Lovesick explorer

Charles Darwin and locket

Iain McCalman recounts Darwin’s difficult journey towards his great scientific moment.

As the voyage entered its final phase before turning back towards the Northern Hemisphere, Darwin found himself overwhelmed by nostalgia, an affliction that Captain Cook had associated with southern voyaging. The long chatty letters from his sisters that had entertained him with Jane Austen-like morsels of gossip about local Shropshire flirtations and marriages contained one piece of news that hurt him badly. Lovely Fanny Owen, the family friend with whom he’d played fantasy games in the woods, she as Housemaid and he as Postillion, had unexpectedly married.

Before leaving England, and with encouragement from her, he’d imagined Fanny as “a nice little wife for the Parsonage”. Now his dream of a quiet home in the English countryside was untenanted by a wife, and he longed to find someone to take Fanny’s place.

Darwin could be pardoned for feeling tired. His body had been weakened by an illness at Valpara'so that some historians have thought to be Chagas’ disease, a mysterious ailment transmitted by the bite of an insect. The rolling Pacific swell also upset his stomach and depressed his spirits. Even the meridian of the Antipodes on December 19, 1835 passed like a mirage. “I looked forward to this airy barrier as a definite point in our voyage homewards; now I find it and all such resting places for the imagination are like shadows, which a man moving onward cannot catch,” he wrote in his diary.

He could not help feeling vexed, after such a prolonged period of sailing, by “the want of room, of seclusion, of rest–the jading feeling of constant hurry–the privation of small luxuries, the comforts of civilisation, domestic society…” The Pacific Ocean loomed like “a tedious waste, a desert of water”; its blue expanses were welcome only for giving him “the time and inclination to measure the future stages of our long voyage of half the world, and wish most earnestly for its termination”.

This ennui was to taint Darwin’s appreciation of many of the places he visited in the remaining year of the voyage–just as it has dulled the evaluation of many historians who have followed in his tracks. Consciously or otherwise, Darwin compared these southern landscapes with a rosy ideal of home. Nostalgic blinkers immunised him to New Zealand’s beautiful Bay of Islands. Oceans of waving ferns seemed “rather desolate”, the best vistas “only occasionally pretty”. Gardens at the missionary village of Paihia were “quite pleasing” only because of their “English flowers…roses of several kinds, honeysuckle, jessamine, stocks and whole hedges of sweet briar”. On departing New Zealand on December 30, 1835, he grumbled that he was “glad to leave”.

Australia and South Africa fared no better. Arriving in New South Wales at the end of a drought-ravaged summer didn’t help, and the young man who had seen a temple-like beauty in the wastes of Patagonia could find little to appreciate in novel southern landscapes. Riding westward from Sydney, he complained of “the arid sterility” of the trees, the monotony of eucalypt foliage, dried-up river-beds and “wearisome” sandstone plains. Van Diemen’s Land was better only because it was greener and more English-looking. King George Sound, in present-day Western Australia, appeared “uninviting”. On March 14, 1836, he left Australian shores “without sorrow or regret”, and a few months later he complained that Cape Town’s lush hinterland was the most uninteresting country he’d seen.

These caustic judgements are unfortunate because they have blinded many commentators to the intellectual significance of Darwin’s last year of travel in the southern oceans. With the exception of his visit to the Galapagos Islands in October 1835, which historians invariably regard as canonical, the key achievements of Darwin’s voyage are assumed to be over once the Beagle heads south for Tahiti.

This is a serious oversight. Some of his most important discoveries were to come among the islands and island continents of the Indian and Pacific oceans. Homesickness might have made him grumpy about the beauty of these landscapes, but it didn’t affect his passion to discover new natural laws. Indeed, the Galapagos visit was only the preamble to an integrated sequence of explorations that opened up entirely new horizons of knowledge and speculation. Darwin quickly appreciated that islands were good to study because of their manageable size; their recent origin as landforms, habitats and societies; and their perplexing organic relationships with neighbouring landmasses.

Darwin’s reading of the second volume of Lyell’s Principles had given him a definite, if loose, agenda for these forthcoming investigations. The islands of the Indian and Pacific oceans, with their confined habitats, would simplify his mission to collect comprehensive samples of plants, birds, insects and animals, and to track their migrations. As in the Andes, he was to use the “uniformitarian” insights and methods of a Lyellian geologist to investigate the physical origins of islands and archipelagos. This meant finding evidence of how slow, everyday and sometimes invisible actions had brought these fragments of land into being, including the forces of volcanic uplift, ocean-floor elevation and subsidence, and coral growth.

Lyell’s book had also alerted Darwin to some of the ways in which recently formed landmasses could become populated by new networks of flora and fauna, able to adapt to local climate and soil. Darwin expected to find some slight and transient variations among these chance strays from mainland “centres of creation”.

As well–and here Darwin’s agenda was as much influenced by his experiences with Fuegian natives in Patagonia–he would investigate how these processes of migration, dispersal and adaptation influenced human populations and societies. In particular, he’d observe how new influxes of people, or “invasive species”, often from “civilised” northern centres such as Britain, had influenced the original “primitive” inhabitants of southern islands or continents and reshaped their natural environments.

Finally, the second volume of Principles had set Darwin thinking about how coral reefs were formed. Lyell, knowing that corals could survive only in relatively shallow water, had, along with several other theorists, speculated that their polypi must grow on top of underwater volcanoes that were being gently elevated from the ocean floor. To Darwin’s mind, though, this failed to explain the different shapes of the three prevalent types of coral reef: barrier reefs, which arose some distance from the shore, their outer sides growing out of deep water; fringing reefs, which grew around volcanic islands; and atoll reefs, which formed a ring or horseshoe shape, with a lagoon nestling inside and drifts of sand and dead coral coalescing into a new “coral island”.

Bizarrely, even though Darwin had yet to see a coral reef, he believed he’d already solved this puzzle. While viewing the vast land elevations on the west coast of South America, he had suddenly thought that there might be corresponding subsidence occurring elsewhere on the seabed. Could this be the explanation for the various types of coral reefs and islands that were known to stud the Pacific and Indian oceans? Had coral reefs grown upward on top of land that was subsiding slowly under the sea?

Sailing among the islands, archipelagos and island continents of the South Seas offered Darwin a set of unique, living laboratories for testing this wildly deductive hypothesis and for honing his knowledge and skills as a theorist of geology, zoology and ethnography.

And though he did not know it at the time, the results of his investigations here would push him several steps closer to a theory he would one day call “modification by descent through natural selection”. Today we know it simply as evolution.

Iain McCalman is Professorial Research Fellow and ARC Federation Fellow at the University of Sydney. This excerpt was taken from his book, Darwin’s Armada: How four voyagers to Australasia won the battle for evolution and changed the world (Penguin, Australia; Norton, USA; Simon & Schuster, UK; 2009).