Making Sense with Sam Harris - #382 — The Eye of Nature

Episode Date: September 6, 2024

Sam Harris speaks with Richard Dawkins about his new book The Genetic Book of the Dead, the genome as a palimpsest, what scientists of the future may do with genetic information, genotypes and phenotypes, embryology and epigenetics, why the Lamarckian theory of acquired characteristics couldn't be true, how environmental selection pressure works, why evolution is hard to think about, human dependence on material culture, the future of genetic enhancement of human beings, viral DNA, symbiotic bacteria, AI and the future of scholarship, resurrecting extinct species, the problem of free speech in the UK, the problem of political Islam and antisemitism in the UK, reflections on Dan Dennett, and other topics. If the Making Sense podcast logo in your player is BLACK, you can SUBSCRIBE to gain access to all full-length episodes at samharris.org/subscribe. Learning how to train your mind is the single greatest investment you can make in life. That’s why Sam Harris created the Waking Up app. From rational mindfulness practice to lessons on some of life’s most important topics, join Sam as he demystifies the practice of meditation and explores the theory behind it.

Welcome to the Making Sense Podcast. This is Sam Harris. Just a note to say that if you're hearing this, you're not currently on our subscriber feed, and will only be hearing the first part of this conversation. In order to access full episodes of the Making Sense Podcast, you'll need to subscribe at samharris.org. There you'll also find our scholarship program, where we offer free accounts to anyone who can't afford one. We don't run ads on the

podcast, and therefore it's made possible entirely through the support of our subscribers. So if you enjoy what we're doing here, please consider becoming one. Well, today's guest needs no introduction. Often one says that and then just gives the introduction anyway, but no, Richard Dawkins actually needs no introduction on this podcast, except to say that he has a new book, which is titled The Genetic Book of the Dead, which we speak about in the first part of the podcast, where we talk about the genome as a kind of palimpsest, what scientists of the future may be able to do with our genetic information, genotypes and phenotypes, embryology and epigenetics, why the Lamarckian theory of acquired characteristics just couldn't be true,

why the Lamarckian theory of acquired characteristics just couldn't be true, how environmental selection pressure actually works, why evolution is so hard to think about, human dependence on material culture, the future of genetic enhancement of human beings, viral DNA, symbiotic bacteria, AI and the future of intellectual life, the prospect of resurrecting extinct species. And then we pivot to politics. We talk about the problem of free speech in the UK, which has reached surprising proportions, as well as the problem of political Islam and anti-Semitism. And then we close with some reflections on our friend Dan Dennett. And now I bring you the one and only Richard Dawkins. I am here with Richard Dawkins.

Richard, thanks for joining me again. Great pleasure, Sam. Thank you. So you have a new book, which I'm sorry to say I have not read in its entirety because I can only spend so much time reading a PDF that gets sent to me. I do not have the physical book yet, but I have read enough to declare that it is fascinating and that people should go out and buy it. So we'll talk a little bit about it, but there are a few other things I want to talk to you about. Yes. But first, how are you and what is your life like these days? I think you and I had lunch about, I don't know, a couple of months ago.

Yes, we did. Are you traveling or what's happening? Yes, well, I'm doing a tour of North America at the moment and then it carries on in Britain and Europe. And I've said it's my final tour. And it's partly to promote the book. In fact, I suppose it's mostly to promote the book. And how long are you on the road for?

Five weeks in North America, and then indefinitely, well, a couple of weeks in Britain and Europe. Nice. Well, needless to say, I hope it's not your final tour, or I hope that doesn't say anything about your longevity. Yeah, I hope so, too. Yeah, my last tour might have been my final tour, too I hope that doesn't say anything about your longevity. Yeah, I hope so too.

My last tour might have been my final tour too, so you never know. So let's touch on the book. The title is the... The Genetic Book of the Dead. The Genetic Book of the Dead, yeah. And it's a reference which you disavow early on. It produces an echo which you disavow early on. It's an echo to the Egyptian books of the dead.

And the Tibetan, I would point out. Yes, and the Tibetan. It's just a kind of poetic illusion, really. It doesn't really discuss those books. There's a kind of vague relevance in that I talk about genes as being immortal in the sense that they go on for generation after generation, whereas bodies are cast aside and die. And so the genes are a kind of set of instructions to the body as to how to not proceed to the afterlife,

as it would be in the Egyptian books of the dead, but how to hand the genes on to the afterlife, which is the next generation and the next and the next and so on. Right. So if we were going to take the analogy literally, and you also draw an analogy, a similar analogy to a palimpsest, which you might describe what that is, but these are both analogies to books. We'll tell our listeners or remind them not to be too pedantic what a palimpsest is. Okay. A palimpsest is a piece of writing which is partially or wholly erased so that you can write again on the same medium. So in the days when there wasn't an abundant ability of paper, people would reuse the same parchment and they would erase what was already there

and then write over it. And I had a dear friend, Bill Hamilton, a very distinguished evolutionist, who wrote postcards where he would economize by writing in blue horizontally, and then he would turn it to a right angle and write in red, carrying on the message. And you could read it by deciphering the coding red-blue and which way it was pointing. You provide an example in the book, which I must say I found difficult to read. I mean, that seemed like a provocation to one's friends to be sending them letters of that kind. Actually, I did manage to decipher, I think it's the red, I forget which color it was, and it's really rather dramatic.

It's something to do with somebody getting his bike rammed or something like that. I didn't really read too much of it. But the point is that the genetic book of the dead is a description in the genes and in the body of an animal of all its ancestral worlds, all the worlds in which its ancestors lived because natural selection has shaped it, has shaped the genes to survive in those worlds. But of course, since its ancestors lived in so many different worlds, old, very old, slightly old, and so on until relatively recent, and then now, it is a palimpsest of writings from all these different ages where they've been partially erased and then written over and then partially erased and written over again. Yeah, I want to go over that statement again just because it's beautiful and I don't want people to miss the import of it. So to come at it from the other side, if we could read the genetic book of the dead, what

would we read there? In the case of any of a human or any mammal, we would read old writings about the sea. When our ancestors before the Devonian era lived in the sea, then we would read writings about the emergence onto the land. We would read writings about subsequent history and so on. In the case of primates going up into the trees, some animals went back into the water, which is remarkable. Having sort of got all tooled up to come onto the land to then go back into the water.

And I've got a subchapter where turtles and tortoises actually came back for the third time. So they came out of the water onto the land, back to the water. So there were land tortoises in the Triassic era, back to the water as sea turtles, where some of them remain, and then back to the land again as modern land tortoises. So that's a double, double doubling back. And what do you imagine future biologists will be able to do with the genome? Okay, I have a sort of recurrent fantasy about a zoologist of the able to do with the genome okay i have a sort of recurrent fantasy about a zoologist of the future scientist of the future i make her female and i call her soft as scientist

of the future and i believe that scientists of the future will be able to read the book which is the animal and its genes and piece together the entire palimpsest of its ancestral history. It's something we can't do at the moment. And parts of the book are about the little preliminary fumbling steps, nursery slopes steps, which we can make towards that end. can make towards that end. Given an unspecified genome, how close are we to being able to predict the phenotype of the animal? Not very close. And that, of course, would be a big problem for the genetic book of the dead.

And much of the book actually is not about genes at all. It's about using the phenotype of an animal to reconstruct the book, which is its set of ancestral histories. SOF, in the future, will be able to do it with the genes, and we can't really do that now. There is no decoding process whereby you can get a genotype and say what the ancestral worlds of this animal were. I think, Richard, we should probably remind people of just, we should define our terms here. What's the difference between a genotype and a phenotype?

Well, a genotype is the set of genes in the animal, and the phenotype is what the genes manifest themselves as. So the phenotype is the body, its behavior, everything that we actually see of the animal. So what I asked you, given the genome, the series of base pairs, the code that's in the nucleus of almost every cell in an animal's body, could we predict what that animal would look like? No. Are we close at all to your knowledge? Not really. What you can do is to say exactly what proteins would be programmed by that animal's genome. But the problem then is that the animal itself is produced by the processes of embryonic development,

which are masterminded by genes via the proteins. But the actual process itself is such that unless you know a lot about the animal already you can't really tell if you're given a wholly new animal that's been found in the seas sorry a whole new genome that has been found and you have no idea what kind of animal it is then you couldn't reconstruct it but if you could say oh yes well this this evidently is a species of kangaroo because it looks like existing kangaroos, then you're away, and then you can do something with it. But if you know nothing about it, the only way to really find out what that animal would

develop as would be to put the genome into a female of the species concerned and let it develop. Yeah, you actually have a very seditious sentence at some point early in the book, which I think you say something like, forgive me for putting dangerous words into your mouth. Yes, I know what you mean. But they were dangerous on the page.

You said something like the best machine for translating a genotype into a phenotype that we know of is a woman or something like that. Yes, that's right. I could have said any female. Yes, right. Well, perhaps we'll return to that combustible topic. Yes.

So what is meant by the word epigenetics and where does that concept come into play here? Epigenetics is, I think, a much misused word. It's really just a word for embryology. The thing is that every cell in your body, every cell in our bodies, has the same genome, the same diploid set of genes. And yet the cells are all different. So liver cells are different from kidney cells, different from muscle cells, and so on. And the reason is epigenetics.

The reason is that some genes are turned on in liver cells and different genes are turned on in kidney cells, different genes are turned on in nerve cells, and so on. That's epigenetics. Now, there has very recently been a suggestion that some of these turnings on of genes can get passed on to the next generation. And this has been shown for a few cases. And the word epigenetics has come to be dubbed onto that process of passing on to the

next generation. And that's unfortunate because it's become a kind of vogue word of great popularity, suggesting a kind of major revolution. Some people have even thought that it looks like Lamarckian inheritance of acquired characteristics, which it really isn't. Well, let's just circle on that concept for a second again, just to capture everybody's understanding. What was the Lamarckian thesis, and to what degree does the heritability of some epigenetic settings cash out that thesis? Okay. Lamarck lived before Darwin, and he had really the only other theory for how evolution could work. And it was a bit mystical.

He had this idea that animals kind of strive to change their way of life. The giraffe by striving to reach their way of life. And they stretch their... The giraffe by striving to reach higher and higher leaves. That's right. It stretches its neck. And then he had two main principles, the principle of use and disuse. The more you use a bit of your body, the bigger it gets. So the more you use certain muscles, the bigger they get.

That's why you go to training. And as the giraffe stretches its neck, everything about the neck stretches. So that's the principle of use and disuse. Then he had the principle of inheritance of acquired characteristics. An animal inherits from its parents those changes which could occur during the parent's own lifetime. So the giraffe's babies inherit a slightly longer neck because the parents stretch their necks. If you exercise your muscles with weight lifting, then your children are born with slightly bigger muscles. That would be the principle of inheritance of acquired characteristics

plus use and disuse. And it's all false. It doesn't happen. Use and disuse happens, but acquired characteristics are not inherited. Now, the modern vogue for what they call epigenetics, where certain genes get turned on, which they do during embryology, those genes that get turned on, if that turning on gets passed on to the next generation, then that is a kind of inheritance of an acquired characteristic. But it's very different from the giraffe's neck. It doesn't have the same adaptive potential. It doesn't have the potential to pass on to the next generation the improved capacity

to survive, which the principle of use and disuse would. That's one reason why it's not Lamarckian. Another reason is that it doesn't go on to subsequent generations. It works only for the next generation, not for the indefinite future, which it would have to in order to be evolutionarily relevant. Yes, let's clarify that point. So let's give an example of what we think actually could be transmitted from generation to generation by way of epigenetics. I mean, what is, forgive me, I'm not close to this literature at all but i believe i've consumed somewhere the idea that uh you know various environmental stresses let's say

the the subjection of of one population to a near genocide i mean some you know generational trauma yes starvation people right starvation could do something to the epigenetic settings of the people. Yeah, it could change the physiology of the children in some way. Right. But it would not go forward to the grandchildren or the great-grandchildren or the great-great-grandchildren. Because it doesn't change the germline of the children. Exactly. It doesn't change the germline. It changes which members of the germline got switched on.

But I don't think it's interesting because it's at least not evolutionary. I mean, it's quite interesting from some points of view. It's not evolutionarily interesting because it doesn't go on to the indefinite future. It would have to go on to the indefinite future to be evolutionarily interesting. By the way, I mean, I think it's quite important, quite interesting to think about why the Lamarckian theory doesn't work. I mean, even if it were true that acquired characteristics were inherited, even if the giraffe's neck was inherited, it would not be good enough, not be a powerful enough theory to explain almost everything about evolution.

If you take something like an eye, where eyes get progressively better at focusing, more clarity, more detail, more precision, that doesn't happen by just use and disuse. It's not the case that the more you use an eye, the more acute the vision becomes. On Darwin's principle, Darwin actually used the phrase, nature is daily and hourly scrutinizing every detail. That's one of the main themes of the Genetic Book of the Dead, that daily and hourly, any tiny detail inside the animal, buried however deeply within the animal, which improves the animal's chance of surviving, then that survives and that can go on to the next generation and the next and the next and the next. Actually, perhaps you can discuss an example of that.

I know you go through many in the book, but the one that I recall is with camouflage with respect to, you know, lizards and moths. Yes, okay. So the thing I want you to illustrate is the point you're making about the daily and hourly scrutiny of the environment. Yes, that's a lovely phrase of Darwin, by the way. The first picture in the book, I think, is this lizard. It lives in the desert. And all over its back, it's got pictures of sand and stones and pebbles. It looks as though it's got a desert painted on its back. And this is camouflage, of course. And there are many other

examples, beautiful examples of camouflage, where in every case you can say that the animals, or rather the environment of the ancestors, is painted on the animal's back. Well, those are very spectacular examples. But the thesis of the genetic book of the dead is that it's more than just skin deep. Exactly the same attention to detail must pervade every tiny scrap of detail all the way through the animal. It's not just the skin. It's more than skin deep. It goes right through the animal. The daily and hourly scrutinizing produces the picture of a desert on the lizard's back, but it also produces every little tiny mote of detail inside the animal which assists its survival. Anything that assists

survival and passing on of genes is fair game for natural selection. The principle of use and disuse and inheritance of acquired characteristics can't do that because it doesn't have this sort of power to adjust to every single detail that Darwinism does, because if it assists survival, it gets through to the next generation and therefore into the future. But explain how this could be so incremental. So you have a moth that looks now exactly like the bark of the tree that is its habitual stopping point,

but obviously no more moth could have evolved fully in one generation quite to look that way so how is each increment justified and solidified by this by the attention of the the daily and hourly attention of the environment you have to start from a an ancestor which looked hardly anything like the bark of a tree. Or think of a stick caterpillar, which is another beautiful example, where a modern stick caterpillar looks uncannily like a stick. It's got little leaf bud scars and everything looks like a stick.

Well, originally the ancestor would hardly have looked like a stick at all. It would have just been a vaguely long-shaped thing, which most caterpillars are. So you're asking the question, how did the incremental process proceed step by step by step to go from a very crude ancestral resemblance to a stick right up to a modern extreme perfection of resemblance to a stick? And the answer, I think, is that the final perfecting stages were provided by full frontal vision by a predator in a good light with full attention playing on the object. Whereas the early stages might have been predators who were just sort of might have thing out of the corner of their eye while flashing past, or maybe in a poor light, or from a long distance away.

So from a long distance away in a poor light and out of the corner of your eye, even a very crude resemblance to a stick will escape the attention, escape the notice of the predator. And that provides the selection pressure to slightly improve the resemblance to a stick. So just the slightest change in the probability of not surviving there is because now you're dealing with just all those occasions where you were barely in the field of view of the predator. all those occasions where you were barely in the field of view of the predator, just that slight modification is enough to encourage that differential success of that adaptation. Exactly. And then the gradient goes steadily upwards because you've got a whole gradient, a whole spectrum of improved seeing conditions. I mean, if the very poor resemblance is good enough to fool a predator

at 100 yards away, then at 90 yards away, it's got to be slightly better in order to. And there are going to be predators that are seeing caterpillars at all those distances. And under poor seeing conditions, the selection pressure produces the first stages in the gradient of improvement to the mimicry. And then the last stages are provided by predators that are looking straight at the caterpillar in a good light, and they're still fooled by it because the resemblance is so perfect. Yeah, it's really just an amazingly beautiful process to think about in that regard. Yes. Why is it so hard to understand this intuitively?

Or perhaps another way of asking the question is, what do you think the barriers are for just a widespread intuitive understanding of the reality of evolution? I suppose partly it's that the time scale involved is so huge and we're not equipped to deal with millions of years, let alone hundreds of millions of years. That's one thing. Isn't the time scale sometimes surprisingly compressed? Sure, it is indeed.

That's right, and that's perfectly true. And in the case of the evolution of mimicry, it could be quite fast. But sort of either present their own impediment, because if it's too short, it just seems like there's not enough time to have accomplished that miracle. And if it's too long, it's very hard to think about. That's right, yes. There's no sweet spot. Well, maybe there is a sweet spot. But it'll vary in the different cases. 100,000 years, that's the sweet spot. Well, maybe there is a sweet spot. But it'll vary in the different cases. 100,000 years, that's the sweet spot.

Well, it depends. I mean, it might be for some cases, and it might be a million years in others. But it probably is surprisingly fast. Another thing I think is that people don't realize that a very, very slight advantage is enough to exert evolutionary change. So when you think about the, can it really be a good, can it really matter whether you've got, say, eyebrows? I have no idea why we have eyebrows, but suppose it's to stop sweat trickling into our eyes. I don't think it is, but just imagine that we have that. I've noticed it does not do a perfect job. That could just be my problem.

Okay. Well, you might say, oh, well, why does it matter if sweat trickles into your eyes? I mean, does that really affect survival? Well, it might, because you might not see the saber tooth approaching quite so soon if your eyes are all gummed up with sweat. Especially if there's sunblock mingled in with the sweat. Especially, yes. And the point is that because we're dealing with genes, the statistical frequencies of genes, as they change in frequency over generations,

any gene that tends to make eyebrows stop the sweat trickling into your eyes, it's not just the one occasion. It's all those thousands of occasions of different individuals where the same gene has its beneficial effect, not only the same individuals at the same time, but through different times. So statistically, a gene can have a very small beneficial effect, but that beneficial effect is kind of multiplied up over all the different individuals that it influences over a larger stretch of time where it does its influencing. And because of that, those genes which are good at helping individuals to survive are the ones that we see, the ones that

actually come through the generations. So even a very slight advantage like stopping sweat trickling into your eyes is enough to do the trick, even though that's counterintuitive. And you ask the question, why is it intuitively so hard to understand? I think that's another reason. What do you make of the fact that human beings seem so imperfectly selected to survive without material culture? Actually, I mean, so like actually David Deutsch, who I know you know, at least by reputation, if not personally over there in Oxford, you know, very smart man. He's made the point that the earth already is essentially a spaceship for us, right? So like if you just leave him out exposed even to an Oxford night, you know,

without the benefit of shelter or clothing or fire or, you know, he's, you know, for at least many nights of the year, he's likely to die of hypothermia, right? So it's like we're just not, we're these naked apes that are not great at survival apart from being in tribal bands who have produced a modicum of material culture and an ability to pass on that culture to subsequent generations. But in and of themselves, each representative of the species devoid of culture, put on a desert island, is liable to die over the course of 72 hours or a week because of just being fundamentally unable to survive when slammed up against raw nature. What do you make of the difference between human beings and basically everything else we see in the living world? I suppose if you were to go back to our time

when we lived for such a long time in Africa, in the savannah, we would have been a lot better at surviving as individuals then. Even then we would have needed culture, but nothing like so much as we do today. I mean, now we have supermarkets, we get our food prepared for us. We don't have to go and get it. We don't have to go and find it or hunt it or kill it or gather it. We just go into a shop and buy it. And we are mollycoddled by electricity and central heating and all that kind of thing. If you were to take not a modern American or Englishman and put him out on the, expose him to the elements, you might die. But if you were to do the same with a Kung Sam from the Kalahari Desert, they're a lot better at surviving than an Australian Aboriginal.

At least in the Kalahari Desert, yeah. Yes, or a native Australian in the Australian outback. They do pretty well. And I think we've co-evolved culturally and genetically. co-evolved culturally and genetically. And when we've gradually emancipated ourselves, I mean, our genes have gradually moved us on into a world in which we, because we are surrounded by culture and culture has been gradually evolving at the same time, well, much faster, then we have become dependent upon the culture which has been evolving at this very rapid rate. Things like wearing clothes, things like taming fire and going on to central heating,

and cooperative living such that we have farmers who grow food for us, so we don't have to grow it ourselves, etc. I think it's not that difficult to understand how it's happened, this co-evolution with culture and technology. What are you expecting us to do with our increasing power to actually engineer changes within our own genomes? If you had a time machine and you could glimpse what we're up to on that front 50 years from now or 100 years from now, what would you expect? We've been changing the genomes of domestic animals and plants for thousands of

years, really very radically. And so the sort of domestic animals that we keep, like cattle and horses and pigs, chickens and pets like dogs dogs are incredibly different from their wild ancestors. And that's been achieved not by manipulation of the genes directly, but by artificial selection. So if you think that a Pekingese and a Chihuahua are actually genetically wolves that have been modified by differential selection by humans, you're now asking the question about the other part of the Darwinian equation, which is mutation. We've shown we can modify animals by selection. We've never done that with humans. And the Nazis tried, and thank goodness they didn't succeed. But I mean, you could have bred, I mean, one could imagine it in thousands of years' time if totalitarian regimes

started selecting humans the way we've selected dogs and cabbages, you could produce all sorts of monstrous humans analogous to producing chihuahuas from wolves. And directionless manipulation, yes, is much quicker. But you don't know what you're doing. Coming back to your earlier question, we don't actually know very much about how to do that. If you wanted to produce a, not just as a human, say you want to produce an animal, take one that hasn't been domesticated, like say a hedgehog. You want to produce a hedgehog which could do the high jump and jump impressively high fences. In principle, you could do it. You could do it by selective breeding. It would take a while, but there's no reason why you shouldn't gradually improve the jumping ability of a hedgehog until it could jump a foot and then two feet and so on. Just the way you

be bred dogs to change from wolves into Pomeranians and Spaniels. But to go into the genome of a hedgehog and say, let's change the genes to make it into a high jumper, that's in principle possible, but would take a lot more knowledge than we have at present for how to do that. The same with humans. I would think that if we just keep making progress, we will eventually have the understanding of the relevant genomes and the technology by which to intrude into our own genomes. We already have CRISPR, and presumably that's only going to get better and better and better understood in terms of the implications of making any change. At a certain point, we already see an appetite for body modification and general strangeness among humans, right? We see people who tattoo their entire bodies.

We see bodybuilders who develop their musculature to the absolute maximum capacity with the aid of a pharmacology that compromises their physical health, right? And this also happens among athletes. their physical health, right? And this also happens among athletes. So there's clearly an appetite for extreme performance and extreme aesthetics that, you know, completely divorced from performance of any kind. You know, even degraded performance, you know, that allows for extreme aesthetics. There's an appetite for that. So once we get the ability to, let's say, modify the tendons and ligaments and muscles in such a way as to make a person analogously strong to a gorilla or a chimpanzee, do you have any doubt that people are going to start doing that the moment that technology becomes remotely democratized?

No, if you're asking me about whether I have doubt to whether people would take advantage of the opportunity, I don't have any doubt. Whereas people do the most extraordinary things, yes, I think that they would. I sometimes say, well, we haven't changed humans by selection, the way we've changed dogs. So why would we change

them by genetic manipulation? But of course, there is an important difference, which is that selection is something that takes many generations. And it could be done by totalitarian regime. This is the question of what you could do to yourself as a consenting adult. What you could do to yourself is another matter, because that could be much quicker. And yes, I suppose that's true, because bodybuilders already, I mean, if you look at some of the pictures of extreme bodybuilders, they are, well, I was going to say grotesque, perhaps that's not unkind, but it shows what can be done by various sorts of manipulation.

And genetic manipulation could be even more powerful than that. So yes, I could imagine that, whether it would just be physical, I mean, maybe you could even produce musical geniuses, make another Mozart or another Bach by this means is a tantalizing thought. I guess I spend very little time thinking about this, you know, the far future or even the near far future with respect to this, but I spend much more time thinking about the implications of artificial intelligence with respect to this, but I spend much more time thinking about the implications of artificial intelligence with respect to this kind of time horizon. But when you think of genetic engineering, it's very hard for me to imagine what would prevent us from going some significant distance down this path, right? I mean, obviously, there are concerns about synthetic biology and the

engineered pandemics and all of that. And also, there are ethical concerns of the sort that you reference with respect to eugenics and totalitarian control of populations. But when you just imagine the technology becoming more and more available to the individual user in the way that, you know, by analogy, in the way that drugs illegal and otherwise are available to people now, you know, anabolic avoid extreme outcomes on a global level i mean i just don't see how yes i think all right we avoid it yeah yeah i quite agree okay well is there anything else in the book that you um want to draw listeners attention to in terms of your purpose in writing it or what you was what was most interesting to you and research there is a sort sting in the tail, I suppose, in the last chapter, which you won't have got to yet, where I make the suggestion that we should regard all our own genes, what we call our own genes, as symbiotic viruses, a gigantic colony of symbiotic viruses. And that's not as radical as it sounds. It doesn't

mean that a whole lot of independent viruses sort of like the flu virus and COVID virus and so on came together in us. It doesn't mean that. It's rather that I make a distinction when looking at parasites or looking at symbionts like viruses or bacteria, between those that get to a new victim by passing through the gametes, passing through the sperms and eggs of the present victim. So imagine a bacterium or a virus whose method of getting from human to human is by eggs or sperms. Then if you think about what they want of the body in which they sit,

what they want is exactly the same as what the body's own genes want. They want the animal to reproduce. They want it to survive, therefore, in order to reproduce. They want it to be sexually attractive. They want it to be a good parent. They want it to rear its young because that's their ticket to the future. So every one of our own genes cooperates with the other genes in our own genome. All the genes in our body cooperate to produce a body because that's their hope for the future. That's the only way they're going to get into the future. And that's what natural selection is all about. Selfish genes are being selected for their capacity to go into the distant future. Now, a virus whose method of getting into the next generation is also via eggs or sperms

has the identical interests at heart, so to speak, as your own genes do. And whereas a virus that has a different method of egress from the present body, like being sneezed out and then breathed in by the next one, or coughed out, or coming out of diarrhea and getting into the water supply and getting drunk by the next victim, those viruses or bacteria have not the same interest at heart. They might want the body to stay alive just long enough to have the next sneeze. But if you make a list of all the desiderata, all the things that they want their body to do, it does not include surviving to reproduce. It does not include being sexually attractive.

It does not include all the other things I mentioned. It might include being sexually attractive if the parasite gets passed on by a sexually transmitted disease. That would be a special case, which kind of proves the rule. So if you were to look at all our own genes, they're just like viruses that have the same interest at heart. And that's what I mean when I say that all our own genes can be thought of as a gigantic colony of viruses which cooperate with each other because they all have the only hope of getting into the future is to pass through the same exit route, the same little vessels, which are the sperms or eggs.

And so why make a distinction between viruses which get passed on by that route and our own genes? You might as well call them all viruses or call them all genes. That's the sort of sting in the tail in the book anyway. It's a provocative analogy. Are we aware of any viruses that target the gametes that way? Oh, yes. And I think it's something like 8% of what we think of as our genome really did come in as separate viruses. If you'd like to continue listening to this conversation, you'll need to subscribe at SamHarris.org. Once you do, you'll get access to all full-length episodes of the Making Sense podcast. The podcast is available to everyone through our scholarship program.

So if you can't afford a subscription, please request a free account on the website. The Making Sense podcast is ad-free and relies entirely on listener support. And you can subscribe now at SamHarris.org.