In Our Time - Evolution

Episode Date: April 15, 1999

Melvyn Bragg examines the future of gene therapy and advances in evolutionary biology. Are we continuing to evolve? If so, what are the signs and if not, why not? And those apes, so very very near us in genetic kinship, why are they so far away in so much else, and will they ever evolve? And is evolution necessarily progression? If so, does our apparent lack of evolution mean lack of progress? Also on the evolutionary front, could electronic devices discover the means of self-replication, and what will that mean for us? The march of the life sciences after the discovery of DNA accelerates by the year but what are the implications?With Professor John Maynard Smith evolutionary biological theorist and Emeritus Professor of Biology at the University of Sussex; Colin Tudge, writer, journalist and Research Fellow at the Centre for Philosophy.

Thanks for downloading the In Our Time podcast. For more details about In Our Time and for our terms of use, please go to BBC.co.com.uk forward slash radio 4. I hope you enjoy the program. Hello. Our knowledge of evolution this century has expanded in ways unimaginable in Darwin's time. The impact of that knowledge and speculation about our origins has been immense and continues to grow.

But how do new ways of thinking affect our understanding of ourselves and our futures? Joining me is one of today's leading evolutionary theorists, Professor John Maynard Smith, now Emeritus Professor of Biology at the University of Sussex. He's particularly renowned for his work on game theory. His best-known book is The Theory of Evolution, which was first published in 1958, since when he's written extensively on evolution.

His most recent work is The Origins of Life, from the Birth of Life to the Origins of Language, which has just been published, and he'll be lecturing on the Origins of Life tomorrow at the Edinburgh Science Festival. I'm also joined by the writer and journalist Colin Tudge, who's currently a research fellow at the Centre for Philosophy. His books have included the day before yesterday,

5 million years of human history, last animals at the zoo, and most recently Neanderthals, bandits, and farmers. Professor John Maynard Smith, we have a greater knowledge of genetics and evolution than possibly could ever have been imagined in Darwin's time. Could you briefly describe what's radically different about the way we understand evolutionary theory now

and the way it was understood, as it were, by Darwin and his contemporaries? Well, it is, as you imply, essentially our knowledge of genetics that has transformed things. Darwin knew that children resembled their parents, but he had no idea how or why, didn't know anything about the mechanism.

Now we understand the mechanism in really quite extraordinary detail as to how it comes about that children get information from their parents about how to grow, if you like. And it's that that has really transformed our ideas about evolution. what my book with my Hungarian friend Osh Safmari does

is to suggest that there have been, we're trying to explain really how things became so complex as they are, and we have suggested that there have been a number of changes in the way in which information is transmitted between generations. Is evolution to do with complexity, do things get more and more complicated? Do they ever get more simple? Oh, things can get more and more simple, if some lineage takes up life as a parasite in somebody's gut,

then they tend to lose their eyes and their legs and become, at first sight, very much simpler. It's only true that some things become more complicated. I mean, it really is true that either an oak tree or an elephant is more complicated than a bacterium. What do you think you make a grimace there, Colin? Well, one thing strikes me as that people, I think, get complexity wrong, because it is the case that complex things always come from simpler things, and some simpler things sometimes come from complex things. And there is a kind of, I think, politically correct idea,

which I'm sure John's not falling into the trap of, but there is, that, as it were, evolution doesn't necessarily lead to complexity, and on the whole it jolly world does, and only sometimes do things get more simple. Well, I don't think there's any rule that any given evolutionary lineage gets more complicated. Indeed, most evolutionary lineage is do absolutely nothing, millions of years or very little. But I certainly agree with you that some things have become more complicated.

And that is what we really want to explain. I mean, people really are rightly astonished at the complexity of a human being or of a, as I say, of an oak tree. I mean, it's not just animals, but plants also, it's extraordinarily complicated. Can I come back to the first question with you again, Colin Touch. What for you have been the main developments in evolutionary theory? Just say this century. Well, actually, one of the main ones is the one that Darwin himself started off, which is really only caught on this century, and I think it's really only been properly enunciated in the last few years by

Dan Dennett, which is that before Darwin, people thought you could not have anything that was complex and certainly anything that was mindful, unless it had been made by something that was even more complex and even more mindful. I mean, John Locke made the point in the 17th century, and nothing will come of nothing. So he more or less approved to his own satisfaction that you had to have a mindful, complex creator. And what Darwin showed was a mechanism by which more complex things could emerge from more simple things or mindful things from non-mindful things by a process that didn't involve a more, a more, you know, an intelligent

creator. That was an extraordinary thing to do. Lots of Darwin's contemporary didn't really realise that that's what he was saying. Darwin realised it himself. And as I say, I think it's only the late 20th century that people, that's really cotton on. People have really cottoned on to that. And are there other developments that you ought to know that? Oh yes. I mean, John said that, you know, the great thing of course is the fusion of Darwin's idea of evolution by means of natural selection with Mendel's idea

that there is this hereditary unit called the gene. I think one of the huge shifts has been since the 1960s. Darwin thought that natural selection operated at the level of the individual. In other words, you know, fast cats would prevail over slow cats. And now it's becoming clear that if you really want to think clearly about evolution, then you have to think about evolution

operating at the level of the gene. In other words, it's the gene for fastness that survives or doesn't survive, rather than the individual itself. This has enormous implications, one of which is that the gene doesn't give a toss about the animal which contains it. So that paradoxically, although the gene is apparently the unit and the expression is the selfish gene, the individuals which contain the selfish gene can be very unselfish themselves. So it gives rise to altruism. Just one second, and this is a terrible digression, but ever since you said John Locke, said nothing will come and nothing. Our mind's been straying off, obviously, from Lear. Did Lotton know he was quoting from Lear? I'm pretty sure he did, I mean he was going. That's fine. It was just a kind of itch. The selfish gene, John Manor-Smith, has been much misunderstood.

Well, I slightly differ, I think, from Colin in the way that I see this issue. Most of the time, well, let me to put it at this, I often think when I'm trying to solve a problem in evolutionary biology, If I was a gene, what would I do? And I sort of put myself in the position of a gene and think like that. But then, of course, I do the sums properly. When I publish it, I don't say that. It's full of algebra when I publish it.

But that's the way I start. But of course, if I was a gene on a chromosome in a human being or in most animals, what I do would be to try to do the best I could for the organism in which I found myself, because I can only get transmitted by that organism. So if I can keep it alive, that's fine. The complication comes is that there is another thing I might do. I might say to hell with the organism I'm in. I'm just going to jump around the place.

I'm going to jump onto other chromosomes. If there's any sex, I'll jump onto the chromosomes that came in from the other individual. I'll spread selfishly, even if it does damage the organism I'm in. and we now know that there are genes that behave in that way. There are a so-called jumping genes that are just entirely selfish and don't do the organism any good. But most genes, as I think to use Richard Dawkins' analogy, are like the eight men in a boat rowing.

I mean, each one of them can only get to the other end if he pulls his oar. I mean, he's got to cooperate. But the other side of the coin, isn't it, that, for example, a gene which is contained in a parent can sacrifice the parent in order, as it were, to spread itself through the offspring, in other words, leading to altruistic behavior?

Well, in this case, perhaps not very altruistic behavior, but it's indeed true. I mean, some very interesting insights into the problems that can arise during pregnancy have arisen from taking the selfish gene point of view. What would I do if I was a gene in the fetus? What would I do if I was a gene in the mother? And the kind of conflicts that arise

can, in fact, lead to quite serious complications in pregnancy. Con the judge, I know that you think that evolution, psychology is very important. Could you explain why you think it's so important? Well, I like very much the idea that there is something called human nature. I mean, Hume wrote treaties on human nature. And I think that, you know, this 18th century notion that we really can understand ourselves and that we are really a certain kind of animal that can be understood,

evolutionary psychology continues that tradition. But the very nice thing about it is that although people who have been on this programme, I think will say that what do you call it, evolutionary psychology deals only, for example, in just so stories. In other words, you can make up anything, and many old tale will do about human psychology. This is precisely the thing which isn't true.

What evolutionary psychology aspires to do is what all good scientists do, which is to deal in testable hypotheses. And the real point then is that, okay, evolutionary psychologists can dream up stories like anybody else and like all scientists have to do. but then they come back to testability. And so what you're now getting is a view of human evolution,

which is not going to be the truth and the whole truth and nothing but the truth, but it's going to be, as scientists say, robust, and you've got something you can build on and go one building on. That makes it very significant indeed. Yes, I'm not quite so convinced about evolutionist psychology, as you are, Colin. I'm fascinated by it, and I listen to it, and I read it. But the number of areas where testable hypotheses so far have been produced,

is rather few, it seems to me. And a lot of evolutionary psychology consists of, I mean, this is unfair, perhaps, of asking a first-year student on some campus in California how many women did you sleep with last night and believing the answer. And I'm afraid I don't. Can I ask you, too, I mean, this is a big question, but if we can, because I announce this in the trial. Why, do you think we're still evolving?

Oh, yes. I mean, significantly, humankind. I think we're still evolving, but I don't imagine we're becoming clever and cleverer or better and better or any of those things. But I do think that during the last 5,000 years, significant changes have occurred in human beings, primarily concerned with our ability to resist infectious disease. That's been the main selective agent, killing some human beings and allowing others to live. and in the spread of Western man across the world, we've killed as many people by giving them measles

as we have by shooting them with rifles. And I think that is, I mean, it's not a very happy story, but the evolutionary consequences in becoming more resistant to disease are important for human beings. You've said in your new book, you talk about the, you say we are currently at a vital stage in our evolutionary development because of the information we can store with the new technology.

And you talk about a technological stage in evolutionary terms. Can you develop that? Well, the whole of our book is about the fact that at intervals during evolution, new ways have evolved of transmitting information between generations. Sex is such an example, for example, that nowadays, ever since the origin of sex, the new individual gets genetic information from, two parents and not from one, and that has enormous consequences for evolution.

And then the origin of language was such an event, because now information can be transmitted between information, not by genes, but by talking by ritual, by myth, by story, by speech, by example, and so on, which is tremendously important. But now we're storing information and transmitting it in a new way electronically. And I really do think we're living through another major, transition in the history of life. And I find it impossible to predict. I don't think scientists are good at predicting the future.

You know, I think you need science fiction writers to do that, and they can be very good at it sometimes. But I think it's going to completely transform the way we live. I don't know what will happen, whether we will start becoming a kind of human beings with electronic prostheses sort of stuck into them all over the place so that we think faster or whatever. I don't know what will happen, but something will. It's very frustrating that you don't know, having sort of set it up. How did you have any projections or prophecies or ideas? Well, I've just been writing a book about Dolly the Sheep, which...

And one of the things about cloning is that it is actually really a handmaid into genetic engineering. It's a way of doing genetic engineering efficiently, which nobody ever says. They think it's a way of duplicating creatures. That's the less important thing. Now, the thing is if you put cloning and genetic engineering together, and you add to that the whole idea of, you know, the human genome project, where you actually work out what the genes really does. then you're getting to a point where you can really effectively create any kind of creature you like, more or less at will.

And whereas there used to be species barriers that made it impossible to breed animals beyond a certain point. Now you really can just invent them. I mean, almost anything that you chose to invent off the top of your head you could create. I find that pretty damn terrifying, and I think it is an evolutionary shift. It's not actually the one that John was talking about quite. But it's enormous. We're entering something that one might call the age of it. biological control and it's as it were us in control of it.

How does this square with the Richard Dawkins notion of memes or doesn't it? Is that yet another thing that's going to? It's a different thing, yeah. But I mean I guess I came into evolution, into an interest in evolution when I was a boy of about 15 or something when I read an extraordinary book called Last and First Men by a man called Ola Stapleton, which is a history of the next thousand million years or so, in which he really argues that human beings will not be able to live a sensible society until they transform themselves genetically.

And that may be interested in genetics, interested in evolution and so on. So we're just at first draft and we're not much good at it and we should actually change ourselves in order to tick along, which is what people, a lot of people dread most, don't they? I think they're probably right to dread it at the moment. At the moment we don't know how to do it. I mean, we can see how it might in principle be done, But that's very different from saying we know how to do it.

Well, Colin Judge was implying that we not only know how to do it, but we could do anything we want. No, no, John's right. I mean, we can know how to do it in principle. One of the things that impresses me is that when people think about technology, they are impressed by the fact that it moves very fast, and therefore they expect things to happen in the next five or ten years. And if you can't see it in the next five or ten years,

they say, oh, well, it's not very interesting. The fact that the matter is that science and technology move extremely fast, but there's a huge amount to get through. so that in reality it might take a century for a technology to unfold. Now we're at the beginning of the whole sort of cloning genetic engineering age. Think 500 years and then you'll begin to see what it can really do. Do you think it's possible to make a distinction between human development and human evolution? Oh, yes.

I mean, if by development one means the changes that go on between an egg and an adult organism, an adult human being, the whole rules are different. I mean, the mechanisms are different. The most exciting thing that's happening in biology right now, actually, I think, is that we are beginning to understand how development works. I mean, even 20 years ago, we had really no notion. Now I think we have a very good notion.

Yeah, can I ask John a theoretical question from what you were saying earlier about the notion of how we transmit information? I mean, one of the big splits in the history of evolution has been between Lamarck, who thought that you inherited the characteristics that were acquired by your parents. So if your father was a blacksmith, you had big muscles because he had big muscles. And Darwin, who said, no, that's not how, I know he was a Lamarckian, really, but who said, no, that's not how it works. You get variants and you inherit the one, you know, some variance pass on.

That acquired characteristics are not transmitted. Their emeritus are not transmitted, exactly so. Now, from what you're saying, this whole idea that one passes on information, from one generation to the next by language and indeed now by electronic storage implies that we are reinventing Lamarckian inheritance and a different mode of evolution. Would you agree with that? Is that right?

I think that is right. I mean, if today someone learns how to do something new which helps and it's adaptive, they can teach their children. And that is passing on an adaptation that acquired during an individual lifetime. So I think that cultural inheritance is indeed Lamarckian,

in a way that genetic inheritance isn't. And in principle, much more efficient, one would say, or not? Well, no, I mean, you have to be careful about this. If Lamarckian inheritance worked at the biological level, then what of most of the acquired characters you've had? I mean, my teeth have fallen out,

my skin is wrinkled, I'm going bald, I'm grey, I'm decrepit, half my neurons have gone. I think you look great. But if I pass those kind of characteristics onto my children, you know, there will be total deterioration. erosion. Most acquired characteristics are bad. Only a small number of them are good.

Do you think that, moving to another tacker, John Manor Smith, do you think that the idea of a belief in God and evolution are still possible to yoke together, or has God dropped out of your picture completely? I think God dropped out of my picture when I realized that I really felt I had to choose between Darwin and the Bible, if you like. I could believe in evolution as the explanation of why I'm like I am or I could believe in God creating me as explanation of why I am. And there's no contest.

You have to accept Darwin's view and regard to creation view as nonsense. On the other hand, you don't regard to creation itself, obviously not nonsense. Is the idea of something behind the creation still the remotest interest you to you? No, it isn't. What is of interest to me is that I do think people, human beings, I, you, all of us have to have beliefs, we have to have feelings, we have to think that it is better to be kind to people than to kill them. We have, if you like to believe that it is better to be faithful to people than disloyal and so on.

And these beliefs we acquire not because they're scientificly. true, but because we read poetry, we know about myths, we're influenced by things other than than pure science, and I think we have to be. And I think myths and poems and stories are incredibly

important in forming our belief systems, and I think we need them. But they're not to do with science. What's your view on that going to? Well, I like the idea of religion without God. I mean, I think it's a mistake to think that if you have a religion, you have to have God. I mean, God is sort of different. I'll leave God to the theologians.

But it seems to me that the kind of things that John was just saying are, in fact, religious statements. And the thing I really like about religion. Well, let's start with David Hume. We've already done John Locke, start with David Hume, who said that the basis of all ethics is an emotional response. Feeling has comes first and after that, you know, you invent an argument which justifies your feeling. It's an interesting fact, it seems to me, that when we discuss moral philosophy these days, ethics, we don't actually talk about the feelings. So, I mean, we have sort of, you see crude things entering into debates like people talk about the yuck fact, you know, which, you know, if you really think something's nasty, then it's probably wrong, that kind of idea.

But the idea that you should actually focus on emotion and feeling has sort of dropped out. And that's exactly, though, what religion does. I mean, it focuses on emotional response. And the kind of thing that, well, the notion of the creation, I mean, that's not necessarily talk about a literal creation. But if you actually think of yourselves as a heuristic device as being part of a creation, it am. immediately gives you a sense that you're somehow responsible for the universe and fellow creatures and so on. Would I be right in saying that the way you talked about that, just a few minutes ago, John, suggested that by reading poetry, this was an add-on that the essential human being was not like that,

ignored that. That was nothing to do with essentiality. This was in some way an add-on. No, I don't think it, that was a false impression of that idea of that impression. I do think that feelings, emotions, beliefs and so on are as important. important a part of a human being, what kind of human being they are and how they behave and so on, as any scientific theory or rationality or anything of that kind. I think it's enormously important that we have stories and myths which inculcate good rather than evil behavior. The trouble is that in the old days one used to justify this story rather than that by saying it's God's law.

If you don't believe in God, how do you justify them? Well, perhaps you don't have to you, just have to feel them. Can I see one other thing? Actually, feeling is very much a part of thinking. I mean, this is just becoming accepted. If you actually want to make a robot that it's truly intelligent, you actually have to give it emotions. It actually has to care, you know,

it has to care what's true and what's not and what's good and what's bad. That's an extraordinary fact, but it is a fact. Well, you see God, obviously, God has an endangered species. This is a terrible segue, colleague. You'll have to forgive that because you talk about the extinction of endangered species. but is the one way of looking at that extinction of species is a natural evolutionary development? Well, it would be if it occurred naturally.

But for example... The meters aren't natural, are they? They destroyed... Might have destroyed dinosaurs. Anything natural about meters? More natural than the measles? I think we have to have sort of what you might call operational definitions. And to me, the idea of natural is what happens when human beings aren't around

and what's artificial is what happens when human beings are around. I mean, it's this sort of world. working definition. And meteors are... But the thing about, let's say, let us take the black rhinoceros, this is the one people bring up. Black rhinoceros have gone very, very endangered, very, very quickly. And people say, well, you know, this is natural.

They've been around 30 million years. They've had their day. I mean, have they held, you know? I mean, they used to be as common as mice about 60 years ago. And the reason that they're going extinct is because they've been shot. Now, you cannot say that shooting something is sort of part of a natural process. It's rather ridiculous. And if you look at the rate of extinction now and compare it with what happens

when human beings are not shooting bullets and building farms and so on. It's been calculated that's at least 100 times greater now than it is at other times. And I don't understand this is a slight variation of what you're saying, but people will very often say that if you try to conserve species that you're somehow being high-handed, whereas they never make the same point about knocking species on the head. I mean, that's just one of those things, you see.

Well, I'm on your side, but what's your view of this, though, that the preservation of species for the sake of preserving the species is something we can do, but we are taking our own view of what should be held on to, aren't we? Yes, but who others view can we take? I think it is enormously important that we should preserve the diversity of life. I think the world would be a poorer place to live in if there were just human beings and their domestic animals and plants.

I mean, it really would. I mean, I wouldn't want to live in it almost. I love the diversity of the world. I was flailing around to try to play a devil's advocate to endangered species argument. I was obviously getting nowhere at all. You think actually that rich men could save a species almost at will, don't you?

Well, I've only written pieces about this. I mean, I genuinely think that one of the creative uses you could make of cloning technology is to take little biopsies of all the creatures that are now around in zoos, stick them in the deep freeze, and in a hundred years' time, you could recapture the genetic diversity

that now exists. and probably for about a million quid or a great deal less, you could do that for an entire species like the Asian elephant, and I'm inclined to say, why not? Look, I've only got four minutes left, and I've got a pile of questions, but I'm just going to go for this one, though. John, can you give us a simple explanation of why some species of ape failed to evolve into humans while others did,

and those who didn't, why aren't they catching up? I wish I knew. I think the crucial thing that humans did was to evolve, symbolic communication language. I mean, what we're doing right now, and no other animals have done it. It's very strange to me that no dinosaur evolved, intelligence and symbolic communication. Why not? You know, there's nothing wrong with them, if I could see. At the moment, our puzzle is to explain why one species did it rather than that lots didn't. It's really hard to explain the origin of language. Colin Tynch. Well, actually, I'd also like to know

what else evolution might do. I mean, not necessarily on this. this planet, but in the universe at large be an interesting thing to plumb. But the other thing is, of course, that being a human being isn't all roses, is it? I mean, there are lots of evolutionary reasons for not going down our path, which would have preempted quite a few others. Yes, yes.

Well, can we just play around with this? You see the origin of language is the key moment. How do you think that could have originated? You must have views on it. I do have views on it, but I'm not sure there. I mean, there are lots of views around. Let me say, not what I think the answer is,

how I think we'll get the answer. I think we have to study the genetic differences between people and in particular people who have problems with language to find out what the genes are and what they were doing before they did language, and then I think we'll know the answer. Conanty? I just want to say that whatever language is,

it's probably not a very big trick, but it's a trick that just makes a huge, huge difference. And the reason for saying that is that one tends to think that everything about us is different. from everything about animals. And it isn't. It's just that we've got this little trick. And when we look more at animals,

we're going to discover a great deal more in them, which is much more like us than we thought. And you think we can maybe give them the trick? No, no, no. Their brains are wired up differently. They probably wouldn't want it. No, but I mean, their brains are not wired up the same way. Is the Human Genome Project going to help us on this, John?

I'm a bit bored by the Human Genome Project. I mean, I work in the area. data is being collected mindlessly and nobody's thinking about it. I mean, roughly, except me. And I cannot see the point. I have all these data, but God. The other thing is, of course, when they've done the genome project,

people say, you know, when you've got all the genes and you'll be able to read the genome. I mean, nonsense. It's just a sort of dictionary, isn't it? That's right. There's no syntax in there, no literature. That's right. It's a dictionary in two foreign languages, that's very difficult.

It can't be useful, though, can't I? Oh, yes. Of course, there are uses. practical uses of the genome project. I think really it is the mindlessness of the enterprise that I find rather depressing. I think science involves thought. Well, Watson, one of the

co-inventors of DNA to be here, James Watson, he would very strongly disagree with you on this one, wouldn't he? And Watson is certainly not mindless. So where does that leave the human genome project in your view, then Colin Dodge? If it's backed by, driven by someone like Watson. Well, okay, Watson's not... Well, fine, Watson's not a stupid person, as you said.

But we are just making a dictionary. That's the point. another 200 years before you begin to see what's really going on in the genome. I mean, this is sort of the mindless beginning of something much bigger is the point. It's a little like Cliving Mount Everest. You do it because it's possible and it's there. Now we have the techniques to sequence the genome. We have to do it, but quite why.

Thank you very much, John Manor-Smith and Colin Tudge. And thank you for listening. We hope you've enjoyed this Radio 4 podcast. You can find hundreds of other programmes about history, science, and philosophy at bbc.com.com.uk forward slash radio four.