop them from having children.
Speaker 1: In order to save our country, and you can't institutionalize
Speaker 1: all of them. So Goddard lobbies very aggressively for state
Speaker 1: laws for sterilization. Tens of thousands of Americans were sterilized
Speaker 1: as a reults of these laws. And in Nazi Germany,
Speaker 1: the Calakak family book was used as prime evidence for
Speaker 1: their own attempts to you know, reshape the human race,
Speaker 1: and not only did they do sterilization, but they went
Speaker 1: further to extermination, all based on this, this faulty line
Speaker 1: of evidence. So I think that no matter what sort
Speaker 1: of scientific discoveries that are happening now one hundred years later,
Speaker 1: we have to look back and see just how easy
Speaker 1: it was for very very intelligent peop poem, for very
Speaker 1: you know, for the for very prominent scientists to leap
Speaker 1: to incredibly harmful, destructive ideas based on their idea that
Speaker 1: they had figured everything out when it comes to our redity.
Speaker 1: So here we are now, and if people are saying like, oh, well,
Speaker 1: you know, it's easy, we will just change these genes
Speaker 1: and everything will be fine, I think we have to
Speaker 1: really question ourselves and ask are we falling prey to
Speaker 1: the same kind of arrogance and simplicity that previous generations
Speaker 1: have fallen prey to. And that's a really clear point.
Speaker 1: A good point that you make in your book is
Speaker 1: about how much damage scientists and not to scientists, that
Speaker 1: all of us can do when the science is poorly interpreted,
Speaker 1: unethically applied. So I think that is an excellent point.
Speaker 1: But it's coming out fast. This genetic research using like
Speaker 1: do you know, wide association studies, some scientists tend to
Speaker 1: get extremely excited over it. Do you fear at all?
Speaker 1: And I do? I personally do fear sometimes that we
Speaker 1: might get too excited over the methods sometimes and lose
Speaker 1: sight of the actual purpose, Like we get so excited about, Wow,
Speaker 1: we invented this new way where we can capture even
Speaker 1: more genes, you know, without actually looking at kind of
Speaker 1: a societal, bigger picture. But both are important to understand, right, Yeah.
Speaker 1: And you know, as a science writer, I find it
Speaker 1: really interesting to go back one hundred years and look
Speaker 1: at sort of how science writers then would talk about
Speaker 1: genetics and talk about these claims about intelligence and genetics,
Speaker 1: and it really does, you know, it really does influence
Speaker 1: my work now as a journalist. You know, certain the
Speaker 1: new York Times. I'm reporting a lot on genetic studies
Speaker 1: on things like intelligence and educational attainment and things like that.
Speaker 1: I think these are really important studies, but I also
Speaker 1: feel like I want to be helping to really set
Speaker 1: the public record straight in the sense that you know,
Speaker 1: it's really to magnificant. For example, that scientists are now
Speaker 1: starting to identify genes or the very first time they're
Speaker 1: up to I think they're up to a few hundred
Speaker 1: now that have a statistically very strong association with how
Speaker 1: people do on intelligence test scores. You know, they are
Speaker 1: passing very rigorous statistical tests. But the catches that each
Speaker 1: one of those genes, you know, the variants might account
Speaker 1: for a tiny fraction of one i Q point. That's
Speaker 1: that's the paradox is to say, like, statistically speaking, this
Speaker 1: is this association is strong, and they're being replicated. So
Speaker 1: they're doing everything that you would you would want in
Speaker 1: good science, But you can't then leave out that final
Speaker 1: step of saying, well what does that add up to?
Speaker 1: And it doesn't add up to very much at all.
Speaker 1: And so you know, to the idea that you could somehow,
Speaker 1: you know, get somebody's DNA and a baby's DNA and
Speaker 1: just predict their intelligence or some other part of their
Speaker 1: life related to intelligence, you know, in adulthood. You can't
Speaker 1: do that. I mean, it's just not possible, you know,
Speaker 1: with what we understand about intelligence. And so so when
Speaker 1: I'm reporting on these things, I want to I am
Speaker 1: trying to strike that balance and not only between you know,
Speaker 1: showing how the science actually works, showing the actual you know,
Speaker 1: limits of the science, but also like to say, like,
Speaker 1: well take that next step and say like, well, what
Speaker 1: is that you know, what do we do with that information?
Speaker 1: You know, So some people are actually claiming that we
Speaker 1: can create what they call precision education based on the
Speaker 1: student's genetics. Robert Pullman is big into that, right he is.
Speaker 1: He is. Yeah, but I've talked to a lot of
Speaker 1: people who are very skeptical of that and sort of
Speaker 1: feel like he's kind of kind of looking past the
Speaker 1: big picture of education, you know. I mean, we've got
Speaker 1: much bigger fish to fry in terms of at least states.
Speaker 1: I mean, you know, like I don't want to even
Speaker 1: hear I don't think we should even be really talking
Speaker 1: that much about these issues until you know, like there
Speaker 1: are up to date textbooks in all schools like things
Speaker 1: like that. I mean, it's just like our schools have
Speaker 1: much bigger problems to deal with, much more urgent issues
Speaker 1: than trying to figure out whether precision education could work
Speaker 1: or not. Maybe I'm gonna play Devil's avocate for a
Speaker 1: second in some sense. So we do know, there's some
Speaker 1: really interesting research showing that certain brain development patterns in
Speaker 1: childhood do predict things like dyslexia, some learning disabilities, and
Speaker 1: that if we sort of catch a risk for some
Speaker 1: of these things early, we can actually cause a better
Speaker 1: trajectory moving forward. So I just recently and edited a
Speaker 1: book on this sort of thing, on kids who are
Speaker 1: twice exceptional, who have a learning disability but also have
Speaker 1: areas of intellectual potential. And so I guess one could argue,
Speaker 1: and I don't know about the genetical, but least it's
Speaker 1: more easy for me to wrap my head around like
Speaker 1: brain scans, you know, in a sense. But you know,
Speaker 1: if someone would make that argument, say that that could
Speaker 1: be informative information, what would you say, Well, it depends
Speaker 1: on what question you're trying to answer. You know, there are, unquestionably,
Speaker 1: you know, some genetic variations that are very clearly linked
Speaker 1: to you know, intellectual developmental disability. You know, we could
Speaker 1: just talk about things like down syndrome. I mean, it's
Speaker 1: like you can see, like having that extra chromosome has
Speaker 1: a clear cut effect, among other things, on how a
Speaker 1: child will learn. I mean, there's there's no question about that.
Speaker 1: And there may be some very important, you know, precise
Speaker 1: links between genes and certain kinds of learning disabilities or
Speaker 1: maybe even certain kinds of learning strengths that could emerge,
Speaker 1: you know, and it might have something to do, let's say,
Speaker 1: with you know, some very narrow part of the learning experience.
Speaker 1: The thing is with the tricky thing with with what
Speaker 1: we call quote unquote intelligence is that it reflects lots
Speaker 1: of different ways of learning and solving problems. You know,
Speaker 1: it's basically it's almost like a there's a correlation between
Speaker 1: between things like memory and solving logic problems and so
Speaker 1: and so forth. And there's definitely something there. I mean,
Speaker 1: I think there's a huge amount of psychological literature to
Speaker 1: show that there's quote unquote something there. But the factor yeah, yeah,
Speaker 1: I mean general intelligence or you know, they're you know,
Speaker 1: they're people are doing using different words for the sort
Speaker 1: of underlying factor, and you know, you can actually see
Speaker 1: that there are genes that have an influence on that,
Speaker 1: and so that does tell you that there's something there,
Speaker 1: but it's so all encompassing that it's very hard. I
Speaker 1: would find it very hard to see how you could
Speaker 1: really get any sort of useful, targeted help by trying
Speaker 1: to look for look at these genes on this list,
Speaker 1: this growing list that are linked to what we call intelligence. Yeah,
Speaker 1: it's a good point. And modern day educational psychologists working
Speaker 1: within my field, they emphasize the global IQ score. It's
Speaker 1: really about how to specific deficits in like a verbal
Speaker 1: processing or auditory processing, et cetera, how that can inform
Speaker 1: a custom tailored intervention. So my argument was not about,
Speaker 1: you know, the global IQ genes, but more about like
Speaker 1: more target specific things that could actually inform interventions. I
Speaker 1: could see that being used alongside A not used exclusively.
Speaker 1: I think that would be a huge problem if we started,
Speaker 1: if we started to use IQ, or so we started
Speaker 1: to use our genetic information a as a sorting mechanism
Speaker 1: and B as you know, the exclusive information of saying, oh, well,
Speaker 1: you know what we don't it predicts more variants than
Speaker 1: family homes. So therefore let's not care about family environment,
Speaker 1: and that would be catastrophic, right, yeah, I mean I
Speaker 1: I think the most interesting potential for this kind of
Speaker 1: research is not actually to try to use it on individuals,
Speaker 1: but actually to try to do more research on large
Speaker 1: groups of people, because you can, for example, test out
Speaker 1: different kinds of ways of improving education. And if you
Speaker 1: can control for genes that are associated with intelligence or
Speaker 1: how long you stay in school, that gives you this
Speaker 1: extra tool, and that actually makes it possible for you
Speaker 1: to get really statistically meaningful results out of actually much
Speaker 1: smaller tests. You know, so if you want to say, okay,
Speaker 1: if we give families money, will that help their kids
Speaker 1: stay in school longer? That's an expensive question to answer.
Speaker 1: But if you have the DNA of these families, you
Speaker 1: can actually then control for genes that you know already
Speaker 1: have an influence on how long people stay in school.
Speaker 1: It's a small influence, you know, genes seem to predict
Speaker 1: things like around ten and twenty percent of the variation
Speaker 1: and how long people stay school. That's small, that's not
Speaker 1: a crystal ball, but that's enough for you to get
Speaker 1: a sort of a leg up on these questions, and
Speaker 1: so I certainly that's where social scientists that I talked to,
Speaker 1: that's where they get excited about these results. Yeah, and
Speaker 1: Paige Harden's r in some good stuff about that, you know,
Speaker 1: good good. So let's move on to mosquitoes. It's a
Speaker 1: less un comfortable topic to discuss, but equally as important.
Speaker 1: So genetically modified mosquitoes. How could this turn into a nightmare?
Speaker 1: Can you think of any anyway? None jumped to mind.
Speaker 1: But that doesn't mean that it couldn't happen. You know,
Speaker 1: there are certainly our cases where we have done things
Speaker 1: in science that had unintended consequences, and certainly introducing genetically
Speaker 1: engineered organisms into the world wild is something that we
Speaker 1: need to do carefully if we do it at all.
Speaker 1: So in the book, I talk about using actually using
Speaker 1: crisper to genetically engineer mosquitos so that they will pass
Speaker 1: down malaria proof genes to their offspring. And the idea
Speaker 1: is that once you do that, that's going to be it.
Speaker 1: I mean, you may not be able to undo that.
Speaker 1: So within a few years, all the mosquitos in an
Speaker 1: area may have these genes. So you know, you want
Speaker 1: to think very carefully before you set those mosquitoes lose.
Speaker 1: On the other hand, you know, you also have to
Speaker 1: take bear in mind that you know, maybe you around
Speaker 1: half a million people die every year of malaria, and
Speaker 1: you know, while we've made a lot of progress with
Speaker 1: all sorts of different treatments, we haven't created a vaccine
Speaker 1: that makes people immune. And you know, the medic cations
Speaker 1: for malaria are not great. So there is an urgent
Speaker 1: need to do something. And so the question is is
Speaker 1: Crisper going to be that? But you know, as you say, like,
Speaker 1: could you wreak havoc with this, well maybe, I mean,
Speaker 1: I don't know. I mean mosquitoes they're a part of
Speaker 1: their ecosystem, and if you tamper with their biology, are
Speaker 1: you going to alter how they interact with other species?
Speaker 1: Will that radiate out into unexpected changes? That's certainly something
Speaker 1: that you know, scientists are looking seriously at. It's just
Speaker 1: as possible as the havoc we can reach by trying
Speaker 1: to alter our own DNA. You know, there's a whole
Speaker 1: bunch of people that would well, once there's technology advances
Speaker 1: to try to live forever, right, to try to like
Speaker 1: change the course of human evolution. So, yeah, all these
Speaker 1: things are really important to discuss, even if we're like
Speaker 1: so many years ahead. It's great that people like you. Again,
Speaker 1: the conversation started so similar topic, genetically modified crops. What
Speaker 1: will this mean for us in the environment. Well, you know,
Speaker 1: this is really moving forward in a way that sort
Speaker 1: of fits in with, you know, the past decades of
Speaker 1: crop engineering, you know, basically saying trying to find ways
Speaker 1: to get crops to grow, to grow better, to grow
Speaker 1: under different conditions, and so on. The advantage that Crisper
Speaker 1: has over some earlier methods is that you, for one thing,
Speaker 1: you can introduce particular mutations that you already have good
Speaker 1: reason to think are going to be effective, rather than say,
Speaker 1: blasting corn plants with X rays and just introducing less
Speaker 1: of random mutations. Before now, the genetic engineering that people
Speaker 1: may be familiar with was really about sort of introducing
Speaker 1: DNA from one species to another, and crisper doesn't require
Speaker 1: that because you can, you know, make tweaks to the
Speaker 1: plant's own own DNA, So you may be able to
Speaker 1: have crops that maybe to grow under you know, drought
Speaker 1: conditions that probably we're going to be facing because of
Speaker 1: climate change. There's a lot of promise to using them
Speaker 1: that way. You know, what I would hope would not
Speaker 1: happen is that companies would use Chris Bird to basically
Speaker 1: engineer crops to be resistant to pesticides. That would then
Speaker 1: lead to massive use of that particular pesticide, which can
Speaker 1: potentially have harm to the environment, and then you know,
Speaker 1: also eventually lead to resistance in the insects or the
Speaker 1: weeds that you're trying to kill, which then forces you
Speaker 1: to go to a different pesticide, which might be even
Speaker 1: more harmful. If we get stuck on that sort of treadmill,
Speaker 1: that could be a problem. Thank you for explaining that.
Speaker 1: And another thing I found really extremely interesting ear book,
Speaker 1: like one of the one hundred things on the list
Speaker 1: our emerging research in the field of developmental biology and
Speaker 1: how the external environment can produce some quirky form of heredity.
Speaker 1: Can you describe that? You talk about it in rats,
Speaker 1: but how they can learn to fear certain odors associated
Speaker 1: with a shock and that can be inherited by the offspring.
Speaker 1: Is that right? Yeah, So this is a part of
Speaker 1: a big area of research known as epigenetics, and you know,
Speaker 1: epigenetics has inspired a huge amount of fascination across the board.
Speaker 1: I mean, it's really interesting how when I give talks
Speaker 1: about heredity, when it's time for Q and A, lots
Speaker 1: of people want to know about epigenetics. And so epigenetics
Speaker 1: basically means, the way I think about it, is the
Speaker 1: control that cells have over their genes to determine which
Speaker 1: genes actually do stuff and which are silent. And it's
Speaker 1: clear that you know, as we develop, our cells shut
Speaker 1: certain genes down pretty much permanently and allow other ones
Speaker 1: to be active. And that's you know, that's how we
Speaker 1: are able to produce you know, hundreds of different kinds
Speaker 1: of tissues in our bodies just from one genome. And
Speaker 1: you know, when your skin cells divide, they make more skin.
Speaker 1: They don't suddenly turn into teeth or something. So it's
Speaker 1: not like epigenetics is some weird fringe idea. It's at
Speaker 1: the center of biology. But you know the fact is
Speaker 1: that also our environment can trigger epigenetic changes in us,
Speaker 1: you know, whether it's stress or some other kind of experience.
Speaker 1: And so some people have said, well, is there any
Speaker 1: way for those changes to actually get passed down to
Speaker 1: the next generation. So if your genes undergo an epigenetic
Speaker 1: change in how they're running. Could your children inherit that change?
Speaker 1: So this would be a sort of a separate channel
Speaker 1: of heredity. And so there's this one very high profile
Speaker 1: experiment that researchers did. They exposed male rats I believe,
Speaker 1: to a it's a harmless odor, and then would give
Speaker 1: them a shock and eventually they learned to associate the
Speaker 1: oder with the shock, and you could sort of measure
Speaker 1: their response. As soon as they smell the odor, they
Speaker 1: knew who something bad was coming. These male rats then
Speaker 1: made it. And then the hops, who you know, had
Speaker 1: only inherited, you know, their the genes and whatever else
Speaker 1: was in the sperm of those male rats, they seem
Speaker 1: to have an odd response to that odor as well. Fascinating,
Speaker 1: but it hasn't been replicated. It's not like people have
Speaker 1: shown that this gets carried down through several generations. So
Speaker 1: there are actually a lot of scientists whore very skeptical
Speaker 1: that this is actually a real result at all. If
Speaker 1: it was, that would be really quite amazing. But you know,
Speaker 1: I think we have to be really cautious about embracing
Speaker 1: these kinds of results. That being said, this kind of
Speaker 1: epigenetic heredity is real it's just not necessarily real in
Speaker 1: us or in rats. In plants, for example, plants to
Speaker 1: get attacked by insects and they can, you know, create
Speaker 1: a bunch of chemicals to ward them off. Their offspring
Speaker 1: are going to respond faster to chemical attacks than other
Speaker 1: plants would, and that gets carried down through generations, and
Speaker 1: so hypogenetic inheritance, this alternate way of inheriting things is
Speaker 1: a real thing. One of my colleagues, who studied prodigies
Speaker 1: in depth, was really interested in a finding that a
Speaker 1: large proportion of his prodigies you'd find that somewhere like
Speaker 1: the great grandfather had a similar talent, you know, that
Speaker 1: seemed to kind of burst forth without too much practice
Speaker 1: in the young child, and that's never been explained, and
Speaker 1: it'd be interesting to see if this can help explain
Speaker 1: that at all. Well, you know, I mean, I guess
Speaker 1: I'd be skeptical that this would go anywhere to explaining that,
Speaker 1: because you know, you'd have to ask, well, how was
Speaker 1: it that that was sort of carried down through the generations,
Speaker 1: and why didn't the intervening generations show it? And see
Speaker 1: how that happens with recessive genes. There's a very clear
Speaker 1: way that that can work, But no one's really come
Speaker 1: up with a good explanation for how epigenetics could work
Speaker 1: in a similar way fair enough. So maybe an alternative
Speaker 1: possibility is just that the child seems to just have
Speaker 1: genes that facilitate that you're learning in that specific domean
Speaker 1: they just happen to get that package of genes from
Speaker 1: the gene pool. I mean, it's interesting to think about.
Speaker 1: It's all very interesting to think about, and you know,
Speaker 1: we were always looking to try to figure out how
Speaker 1: children turn out the way they are. It's very tempting, though,
Speaker 1: to look at their ancestors and do a kind of
Speaker 1: pattern matching experiment, and you may just be seeing connections
Speaker 1: that really aren't there. That is just a random association.
Speaker 1: So let's move on to human chimeras, people whose bodies
Speaker 1: contain a multitude of genomes or just a different you know, genomes.
Speaker 1: Can you describe that a little bit. Yeah, So we'd
Speaker 1: like to think that we inherit a genome that's a
Speaker 1: combination of DNA from our two parents, and there's just
Speaker 1: one genome and that's who we are. But the fact
Speaker 1: is that we can inherit different genomes. So some people
Speaker 1: are actually a combination of twins, where some of their
Speaker 1: cells come from one of the twins and some of
Speaker 1: them the cells come from the other. And this they
Speaker 1: mightn't even know they had a twin. The twin may
Speaker 1: have died in the uterus before birth. It's also what's
Speaker 1: also remarkable is that people can actually pass their DNA
Speaker 1: to their mothers before they're born, and so mothers can
Speaker 1: actually become chimeras where FETO cells actually take root and
Speaker 1: their bodies, even in their brains and develop into neurons.
Speaker 1: So you know, a lot of us are in fact chimeras,
Speaker 1: and you know, it used to be thought it as
Speaker 1: like a bizarre freak of nature, but I'd say that
Speaker 1: a substantial fraction of humans are chimeras well. I didn't
Speaker 1: know that till I read your book. So that's a
Speaker 1: really extraordinarily interesting. Let me ask you a little bit
Speaker 1: about your own personal experience, because I know that you've
Speaker 1: got your our own genome sequence, and you know, like
Speaker 1: Americans are obsessed with understand their ancestry and twenty three
Speaker 1: and me and stuff like, that's not what did you
Speaker 1: personally learn from sequencing your own DNA? And what do
Speaker 1: you think some of the limits of that knowledge are
Speaker 1: at this point in time. I think that we have
Speaker 1: been waiting for this moment when we can look at
Speaker 1: our own DNA, look at our own genomes, and we've
Speaker 1: been anticipating this as a profound, almost mystical experience, and
Speaker 1: I think we've been enabled buy that by some of
Speaker 1: these companies that offer these services. I don't think that
Speaker 1: the experience is going to match up with those expectations
Speaker 1: for most people. Now, some people are going to discover
Speaker 1: that they have some mutations they should be concerned about.
Speaker 1: You know, people who have a family history of any
Speaker 1: particular disease actually should just go to their doctor anyway
Speaker 1: and just try to get genetic testing that's more reliable
Speaker 1: in these director consumer things. But you know, for me
Speaker 1: getting my whole genome sequenced, you know, fortunately I didn't
Speaker 1: discover anything really scary in there, but it was an
Speaker 1: opportunity to learn how my genome, like thousands of other genomes,
Speaker 1: can be studied to understand really the history of our
Speaker 1: whole species. You know, how our ancestors interbred with Neanderthals
Speaker 1: and other vanished kinds of people, how certain genes arose
Speaker 1: and became more common, even sometimes when these are genes
Speaker 1: that could be associated with disease. So I think that
Speaker 1: the best way to approach the possibility of looking at
Speaker 1: your own DNA is seeing it as a way not
Speaker 1: to learn about yourself in a kind of narcissistic way,
Speaker 1: but to learn about your species. Well that's a great point.
Speaker 1: And thank you so much for your time today and
Speaker 1: for ranks such a beautiful and informative book. Oh My Pleasure.
Speaker 1: Thanks a lot for having me. It was good talking
Speaker 1: to you. Thanks for listening to the Psychology Podcast. I
Speaker 1: hope you enjoyed this episode. If you'd like to react
Speaker 1: in some way to something you heard, I encourage you
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