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Charles Darwin

Page 7

by A. N. Wilson


  Both Lamarck’s and Brocchi’s ideas were taught to Darwin at Edinburgh, and their ideas were played against one another. At that stage of history, the fossil evidence was much patchier than it is today. A palaeontologist such as Niles Eldredge, who with Stephen Jay Gould pioneered the idea of punctuated equilibrium – evolution proceeding by leaps – demonstrated that Brocchi is a much more reliable witness. Brocchi was partly able to be more accurate through sheer luck; Lamarck’s Paris basin fossils were between fifty-six and thirty-four million years old (Eocene), whereas Brocchi was able to study much more recent fossils, in five-million-year-old Upper Tertiary Miocene–Pleistocene strata. He estimated that some 50 per cent of the fossils he discovered were of species which could still be found swimming, or living, in Italian waters during the early nineteenth century. He saw that while some species change, many do not. Species do not necessarily change much over time, if at all. The cause of the origin of species – that would perhaps never be explained by science. The debate about natural processes – that was already under way when Darwin began to study science in Edinburgh. Very typically, Darwin, in the autobiography he wrote for his family to read when he was sixty-seven years old, dismissed Jameson’s lectures as ‘incredibly dull’.41 It is only by a patient reassembling of the evidence – evidence that Jameson knew the work both of Brocchi and Lamarck, evidence that Charles Lyell used Brocchi’s work – that modern Darwin scholars have been able to trace the origins of his ideas.

  As well as attending the Jameson course, Darwin, as a member of the Plinian, had a more social life than he would have done clinging to Ras’s coat-tails. He went to meetings of the Wernerian Society (geology again) and he went to hear Sir Walter Scott speak at the Royal Society of Edinburgh. They were small dinners, with about thirty men attending.42 Darwin would have been aware, as he looked at the noble face of the great novelist – for all Edinburgh knew of it – that Sir Walter was a ruined man. It had been in January 1826, when Ras and Darwin had been in Edinburgh three months, that Scott wrote in his journal the unforgettable line, ‘came through cold roads to as cold news’ – the news that money borrowed by his printers from his publishers, which Scott had agreed to guarantee, had all been lost, and that he must ‘with his own right hand’ write off the debt, a prodigy of scribbling which exhausted Scott and killed him finally in 1832.

  It has been rightly said that ‘from November 1826 to April 1827 Darwin . . . led a tripartite life’.43 There were the medical studies, his prime reason for being in Edinburgh. Secondly, there were the studies of geology and zoology at Jameson’s lectures, a more or less daily occurrence, which were the vital preparation for his life as a naturalist. There was also a third life, his membership of the Plinian Society, which enabled his friendship with the first great intellectual influence upon his life and mind: Robert Edmond Grant (1793–1874).

  Robert Grant, sixteen years Darwin’s senior, and a bachelor, became a role model. Like Darwin, he had studied medicine at Edinburgh, but substantial family money had liberated him from the need to practise as a physician. Instead, he had devoted himself to science. He studied in Paris, where he not only absorbed much scientific skill, but also quickened his taste for radical politics. He became a distinguished zoologist, and made himself an expert on the marine life of the Scottish coast. Keith Thomson’s book The Young Charles Darwin (2009) has brought into sharper relief than any previous biographies the debt Darwin owed to Grant, and, rather less creditably, the extent to which Darwin attempted to play this down when he had become a famous scientist. We shall see that this is an absolutely habitual trait of Darwin’s who was a self-mythologizer, a man who wanted to represent himself, when the moment was ripe, as the pioneer evolutionist.

  Grant, a shy, diffident bachelor, clearly took a shine to Darwin, seeing his potential as a man of science. It scarcely required second sight to perceive these qualities in the young medical student, however, given his surname, and given that Grant was an avid reader of Darwin’s grandfather, above all of Zoonomia. One of the most misleading paragraphs in the entire Autobiography describes a conversation with Grant about evolution.

  He one day, when we were walking together, burst forth in high admiration of Lamarck and his views on evolution. I listened in silent astonishment and as far as I can judge, without any effect on my mind. I had previously read the Zoönomia of my grandfather, in which similar views are maintained, but without producing any effect on me. Nevertheless it is probable that the hearing rather early in life such views maintained and praised may have favoured my upholding them under a different form in my Origin of Species.44

  Keith Thomson has demonstrated, in The Young Charles Darwin, how extremely improbable it is that Darwin could have felt ‘astonishment’ at Grant’s Lamarckian views. ‘His Autobiography’s misdirections and forgetfulness may be rather convenient. Even while he enjoyed a well-earned, heralded career in his old age, Darwin was incapable of sharing credit, of finding the shades and subtleties of intellectual debt that any creative person knows.’45

  My own belief is that, by the time he wrote his Autobiography, Darwin – who had been failing to acknowledge intellectual debts and influences all his life, and who had his head turned further by the hero-worship of Huxley – was actually incapable of remembering, at some visceral level, that anyone beside himself had ever believed in evolution before 1859. In youth, however, his observant eyes were directed with equal beadiness upon the natural world and the main chance. Jameson and Grant could see in the young Darwin a genuinely brilliant naturalist in the making. In a paper to the Plinian Society, given when he was a mere eighteen years old, Darwin demonstrated that the little globular bodies (then sometimes called sea peppercorns) which had been supposed to be the young state of the (seaweed) Fucus loreus were in fact the egg-cases of the wormlike Pontobdella muricata, a marine leech. He also had discovered, in spite of being shy of the dissecting knife, that the so-called ova of Flustra had independent movement by means of cilia and were in fact larvae.46 This was Darwin’s first real scientific discovery, and it exploded one of Grant’s pet theories, that these flustrae were midway between animals and plants. Grant felt some displeasure at being upstaged by his protégé, and so he tried to upstage Darwin, by giving the new information about ‘flustrae’ in a paper of his own, three days before Darwin’s presentation to the Plinian. He gave no acknowledgement to Darwin for his discovery. Darwin boldly went ahead three days later and read his paper to the Plinian, making it clear that the discovery had been his own. This shabby behaviour by an older and well-established scientist, who even later was only grudging in half admitting Darwin’s discovery, no doubt coloured Darwin’s sour memories of Grant in the Autobiography. He had made his first genuine discoveries and Grant had been ungenerous. They were, however, small discoveries. Grant’s opening Darwin’s eyes to the truth of his grandfather’s evolutionary theory was a huge thing, and, had Darwin been of a different character, he would have admitted that evolution was, as it were, the family business. As far as Western scientific thought was concerned, certainly from the late eighteenth century onward, Erasmus Darwin was its father. Yet Darwin asks us to believe that reading Zoonomia, the work which expounded the idea that species evolved into one another, was an experience he underwent without it ‘producing any effect on me’. Any? Really?

  The towering figure of natural history and life-science in the eighteenth century had, arguably, been the great Swedish naturalist Carolus Linnaeus (Carl von Linne, 1707–78). His attempt at a comprehensive plant-classification – Genera Plantarum, of 1737 – was the starting point of modern systematic botany. It was also, by extension, a starting point for looking at, and classifying, fauna as well as flora. Linnaeus’s system implied a fixity of species: else how could it be possible to distinguish one from another? His main purpose, however, was to classify, not to theorize, and if the effect of his work was to strengthen, among many naturalists, the notion of fixity of species, this was not his primary intention.
Whereas in the sphere of astronomy, from the seventeenth century onwards, Western humanity had been haunted by a sense of boundless space, following the divinely ordered laws laid bare by Isaac Newton, the earth seemed, by the science of Linnaeus and by the whole notion of taxonomy, or classification of species, to have been limited. It is worth reiterating, however, that belief in the fixity of homologues did not prevent Linnaeus or any taxonomist since from believing in a slow process of adaptive change within the species. The homologues are novelties of nature. They are features which appear to have no predecessors, no transitional forms leading up to them. They are there. It is from these fixed forms that fossil evidence, palaeontology, measures descent by modification or extinction.47

  The taxonomists’, however, was not the only perception of the world in the eighteenth century. There were the travellers, in fact and in imagination. Benoît de Maillet (1656–1738) was a traveller and French government official who was not a professional scientist. He was, however, one of the first to make observations which would change our perceptions of the world. He noted, for example, that fossil plants were of a species which ‘exist no more’.48 He understood that, just as the telescope had revealed the infinite dance of the planets, so we should eventually see that ‘this whole System which we see, this fine Order which we admire, are subject to Changes’. And what held good for the spheres held good for the planet earth. Above all, he was bold enough to acknowledge that there were creatures in the Dutch Indies, orang-outangs, of whom ‘it would be rashness to pronounce they were only brutes’. He quoted a Chinese author who had declared that ‘men were only a species of Apes more perfect than those which did not speak’.49

  The sense of variety in the world, which the travellers excited in their readers, led inevitably to a sense of adaptive change within species. This in turn led to the wild speculation that species might not be fixed, that one species might evolve into another, as Erasmus Darwin believed. James Burnett (1714–99), a Scottish judge who took the title Lord Monboddo, was an intellect of great originality. He studied humankind as if it were a branch of the animal kingdom, and collected information about primitive tribes for the light this might throw on more ‘advanced’ human groupings. His views, naturally, invited the derision of contemporaries. In Boswell’s Life of Johnson, which Darwin read in his first year at Edinburgh, he would have found the friends laughing over Dr Johnson’s quip that Rousseau ‘knows he is talking nonsense . . . But I am afraid (chuckling and laughing) Monboddo does not know he is talking nonsense.’50 On another occasion, Johnson said, ‘Conjecture, as to things useful, is good; but conjecture as to what would be useless to know, such as whether men went upon all four, is very idle.’51 When Boswell took Johnson to Edinburgh in 1773, they were able to meet lawyers who discussed Monboddo’s belief that he could teach an orang-outang to speak. His view that men might once have had tails of course gave rise to the joke that he himself had a tail, Johnson opining on one occasion that Monboddo was ‘as jealous of his tail as a squirrel’.52

  These pleasantries however were the beginnings of an unease. What if Monboddo were right? What if the clear borderline between one Linnaean category and another were less firm than human beings might hope? The flickering of doubt about such matters is seen in the writings of the Comte de Buffon (1707–88). His survey of the natural world, Histoire naturelle, advanced a number of tentative hints in the direction of evolution, only to withdraw them. But he could see that species change or, as he would say, degenerate. Whereas the optimistic Charles Darwin, typically Victorian, saw evolution as a metaphor of progress, with each evolving species being better than the last, the pessimistic Buffon saw the changes in nature as a process of decline. Yet in many ways he had anticipated the ‘uniformitarianism’ of James Hutton – the belief that changes in nature were all part of the system, as it were, and not attributable in each case to external intervention by the Deity. Somewhat malgré lui, therefore, Buffon was a kind of evolutionist. Comparing species in the New World which are similar to those in Europe, he wrote, ‘They have remote relations . . . which seem to indicate something common in their formation, and lead us to causes of degeneration (that is, evolution) more ancient, perhaps, than all the others.’53

  Buffon was far from being alone in his hunch, not only that species – the human species included – were not fixed, any more than rocks and stones and trees were fixed, and also that life was in some impenetrable way interconnected. Darwin had questioned Grant’s idea that plants and animals once had a common parentage, but such ideas were far from unusual in the time of the Enlightenment. Goethe’s Essay on the Metamorphosis of Plants (Versuch die Metamorphose der Pflanzen zu erklären) of 1790 had been a deliberate riposte to Linnaeus, suggesting that all botany was in a state of flux, one species deriving from another.54 Goethe believed that all life – plant, animal and human – had a single source, and it was his distinction, in anatomy and osteology, to have discovered the intermaxillary bone, in 1784. Hitherto, it had been maintained that man was demonstrably different from the apes and other mammals because he had no intermaxillary bone (this is the bone in the upper jaw anterior to the maxilla bone). It was left to the scientist-poet to prove the professional anatomists wrong. ‘Indeed, man is most intimately allied to animals. The coordination of the Whole makes every creature to be that which it is, and man is as much man through the form of his upper jaw, as through the form and nature of the last joint of his little toe. And thus is every creature, but a note of the great harmony, which must be studied in the Whole, or else it is nothing but a dead letter.’55

  Goethe had certainly read Erasmus Darwin. Indeed, it would have been hard to find a cultivated reader, let alone one with scientific interests, in the period 1780–1830 who had not read Erasmus Darwin, which is what makes Charles Darwin’s claim to be untouched by his grandfather’s ideas all the more improbable.

  Erasmus Darwin, in his books Zoonomia and The Temple of Nature, had proposed that all life originated from non-life in the ocean bed. All life, moreover, sprang from what he called a ‘filament’, an ur-life-form. Every form of life on earth, according to Dr Erasmus, had evolved from this original filament. The first volume of Zoonomia consisted of forty essays on a whole variety of scientific subjects, but all, basically, reverting to the original theory.

  Would it be too bold to imagine, that in the great length of time since the earth began to exist, perhaps millions of ages before the commencement of the history of mankind, would it be too bold to imagine, that all warm-blooded animals have arisen from one living filament, which THE FIRST GREAT CAUSE endued with animality, with the power of acquiring new parts, attended with new propensities, directed by irritations, sensations, volitions, and associations; and thus possessing the faculty of continuing to improve by its own inherent activity, and of delivering down these improvements by generation to its posterity, world without end.56

  There, in essence, is the theory of evolution. Erasmus Darwin had worked it out in the 1770s, although Zoonomia was not published until 1794. In 1796, Tom Wedgwood, Sukey’s brilliant, troubled elder brother, arranged for his friend, protégé and fellow junkie Samuel Taylor Coleridge to visit Erasmus Darwin in Derby. The philosopher-poet declared, ‘Derby is full of curiosities, the cotton, the silk mills, Wright, the painter, and Dr Darwin, the everything, except the Christian! Dr Darwin possesses, perhaps, a greater range of knowledge than any other man in Europe, and is the most inventive of philosophical men. He thinks in a new train on all subjects except religion.’57 It is true that ideas emanate from individuals, and that Erasmus Darwin was an original. It is also true that ideas are ‘in the air’ – witness the fact that Alfred Russel Wallace would hit upon the idea of evolution by means of natural selection just as Charles Darwin was preparing to publish his thoughts on the subject in the late 1850s. Shortly after Erasmus Darwin published Zoonomia, a zoologist at the Muséum National d’Histoire Naturelle in Paris (the former Jardin du Roi) published his own version of some ver
y similar ideas. This was the Chevalier Jean-Baptiste de la Marck. His Systèmes des animaux sans vertèbres appeared in 1801 and his Philosophie zoologique followed in 1809. De la Marck – Lamarck as he is invariably known – had read Erasmus Darwin, but it would seem that he had arrived at almost identical views of evolution independently, partly as a result of enormous knowledge and widespread research, partly after reading de Maillet, Buffon and others. Here we find the same essential story: that all natural life is one, deriving from a simple source. Even humanity is part of this chain of life. Lamarck proposed a constant and spontaneous generation of life – similar to the scala naturae of the ancients, often known as the great chain of being. Lamarck, like Robespierre and other French Revolutionists, and like Voltaire before them, was a Deist. He believed that the Creator had set this process in motion, and then, as it were, sat back. Although Dr Darwin writes of ‘THE FIRST GREAT CAUSE’ having started the evolutionary generative process, one suspects that if one hoisted his mighty form on to a truth machine one might have found him to be an atheist. Whichever side of the divide the two thinkers were to jump, there was no need, in their philosophical system, for an interventionist Deity. Nature was running itself, and one life-form was evolving into the next. Humanity derived from apes. ‘It could easily be shown that his [man’s] special characters are all due to long-standing changes in his activities and in the habits which he has adopted’, as Erasmus wrote.58

 

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