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Darwin and evolution

Celebrating the 200th anniversary of Charles Darwin's birth - and considering his work: Darwin and evolution.

Why is Charles Darwin commonly held up as the father of the theory of evolution? Ben Valsler spoke to Darwin biographer Jim Moore, and he began by asking him what drove Darwin to formulate the concept of evolution in the face of what was, initially, profound religious and political hostility to his ideas.

Jim Moore: Darwin was driven by different things at different times, just like all of us. He was complex; he changed; he became more conservative generally speaking as he got older, but if you mean what drove Darwin to become an evolutionist, one has to say it has to be something as powerful as the forces that were ranged against evolutionists.

When Darwin is less than 30 years old, he comes back from travelling around the world – most of it was on land, not at sea – but he gets home, and within weeks, probably a few months, he’s become an evolutionist. Why does he do that? It’s a bad career move, and in our new book, Darwin’s Sacred Cause, Adrian Desmond and I say that that powerful drive that overcame the social stigma of being an evolutionist was Darwin’s radical belief in the unity of all life.

That common descent unites every species, the human race as well as all races of animals and plants, and that leads him to a powerful image that was part of the ideological foundations of the anti-slavery movement. The notion of a family tree of humanity for traditional Christians rooted in Adam and Eve as the father and mother of humankind. Darwin takes it a step further and unites everyone and says that it’s our arrogance to believe that we’re not related to animals; it’s the arrogance of the slaveholder lording over his slaves whom he likes to regard as another species.

Charles Darwin. Image: Jupiterimages Corporation.

Ben Valsler: This may well have been the driving force but still, it was a long time before he published. It was a long time before these ideas actually made it out there. Was there a tempering force as well that made him look for all the right evidence and made him make sure he could prove this before he would publish?

Jim: Darwin kept his thoughts to himself to begin with. He was in the process of becoming involved in the Royal Society as secretary of the Geological Society of London. He was welcomed to the inner sanctum of elite natural history. His sponsors were Cambridge clergymen, professors; he had a grant from the Whig Chancellor of the Exchequer, a huge amount of money to publish his Beagle research. He was a young man on the make. He was pushing all the right buttons, he was going all the right places, and yet he carried this terrible secret in his private notebooks. He needed a theory, and he began calling his speculations ‘my theory.’

That was his project, ‘my theory,’ and towards the end of 1838 he works out what we now call natural selection. By 1839, when he’s getting married and having children, he’s developed that, and he knows within three years – he leaves London, he takes shelter in the countryside – he knows he’s onto something really big. It’s going to change the course of the history of science if he can convince people.

Now, at that stage you don’t go public. You take every precaution that’s necessary to convince people beforehand that what you carry with you is true. It’s not disreputable; it’s the answer to the mystery of the diversity of life on earth.

So, he commits himself for the next 17 years, that’s sort of 20 years in all since he devises natural selection, to answering in advance every conceivable objection that the heavyweights of science in his day could bring against what he’s doing, and that leads him into huge research projects. And finally he gets around to putting pen to paper and he plans a huge book, maybe a half million words in three volumes which no one would read, and in the middle of all of that, you know, he gets outed by this guy named Wallace, everyone knows this story, Darwin has to condense his work into something which he entitles On the Origin of Species.

Ben: Do you think the pressure of having these other younger researchers formulating very, very similar theories based on very similar principles, Wallace was looking at series of islands much like Darwin had, do you think this forced him to make some concessions in his work?

Jim: Darwin was not aware that Wallace was working on a theory, until the paper arrived in June 1858. Darwin felt safe in his non-competitive ecological niche as a theoriser of evolution. He knew that all the other theorisers were discredited or spoke ill of. He wasn’t like them. He wasn’t telling anybody what he was like. He still believed he had an inside track on natural selection.

Now, what did he do with that theory once he knew that Wallace was onto the same thing? He believed Wallace was onto the same thing. Darwin read the paper in haste; we can all see now that they are not talking about the same thing in the same way – Wallace rejects the selection analogy for example. Absolutely basic analogy with domestic animal breeding, Wallace absolutely rejects it, always rejects it. So there’s a fundamental difference between Darwin and Wallace to begin with.

I can’t see that Darwin gives up anything. I’d have to think about it for a while before I gave you a technical answer, but it seems to be that what Wallace says and does over the next 10 to 15 years makes Darwin more attached to what he always thought. Wallace did push him hard, and Darwin said once, “It terrifies me to disagree with you,” and that was public hyperbolae, but this unprepossessing sort of guy, who left school when he was 13, he didn’t go to Cambridge. I mean he would have, Wallace would have joined The Open University and he’d have got a fine PhD, had there been an Open University in 1840.

This was an incredibly bright and underused talent, you know, and Darwin knew that. You know, they were socially chalk and cheese, and yet this guy was dorking him, and Darwin took preventative measures, hedging about his theories to make sure, obvious example is sexual selection, Darwin is so goaded by Wallace, because Wallace doesn’t believe that male competition and female choice causes sexual dimorphism in nature.

Darwin expands his work on sexual selection so two thirds of his book, on ‘The Descent of Man’, and Selection in Relation to Sex is the rest of the title, two thirds of that book is about birds and bees and pigeons and furry mammals before he ever gets to humans. Typical Darwin, he has to do the whole panoply of nature to prove that sexual selection is right and (brackets) Wallace is wrong.

Ben: And finally, what was it about Darwin that means that he stands out now? There were other people researching similar things that may not have hit exactly the same theory, but Darwin really was the man that stands out as being the father of evolution.

Jim: Evolution needs a father, as Steve Jones would say. Newton is pictured by Blake’s geometer outside the British library on Euston Road - unfairly perhaps. You think of Einstein. You think of Einstein as a brain, you know. You might think of Freud as being something really slippery. But Darwin’s a grandpa! He has a beard. He has a big family. He’s wealthy. He lives in the country. He’s contented. He cut the image of what it was like to be a gentleman of science in his day, and he still does.

Darwin is cuddly. Apart from the fact that this old man is not reliable with children because he teaches them falsehoods, some people say, this old gent is like anybody’s grandpa. You could really warm to the guy.

Now I’ve studied Darwin for many, many, many years, and I’m not particularly enamoured of him. The more I’ve got to know him, I suppose the more I’ve got to know anybody, the less I’ve been enamoured of him.

Listen to the whole programme, originally broadcast on BBC Radio Five Live, March 2009.

Find out more

Explore the reality behind the man and his theories: Darwin

Watch Jim Moore talking about his discovery of Darwin’s motivation

Conferences take a lot out of you. No, really, they do. It’s hard work concentrating so hard for so long and I’m beginning to find my mind wandering more often in the talks. Which usually means I miss some critical piece of information and then I’m lost. Or, more interestingly, I enter that odd, semi-conscious state in which my brain is partly asleep but also concentrating hard and the physical things around me momentarily take on unexpected properties. I’m beginning to wonder if the likes of Hunter S. Thompson and William Burroughs spent a lot of time going to five-day conferences. When I manage to keep my mind on the task in hand, today’s talks are very interesting (even without the perceptual enhancement through sleep-deprivation). John Thompson from the University of California, Santa Cruz, gave this morning’s plenary lecture and a cracking tour de force it was too, as you can hear from my interview with him. He took us through the current thinking on how evolution acts not directly on organisms themselves but on the interactions between them. Species eat other species or otherwise depend on each other (where would insect-pollinated flowers be without their co-evolved partners-in-fertilisation?) and evolution can make its presence felt here. But don’t take my word for it; listen to John Thompson himself – he tells it much better.

After John’s talk I was looking forward to the session on Early Evolution, not least because my colleague from Sussex, Joel Peck, was speaking. But since the acoustics in the lecture theatre made the talks muffled and indistinct, I reluctantly decided to go elsewhere in search of a session that was interesting and easy to hear. I don’t think I was in much of a receptive state though. I feel sorry for anyone scheduled to speak on the last day of a long conference: you have your talk hanging over you the entire time; nobody hears what you’ve got to say until it’s too late to talk about it over a beer or three; and no matter how interesting your material, the audience will struggle to take it in simply because the previous few days are starting to make their physical influence felt.

And that - other than the final social event in the form of the conference ‘banquet’ - was it. If there’s a general impression I’m taking away from the conference it’s how willing evolutionary biologists currently are to re-examine previously rejected ideas. Take the Levels of Selection issue these blogs started with. Rather than rejecting ideas of group selection outright, a growing number of biologists seem comfortable with the suggestion that such a maligned idea might not apply under certain, particular conditions after all. Or the concept, discussed by Richard Palmer in his interview, that the genome might somehow be able to hijack variation that is solely due to the environment (such as the handedness of lobsters) and impose a genetic basis upon it (such as handedness of fiddler crabs). Previously this might have been instantly dismissed as Lamarckianism (and probably still is by many), but that doesn’t stop some asking if, after all, it might not occasionally happen in some modified form and if so, wouldn’t it be something if we could find out how?

Investigating the limits of ideas is exactly what science and scientists ought to be doing. It may be that the conditions under which a process works turn out to be too restrictive for it ever to occur. So be it. Or those conditions may be restrictive but may occur occasionally. So be it: as mentioned in the discussion on The Origins of Life on the Darwin Forum, rare events in the history of life have sometimes been exceptionally important. Or it may be that new or resurrected ideas are very necessary to gain a fuller understanding of evolution. So be that too. The advances over the last few decades have changed a lot of things in biology and caused us to question what we have taken for granted. That can only be a good thing. Question, experiment and then accept what the results of those experiments tell you – there’s the rational recipe.

Maybe I was lucky with the people I talked to and the sessions I attended - other experiences of the European Society for Evolutionary Biology conference may well be different. Leaving it though, I feel encouraged and completely unable to concentrate on another talk for a day or two.

About the author

Paul Craze is an evolutionary ecologist based at the Universities of Bristol and Sussex. He's an invited contributor to our Darwin and Evolution forum and contributes to The Open University's Evolution course. Paul also performs in an unusual band with some editors of Nature.

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Once upon a time I did some molecular biology. I wasn’t very good at it. I guess some people have the knack of working meticulously and imaginatively with tiny amounts of chemicals and some don’t. I don’t. Plus, I wanted to collect my data in the open air and the opportunities for al fresco molecular biology are a bit limited to say the least. The aim of my failed attempt at molecular biology was to better understand ‘transposable elements’ and what they mean for evolution and, despite my sometimes spectacular inability to discover anything about the little buggers at the laboratory bench, I’ve kept up an interest in them.

So I was very pleased to see that the plenary lecture of Day Four of the conference was by Cristina Vieira, from the University of Lyon in France, on Transposable Elements and Genome Evolution. You can hear a lot more about them in the interview I did with Cristina after her lecture but just to fill in a bit of the background: transposable elements are part of the so-called ‘junk’ DNA that’s been found to occupy huge parts of the genomes of many organisms. In fact, 50% or more of the human genome turns out to be transposable elements or bits of transposable elements. It’s not completely clear where they come from but many seem to be the result of viruses that have found their way into the genome and have taken up permanent residence. All a transposable element does is jump from one place in the genome to another, sometimes by cutting itself out and reinserting, or making a copy of itself and having the copy insert somewhere else, depending on which type of transposable element it is - hence their nickname of ‘jumping genes’.

Of course, having these things jumping around your genome, inserting themselves all over the place like the ultimate molecular parasite, is going to cause a lot of disruption and mutation. That’s why most species have evolved ways of stopping transposable elements from moving. These mechanisms tend to involve changing the scaffolding of the DNA (not the sequence itself) so that it shuts down; something that can change the genome even further. So, as you can hear directly from Cristina, both the transposable elements and the counter attacks a body’s cells mount against them can generate very large amounts of variation. And, since it’s variation that evolution works on, that makes them interesting for evolutionary biologists.

About the author

Paul Craze is an evolutionary ecologist based at the Universities of Bristol and Sussex. He's an invited contributor to our Darwin and Evolution forum and contributes to The Open University's Evolution course. Paul also performs in an unusual band with some editors of Nature.

Subscribe to Paul Craze's posts