The Invention of Nature

by Andrea Wulf

  When he was on board the Beagle, Darwin followed a routine that never changed much. In the mornings he joined FitzRoy for breakfast and then both men turned to their respective tasks, the captain surveying and dealing with his paperwork while Darwin investigated his specimens and wrote up his notes. Darwin worked in the poop cabin at the big chart table where the assistant surveyor also had his maps. In one corner Darwin had set up his microscope and notebooks. There he dissected, labelled, preserved and dried his specimens. The space was cramped but he thought it was the perfect study for a naturalist because ‘everything is so close at hand’.

  Outside on deck the fossil bones had to be cleaned and jellyfish had to be caught. In the evenings, Darwin shared his meals with FitzRoy but once in a while he was invited to join the rest of the crew in the more boisterous mess-room which he always enjoyed. With the Beagle sailing up and down the coast working on the survey, there was plenty of fresh food available. They ate tuna, turtle and shark, as well as ostrich dumplings and armadillos which, Darwin wrote home, without their armoured shells looked and tasted just like duck.

  Darwin adored his new life. He was popular with the crew who called him ‘Philos’ and ‘flycatcher’. His passion for nature was infectious and soon many of the others became collectors too, helping to augment his specimens. One officer teased him about the ‘damned beastly bedevilment’ of barrels, crates and bones on deck, saying that ‘if I were the skipper, I would soon have you and all your mess out of the place.’ Whenever they arrived at a trading port from where vessels were sailing to England, Darwin would dispatch his trunks filled with fossils, bird skins and pressed plants to Henslow in Cambridge, as well as sending letters home.

  As they sailed on, Darwin felt even more urgently the need to read everything that Humboldt had written. When they reached Rio de Janeiro, in April 1832, he had written home, asking his brother to send Humboldt’s Views of Nature to Montevideo in Uruguay where he would be able to pick it up at a later stage. His brother duly sent books – not Views of Nature but Humboldt’s latest publication Fragmens de géologie et de climatologie asiatiques which was the result of the Russian expedition, as well as the Political Essay on the Kingdom of New Spain.

  Throughout the Beagle’s voyage, Darwin was engaged in an inner dialogue with Humboldt – pencil in hand, highlighting sections in Personal Narrative. Humboldt’s descriptions were almost like a template for Darwin’s own experiences. When Darwin first saw the star constellations of the southern hemisphere, he was reminded of Humboldt’s descriptions. Or later when he saw the Chilean plains after days of exploring the untamed forest, Darwin’s reaction exactly echoed Humboldt’s on entering the Llanos in Venezuela after the Orinoco expedition. Humboldt had written of ‘new sensations’ and the delight of being able to ‘see’ again after the long weeks in the dense rainforest, and now Darwin described how the views were ‘very refreshing, after being hemmed in & buried amongst the wilderness of trees’.

  Similarly, Darwin’s diary entry about an earthquake that he experienced on 20 February 1835, in Valdivia in southern Chile, was almost a summary of what Humboldt wrote about his first earthquake in Cumaná in 1799. Humboldt had remarked how the earthquake in ‘one instant is sufficient to destroy long illusions’ – in Darwin’s journal it became ‘an earthquake like this at once destroys the oldest associations.’3

  There were countless such examples – and even Darwin’s discussion of kelp at the coast of Tierra del Fuego as the most essential plant in the food chain was strikingly similar to Humboldt’s description of the Mauritia palms as a keystone species that ‘spreads life’ in the Llanos. The great aquatic forests of kelp, Darwin wrote, supported a vast array of life forms, from tiny hydra-like polyps to molluscs, small fish and crabs – all of which in turn fed cormorants, otters, seals and finally, of course, the indigenous tribes. Humboldt informed Darwin’s understanding of nature as an ecological system. Like the destruction of a tropical forest, Darwin said, the eradication of kelp would cause the loss of uncountable species as well as probably wiping out the native population of Fuegians.

  Darwin modelled his own writing on Humboldt’s, fusing scientific writing with poetic description to such an extent that his journal of the Beagle voyage became remarkably similar in style and content to the Personal Narrative. So much so that his sister complained after receiving a first part of his journal in October 1832 ‘that you had, probably from reading so much of Humboldt, got his phraseology’, and ‘the kind of flowery french expressions which he uses’. Others were more complimentary and told Darwin later how delighted they were with his ‘vivid, Humboldt-like pictures’.

  Humboldt showed Darwin how to investigate the natural world not from the claustrophobic angle of a geologist or zoologist, but from within and without. Both Humboldt and Darwin had the rare ability to focus in on the smallest detail – from a fleck of lichen to a tiny beetle – and then to pull back and out to examine global and comparative patterns. This flexibility of perspective allowed them both to understand the world in a completely new way. It was telescopic and microscopic, sweepingly panoramic and down to cellular levels, and moving in time from the distant geological past to the future economy of native populations.

  In September 1835, a little less than four years after leaving England, the Beagle finally departed from South America to continue circumnavigating of the globe. They sailed from Lima to the Galapagos Islands, which lay 600 miles west off the Ecuadorian coast. These were strange barren islands on which birds and reptiles lived that were so tame and unaccustomed to humans that they could be easily caught. Here Darwin investigated rocks and geological formations, collected finches and mockingbirds and measured the size of the giant tortoises that roamed the islands. But it was only when he eventually returned to England and examined his collections that it became clear how important the Galapagos Islands would become for Darwin’s evolutionary theory. For Darwin the islands marked a turning point, although he didn’t realize it at the time.

  After five weeks in the Galapagos, the Beagle sailed on into the emptiness of the South Pacific towards Tahiti, and from there to New Zealand and Australia. From the western coast of Australia they crossed the Indian Ocean and rounded the tip of South Africa before sailing across the Atlantic Ocean back to South America. The last months of the voyage were hard on everybody. ‘There never was a Ship,’ Darwin wrote, ‘so full of home-sick heroes.’ Whenever they met merchant vessels during those weeks, he felt the ‘most dangerous inclination to bolt’ and jump ship, he admitted. They had been away for almost five years – so long, that he found himself dreaming of England’s green and pleasant lands.

  On 1 August 1836, after crossing the Indian Ocean and then the Atlantic, they briefly stopped in Bahia in Brazil, where they had made their first South American landfall at the end of February 1832, before finally turning north for the last leg of their voyage. Seeing Bahia was a sobering experience for Darwin. Instead of admiring the tropical blooms in the Brazilian rainforest as he had during their first visit, he now longed to see stately horse chestnuts in an English park. He was desperate to get home. He had had enough of this ‘zig-zag manner’ of sailing, he wrote to his sister. ‘I loathe, I abhor the sea, & all ships which sail on it.’

  By the end of September they passed the Azores in the northern Atlantic and sailed towards England. Darwin was in his cabin, as seasick as he had been on his first day. Even after all these years, he was still not used to the rhythm of the sea and moaned, ‘I hate every wave of the ocean.’ Lying in his hammock, he filled his bulging journal with his last observations, summing up his thoughts about the previous five years. First impressions, he noted in one of his very last entries, were often shaped by preconceived ideas. ‘All mine were taken from the vivid descriptions in the Personal Narrative.’

  On 2 October 1836, almost five years after leaving England, the Beagle sailed into Falmouth harbour on the south coast of Cornwall. In order to complete his survey, Captain FitzRoy
had still to take one more longitudinal measurement in Plymouth, at exactly the same location where he had taken his first. Darwin, though, disembarked in Falmouth. He couldn’t wait to catch the mail coach to Shrewsbury to see his family.

  As the carriage rattled north, he stared out of the window, watching the undulating patchwork of fields and hedgerows unfold. The fields seemed much greener than usual, he thought, but when he asked the other passengers to confirm his observation, they looked at him blankly. After more than forty-eight hours in the coach, Darwin arrived late at night in Shrewsbury and quietly slipped into the house because he didn’t want to wake his father and sisters. When he walked into the breakfast room the next morning, they couldn’t believe their eyes. He was back and in one piece – but ‘looking very thin’, his sister said. There was so much to talk about, but Darwin could only stay a few days because he had to go to London to unload his trunks from the Beagle.

  Darwin returned to a country that was still ruled by the same king, William IV, but two important Parliamentary Acts had been passed during his long absence. In June 1832, after immense political battles, the controversial Reform Bill had become law – a big first step towards democracy as it gave cities that had grown during the Industrial Revolution seats in the House of Commons for the first time and extended the vote from wealthy landowners to the upper middle classes. Darwin’s family, who supported the bill, had kept Darwin up to date about the wrangling in parliament as best they could through the letters they sent him during the Beagle voyage. The other exciting news was the passage of the Slavery Abolition Act in August 1834, while Darwin had been in Chile. Though the slave trade had already been banned in 1807, this new Act now prohibited slavery in most parts of the British Empire. The Darwin and Wedgwood families, who had long been part of the anti-slavery movement, were delighted as, of course, was Humboldt who had fiercely argued against the enslavement of fellow human beings ever since his Latin America expedition.

  Most important for Darwin, though, was news from the scientific world. He had enough material to publish several books and the idea of becoming a clergyman had long since evaporated. His trunks were stuffed with specimens – birds, animals, insects, plants, rocks and giant fossil bones – and his notebooks were tightly filled with observations and ideas. Darwin now wanted to establish himself in the scientific community. In preparation he had already written to his old friend, the botanist John Stevens Henslow, a few months earlier from the remote island of St Helena in the South Atlantic, asking him to ease his entrance into the Geological Society. He was keen to show off his treasures, and British scientists, who had followed the Beagle’s adventures through letters and reports that had been circulated by newspapers, were longing to meet him. ‘The voyage of the Beagle,’ Darwin later wrote, ‘has been by far the most important event in my life and has determined my whole career.’

  In London Darwin dashed through town to meetings at the Royal Society, the Geological Society and the Zoological Society, as well as working on his papers. He had the best scientists examining his collections – anatomists and ornithologists as well as those classifying fossils, fish, reptiles and mammals.4 One immediate project was to edit his journal for publication. When the Voyage of the Beagle was published in 1839, it made Darwin famous. He wrote about plants, animals and geology but also about the colour of the sky, the sense of light, the stillness of the air and the haze of the atmosphere – like a painter with lively brushstrokes. Like Humboldt, Darwin recorded his emotional responses to nature, as well as providing scientific data and information about indigenous people.

  When the first copies came off the printing presses in mid-May 1839, Darwin sent one to Humboldt in Berlin. Not knowing where to direct his correspondence, Darwin asked a friend ‘for I know no more than if I had to write to the King of Prussia & the Emperor of all the Russias’. Nervous about sending the book to his idol, Darwin employed flattery and wrote in his covering letter that it had been Humboldt’s accounts of South America that had made him want to travel. He had copied out long passages from Personal Narrative, Darwin told Humboldt, so that ‘they might ever be present in my mind’.

  Darwin needn’t have worried. When Humboldt received his copy, he replied with a long letter, praising it as an ‘excellent and admirable book’. If his own work had inspired a book like the Voyage of the Beagle, then that was his greatest success. ‘You have an excellent future ahead of you,’ he wrote. Here was the most famous scientist of the age, graciously telling the thirty-year-old Darwin that he held the torch of science. Though forty years Darwin’s senior, Humboldt had immediately recognized a kindred spirit.

  Humboldt’s letter was not one of shallow compliments – line after line he commented on Darwin’s observations, quoting page numbers, listing examples and discussing arguments. Humboldt had read every page of Darwin’s account. Even better, he also wrote a letter to the Geographical Society in London – which was published in the society’s journal for all to read – stating that Darwin’s book was ‘one of the most remarkable works that, in the course of a long life, I have had the pleasure to see published’. Darwin was ecstatic. ‘Few things in my life have gratified me more,’ he said, ‘even a young author cannot gorge such a mouthful of flattery.’ He was honoured to receive such public praise, Darwin told Humboldt. When Humboldt later instigated a German translation of Voyage of the Beagle, Darwin wrote to a friend, ‘I must with unpardonable vanity boast to you.’

  Darwin was in a frenzy. He worked on a wide range of subjects from coral reefs and volcanoes to earthworms. ‘I cannot bear to leave my work even for half a day,’ he admitted to his old teacher and friend, John Stevens Henslow. He worked so much that he had heart palpitations which seemed always to occur, he said, when something ‘flurries me’. One reason might have been an exciting discovery about the bird specimens that they had brought back from the Galapagos Islands. As Darwin analysed his finds, he began to deliberate on the idea that species might evolve – the transmutation of species, as it was then called.

  The different finches and mockingbirds that they had collected on the different islands were not, as Darwin had initially thought, just variations of the familiar birds on the mainland. When the British ornithologist John Gould – who identified the birds after the Beagle’s return – declared that they were indeed different species, Darwin worked out that each island had its own endemic species. As the islands themselves were of relatively recent volcanic origin, there were only two possible explanations: either God had created these species specifically for the Galapagos, or in their geographical isolation they had all evolved from a common ancestor that had migrated to the islands.

  Darwin’s finches from the Galapagos Islands (Illustration Credit 17.3)

  The implications were revolutionary. If God had created plants and animals in the first place, did the concept of evolving species imply that he had made initial mistakes? Similarly, if species became extinct and God continuously made new ones, did this mean that he constantly changed his mind? It was a terrifying thought for many scientists. The discussion about the possible transmutation of species had been rumbling on for a while. Darwin’s grandfather Erasmus had already written about it in his book Zoomania, as had Jean-Baptiste Lamarck, Humboldt’s old acquaintance from the natural history museum in the Jardin des Plantes in Paris.

  In the first decade of the nineteenth century Lamarck had declared that, influenced by their environment, organisms might change along a progressive trajectory. In 1830, the year before Darwin set sail on the Beagle, the battle between the ideas of mutable species versus fixed species had turned into a vicious public row at the Académie des Sciences in Paris.5 Humboldt had attended the fierce discussions at the Académie during a visit to Paris from Berlin, whispering a running commentary of disparaging remarks about the fixed species arguments to the scientists sitting next to him. Already in Views of Nature, more than two decades previously, Humboldt had written about the ‘gradual transformations of species
’.

  Darwin was also convinced that the idea of fixed species was wrong. Everything was in flux, or, as Humboldt said, if the earth was changing, if land and sea were moving, if temperatures were cooling or rising – then all organisms ‘must also have been subjected to various alterations’. If the environment influenced the development of organisms, then scientists needed to investigate climates and habitats more closely. Therefore, the focus of Darwin’s new thinking became the distribution of organisms across the globe, which was Humboldt’s specialty – at least for the world of plants. Plant geography, Darwin said, was a ‘key-stone of the laws of creation’.

  As Humboldt had compared plant families on different continents and from different climates, he had discovered vegetation zones. He had seen how similar environments often contained closely related plants, even when divided by oceans or mountain ranges. Yet this was confusing too because despite these analogies across continents, a similar climate didn’t always, or even necessarily, produce similar plants or animals.

  As Darwin read Personal Narrative, he highlighted many of these examples.6 Why was it, Humboldt had asked, that the birds in India were less colourful than those in South America, or why was the tiger only found in Asia? Why were the great crocodiles so plentiful in the Lower Orinoco but absent from the Upper Orinoco? Darwin was fascinated by these examples and often added his own comments in the margins of his copy of Personal Narrative: ‘like Patagonia’, ‘in Paraguay’, ‘like Guanaco’ or sometimes just an affirmative ‘yes’ or ‘!’.