Charles Darwin

by A. N. Wilson

  Darwinism is not simply an argument that the forms of nature come into being by common descent. It proposes that every form in nature, every distinctive, taxa-defining novelty has come into being by a gradual process of adaptation and change.

  It is crucial to realize – as Darwin’s fluidity of mind seems not to have done – that these are two quite separate claims. Alfred Russel Wallace’s famous ‘Sarawak Law’ paper of 1855 had demonstrated that ‘Every species has come into existence coincident both in space and time with a pre-existing closely allied species.’6 It was called the Sarawak Law because Wallace had written his essay, so remarkably like Darwin’s theory, in the wet season, in a little house at the mouth of the Sarawak river, at the foot of a mountain in the Malay Archipelago.7 It is impossible to doubt that descent by modification occurs. For example, the first amphibians which most closely resemble the fish lived in the same geographical region and at the same time (the Late Devonian). This suggests an ancestor–descendant relationship.

  What Darwin introduced into the argument – as did Wallace four years after his ‘Sarawak Law’ paper – is something which has never been demonstrated. This is that the evolutionary novelties which make for a new ‘species’, and the highly complex homologues which are to be found in the new species, have come about as a result of a slow process.

  What we can now see is that while some adaptation, of the kind noted in the Galápagos finches, or of the kind chronicled in Wallace’s ‘Sarawak Law’, takes place within an immutable Bauplan, there is no evidence of the homologues themselves having come into being as a process of adaptation. Etienne Geoffroy Saint-Hilaire’s picture, in the early nineteenth century, followed to some extent by Owen, was that all animals shared the same basic body-plan – a plan which was fixed. Darwin and the Darwinists believed they had destroyed this idea, and replaced it with the picture of gradual adaptation and change. Evolutionary developmental biology, however, shows that new homologues do indeed appear complete, fixed. For example: some ancestral chordate switched its body-plan from the design previously shared with all animal groups, in which the nerve chord is in a ventral position and the heart and the main blood vessel are placed dorsally, to a design which is the exact reverse: the nerve chord is placed dorsally and the heart is placed ventrally. This has remained invariable in all chordates since. The same genes are involved in specifying the dorsal–ventral axis of chordates and non-chordates. The older nineteenth-century biologists have been proved right, and Darwin wrong.

  Michael Denton puts it like this. There is no evidence for all changes in our ancestral evolutionary history having been adaptive or gradual. And if ‘the pentadactyl limb or the insect Bauplan are also a-functional patterns, like the thirty-four petals of a field daisy or the shape of a maple leaf, then the whole Darwinian enterprise breaks down’.8

  Darwin was honest enough to admit, in his Chapter Six, that there were ‘Difficulties on [sic] the theory’. For example, ‘why, if species have descended from other species by insensibly fine gradations, do we not everywhere see innumerable transitional forms? Why is not all nature in confusion instead of the species being, as we see them, well defined?’

  Darwin’s way of arguing was one which could be described as slithery. He presented difficulties, but then waved them away rather in the manner of a conjuror covering his top hat with a silk handkerchief. He assured the readers of The Origin of Species that the fossil records were imperfect. ‘The crust of the earth is a vast museum . . .’9 Sooner or later the doors of the museum will open. The public – you and I – will be allowed in to view the conclusive evidence provided by the exhibits.

  Well, a lot of fossil evidence has been unearthed since 1859. There is some evidence of intermediate forms linking major groups of vertebrates. That is, there are some ‘missing links’ – the Panderichthys, an intermediate form of fish–amphibian; the Thrinaxodon, a mammal-like reptile; the Pezosiren, a land-mammal–seacow intermediate. We should expect, though, if Darwin were correct, that there would be hundreds, thousands of examples of such transitions. Fossil evidence is vastly more comprehensive in our day than in the nineteenth century, and it simply fails to endorse the Darwinian theories of gradualism. For Darwin to be right, all novelties in nature have to be explained by gradual mutation. Stephen Jay Gould, one of the most distinguished palaeontologists of the twentieth century, quipped that the absence of transitional forms was ‘the trade secret of palaeontology’.10

  There has never been a coherent explanation of the emergence of highly complex forms. Darwin, again, acknowledged this. ‘To suppose that the eye, with all its illimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.’11

  Darwin contended that, in spite of the apparent absurdity, a complex organ such as the eye could, little by little, evolve rather than appearing ready-formed. Whatever conclusion a modern reader draws from this old chestnut, it is perhaps only fair to mention the gallant effort made by two Swedish biologists, Dan-Eric Nilsson and Susanne Pelger, who in 1994 published their findings after experiments with a computer model: ‘A Pessimistic Estimate of the Time Required for an Eye to Evolve’.12 By speeding up the whole process on a computer, Nilsson and Pelger have demonstrated that it would take ‘only’ about 364,000 generations to evolve a good fish eye with a lens. Their ‘pessimistic’ estimate was so called because they deliberately, in their experiments, stacked the odds against themselves. It would probably take less time for the fish eye to evolve.13 Perhaps half a million years. As Richard Dawkins wrote, ‘And that is a very, very short time indeed, by geological standards. It is so short that, in the strata of the ancient eras we are talking about, it would be indistinguishable from instantaneous.’14 I have said it is fair to mention Nilsson and Pelger, because they have demonstrated how a fish eye – or any other type of eye, come to that – could evolve. Darwin has to this extent been shown to be propounding a theory which could never have been proved in his lifetime, but which, 150 years later, is demonstrated to be, at least, possible. Having been fair to the Swedish biologists, it is also necessary to be fair to the haddock or the bream, who might, if capable of speech, have wanted to say to Professor Dawkins, ‘Half a million years might seem to be “instantaneous” in Oxford, but down here on the ocean bed, when we needed an eye to protect us from predators such as sharks, it seems rather a long time.’

  Darwin wrote in complete ignorance of the modern science of genetics, and what he knew of embryology was, by the standards of our times, primitive in the extreme. We know that the same genes control the development of the same organs in a widely different range of species. For example, a gene called Pax6, in the fruit fly Drosophila melanogaster, controls and co-ordinates some 2,000 other genes to make its eyes, which have multiple lenses. In the mouse, however, this same gene, Pax6, regulates different genes to make the mouse’s single-lensed eyes. Remove the Pax6 gene from a fruit fly and place it into a frog and it will produce frog eyes. These facts are perhaps best explained by the hypothesis that this wide range of species carry genes which have been conserved across the centuries of evolutionary history from a common ancestor. Once we know about the existence of these genes, however, the ponderous and improbable theory of Darwin – that the complex mechanism of optic nerves came into being over hundreds of thousands of years – becomes completely unnecessary. The gene is already present, and will organize and control, here a frog eye, here the eye of a newt, here the eye of Galileo looking through his telescope.15

  For Darwin’s original readers, however, the puzzle of the evolution of the eye would be only one of the phenomena which assailed the imagination. For its author, the book might have been only an abstract. For most readers, even for most scientists, it must have seemed, like Humboldt’s Kosmos in an earlier generation, a book which was in effect about ev
erything. The author’s sheer range still has the capacity to dazzle. The book takes us to every corner of the known world. It leads us through the unfolding succession of geological eras, as previously explored by Lyell. It looks at fossils and is honest enough to say that, as far as proving the theory of natural selection goes, the evidence is inconclusive. From woodpeckers and pigeons to whales and bees, from the strange evidence, and non-evidence, of fossilized trees and extinct species, it appears to consider every species which had ever existed – every one, that is to say, except humanity. About the origins of species generally, Darwin was, in his hesitant, modest tone, expansive and eloquent. About humanity he was, as yet, silent. Knowing the kind of reaction he could expect from those who still equated the belief in the fixity of species with theology, he ended on a lyrical but also unapologetic note. It was a clarion call for a new way of viewing existence itself. ‘There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.’16

  It is almost certain, if you, the reader of The Origin of Species in the twenty-first century possess a copy of the book, that you have read the first edition, unless you read the old Everyman edition (published by J. M. Dent & Sons Ltd, 1928), which reproduced Darwin’s sixth edition with all his doubts and qualifications. The two copies which sit on my table as I write are, on the one hand, a paperback, edited for Penguin Classics by J. W. Burrow, and on the other, edited with an introduction by Edward O. Wilson for W. W. Norton & Company, New York, with the self-explanatory title, From So Simple a Beginning: The Four Great Books of Charles Darwin. Burrow explains, ‘The edition here is the first edition. There were six editions published in Darwin’s lifetime, and a large number of changes were made . . . Not only does the first edition possess a unique historical interest . . . but it also presents in many ways a more clear-cut and forceful version of Darwin’s theories than the later editions, in which Darwin weakened his argument in an attempt to meet criticisms.’

  Edward O. Wilson, introducing what he calls ‘the greatest scientific book of all time’, also chooses to reproduce the first thoughts of its author, rather than his last. Yet, as Peter J. Vorzimmer wrote in 1970, ‘the story of Darwin’s handling of his theory of natural selection after 1859 is one of documented qualification and nagging doubt’.17 In some senses, the story of Darwin’s life, from the time of The Origin’s publication to the time of his death, was the story of these doubts, so that to read only the first edition, as though it were an unalterable sacred text, is to distort the story. The Botany School Library in Cambridge (England) contains Darwin’s collection of learned offprints and articles by other scientists, nearly all reflective upon his evolutionary theory. Darwin’s annotations and marginalia to these printed works amount to over a hundred thousand words, and reflect twenty-three years of doubt. He never withdrew his theory, but he made many emendations to it, based upon the scientific objections which he discovered in the writings of others. Darwin, even more than Chambers in Vestiges, taught the world to see that nature is not in a fixed or still condition. It is on the move. So, too, is the mind of any serious scientist. Some of the moves which Darwin made, in response to critiques of his work, were away from the truth. Hamlet took over from the confident scientist. What the biographer notes is that Darwin himself, doughty as a warrior for his theory, nevertheless had many moments either of doubting it or (which is different) of not seeing how it could be defended. The young man who wished to be another Humboldt, a great scientist who would explain everything, had, like a child in a fairy story, been punished by being granted his wish. It was by no means always a happy experience. The rest of our story, then, is of Darwin tacking this way and that in stormy seas, allowing his allies (especially Huxley) to fight his battles, while he retreated into the calmer joys of pure natural history, devoting, for example, to earthworms the patient attention which might have been theirs had his life followed a different path, had he never set sail on the Beagle and had he taken orders and become a naturalist-parson in the Gilbert White mould. The stockade of family life would, through these last decades, keep him safe and sane, but the storms without were violent. Some accounts of Darwin’s life speak as if the storms were theological; as if, confronted with the impersonal processes of natural selection, it was from Church and clergy, all challenged to take leave of their God, that Darwin suffered his most cutting assaults. As any perusal of the various editions of Lyell’s Geology would show, or as you would learn from the Westminster Review in its many editions, or as the translations from the German of Mary Ann Evans (aka George Eliot) would make plain, Victorian intellectuals had been wrestling with religious doubt for years before Darwin published The Origin. His book might have confirmed some in their unbelief, but it was not essentially atheistic in texture. After all, the belief in a Creator is distinct from a theory about how the creation came into being. The notion that ‘the Church’ was the first to attack Darwin came about because some of the more established academic scientists were at the older universities; and Fellows of colleges in Oxford and Cambridge in those days were clergymen. Many of Darwin’s most enthusiastic supporters, however, were Christians. Embarrassing as Darwin might find the disapproval of the cloth, and painful as he found his religious difference from Emma, what was professionally troubling to him, was his difficulty in persuading his fellow scientists.

  13

  The Oxford Debate and its Aftermath

  THE BRITISH ASSOCIATION for the Advancement of Science (BAAS) held its meetings in a variety of venues, and the meeting for the summer of 1860 was scheduled to happen in Oxford. Darwin planned to attend, together with Lyell and Hooker. He even made inquiries about taking lodgings in the town,1 and he looked forward to walks round college gardens with Hooker.2 It was somehow inevitable, however, that from Darwin’s great scene, the Oxford debate, the chief player should be absent. Etty became ill in the course of the summer, and this provided the perfect excuse for him not to attend the meeting. When she showed signs of improvement, it was necessary for his own body, with all its familiar psychosomatic manifestations, to come to the rescue. To Lyell, on 25 June, he wrote, ‘I have given up Oxford; for my stomach has utterly broken down & I am forced to go on Thursday for a little water-cure, to “Dr Lanes Sudbrook Park, Richmond Surrey”, where I shall stay a week.’3

  So it was that Darwin never came to meet the man who had written an especially hostile review of The Origin of Species for the Quarterly Review, Samuel Wilberforce.

  Wilberforce’s review highlighted two problems with the theory of natural selection, as expounded by Darwin. The first concerned the analogy Darwin wished to draw with the selective breeding of domesticated species. Darwin envisaged natural selection, a sort of impersonal deity, ‘daily and hourly’ scrutinizing species over the space of entire geological epochs. The problem with the analogy, Wilberforce said, was that domestic breeders do not, in fact, create new species – they merely modify existing species – and the wild descendants of domesticated types, rather than continuing to ‘develop’, in fact revert to the original type. If anything, therefore, the behaviour of animals under domestication disproved rather than proved the Darwinian thesis.

  Wilberforce’s second accusation was that Darwin, if not misrepresenting Lyell, misused him. Lyell’s Geology shows that there is no geological evidence which proves the existence of transitional forms, of one species turning into another. Darwin acknowledged ‘gaps’ in the geological evidence, but appeared to be enlisting Lyell for his argument. In fact, there were no ‘gaps’, simply insufficient evidence. Darwin acknowledged that Wilberforce’s argument was ‘uncommonly clever’ and that he ‘picks out with skill all the most conjectural parts, and brings forward well all the difficulties’.4

  As far as I know, no Darwinian has ever given
a satisfactory answer to Wilberforce’s two points. The significance of Wilberforce, however, from a mythic perspective, was not that he was a scientist, but that he was a bishop, the Bishop of Oxford no less. As a young man, an undergraduate at Oriel College, he had sat at the feet of the ‘Noetics’, those dons who in the 1820s were considered to be dangerously in the vanguard of progressive thought. Never a professional scientist, Wilberforce was nevertheless a clever man, with a first-class degree in mathematics, who kept up his scientific interests while being successively a parish priest in the country, Dean of Westminster and Bishop of Oxford. In 1850, he attended Owen’s entire course of lectures on anatomy. ‘I could give the Bishop of Oxford a certificate for most regular attendance,’ wrote Owen.5

  Wilberforce, his father William canonized by history as the philanthropist whose tireless zeal led to the abolition of the slave trade in the British Empire, was doomed to be one of history’s losers – the man who pompously and facetiously belittled the theory of evolution. In a sense, whether he did so qua bishop or qua supporter of the scientific orthodoxy of his day no longer matters. He could not know, as he prepared for the Oxford conference, that for almost everyone in future times he would be ‘Soapy Sam’, the man who set himself up against scientific truth.

  When the BAAS met in 1845, Herschel had devoted his Presidential Address to denouncing Vestiges for religious heresy. It was a measure of how that book had changed the atmosphere that, by 1860, no mention at all was made of The Origin in the Presidential Address. It was, nevertheless, on everyone’s mind. Two separate papers, on different days of the meeting, promised, however, to devote themselves to Darwinian questions. On Thursday 28 June, the Oxford Professor of Botany, Charles Daubeny, presented a paper, ‘On the Final Causes of Sexuality of Plants with Particular Reference to Mr Darwin’s Work “On the Origin of Species by Natural Selection”’. He broadly speaking supported Darwin’s theory. Both Owen and Huxley were present. When Daubeny had finished, Huxley was asked if he would like to make a contribution. He declined, stating – quite strangely, given the later significance with which he invested the BAAS meeting – that he did not think a public venue of this kind was a suitable place to discuss Darwin’s theory, because ‘sentiment would unduly interfere with intellect’.