Origin of the Species

From After Our Time wiki

[edit] Transcript

Melvyn Bragg: Hello, in the middle of the last century two men, Gregor Mendel an Austrian monk and Charles Darwin an English Naturalist, established the central theories of modern Biology and changed the way the world thinks. Darwin's "On the Origin of Species" has been described as "the book of the millennium", quote, "the only best seller to change man's conception of himself", unquote. Through the rediscovery of Mendel's work in the early decades of our century, evolution inheritance all about genes.

Two scientists trying to make sense of this tangled history are Steve Jones, Professor of Genetics at University College, London and Dr Matt Ridley, science journalist and Chairman of the International Centre for Life. Steve Jones is the author of "Almost Like a Whale" which updates Darwin's "On the Origin of Species", it's been widely, and I think rightly acclaimed as a remarkable, bold and very readable book. Matt Ridley has written another captivating book. His is on the special nature of human beings on the genome, which is the complete set of genes contained in a human being's 23 pairs of chromosomes. His book is called "Genome:The autobiography of a species in 23 chapters".

Steve Jones, you call the logic of the logic of the "Origin of the Species" quote, "as powerful today as when it was written", so what moved you to re-write it?

Steve Jones: Erm the feeling that really we have to keep explaining why we believe what we believe. Everybody believes, for example now, I think almost everybody believes that sun does not go round the Earth , we think it's the other way around. We all know that. But if you were to ask people why we know that, they might begin to stutter a bit, we can certainly talk about satellites and so on, but they wouldn't, probably wouldn't know Galileo's explanation, which is very subtle and had to do with the movement of "wandering stars" and "fixed stars" and evolution is much the same, we all believe, or we most of us believe perhaps that we evolved, but if you're pushed into a corner and said "Why do you believe that?" it might be rather hard to do. So the thing about "The Origin of Species", it is a remarkable work, it's structure is fantastically powerful, Darwin called it "one long argument", and it's a wonderful book, but of course he was writing in 1859, before modern Biology began, so what I've tried to do, perhaps rather too boldly, is to use that structure, that framework as a kind of scaffolding around which to build a modern building.

Melvyn Bragg: Why do you think that "On the Origin of Species" has remained so intact, when roughly similarly influential books around the same time, and the first half of the century like "Das Capital" and Freud's "Interpretation of Dreams" have been shot at and often shot down very much.

Steve Jones: I think that's a simple one, it's science, and in science, things are generally speaking, if they're true, they're established, they tend to stay upright, that doesn't always happen, it didn't happen to Physics, and it may well be that they'll be a new Quantum Theory of evolution that we can't even contemplate yet, but we haven't got there yet.

And it's so clearly correct, and it so clearly explains things that were previously inexplicable that it's stood up remarkably well, and the thing which saddens me slightly about the people who attack "The Origin ", particularly from the creationist end, is they make such a bad job of it . If they could come up with some convincing facts that it doesn't explain, then I'd listen to them, but instead they just waffle.

Melvyn Bragg: What would have surprised Darwin about what you've written?

Steve Jones: I think genetics more than anything else. It would have greatly cleared his mind too. Darwin was... you know I keep saying this in a boring fashion but it's true, I mean Darwin was the most extraordinary genius, and he was the best kind of genius, he was that very rare thing which was a modest scientist. Those two things don't often go together, it's a bit like "Scottish Amicable"and so on, there's a contradiction in terms. He immediately realised when somebody pointed out to him that his theory was flawed because his theory of inheritance which was roughly speaking the mixing of the bloods, of dilution, if that happened any advantageous character would be diluted out, so evolution couldn't work, and Darwin was honest and he saw that straight away, and he spent really much of the rest of his life trying to get round that problem. He didn't know of course, but the problem had been solved by Gregor Mendel, about whom Darwin knew nothing.

Melvyn Bragg: Matt Ridley, when you came to write your book, how influential was Darwin on you, and how is that absorbed into your book on the human genome?

Matt Ridley: Well I think that the human genome does in a way vindicate an awful lot of what Darwin said, and the, you know, the history of species, the history of how they diverge, the history of our own species...

Melvyn Bragg: Why does it vindicate it? Could you just explain that?

Matt Ridley: Well, if you take for example the origin of life, or something like that, we can now trace back to... we can find that there's a universal genetic code, all living organisms from beech trees to bacteria use the same genetic code, they use the same material DNA, and they use the same way of interpreting it, and that implies a common origin, and then if you look at particular genes themselves, you can find a bunch of genes called the Hock's genes, in humans on chromosome 12, which determine the body pattern of the embryo.

They lay out which is the head and which is the tail as it were, and exactly the same genes are in fruit flies, so much so that if you take a gene out of a human and put into a fruit fly it performs the same function.

The fruit fly mechanism can recognise it, and that implies that the common ancestor of humans and fruit flies which we know lived more than 600 million years ago had this mechanism in it. Now you know that's the kind of thing where, the kind of thing which the fossils can't tell you, but the genes can add to the story.

Melvyn Bragg: That's why you called your book an autobiography obviously, or subtitled it the autobiography? Can you just explain that a bit further, why these 23 chromosomes give us the autobiography of the human race?

Matt Ridley: Well it's a slight, it's a slight erm... sleight of hand, perhaps, because the way I've written the book, I start with the origin of life and find a gene on chromosome 1 that is very ancient and we share in common with a lot of other creatures and I gradually work my way up to much more human issues at the end. But that doesn't imply that chromosome 1 came first, or anything like that. I mean chromosome 2, I talk about the evolution of humans from apes, and the reason for that is that chromosome 2 is actually two ape chromosomes that fused, in all the other apes there are 24 pairs of chromosomes not 23, and the difference being that two of them fused when we came along. So I say rather facetiously that on the place where they fused that must be where the human soul has a gene, which of course I don't mean literally, but it's an excuse to talk about that thing.

The autobiography point is again it's a bit of a conceit, because what I'm saying is that the genes record everything that's happened, both to our species and to the species that went before them, and so in a sense if you can read it, as we now can for the first time, you can learn a lot about what happened to us in our formative years, several hundred million years ago.

Melvyn Bragg: Steve Jones, do you admire Darwin the more that his theory and his theses hold strongly despite the fact that he knew nothing about genetics?

Steve Jones: Yes I think so, I mean, one as a Biologist is more or less forced to chant the Darwin mantra from the cradle onwards. I always believed Darwin to be a genius, although I won't admit when I first read "The Origin of Species" that I wasn't as young as I ought to have been, but now rather like the theory of evolution itself, I know he was a genius, I mean you can see the strength of his argument, and you can see... what I like most about him was his willingness to see the weakness, his own weaknesses. Half the book is pointing at the possible weaknesses in his case.

Melvyn Bragg: ... areas of the culture, and that people used Darwin so often, so... not all that loosely as well, they try to follow his ideas. He's now the way we think about many things isn't he?

Steve Jones: I think in part because it's a tremendously simple idea, all it is, as Matt said, is it's "descent with modification", things are passed on from generation to generation and they change as they do. Now that seems a rather banal statement, but to the 19th century it was astonishing. There is a fatal tendency to use Darwinism where it really could not be used. Darwin himself was very reluctant to use his theory to explain human society, let's say, and there's a tendency in Darwin... for evolution to be rather like a sofa, it moulds itself to the buttocks of the last person to sit on it, so you find for example Karl Marx was tremendously keen on Darwinism as the rationale for Communism, whereas Herbert Spencer who invented that slightly unfortunate phrase "the survival of the fittest" and is buried just across, as you know, in Highgate Cemetery from Karl Marx, he was a great proponent of the idea that Darwinism made Capitalism okay. Sydney Webb thought Darwinism made Liberalism okay, so any one of the three party conferences going on now, you could have a Darwinist on the platform and he'd feel perfectly at home, and under those circumstances of course, it really has no use at all, because it's simply being used like religion to explain any conceivable pattern of human behaviour or society, and that's just empty.

Melvyn Bragg: A lot of people would say that religion isn't empty, and clearly you believe that Darwinism isn't empty, so although it's plastic and elastic, there's still something hard at the core of it, obviously.

Steve Jones: Oh definitely, I mean most definitely, as Matt's book makes very clear. Darwin would have loved to have read "Genome", because it would have reminded him very strongly of those terribly terribly boring books on comparative anatomy that 19th century Biologists used to read, you know "The map of the cat or the insect". All that Molecular Biology is, is comparative anatomy plus an enormous research grant.

Melvyn Bragg: Let's go on to this Human Genome Project. Now you say in your book Matt, "In a few short years we'll have moved from... ", I'm quoting you, "... from knowing almost nothing about our genes to knowing everything. I genuinely believe that we're living through the greatest intellectual moment in history, full stop, bar none. ", end quote, that's a big claim, but just, can you briefly tell us where we are with the Human Genome Project, and why you think it's so fantastic?

Matt Ridley: Well the story starts 50 years ago, when we didn't know what genes were, we knew they existed and we knew they influenced inheritance, we had no idea how they worked, and then came the discovery that they were digital codes, they were essentially text, they were like books, they were written in linear digital codes and they were instruction manuals, and that really was what Watson and Crick discovered in 1953, and in the 50 years since then we've understood a lot about how they work, but we are now for the very first time, in a position, when I say "we" I don't mean myself, I mean the science in general is, for the very first time, in a position to read the complete instruction manual for human beings. It's a very long book, it's 800 times as long as the bible, and we've got 100 million million copies of it inside ourselves as we sit here, and yet this Winter, we've read about 20-25% of it, a lot of in this country at the Sanger centre, and this Winter that will go from 25% to about 95%. By February or March next year, they're predicting that they will have the whole thing deciphered and worked out. Now it's then decades before we understand everything that's in it, but we've got it to look at, we've got it to explore.

Melvyn Bragg: So what have we got then Steve Jones, with this Human Genome Project? What have we got?

Steve Jones: Well we've got a banal image, a manual, but my fear is that the manual maybe written in Chinese. We have something which is a great string of the four letters A, G, C & T, it's a long, long way from having that, to knowing how it works, so I mean I often... I remind myself that the structure of the heart, the human heart was discovered by Vesalius in the 15th century and the first heart transplant was in the 1960s. I'm not saying there's going to be that much of a gap between seeing what the heart of ourselves looks like, and not only understanding how it works, but doing something about it. But the gap is going to be longer than most people think.

Melvyn Bragg: Do you think that for Darwin, Matt Ridley, natural selection acted solely on the individual? Do you think that translated to the genetic level we're talking about the selfish gene again ?

Matt Ridley : Well I do think that that's... and I may not be quite at one with Steve here, I do think that that's one of the big things that's happened in the past century, is that the transformation of evolution from essentially a theory about individual struggle, to a theory about genetic struggle, because... and in fact the structure of the human genome as we look at it, does bear this out to a remarkable degree, particularly the huge quantities of what's known as "selfish DNA" that's in there, or "junk DNA". Stuff that's in there because it's good at being in there, it's good at getting itself copied, it serves no purpose for the individual, it's simply there because it's good for itself as it were. It's dead retro viruses and things like that, and essentially what the theory of the selfish gene does is say that quite often what counts is the survival of genes, that genes... that individuals often do things that are bad for themselves, but good for their genes, and this enables them, this explains the problem which Darwin wrestled with of altruism, of why people are nice to each other, because if it's a struggle between individuals then they shouldn't be nice to each other. So... but if for example, if you take the example of human beings having children essentially because their sort of instructed by their genes to want to have children, they enjoy the experience because they're built with instincts to enjoy the experience. In fact it's a pretty thankless task for the individual, but it serves the purposes of the genes.

Melvyn Bragg: What's your take on that?

Steve Jones: Well I think that's obviously true, that in some sense, that Darwin again with his great genius saw a huge problem in his theory, was the evolution of sterile insects, how could evolution possibly make something that's sterile? And the answer was he saw at once that it's because the sterile helped their relatives who now we'd say have the same genes to make more copies of those genes.

Now in some senses that's true, the genes are in control. But one has to be rather careful to understand how little that means. I mean I got here this morning, I could say my legs are in control. My legs dragged me out of bed, down to the taxi that arrived on time, and into Broadcasting House, but that isn't actually saying very much or interesting at all. People overuse the power of the gene as an alibi. I'm often reminded of the Flanders and Swan song about cannibalism, "You can't eat people", and there's this very funny song about a young lad, a cannibal lad, arguing with his father about the morals of eating people, and his father comes out with the perfect Biological answer, he says "If God hadn't meant us to eat people, he wouldn't have made us of meat" , and that makes perfect sense, but is actually rather empty, and if the same argument is used by those who utilise DNA as the universal excuse for human behaviour, sure we're made of DNA, but my answer is "so what?".

Melvyn Bragg: And your answer to that Matt Ridley?

Matt Ridley: Well I disagree there. I think that it is absolutely central to understand the way in which genes play a sort of autonomous is the wrong word but that evolution is often happening at the level of the gene, rather than at the level of the individual , and you know the difference between evolutionary theory in sort of Darwin's time was that he didn't really appreciate that. For example nowadays a lot of ... nearly all research that goes on in animal behaviour, into things like sexual selection, sperm competition, all these other kinds of theories that are used to explain the way animals behave and how they interact, that uses the concept of the selfish gene very centrally to it, and you couldn't really understand those kinds of theories without that. So I do think that it is.. it's more than just another way of looking at it, it has actually had explanatory power as well.

Melvyn Bragg: I want to come back to evolution in a moment but to stick with this. What do you think about the ideas of genetic... you obviously don't give much credence to any ideas of genetic determinism do you?

Steve Jones: Oh I think I do . I mean if you are in the laboratory where I work, where people work on diseases like Cystic Fibrosis, or Muscular Dystrophy and so on, it's utterly foolish to say that there's no such thing as genetic determinism. I mean genetics is tremendously important. Roughly speaking, two people out of every three listening to this programme will die for reasons that are directly connected to the genes that they carry. The proportion , as we learn more, might even go up, so there's genetic determinismin that sense . But I often think that genetics tells us everything about... that's important about being human, apart from the interesting stuff

When we get to things like freewill, society, politics, genetics really can't tell you very much at all. I mean if you talk about the sexual selection game we have and have had in the world, many, many different systems of sexual behaviour: You've got polygamy and so on, you've got... in our own societies we've sort of changed in the last 50 years , to a kind of serial monogamy as an acceptable way of life. Now that's happened in a time that's an instant to evolution, it could not have evolved, our behaviour has changed for purely social reasons , and really that's the thing which is unique about the human species. We're the one creature that doesn't evolve in the traditional Darwinian way. The site of our evolution has moved from body to mind. And that is so important that the bodily constraints have really begun to lose their power.

Melvyn Bragg: Well isn't that something you were saying in your book as well Matt Ridley, that there are other sorts of determinism?

Matt Ridley: Well I yes... I mean I certainly think that in us there has been a delegation of responsibility if you like from the genes to the brain, much more than in most species, although I do think that there are... we perhaps underestimate the extent to which our evolutionary heritage still influences the way we behave. But I do think it's important when using this word "determinism" to realise that there are other sorts of determinism than genetic determinism. If you believe that your character and personality was formed by your upbringing that's just as deterministic as saying it was formed by your genes.

Melvyn Bragg: Is there any way of measuring how much of ones personality, your personality is formed by your genes? How much by your parents, how much by your peers? Can you... are we any where near a measure, look it's 33:33:33 or 40:40:20 or whatever?

Matt Ridley: Well I think there is, I mean I do think it's misleading to put an exact figure on it and because often what you're talking about is the genetic influences that only take place in certain environmental conditions etc so the two work together, they don't work in opposition, but the studies of twins in the past 20-30 years have now been made very systematic and well-controlled. They started out, interestingly these studies attempting to establish the power of environment, in other words they separated twins, brought up in different environments, were expected to show differences that proved the power of parental influence and so on, and frankly they've produced exactly the opposite results. They've proved that something like half or 40% of personality, with the proviso that that's a meaningless figure comes from inside us, from the genes largely, and a large chunk comes from the peer group environment, but terribly little seems to come from our parents. And that result comes up again and again, now it may at some point be proved to be wrong, but so far its looking pretty robust.

Melvyn Bragg: Steve Jones are we still evolving or is what's happening to us that's interesting, as you say, to do with the culture that we've created which has very little to do with evolution in the Darwinian sense?

Steve Jones: I would say the latter really, I mean when we talk about variation in personality and behaviour I notice that I'm talking to two Oxford graduates here! Now who's to deny that one's environment is important? What I find extraordinary, and I don't, certainly don't put Matt Ridley in this context is those who believe most passionately in the power of the genes are the ones who send their kids to private schools! Now if the genes are so important why not send them to your local comprehensive? You know the genes are important in a very, very obvious way, genes make brains, brains make behaviour, but we can do far more to improve the prospects of our children by changing the environment than anything we can do with a gene, so why all this fascination with genes? I don't understand it.

Melvyn Bragg: But let's get back to a point that maybe I expressed too bluntly, but I'm going to come back to you, do you think that we, individuals, human beings, is there any measure in which we are still evolving? Are our toes getting less useful, and shrinking? Are our brains getting bigger? Are we going to change in the next 10, 000 years? Or are we on a completely different route now that we are so much in control of so much of our culture in a wider sense in terms of medicine and habitation and so on?

Steve Jones: I'm less optimistic than to suggest that the latter is true. I mean let's take for example a nasty piece of evolution that's started happening in the last 20 years, which is the spread of the AIDS virus. Now, you know that's really a terrifying event , far more terrifying than most people realise given the situation in Africa . It's clear now that there are some people who can become infected by AIDS, the virus, and not develop the disease at all, and the reason it turns out is that they carry a particular genetic variant that makes that virus... makes it very hard for the virus to get into their cells. They will survive, they will pass on their genes, therefore in years to come, we may well evolve some kind of resistance to AIDS. Now, we are evolving in that sense . However having said that the thing which is most astonishing about us as a species is how little we have evolved in the last 100, 000 years or so , lets say. If, as I often say, if a Cro-Magnon man from thousands and thousands of years ago were to get on to me... on to the next seat to me on the tube, particularly in Camden Town where I live, you know I really wouldn't think twice about it, I mean I might think, "oh another Camden native, why don't I move?" as I think almost every day! But of course his life and experience was unutterably different from anything that we know. But his body was much the same, and I rather think that's what's likely to happen to us in the future. We will evolve in the sense, for example, that because people move, our skin colour will change, I'm sure over the next few thousand years to a sort of muddy brown over the world , but I think our societies will evolve much faster than that.

Matt Ridley: I think there are things that have gone on under the skin as it were of us that show evolution in action. I mean for example, the tolerance of lactose, of milk is something that's changed dramatically, you know, we can drink milk as adults, most of us in this society. A lot of people in different societies in the world can't , and that's an evolutionary change with the invention of dairy farming for example, and even today, the invention of in-vitro fertilisation, particularly some of the later forms of it, mean that infertility no longer means that you're infertile, if you see what I mean.

Melvyn Bragg: I realise I'm talking to two men who've written books that are packed with information, full of all sorts of entertainment as well as theory, so I'm just nipping in and out, but I don't want to finish the programme without going into the business of genetic determinism with regard to... let's take one example, the plea for the criminal gene. We have the Steven Mobley trial... defence as were, saying "I come from a criminal family, therefore I'm a criminal, therefore I'm not responsible, therefore I must be let off, or treated ... " , whatever. Now I get an impression of complication from your book Matt, and certainly from your book Steve. Are we any where near that possibility of saying "that particular gene, number X, on chromosome number... is responsible for that particular thing"? A) Are we near it? And if we are what does that imply?

Matt Ridley: I think we're near it in a few cases. I mean I think there are going to be some very rare cases where violence clearly does run in a particular family, and it clearly runs in that family because there is a particular gene that is different in that family.

Melvyn Bragg: Has that been proved, have they checked right down the family... ?

Matt Ridley: Yes.

Melvyn Bragg: ...right.

Matt Ridley: There have been one or two cases of that. But on the whole, what you're going to find is that there are a number of genes to do with sort of the testosterone system that cause young men to go through a period when they're more violent at the start of adulthood, in certain environments and not in others, and as Steve says there's very little genetic that one would want to do about changing that. I think the interesting thing about, as it were, a genetic plea, "I couldn't do it 'cause my genes made me do it". There's no difference there, between a plea of... between that and a plea of temporary insanity, which we're quite used to dealing with in the courts. We draw the line in the grey area, we say, "hang on a minute", there's a certain... you know, there's a degree of insanity that we accept as an excuse, and there's a degree that we don't, that we say, "no you have responsibility for your actions". What fascinates me is the way people actually are very ready to surrender their freewill, that they rush to the horoscopes to see what's going to happen to them, as if it was determined by them, they believe in all sorts of other ways in which their characters were formed. People aren't all that ready to accept freewill. We have got freewill because our determinisms interact . I mean my determinism interacts with yours, and that ends up being thoroughly unpredictable

Melvyn Bragg: What's your view on this, Steve?

Steve Jones: I think that's clearly true. The interesting thing though, let's take this case of this American who used the genetic defence in Georgia . He's still on death row, waiting for the courts decision. The state of Texas has changed it's rule effectively to make it the case that anybody who says that they were under genetic control, they should be executed because they can't be cured!

Melvyn Bragg: Your hero Charles Darwin, described free will as quote, "a delusion, caused by our inability to analyse our own motives".

Steve Jones: You know, I didn't know that!! I shall put that in my next book!

Matt Ridley: I think it's in my book actually! (laughter) Just on that, I do think it's interesting that we ... if environmental determinism... determinism by our upbringing is external, it comes from outside, genetic determinism comes from within, and in the end it's a contest between what comes from inside us and what comes from outside us and if you put it in those terms, what comes from inside us is not so frightening.

Melvyn Bragg: Erm, we began this programme, and near the top I quoted Matt Ridley saying, "this is the greatest intellectual moment in history", what's your view of that Steve?

Steve Jones: This today, this the century, erm I'm kind of forced to agree I have to say, I mean certain... in Biological history that's for sure. Biologists always have this terrible thing called "Physics envy", we all wish we were Physicists. We're not smart enough to be Physicists, so if we exclude Newton from this and Einstein I would say yes.

Melvyn Bragg: Well thank you both very much. That's our first programme, they're terrific books "Almost Like a Whale" by Steve Jones and "Genome: The autobiography of the species" by Matt Ridley. Thank you very much for listening. Next week we'll be talking with Marina Waughn and John Allen Paulos. That's it, thanks for listening, goodbye.