In 2009 two important commemorative events coincide—the bicentennial of Charles Darwin’s birth, coincidentally on the same day as Abraham Lincoln’s, and the sesquicentennial of publication of Darwin’s pioneering work On the Origin of Species by Means of Natural Selection. Universities and natural history museums around the world are celebrating Darwin’s achievement throughout the year. Here we take a fresh look at the voyage that turned Darwin into one of science’s greatest thinkers.
Charles Darwin was only twenty-two years old when he was offered the opportunity of a lifetime. Those years afloat have become part of history. Darwin’s voyage on the Beagle is famous for turning his mind toward evolutionary theory, for giving him the intellectual stamina and materials to support such a theory, and for the romantic symbolism of his movement toward such an unexpected yet magnificent goal.
Darwin himself certainly appreciated the impact of the voyage. For him, the Beagle voyage opened the door to exceptional sights and opportunities—the impressive landscapes of South America, the fecundity of the tropics, dramatic encounters with other cultures and ways of life, hazardous travels off the beaten track, exotic islands, and countless moments when his imagination was powerfully stirred. On his return, his Beagle successes enabled him to join the world of natural history experts, and inspired the evolutionary views that he expressed in 1859 in On the Origin of Species. “The voyage of the Beagle has been by far the most important event in my life and has determined my whole career,” he declared in his autobiography.
The story has often been told. But there are always fresh perspectives to find in the comprehensive Darwin Archives, mostly housed in Cambridge University Library, but also in a fine collection at the American Philosophical Society in Philadelphia. In 1831, when the invitation to travel on the Beagle arrived in Darwin’s hands, he had just completed his BA degree at Cambridge University in England, and he was expecting to return in the fall for theological training. Yet this simple statement hardly conveys the intensity of family debate during the previous few years. Darwin’s father despaired of him ever settling into a useful career, for Darwin had recoiled from an early medical training in Edinburgh, and now (in his father’s eyes) seemed to be specializing in hunting, shooting, and fishing. Hence Dr. Darwin had decided that his son’s future should be that of a minister in the Anglican church, a decision with which Darwin concurred, although he said he had some minor doctrinal doubts. Much later, Darwin appreciated the irony of this possible future. Yet it perhaps accounts for his eventual reluctance to challenge directly the teachings of the church and his respect for those acquaintances who were committed believers.
In fact, Darwin was already an excellent naturalist. At Cambridge he longed to make a contribution to natural history at a time when science was not yet a structured profession. He spent so many of his university days pursuing animals and plants, especially collecting beetles, that he attracted the attention of John Stevens Henslow, the botany professor. Henslow introduced Darwin to some of the cutting-edge issues in the botanical sciences of the day and invited him to scientific parties to meet the famous men of the university.
In this way, Darwin himself became a young man of note. He was particularly inspired by the writings of Alexander von Humboldt, and early in 1831 began making plans for a natural history expedition echoing Humboldt’s remarkable scientific journey to Tenerife. When this fell through, the professor of geology, Adam Sedgwick, took him as an assistant for two weeks of summer fieldwork examining the earliest known rocks in Wales. Sedgwick taught Darwin geology in the field and showed him the rationale for sound scientific decisions. These two weeks gave Darwin a lifelong love for geology. Then he went to his uncle’s country house for the August game-bird shooting.
On his return to the family home in Shrewsbury, Darwin found a letter from Henslow offering him a voyage round the world on a British survey ship, HMS Beagle. The invitation had come through several hands and was unusual, even in its own day. It originated from Captain Robert FitzRoy, who requested permission from the Admiralty to take with him a gentleman who could make good use of the journey by collecting natural history specimens. Such a gentleman would share the captain’s facilities as a guest and was expected to pay his own way. Normally, the British government expected the ship’s surgeon to collect useful information about the countries visited, so perhaps FitzRoy had an older tradition in mind, harking back to James Cook’s Pacific voyages, which were accompanied by the naturalist Joseph Banks. In Darwin’s case, the elite social network that linked government, naval administration, and the old universities had led to a number of Cambridge professors being consulted. At one point, Henslow thought he would like to go. Instead, Henslow recommended Darwin “not on the supposition of yr. being a finished Naturalist, but as amply qualified for collecting, observing, & noting any thing worthy to be noted in Natural History. . . . Don’t put on any modest doubts or fears about your disqualifications for I assure you I think you are the very man they are in search of.”
The prospect of traveling across the world’s oceans in a British survey ship ran far beyond Darwin’s wildest dreams. At first, Dr. Darwin felt his son should not accept. The whole plan was “a wild scheme,” he declared. Disappointed, Darwin wrote down his father’s objections. Prime among them was “disreputable to my character as a clergyman hereafter . . . I should never settle down to a steady life . . . you should consider it as again changing my profession . . . that it would be a useless undertaking.” Fortunately, Dr. Darwin was persuaded otherwise by his brother-in-law, Josiah Wedgwood, who had always thought very highly of the young Darwin. Closely linked by marriage and friendship, the Darwin and Wedgwood families had done much to transform British thought in the Industrial Revolution. In the next generation, Dr. Darwin had married Susanna, the daughter of that first Josiah Wedgwood. Now, the older generation decided that the young man could go.
Today the multimedia fame of the Beagle voyage sometimes makes it hard to remember that its purpose was not to take Darwin round the world but to carry out British Admiralty instructions. The ship had been commissioned to complete and extend an earlier hydrographic survey of South American waters that had taken place from 1825 to 1830. FitzRoy had joined the Beagle two years into that former voyage. The area was significant to the British government for commercial, national, and naval reasons, buttressed by the Admiralty’s preoccupation with accurate naval charts and safe harbors. The Hydrographer’s Office was renowned for sending out a great many surveying expeditions in the lull after the Napoleonic wars to promote and exploit British interests overseas, and FitzRoy’s interest in science encouraged him to equip the ship for its second voyage with several sophisticated instruments and a number of chronometers for taking latitude measurements around the globe. The voyage lasted from December 1831 to October 1836, with most of the time being spent in South American waters. Excitingly for Darwin, the expedition was due to return via the Pacific and Indian oceans. It offered him a circumnavigation of the globe.
Nonetheless, Darwin’s voyage was mostly on land. Wherever it was convenient, FitzRoy arranged to leave Darwin ashore so that he could pursue his scientific observations. The two men would rendezvous several weeks later and move on to another area. This method of traveling allowed Darwin to make major expeditions in South America and on occasion to rent a small house as a base for his natural history explorations. His diary, later reworked into a travelogue, Journal of Researches (now usually known as The Voyage of the Beagle), describes his adventures. At times he rode out with gauchos, making his way through political rebellions or embarking on shooting expeditions to get meat for Christmas dinner. In Tierra del Fuego, he saved his crewmates by rescuing a rowboat from a tidal wave. He saw stars from the top of the Andes, climbed mountains in Tahiti, felt his blood boil over the slavery that was still legal in Brazil, admired girls in Valparaiso, and splashed around in coral lagoons in search of evidence for their formation. These exploits were all recounted in a wonderful series of letters home to his sisters that still exist in the archive. Over the years, Darwin’s sisters saw his ambitions changing, his confidence emerging. Indeed, they may have discerned how unlikely it was that he would now become a clergyman.
Interspersed with these cheerful narratives were requests for money from his father. Because Darwin’s participation in the voyage was an independently funded enterprise, Dr. Darwin arranged for cash to be made available for his son at a succession of out-of-the-way places around the globe. Darwin had said before the voyage that he would have to be “deuced clever” to spend money while at sea. Amused, Dr. Darwin replied, “but they tell me you are very clever.” Setting sail for Tahiti from the coast of South America, Darwin wrote home to his sisters, “I verily believe I could spend money in the very moon. . . . My Fathers patience must be exhausted.”
During the voyage Darwin collected nearly ten thousand specimens of plants, animals, rocks, and fossils, and sent them back to England in the Admiralty’s barrels and crates. He recorded a detailed inventory of his discoveries that would sustain years of study and publication and prove fundamental to his theory of evolution. Best of all, he developed a highly creative scientific imagination. Galloping, walking, sailing, or climbing—he thoroughly enjoyed the exciting outdoor life that this voyage presented. At the same time, either while looking down the microscope in his cabin or resting in his hammock feeling queasy with seasickness, he had plenty of opportunity to let his mind wander over the fundamental problems facing scientists in the early years of the nineteenth century.
High among these was the question of the “design” of living beings. In Darwin’s day, most naturalists believed that all organisms, including humans, were created ideally suited for the conditions in which they were to live. While there was debate over exactly how this might happen, and anxiety over those cases where animals or plants did not seem to be “perfectly adapted” to their place in nature, the general view was that the world presented a harmonious collection of living kinds, a concept usually referred to as the balance of nature. Many believed that God was the source of this harmonious design, although increasing numbers of radical critics and nonconformists were starting to put forward alternative suggestions. The theological author William Paley expressed the establishment view by writing that the existence of design in the natural world presupposed the existence of a designer—as he put it, the existence of a beautifully contrived mechanism such as a watch logically required the existence of a watchmaker. Darwin had been much impressed by Paley’s Natural Theology while a student at Cambridge; and his greatest achievement ultimately lay in providing a different explanation for the apparent design of all living beings. In the Origin of Species Darwin replaced Paley’s ideas by setting out an entirely natural explanation for the same phenomena based on the selection and preservation of adaptations. It is a key point of Darwin’s voyage that he was able to move beyond the conventional view and think about the origins of adaptations, especially those that did not seem perfect.
Despite this sense that nature reflected a divine plan, few naturalists at that time believed in the Bible stories as a valid scientific explanation of the origins of the world. Long beforehand, theological modernization encouraged literal views to give way to allegorical understandings of the first few verses of the Christian Bible. And the rise of geological science in the eighteenth century had added weight to that reevaluation. But the creation of human beings was still thought to be something special, a miracle occurring outside the world of scientific fact. The issue as Darwin encountered it was to find ways of explaining the origin and design of living beings through natural “causes,” while yet retaining a separate and sincere belief in the divine.
Even so, Darwin was not an evolutionist during his time on board the Beagle. Recent research into his work on board, his notebooks and other writings, the busy round of meetings, library researches and scientific societies into which he threw himself after returning to England, and the more considered inspection of his specimens under the eyes of experienced naturalists in London and Cambridge, all add up to the conclusion that Darwin only became committed to the idea of transmutation in the middle of March 1837, some five months after the Beagle had docked in England. The customary image of Darwin voyaging alone through turbulent seas of thought as he paced the deck of the Beagle is something of a cinematic fantasy. Reality was rather different.
Without question, his travels were the essential foundation for arriving at this momentous conclusion. Darwin retrospectively listed the three factors that he thought influenced him most during the voyage. First were the mammal fossils he found in Uruguay and Argentina, which displayed a continuity with current species of the area. In an estuary by Buenos Aires he unearthed the remains of giant animals that turned out to be extinct versions of the capybaras, armadillos, and llamas that run around the pampas today. He started to wonder why animals should display the same anatomical structures across vast epochs of time. Second, he laughed to recall how he discovered an unknown species of rhea—the South American ostrich. This bird had been shot for the cooking pot and was already half-eaten before he noticed it was much smaller than the usual sort. The salvaged remains accompanied him back to England and were later given the name Rhea darwinii. The two species of rhea occupied their own territories. Later on, he came to see how those relationships across time—the fossil and the modern—might mirror relationships across the landscape, where one species replaced another in the topographical sense. This feature of the animal world suggested some kind of underlying genealogical tree.
Third, and most important, were the Galápagos animals. Ironically, what proved to be the most famous collection of all, the birds from the Galápagos, was carelessly labeled. Darwin did not notice the diversification of species on separate islands during the Beagle’s five-week visit. Identifying the skins consequently proved tricky when he returned to London, and he had to ask some of his former crewmates if he could borrow their specimens.
Nonetheless, the Galápagos Islands impressed him greatly. He was fascinated by the land and sea iguanas, the giant tortoises, the mockingbirds and other birds, as well as the volcanic geology and arid landscape. How had the animals gotten there? And why were they found only there? He alluded to the likely relationship between the islands and the mainland in his ornithological notes on the return voyage. These remarks, and remarks made in another notebook begun on the way home, indicate that he wondered about the possibility of transmutation. At Cape Town in June 1836 he may have discussed the creation of species by natural means with John Herschel, the British astronomer, who was there observing the Southern stars. Species origins by natural causes was an interesting idea already circulating among British reformers and avant-garde scientists although it ran counter to the story of the Garden of Eden.
Less generally known is that Darwin regarded himself mostly as a geologist during the voyage. He traveled with a copy of Charles Lyell’s pathbreaking summary of a new way of thinking about geological processes, Principles of Geology, published in 1830–1833. This book influenced Darwin greatly. He was convinced by Lyell’s argument that all changes in the earth’s surface were the result of a gradual accumulation of many small events. Darwin took this idea, applied it to biology, and turned it into a lasting methodology that lies at the heart of his Origin of Species. For the rest of his life, he remained committed to the concept that many small changes can add up to larger effects.
One aspect of Lyell’s reinterpretation of the globe was particularly important. Lyell proposed that great slabs of the earth’s crust, fueled by volcanoes and great pressures under the surface, moved up and down relative to the sea. Lyell’s suggestions seemed to be literally played out in front of Darwin. He witnessed volcanoes, experienced an earthquake, and tramped across the Patagonian plains with FitzRoy, discussing their probable origin by elevation from a shallow coastal bay. Everywhere they visited along the coast, Darwin found rocks and former parts of the seabed now exposed to the elements, sometimes with mussels and limpets still attached, suggesting that the seafloor had been pushed up by subterranean forces. All this was very new and provocative. One great excitement was finding marine shells at a considerable height in northern Chile. Another was a small forest of silicified trees on the top of a mountain pass that matched fossils in the valley below. It seemed to Darwin that the mountain ranges had risen from coastal levels very recently in geological terms. Darwin found this type of detective work exhilarating. “I cannot express the delight, which I felt at such a famous winding up of all my geology in S. America. I literally could hardly sleep at nights for thinking over my days work,” he wrote to his sisters from Valparaiso.
The most unsettling of all Darwin’s encounters, however, was with the indigenous inhabitants of Tierra del Fuego. He was stunned by their naked savage state, particularly in comparison with the three Fuegians on board the ship. The shipboard three had been taken to England by FitzRoy on the previous Beagle voyage and educated and converted to Christianity at FitzRoy’s expense. They were being repatriated in a Protestant mission station that FitzRoy intended to set up in Tierra del Fuego. They were thoroughly Anglicized, Darwin recorded. “I would not have believed how entire the difference between savage & civilized man is. It is greater than between a wild & domesticated animal.”
These three, plus a missionary, were settled in Woollya Cove, in the Beagle Channel, in 1835 while the Beagle carried out its geographical survey. To the captain’s dismay, the attempt was a dreadful failure. For Darwin, the lesson was very instructive. He saw that humans were all the same under the skin—it was only different levels of education and what he called “civilization” that separated them. For the rest of the voyage, Darwin and FitzRoy paid special attention to the work of Protestant missionaries at other ports of call, especially in Tahiti and New Zealand. When they arrived in South Africa, they noticed that residents were critical of the local missionaries’ wish to buy land. Together, they wrote a letter to the South African Christian Recorder, asking settlers to think more positively about the good work that missionaries were doing in spreading the values of civilization.
So what kind of man returned? Stepping off the ship in Falmouth harbor in October 1836, Darwin was tired of the sea but had had the time of his life. He had seen places and done things that few young men could hope to do. As a thinker he had diversified and matured. Only a few months later he engaged seriously with the difficult and challenging idea of evolution, as yet with no notion of any mechanism that might explain how it came about. After two years of hard thinking and wide reading, he found the concept of differential survival in Thomas Malthus’s theory of population and arrived at the conclusion that “favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species.” Here, as he recorded in his autobiography, he had found “a theory by which to work.”
In short, he returned from the Beagle with the foundations for a lifetime’s study that would lead to the publication of On the Origin of Species more than two decades later. Little did Darwin know, as he made his way home from the final landfall, how heated and long-lasting the evolutionary controversies would be.