In Our Time - Darwin: The Voyage of the Beagle

Episode Date: January 6, 2009

To celebrate the 200th anniversary of the birth of Charles Darwin and the 150th anniversary of the publication of On the Origin of Species, Melvyn Bragg presents a series about Darwin's life and work.Darwin's expedition aboard the Beagle in December 1831 and how his work during the voyage influenced and provided evidence for his theories.Featuring contributions from Darwin biographer Jim Moore, Steve Jones, geneticist at University College London, David Norman, Fellow of Christ's College Cambridge and Jenny Clack, curator of the University.

This BBC podcast is supported by ads outside the UK. Thank you for downloading this episode of In Our Time. For more details about it in our time and for our terms of use, please go to BBC.co.com.uk slash radio four. I hope you enjoy the programme. Now Melvin Bragg continues his search for Charles Darwin and his idea of evolution by natural selection. Part two, The Beagle, the Finch and the Megatherium

joins Darwin as he sets off on Around the World Adventure and examines how the things he saw and the animals, rocks and fossils he brought back, made him famous, and helped provide the evidence for his developing ideas. Yesterday on Darwin in our time, we left the 22-year-old Darwin on the cusp of a grand adventure, a voyage on a ship called the Beagle to map the coast of South America. It would take five years, at that stage, a quarter of the 22-year-old Darwin's life,

and would radically change his ambitions, his understanding of the world and his status as a naturalist. We're in Darwin's rooms in Christ's College, Cambridge. paneled, wonderful windows overlooking a small quad, and I'm joined by David Norman, reader in vertebrid paleobiology and fellow of this college. Steve Jones, Professor of Genoa, a biographer of Darwin. Jim Moore, what kind of a boat was the Beagle?

How big was it, and who was Darwin sailing with? HMS Beagle was a Royal Navy 10-gun brig, 30 metres long and about 8 or 9 metres wide. Remember the coffin class of Briggs because of their instability. not particularly successful as a warship. It had been adapted purposefully to sail on this voyage, and it was immensely crowded with 70-odd people. Steve Jones.

Charles Darwin had a share cabin with the captain of the boat. All his specimens were jammed in there. I think the level of claustrophobia must have been absolutely terrifying, and of course there were all men that didn't make life any easier. After having been twice driven back by heavy southwestern gales, her majesty's ship Beagle, a ten-gun brig, under the command of Captain Fitzroy, sailed from Devonport on the 27th of December 1831. The object of the expedition was to complete the survey of Patagonia and Tierra del Fuego,

to survey the shores of Chile, Peru and some of the islands in the Pacific, and to carry a chain of chronometrical measurements around the world. There'd be no one. Apocryphally, Charles Dharman was seasick, and he was to discover this on the voyage of the beagle. I think any excuse that he found to spend time on land and do his adventures and collecting on land, and were greatly received as far as he was concerned. But you can't imagine the misery he went through for persistent periods of time of being seasick. It must be awful.

On the 6th of January, we reached Tenerife, but were prevented landing by fears of our bringing in the cholera. The next morning, we saw the sun rise behind the rugged outline of the Grand Canary Island. The Beagle voyage was a boy's own adventure. Darwin was 22 years old. Captain Fitzroy was only 26, and most of them must have been late teenagers and in their early 20s. You can see then why Fitzroy needed a companion like Don, a gentleman like himself,

even though the two of them were chalk and cheese politically. Extraordinary responsibility to take about that size all around the world. Among the scenes which are deeply impressed on my mind, none exceeding sublimity the primeval forests, underfaced by the hand of man, temples filled with the varied productions of the God of nature. No one can stand in these solitudes unmoved and not feel that there is more in man than the mere breath of his body.

Fitzroy really didn't realise what he was also taking on board. There was actually a raw intellect here that would be asking questions and probing questions about the earth and the process of life. And as the voyage progressed, as he began to question what he was, was seeing the variety and variation of nature, then the more he began to question some of the cardinal values of people like Fitzroy.

And they had some extremely unpleasant disagreements, although as gentlemen, they did actually in the end make up. I think there must have been moments during the voyage when Fitzroy quite wondered what he'd taken on board. So it wasn't all fun and games. I'm sure there was quite a lot of personal quarrels that went on. Can you tell us, Jim, were the principal reading matter that Darwin took with him? The most important books Darwin took were Charles Lyell's principles of geology.

The first volume was given to Darwin as they left by Fitzroy himself. This was the latest textbook on how to reason in the earth sciences. It established principles which Darwin took on board quite literally and applied to what he saw. Darwin was interested in geodynamics. He was interested in what made the earth. Earth's crust the way it is. Do you, David? Some of the most important influences on him must have been in South America

because he witnessed an earthquake in Concepcion. A bad earthquake at once destroys our oldest associations. The earth, the very emblem of solidity, has moved beneath our feet like a thin crust over a fluid. One second of time has created in the mind a strange idea of insecurity, which hours of reflection would not have produced. After the earthquake, he noticed that the sea level in the area on the seashore had been lifted up and marine animals were just stranded on this raised seashore. He also realised that earthquakes were linked to volcanic eruption. He tied these two together within the dynamic earth.

So he realised there was a huge interlinked set of phenomena, volcanoes, earthquakes and elevation of the land. He was also studying people, wasn't it, Jim Mar? He was. When Darwin got to South America, he was tuned to understand racial differences because his family had brought him up in anti-slavery, and here he found slavery in the raw. This shocked him. I may mention one very trifling anecdote,

which at the time struck me more forcibly than any other story of cruelty. I was crossing a ferry with a negro, who was uncommonly stupid. in endeavouring to make him understand, I talked loud and made signs. In doom which I passed my hand near his face, he, I suppose, thought I was in a passion and was going to strike him. For instantly, with a frightened look and half-shut eyes, he dropped his hands. I shall never forget my feelings of surprise, disgust and shame at seeing a great powerful man, afraid even to ward off a blow,

directed as he thought at his face. This man had been trained to a degradation lower than the slavery of the most helpless animal. That made Darwin wonder how humans could be created so high and so low. Could the same God have created Cambridge Dons and these savages who lay upon the ground and lived hand to mouth? This, I think, was the most disturbing intellectual experience in Darwin's entire life. It shook him to the core to see naked people his own age, surviving in a hostile environment. And, of course, he was seeing them not only as people, but as living organisms. Can we try to imagine or speculate?

What did the Charles Darwin who stepped off the beagle know that the Charles Darwin who stepped onto the beagle from Cambridge did not know? Steve? I guess what he saw on his journey. was the transforming power of time, really. The realization that very, very slight and trivial effects, very slow events can have enormous effects given enough years. He says somewhere that the maxim de minima non-cure at Lex does not apply to biology. The maxim that the law takes no account of trifles does not apply to biology.

So the tiny and apparently unimportant changes can have grotesquely huge effects given a long enough time. And I think that's what really struck him on the beagle. I suppose if there's one word, it's patterns. There was a method in his collecting. He didn't just pick up pebbles on the seashore. He wanted to know why certain things were where they were and not in other places. That is to say he was a philosophical naturalist.

He was interested in causes. Why are similar things in different environments? Why are different things in the same kind of environments? Why does the fauna change from one side of the Andes to the other? Why do the ostriches in South America change from north to south? Why do you find different races of people in different places? These were all part of the same problematic. All of these things come together in the most extraordinary synthesis in this young man's mind.

When he came back from the Beagle voyage, he was a collector, but a much better collector than he had been before. But he was trembling on the edge of having what he called, a theory to work with. And remember, he's still in his 20s. In conclusion, it appears to me that nothing can be more improving to a young naturalist than a journey in distant countries. The excitement from the novelty of objects and the chance of success stimulate him to increased activity. Moreover, as a number of isolated facts soon become uninteresting,

the habit of comparison leads to generalization. The Beagle returned to Plymouth in October 1836 and the Charles Darwin that stepped off it had no doubt about the direction of his future life. From this point on, Darwin, the would-be priest, avid collector and occasional dissolute, was, or at least he saw himself as a geologist. Darwin had collected hundreds of samples of rocks, animals, fossils, far more than could ever be held on a boat.

He chipped them all back to Cambridge and to his mentor, John Stevens Henslow. So when Darwin returned, both they and a small measure of scientific fame for their collector were waiting for him at Cambridge. And some of them are still here, where I am, in the Cedric Museum in Cambridge. I'm joined by David Norman, the director of the Cedric Museum, and Jim Moore. People talk about Darwin and Galapagos, and one of the first things that comes to mind is finches. It's nearly always animals. But the rocks that he brought back are very important indeed, and the number he brought back,

What can we read into this about Darwin's interests? As a very, very simple numerical observation of what he thought he was on the voyage of the Beagle, he put together about 360 pages worth of zoological notes and about 1,400 pages of geological notes. So clearly, while he was on the Beagle, while he was doing his interpretative work, the large emphasis was on rocks and geology. Geology was very important and very disturbing for people at the time, and Ruskin thought that geologists in themselves were destroying his idea of God,

the clinking of hammers that he talked about. So can you bring us into the picture of why geology so excited the minds of these intelligent young people? It was at a time of sort of equipoise about how you did science and how you made observations about the world about you. And it was at a time where you could either sit in an armchair and come up with very, very grandiose schemes that explained the structure. and history of the earth. Or, as the Geological Society

tried to demonstrate, you actually had to go out and do fieldwork. You had to make observations in the field, and only after you brought material, made observations, and began to integrate those observations, could you really genuinely come up with a proper credible theory? And in

the rocks here, Jim Mohe is looking for fossils of course, and finding them. We have them around us. For all geologists, no one just looked at rocks. They wanted to know whether there were beings in those rocks. Darwin was collecting rock samples from different places to figure out how the continent of South America particularly was formed, and he was collecting the adjacent fossils where he could find them as a further clue to how life was correlated with the geological changes.

What Darwin was trying to do was generating theory of the earth. It was a very common sort of aim amongst natural philosophers, not scientists, natural philosophers. They were trying to come up with a theory of how the earth worked and making observations that he was doing on this global trip around the world. One hope of that was that he would see, in a practical way, the earth working. And as the voyage passed, Darwin realized that there was a missing element in Lyle's system. And it was where life came from. Despite the abundance of rocks and fossils, many of the most famous items in Darwin's collection were animals,

and in the University of Museum of Zoology, Cambridge, which is where I am at the moment, they housed some of the things that Darwin had to kill before he sent them home. They would help him answer one of the great questions on his mind, the problem is speciation, or how species developed, and what the relationships were between them. The museum houses octopuses from Cape Verde,

marine sponges, bottled fish, but most famously, Galapagos Finches. So we're standing beside the Darwin, finches, Steve Jones, here in the Museum of Zoology in Cambridge. What sort of finches are they, first of all? Well, the finches, they're insect-eating birds. Most of them, some of them

crack open seeds, some of them actually use tools in order to hoike out insect larvae from rotten fruits. They're often painted as the sort of eureka moment, the finch moment in evolution. These finches are from the Galapagos. They are from the Galapagos. When they had life, they were in the Galapagos. Exactly.

And Darwin, without doubt, did collect them. There's no question of that. But it wasn't, you know, it wasn't that magic moment. In fact, he jumbled all his finches together, and he didn't even know what challenge they came from initially. He was actually much more interested and struck by things like the giant tortoises. He landed on one island, and he stayed there for several days, camping. And as people did in those days, killing off and eating the tortoises,

which is unthinkable now, the names. And he noted that on this particular island, the tortoises were blacker and had a sweeter taste than those on a different island. And that's a very unusual sort of conjunction of them. taxonomy and gastronomy really. And it really was a statement, hang on, why aren't all the tortoises are the same? If they were made by God,

why do we have different tortoises and different islands? Now, since then, the same notion has emerged with these finches. And a huge amount of absolutely brilliant research has been done on these finches, but not by Darwin. So is that why I got into the air that Darwin finches

are the key because of what happened post-Darwin? I think so, yes. And they are a beautiful exemplar of something which Darwin never imagined would be possible. An exemplar of seeing evolution happening in front of your eyes. But if the truth... Can you just spell that out for us on that? How is evolution happening before your eyes with the finches?

Because it has captured the public imagination. Yes. People know about El Nino, this change in climate that takes place every few years and they're going to have a bus. Everything goes green and then everything burns up. And a very heroic British couple, the grants have been following these birds for 30 or 40 years now. And they can see that after an El Nino, what happens is only a tiny proportion of them survived. And the ones that survived of one particular species are those with big, heavy, exceptionally heavy beaks,

which are able to crack open the dry seeds, the heavy, hard seeds, that's all that's left to eat. As the weather gets better again, the small beaks creep back in once more. So you see evolution happening, which would have been unthinkable to Darwin. So maybe these finches are more iconic than perhaps I make out. You think the mockingbird has been undeservedly neglected. Yes, the poor old mockingbird. It is the mockingbird that Darwin actually commented on as being different on different islands

who saw that there were different but related species. And you could see really how Darwin, on the Galapagos almost couldn't fail to notice the fact that there were unique forms of life there, that was somewhat similar but rather different from the forms of life in South America. And this is one of them. My attention was first thoroughly aroused by comparing together the numerous specimens,

shot by myself and several other parties on board, of the mocking thrushes, when, to my astonishment, I discovered that all those from Charles Island belong to one species, all from Albem Island to another, and all from James and Chatham Islands, between which two other islands are situated as connecting links, belong to a third. These two latter species are closely allied, and would by some ornithologists be considered as only well-marked races or varieties. But the first species is very distinct.

What we've got here is an octopus collected by Charles Darwin looking like so many of the things I spent my life looking at, something disgusting in a glass vessel, with all kinds of suckers and so on. And he collected this one of the Cape Verde Islands at the very beginning of the Beagle voyage. And he noticed that the darker,

from sight to side of the pond. They can change colour. He's being a natural historian. And soon he began to realise that octopuses, squids and the like are all related, that they've all changed over time they've evolved. Jim Moore. Darwin was fascinated by the great diversity and the intricate beauty of many of these organisms. Once he threw his dredging bucket out behind the beagle and hauled in a huge array of marine invertebrates. And he wrote in his diary, said, it makes me wonder why God created so much beauty out here where there's no one to observe it. That's an interesting problem.

He put his finger on any number of things that called for a solution that wasn't God directly creating things in places. But laws, Darwin is on a quest for the laws of nature, the laws of life, he says, when he gets back in London, on the beagle voyage. We've come backstage in the museum into the bird store where there's a gallery of stuffed birds all around us and in front of us a duck, a significant duck.

Steve Judge, can he explain why this duck is significant? Well, this dock did not die in vain, although I probably felt that it did. He was hit smartly on the back of the head with a geological hammer, and at the other end of the hammer was Charles Darwin himself. And you tend to forget that actually being a collector

can be rather a bloody business. and Darwin went out and shot. He was a very good shot. He shot, he strangled, he beat, he garotted, he poisoned. And of course he was a biologist, so he had to do it. At least he didn't eat this one. He's famous for having discovered one species of bird in South America, Darwin's rear, which is a flightless bird,

which he had for his dinner one night by mistake. But fortunately he could reassemble the remains from his plate. To continue that for a moment, Jimo, we're still in Cambridge, although we do see him in another world, in the bowels of this extraordinary museum. And he is a young gentleman of means, and he rides to hounds, and he hunts, and to pursue what Steve said, to take it further.

There's little compunction about the slaughter of the animals he was to treasure. Darwin was a bit of a paradox here, because he had aversion for blood, and you believe he inherited that from his father. He did not approve of cruelty. He never did in his life, nor did his family. He was brought up on anti-crualty. At the same time, he had an ambition to be,

praised for his ability to collect. And he believed that he had a collecting instinct. So he was giving vent to that all around the world and slaughtering animals. Just to pin this down with both of you, it is from the collecting, from the assiduous collecting year and year out, beetles and onto ducks, dead ducks,

that he builds up his theory. Yes, I think in the end, you can't do science without facts. many philosophers and the theoreticians picked up Darwin's theories as they still do and didn't bother with fact. Herbert Spencer was a famous one and it was said of Herbert Spencer that his definition of a tragedy was a beautiful theory killed by an ugly fact and what Darwin specialised him was ugly facts

and he got all those ugly facts together and he formed of them a beautiful theory. Still in this extraordinary museum we're standing in front of a collection of the barnacles he brought back in front of men I'm joined by Jenny Clack, who's professor and curator of vertebrate paleontology, here at the Zoological Museum in Cambridge. Can you talk about this barnacle? Yes. In fact, his barnacle work started stimulated by a curious barnacle he found on the Beagle expedition in South America.

He started by describing this particular peculiar one that he found. But he also wanted to understand how you do classification. And the barnacles were a particularly puzzling group at that point. And so he thought, right, well, I'll describe this one peculiar one. And that sort of mushroomed into an eight-year study, really starting a few years after he got back from the Beagle expedition. He went on to investigate the relationships between barnacles, finding that, for example, in some barnacles, the males were absolutely minute, and actually lived inside the females. and by looking at the differences between the males and the females

and between different species which have got different shapes, try to think about what a species was and how he differentiated it from other species. Darwin spent eight years working on barnacles, wrote four stunningly boring books on them. Steve Jones. Which are still the standard work on the taxonomy of barnacles. He dissected thousands of specimens.

He described them in eye-watering detail. He analysed their fossils. He made a family tree of barnacles. And once you begin to make a family tree, almost by definition, you have in your mind the notion of shared descent from a common ancestor. And once you have that, you have it.

You have evolution. If we walk over here, Steve, we're at the other end of the scale from a barnacle. We're in front of a megatherium, not the one that Darwin brought back, but very alike. Can you tell the listeners about it? Well, a megatherium is at the other end of a scale from a barnacle.

It's an enormous extinct sloth. This is, what, 12, 15 feet high, and it's being very slothful at the moment because its bones have been paced together. And this is the remnant we now know of an extraordinary gang of mammals that lived in South America when South America was still separate from North America,

giant creatures of many kinds, all of which were driven to extinction by aggressive invaders from the north. And Darwin found an example of this in Chile, collected most of it and brought it back. This sloth is arranged in this museum in rather the way that many extinct mammals were supposed to be. Its nose is up in the air.

Why? Because it's trying to escape from Noah's flood, which has washed it off the surface of the earth. It didn't take long, though, for Darwin to see the faults in that argument. We joined again by Jim Moore. When he got back, Darwin realized that there were pint-sized versions of this enormous mammal still existing in South America. And it made him wonder, why did God go on creating smaller versions?

versions of the same thing, if God created. Maybe there was some kind of rule that governed the way sloths are introduced into an unchanging environment. In other words, a law. It was part of what got Darwin started developing a theory, my theory. Was the Victorian public aware of this? And if so, how did they react? I think the scientific public was very much aware of it. Professor Henslow and Professor Sedgwick, both at Tottenham, Cambridge, sang his praises, and everyone admired what this young man out in South America was capable of. When Darwin heard that his name was on everyone's tongue, his hammer, his geological hammer, made the rocks ring in the Falkland Islands.

It spurred him on in science. And it was immediately clear when Darwin came back that here we had a collector extraordinaire with the ability to collect and to classify and to understand an astounding diversity of creatures, from barnacles to birds. And I think that made his reputation. Darwin won the gold medal of the Royal Society when he was still a young man. He was by no means a shrinking violet. Charles Darwin was 28 and his star was rising.

He was developing his ideas and upping his standing. He became a fellow of the Geological Society of London and had presented a paper to the Zoological Society in London. Although Edinburgh and Cambridge had helped to make him, Darwin was increasingly pulled towards London, fated by the scientific institutions there. It was becoming the centre of his intellectual world, and on the 6th of March 1837, he moved there. Steve Jones. The notion of change was in the air in London, not only in the world of biology, of course the world of politics or the religion.

What it seemed to be static, you know, the plates were shifting, although we knew nothing about continental plates at the time. And that's the me here which Darwin joined. Jim Moore, science was political, particularly the life sciences, could threaten social stability if they were taught in the wrong way. And we're talking about the great reform movements getting underway, we talk about chartersome getting in a way,

we talk about the still reverberations of the French Revolution becoming anglicized once more, as it were. Already geology had threatened to a certain extent because it extended time scale, perhaps the book of Genesis and the Bible weren't reliable. But more importantly, to believe in transmutation, that is the natural evolution of new species, was believed to culminate necessarily in the bestialization of human beings.

And if humans were only beasts, it meant the overthrow of the established religion of Christianity and therefore of social stability. All Darwin's friends accepted that political connection. We're in the Grand Zoological Museum at University College. London. What was Darwin's relationship with Grant and why is it important? Steve Jones. Grant was his teacher, his amanuensis in Edinburgh and he took Darwin on no doubt Chile field trips to the Firth of Fourth where they connected various kinds of animals. Darwin wrote his first scientific

note about some obscure marine creature in the Firth of Fourth with the encouragement of Grant. Darwin belonged to a rather exclusive student society called the Plenian Society in Edinburgh. And if he was the Student Biological Society, which was very taxonomic and descriptive in its nature, and if you look at their records, there are some rather odd crossings out at Darwin's time, and there seems to be some hint of evolution creeping into them, and they take them out. So Grant really was important in introducing Darwin to the world of animal biology. When Darwin returned to London, Grant had to go to him to ask whether he could describe the coral specimens Darwin had brought back from work. the Beagle, and he didn't get the job. He was the only person we know who actually applied to Darwin

to work for him, and Darwin apparently snubbed him. It all really came to a head at a meeting of the Zoological Society where the old guard assembled to almost ritually humiliate Grant because of his attempts to reform this old gentleman's club, the Zoological Society. And as a result, Grant was pushed to the margin of London science where he remained. But it's quite a break, isn't it? From the way you tell it, Jim, Grant seems to have been rather badly treated. You could say that, yes. But he was an oddball.

He was always an oddball. He was a oddball without being badly treated. Lots of oddball, they don't deserve to be badly treated. He was tall. He was satirical. Sarcastic, even. He was a Scot. They got him, didn't they?

Why did they get him? There is a rumor. It's not much more than that, but it descends from Professor Zoology to Professor Zoology. in UCL, that actually one of the reasons was that Grant was a homosexual. And this was, of course, almost unthinkable, all of it was certainly doable. In the area of UCL, there were a number of famous homosexual male brothels. And there is this undercurrent that there may have been the break,

which is really almost complete, may have had something to do with that. He was also a radical Democrat. He wanted the disestablishment of the church. He used the evidence in this museum to establish a view of life's history. on earth and development naturally, which came out of revolutionary France and from Lamarck. This was considered to be bad science, bad politics, and abominable religion. Can we just tell the listeners in rather more detail why we are in this particular museum, Steve, and as your office is just above it, perhaps you can just give a brief description of it.

This is the Grant Museum, and it's a beautiful Victorian museum, which, to use Dund Thomas's famous phrase, is a museum that should have been in a museum. Thousands and thousands of waves of waves of bones jammed into Victorian cases, a lot of it not on show because it's so big. We have basically the whole of life. Now somewhat jumbled together,

but in his day, far from that. And these are some of his actual specimens. There's an eye-eye, the tusk of a mammoth, some dolphins looking rather sad. We have sea urchins, sea stars, we have starfish, A specimen here which would have been familiar to Darwin

and this is a marine iguana now permanently in liquid I often think it's impossible to have too many moles and what we've got down there is maybe 30 or 40 moles or pickled together in some great moleish holocaust here we have a very eclectic collection of rather disgusting things in glass jars filled with liquid

the fetus of a thin whale Darwin would have liked that because of course the fact that the fetus of a fin whale looks a bit like the human fetus was really an important part in his argument for common descent. Able jar of assorted reptiles, the brains of various

apes and monkeys, and that of course was a great interest to comparative anatomy because it might tell us something about the human brain. If you've seen this in its original form, there would have been a great chain of being. You'd have started at the lowest form of life, which would seamlessly have gone through until he got Robert Grant himself.

And that's really his mistake, the idea that it was progress. So really we've got a microcosm of biology just before it made sense. This rather disgusting thing in a glass bottle is a thylacine.

As Queen Victoria settled on the British throne, Charles Darwin sat down in July 1837, four months after coming to London, and made a small sketch of an idea that would come to dominate the scientific, intellectual and religious agenda of Queen Victoria's age. It was a

single line, dividing and dividing again into many lines. It looked like a tree, and it was of sorts, an evolutionary tree that represented the idea that all the various creatures Darwin had studied. All the myriad of life itself came from a single origin, a single line that had diverged and diverged again into all the creatures on God's earth. Can you characterize the sketch, Steve Jones? Well, the sketch is indeed a family tree. It's very preliminary.

It's got one long branch and then a series of sub-branches which split into twigs. And next to it is a sentence which begins with two pregnant words, I think. And clearly that's the very important words. He's begun to think about the meaning of what he found. And what he discovered was really what I think of as the grammar of biology. You can't speak a language without understanding the grammar. Darwin realized that biology is a language. It has a structure.

it all hangs together, it makes sense, and that sketch is really haunted biology ever sense. I'm at the moment trying to get it applicate onto the front of this building as an enormous gold object. It probably won't happen. But it is the most important diagram in biology, without question. And from that, everything else follows. To understand Darwin in his day,

we have to see that that tree was heretical because it grew by itself God didn't create the species out on the twigs separately and miraculously. That whole tree of life grew up through time. It's worth a thousand words of that picture. 2000, 10,000. He shows the branches that have failed. He draws a line through them.

He says, that's a line that went extinct. That's a line that went extinct. These are the ones that are left. He labels the twigs, A, B, C, D. He's got the whole apparatus up and running. He was really almost the first biologist to think deeply about the whole of biology. That's the beginning of the theory, the theory that everything is interconnected. He was a polymath of biology.

Most people were specialists from one group or another, and it was almost a matter of egotism to assume that your own group was unique and separate from all the others. He knew so much that he saw the big picture. Darwin believed that life fitted on one tree. Why did he choose a family tree as his image for life's history on Earth? The answer is that he believed all human varieties. belong to one family. All the races were one in their source of life. There was a human background

to this. Steve Jones, would you like to develop then? Yes, that's true. I mean, I think this is one of the cases, a slightly rare case, where Darwin's intellectual and scientific life was clearly influenced by his political media because it was the general belief then, and the belief came back, and it's still around to some degree, that the race is so-called of human, of human were very, very different from each other and indeed sprang from different stocks. And if you believe that, that's an extremely convenient alibi for all kinds of nasty politics.

I mean, Slave-older certainly believed that. And I think that this unity of life, which is summarized in this tree, clearly had implicit in it, the unity of human life too. So it's a wonderful example of intellectual, radical, scientific, and without, as it were, mentioning it at this stage, deeply anti-the-accepted religious version. That's true, but I always feel,

I think most scientists feel, that one has to separate the science from the scientist. In the end, what's wonderful about that diagram is that it's right about biology. Darwin seemed to be poised over a profound new idea, but success was no guarantee of health, and in September 1837, Darwin suffered palpit suffered palpitations of the heart, which would play games throughout his life.

Recuperating in his hometown of Shrewsbury, he was introduced to his cousin, Emma Wedgwood, who mended his heart and then won it. Charles Darwin and Emma Wedgwood fell in love. But ever a man of method, he drew up two lists. One called marry, one called not marry, and he worked through the pros and cons. He concluded that a constant companion and a friend in old age outweighed, less money for books and the terrible loss of time. Steve Jones were in the Darwin Lecture Theatre

and one lecture is just breaking up and some of them are staying for the next lecture and some are not. So that's the background. Why are we in this particular room? Well, this is, when I teach it here, as I often do, I say I'm speaking to you from Charles Darwin's bunker. And that's literally true because this is the site of Charles Darwin's house in Gower Street, which he moved to, just as he was married.

They called it McCaw Cottage because of the... the garious decoration, so not much has changed as you can see. There was a dead dog in the back garden. They had to get rid of before his wife would agree to move in. So they came here from Wales, Charles and Emma, a married couple here. Jim Moore, have you any idea what it was like for them to settle in here? It was a great relief. Darwin was dying to get married.

He'd been biting the bullet for years. Emma wanted to take her time. They rushed into the wedding. It was the end of January 1839. He'd sorted out the house. He'd furnished it. He'd organized a cook and housekeeper and installed Emma with the fires glowing bright. And then the walls began to move in and the shutters close and Darwin found a protective cocoon. He had a guardian angel in his house who knew him intimately. They began having children almost immediately. And Darwin's withdrawal from the world continued.

When he made those lists about whether to have a wife or not to have a wife, have a wife. He was convincing in his list, but his choice worked out extraordinarily well for him as a professional working man, Steve Jones. I think his marriage in the end was extraordinarily happy. He had many children. He notes at some moment that his wife had been very lazy recently because they hadn't had a baby for more than a year. So it was obviously a sexually quite contented marriage too. Finally, in this place, as the lecture room fills up for the next lecture, Jim Moore, what about Darwin's own thoughts at this time around these two or three years? He's still reading massively. Can you give us some

idea of the main things that he's reading? Darwin's reading everything for his notebook. By now he has a series of five or six transmutation notebooks. These are kept entirely private. He's filling them with information from books on theology, on economics, and what we would call sociology, as well as every branch of natural history. He's reaching out in all directions in a most scientifically disreputable manner. 1839 was his year.

That year he published his Beagle journal. That year he became a fellow of the Royal Society. That year he got married. That year he finished his last transmutation notebook. Right, we're better leave now. The next lecture is about to commence. Thank you. Thank you very much.

So we've gone up in the lift from the basement of the Darwin building from the lecture theatre into Steve Jones' office. Myself, Steve and Jim. So at the beginning of the time, before we move on the next programme, of the long wait, why he did not publish ideas that he seemed to be poised to publish. Why, in your view, did he not publish around 1842? I think he felt he wasn't ready. He was a good scientist. He wanted evidence. Ideas were not enough. He wanted facts. And he set out to find those facts

from perhaps rather unlikely field, which is working on barnacles. And for eight years, he studied barnacles and became a great expert. He would happily have spent the rest of his life accumulating facts, probably, and not publishing his theory perhaps until he died. Darwin's scientific reasons for not publishing were also political and religious. The scientists, so-called, the naturalist that he looked up to and who had sponsored his career, believed in their hearts that his program of evolution was wrong and immoral if published.

He had his respectability to defend, he had his family to defend. He could not go public with something that wasn't well thought through. It was huge. He understood its ramifications. He also understood the problems he would get into if he did publish. And those would, first of all, be because of its religious and political implications. The naturalists he looked up to most of all were clergymen and devout men of science. He could not publish something.

that would be seen to subvert the foundations of religion and social order. How did he talk to anyone about the true nature, what we might call the ultimate nature of his thinking? No one. He had talked to no one possibly except members of his family. His father knew. We can be quite sure his father knew. His father's advice about this was kept in two notebooks with private written on the front.

He kept all his notebooks private, all of his speculations private. He probably told his brother. His brother was a free thinker. Nothing shocked him. He told his wife, and this became a sore point in their relationship. Can I just develop this business of his wife's upset there? What do we know about that, and how do you mind was it to this particular period in his life, Steve Jones? Certainly, as the model became more overt and as his wife was drawn into his private world, she was deeply shocked, and it was a deeply shocking idea. And I think actually it did cause quite a family problem, which was a microcosm of the much larger problem which it caused to society. Darwin didn't publish his ideas for another 17 years, and only then, because his hand was forced by Alfred Russell Wallace,

who had hit upon a similar idea. Darwin rushed to print, and in 1859, one of the most important scientific books ever written rolled off the presses of John Murray, on the Origin of Species by Charles Darwin. Join me tomorrow in Darwin in our time to learn about that book, the ideas within it, and the storm they created, one that would roll out from Darwin's mind through the societies, the Lanayan Society, the Geological Society, into a voracious Victorian public, and then controversially into the world, one that's still rolling today. Darwin, in Our Time, was presented by Melvin Bragg and produced by James Cook.

There are many more radio for arts and discussion programmes to download for free. Find these on the website at BBC.com.com.com. The crew of NASA's Artemis II mission have successfully completed their voyage around the moon. This is what we've been waiting for for 50 years. Traveling further from the Earth than any human has ever gone before. And 13 minutes, the BBC Space Podcast told the inside story with audio from the mission and insight from experts at NASA. That's the way it is in spaceflight. There are a lot of tough questions.

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