Happy Birthday Linnaeus

The great biological classifier celebrates his 300th birthday in 2007, while Buffon, born the same year and Linnaeus’s greatest rival, has been forgotten. Are we celebrating the wrong birthday?

BY RICHARD CONNIFF

ome and stand here,” said part scientific name, its genus Ca guide in a room on the and its species. Homo sapiens, second floor of the house where for instance, was a name the naturalist Carl Linnaeus Linnaeus coined. People today lived with his wife, five chil- tend to take his system for dren, several monkeys, parrots, granted, and scientific names and a pet raccoon. The house, such as E. coli and C. elegans in Uppsala, Sweden, is now have become part of the com- the Linnaeus Museum. “Do mon language. Of Linnaeus you feel the way the floor is himself, even biologists spe- worn away under your feet?” cializing in natural history generally know little or noth- Linnaeus stood on this ing. spot to lecture his students, in a corner of the room where the But for those who had professorial elbow naturally struggled to make sense of eases back onto the carved the world before Linnaeus, mantle. By all accounts, he the system he invented was was a charismatic teacher, cause for jubilation. “When both ribald and full of reli- Linnaeus started,” says gious fervor for the wonders Thierry Hoquet, a science his- of the natural world. The torian at the University of words Linnaeus spoke here Paris X—Nanterre, “natural inspired nineteen of his stu- history was a mess, and people Linnaeus’s sexual system for classi- dents to undertake voyages of fying flowering plants appears in the needed guidelines. Do you exploration to the far corners 1736 edition of his Species know in Greek mythology of the Earth. He called them Plantarum. Linnaeus first assigned the story of how Ariadne his “apostles,” praised their the flowering plants to classes fell in love with Theseus, and according to the number of stamens, every “immortal” discovery, or male parts, of each flower, and fur- gave him a ball of thread to and saw half of them die over- ther differentiated each class into help him find his way out of seas in the service of his mis- orders according to the number of the Minotaur’s Labyrinth? sion. His ideas would also pistils, or female parts. Linnaeus gave us the thread.” prove indispensable to later explorers, from Captain James Cook and Charles Having followed that thread myself, I wanted Darwin to biologists of the present day. to know more about Linnaeus. A good way to do it, it seemed to me, was to look not just at Linnaeus, Linnaeus was, of course, the inventor of the but also at his underappreciated French rival, system by which every living species gets its two- Georges-Louis Leclerc, Comte de Buffon, whose

“Happy Birthday, Linnaeus,” Richard Conniff. Natural History. December2006/January 2007, pp. 42–47. Copyright © Natural History Magazine, 2007. Reprinted by permission. 1 2 Happy Birthday Linnaeus encyclopedic Histoire naturelle became one of the best sellers of the eighteenth century. Both men were born in 1707, and so both are rapidly approaching their 300th birthdays. And both struggled with the same fun- damental questions, which still trou- ble biologists today: What exactly is a species? Where does one species end and another begin? How do species and habitats affect each other?

Both Linnaeus and Buffon were towering figures in their day, and each despised the other. Linnaeus regarded himself as anointed by God to bring order to the chaos of creation. Buffon, who was in many ways the deeper thinker, questioned the very idea of creation and provided crucial scientif- ic evidence against Biblical assump- tions about the age of the Earth. Linnaeus focused his relentless ener- gy on naming species and organizing them into groups. Buffon ridiculed the whole idea of imposing order on nature, preferring instead to focus on how species behaved and how they related to one another.

And yet with the questions they asked, Linnaeus and Buffon together launched one of the greatest intellec- tual quests in history—to understand life on Earth in all its diversity. In place of the animal folklore that earli- Botanical expedition to Lapland, where Linaeus acquired the er naturalists had complacently costume depicted in the 1775 lithograph, helped establish repeated since Roman times, they Linaeus’s image as an explorer and proved critical to his suc- demanded specimens and eyewitness cess. Linnaeus portrayed his expedition as a perilous adven- ture among dangerous natives, though he probably spent only accounts. When they began their a few weeks among the Sami people there. work, the number of species known to science was no more than a few thou- sand. Today, it numbers about 1.7 million. Linnaeus Americas seemed to carry some bizarre new crea- will get much of the credit for that, in tercentennial ture: an opossum appeared on the crowded London events around the world in the coming year. quays, an iguana in Antwerp, a chambered nautilus But as I learned about Buffon, whose own ter- shell in Paris. How did such creatures live? Where centennial will be largely ignored, I began to did they fit in the scheme of creation? How did they wonder: could it be that we’re celebrating the affect ideas about our own species? Naturalists wrong birthday? caught in the tide of strange new life-forms had no language or methodology for discussing such ques- The known world at the start of the eighteenth tions. They could not agree on how to name the century did not include Antarctica, nor much more plants and animals in their own backyards. How than a glimpse of the coast of Australia. But every could they possibly make sense of species at the ship coming home from Africa, Asia, and the opposite ends of the Earth? Happy Birthday Linnaeus 3 Linnaeus was hardly an obvious candidate to in bed with one husband (two pistils and one provide the answer. He was a provincial, descended stamen). from four generations of Lutheran parsons in the Swedish countryside. But he was a careful observer Sex undoubtedly attracted newcomers to the of plants and animals, and compulsively organized charms of botany, and the simplicity of the about recording his observations. He was also ambi- Linnaean system gave them confidence in their tious and spectacularly egotistical (“Nobody has identifications. The French philosopher Jean- been a greater botanist or zoologist,” he once Jacques Rousseau later celebrated the Linnaean sys- wrote). By the age of twenty-five he had already tem as a source of “great pleasure,” because the completed an expedition to Lapland, sponsored by layperson was no longer confined to making isolat- the Royal Society of Science in Uppsala. He later ed observations. Testimonials of delight and grati- depicted his journey as a perilous adventure among tude arrived from around the world. By the time he dangerous natives in uncharted regions. But in her was thirty-three, Linnaeus was already boasting that 1999 biography, Linnaeus: Nature and Nation, the scholars abroad regarded him on a par with Newton historian Lisbet Koerner of Imperial College and Galileo. London concludes that he probably spent no more than a few weeks among the Sami people there. He Then, as now, Uppsala was a college town of also claimed double the distance he actually trav- pink-, cream-, and ochre-colored buildings arranged eled, possibly because he was being paid by the around a pretty little river, the Fyrisån. The garden mile. where Linnaeus practiced his craft as a botanist and as a professor at Uppsala University His image as an explorer proved critical to his occupies much of a city block in the middle of town, success. In Amsterdam, London, and Paris, he with his house on one corner. From here, Linnaeus dressed in a showy variation on the native costume used to lead regular collecting excursions into the of the Sami. Together with his buoyant personality, local countryside joined by as many as 300 people the figure he cut gained him entrée with the leading at a time. With his characteristic passion for order, scientists of the day. He quickly impressed his new Linnaeus organized them into platoons. They armed friends with his ideas about the classification of themselves with butterfly nets and carried their tro- species, which he published as Systema naturae, at phies home pinned to their hats. Kettle drums and the age of twenty-eight. hunting horns announced their jubilant return at the end of the day, accompanied by cries of “Long Live The Linnaean system incorporated three Linnaeus!” important innovations, none of them completely original. First, Linnaeus classified flowering plants From the start, Linnaeus also attracted critics. according to the number of stamens and pistils, the The German botanist Johann Georg Siegesbeck male and female parts, in each flower. Such a sim- protested that Linnaeus was turning innocent flower plistic sexual system was, he knew, artificial (other gardens into beds of harlotry. Linnaeus, who suf- botanists soon replaced it with a reliance on a fered criticism poorly, responded by giving the broader range of traits). But it instantly opened up name Siegesbeckia to a small, foul-smelling weed. the botanical world to anyone who could look into a Another vocal critic, though not on sexual grounds, flower and count. Second, he devised precise rules was the French naturalist Buffon. for describing any species, which, again, even beginners could follow. And third, he gradually he Jardin des Plantes in Paris is today an introduced his binomial system. A species that used Tenclosed compound of rose gardens, tree-lined to suffer under the name Arum summis labris degus- alleys, and museums about the natural world. tantes mutos reddens became instead simply Arum Georges-Louis Leclerc, a son of provincial bour- maculatum. geoisie, assumed the powerful title of administrator here in 1739, when he was just thirty-two. During innaeus shrewdly served up this new system the next half-century, he more than doubled the size Lwith a lyrical dollop of sexual innuendo. He of the Royal Botanical Garden, as it was then described flower petals as “the bridal bed,” per- known, to its present sixty-four acres. He also laid fumed and hung with “precious bed-curtains,” the foundations for what was to become the awaiting “the time for the bridegroom to embrace Muséum national d’Histoire naturelle, one of the his beloved bride.” He spoke blithely of two brides finest natural history museums in the world. Leclerc 4 Happy Birthday Linnaeus tion of natural artifacts, taking on his new task with such enthusiasm that he eventually wrote thirty-six volumes of his encyclopedic Histoire naturelle. It became an attempt to syn- thesize everything then known about the animal and mineral worlds. The Histoire naturelle was an immediate best seller— and remained a pillar of French literature until Buffon’s lofty prose fell out of favor in mid-twentieth century.

What made Buffon different was not just his style, but also his scrupulous avoidance of religious or supernatural explanations. Linnaeus and most other contemporaries still rooted their defini- tion of species in the plants and animals created by God to populate Eden. Buffon, by contrast, thought it was absurd to imagine God being “very busy with the way a beetle’s wing should fold.” He defined a species scientifically, as a group of animals breeding together over time.

Such departures from orthodoxy angered religious authorities, who pre- sented Buffon with a list of fourteen “reprehensible statements.” Buffon duti- fully signed a declaration of his faith in Scripture. (“It is better to be humble than hung,” he remarked.) But he left his “reprehensible statements” unaltered.

Buffon’s keen interest in habitat and Cherubs and a trumpet-bearing angel weave garlands about the image of Linaeus in this adulatory, 1806, portrait by behavior anticipated sciences such as Francesco Bartolozzi. The religious iconography reflects ecology and ethology, which were still Linaeus’s Bible-based beliefs, an integral part of his scientif- 200 years in the future. And though he ic approach. Like most of his contemporaries, Linnaeus root- had no inkling of evolution, he wrote ed his definition of species in the plants and animals with which the God of Benesis populated Eden. about how species could be transformed by their habitat. He believed, for instance, that a cold, wet climate caused was a talented administrator, politically adroit, a animals in the Americas to be smaller. (His friend confidante of everyone from Benjamin Franklin to Thomas Jefferson, then the American ambas- King Louis XV. But the key to his reputation was sador to Paris, gently corrected this error by his writing, which made him internationally famous presenting the Royal Botanical Garden with as Buffon—later Comte, or Count, of Buffon—a the hide of a moose.) Buffon’s aim was to name taken from a small Burgundy village near his incorporate particular observations about ani- country home in Montbard. mals into general theories about the natural world, and it earned him a reputation as “the From 1740 on, Buffon spent half the year Pliny and the Aristotle of France.” Given the egos in Montbard (“Paris is hell,” he wrote). Here involved, a clash with the “Newton and Galileo” of Buffon set out to catalogue the king’s collec- Sweden was inevitable. Happy Birthday Linnaeus 5 uffon struck the first blow in the Bmid-1740s, attacking Linnaeus for imposing an artificial order on the disor- derly natural world. He gleefully pointed out absurdities in the groups Linnaeus had proposed. Did tulips really belong with barberries? Or elm trees with car- rots? Linnaeus had mistakenly grouped those species together because he did not realize that a particular trait—the num- ber of pistils and stamens, for instance— could evolve independently even in the most distantly related species. It was even worse in zoology. On the basis of dental structure, for instance, humans and monkeys both turned up in the order Anthropomorpha. But so did two-toed sloths. “One must really be obsessed with classifying to put such different beings together,” Buffon wrote.

Linnaeus dismissed his antagonist as a “hater of all methods,” who deliv- ered “few observations” and much “beautiful ornate French.” He quoted the Bible (“And I have cut off all thine ene- mies out of thy sight”) to prophesy that the “Frenchman named Buffon” who “always wrote against Linnaeus” would suffer the wrath of God.

Buffon’s objections to the Linnaean system arose partly from sincere belief. “Nature moves through unknown grada- tions and consequently she cannot be a party to these divisions,” he wrote, Books, a globe, and a few animals serve as decorative ele- “because she passes from one species to ments in this 1769 portrait of Buffon, in contrast to the reli- another species, and often from one gious imagery in the painting of Linnaeus on the previous genus to another genus, by imperceptible page. Unlike Linnaeus, Buffon scrupulously avoided reli- nuances.” gious and supernatural explanations. Buffor suggested that animals were not immutable forms created by God, but rather adapted to their habitats. He was highlighting a problem that bedevils biologists to this day. The Linnaean system, even in its modern er on the basis of traits they have in common. Then form, is far from perfect. New evidence routinely they fight. obliges taxonomists to move species from one genus to another, or even to an entirely different But if the system Linnaeus invented is so order. At times, the revised groupings can seem as flawed, why has his reputation endured? Partly it’s absurd as the ones Buffon lampooned. Buffon was because binomial identification has proved so con- also correct in arguing that the Linnaean system is venient. And partly it’s because Linnaeus was often arbitrary. Taxonomic “splitters” tend to recog- extraordinarily lucky. Although he was thinking nize new species on the basis of relatively small dif- about God and creation, he developed a rudimenta- ferences. Taxonomic “lumpers” group them togeth- ry hierarchy of classification that would prove con- 6 Happy Birthday Linnaeus

Le Jardin des Plantes, the most important botanical garden in France, is depicted around 1805. In his half-century as its administrator, Buffon more than doubled its size. According to one story, Buffon’s son was sent to the guillotine during the French Revolution by former neighbors that Buffon peré had evicted in the course of expanding the garden. genial, a century later, to the new evolutionary England, where the cult of Linnaeus was particular- thinking of Darwin. His timing was also impecca- ly devout. (Even in the eighteenth century he was ble. -He provided a coherent system of classifica- celebrated there as “the immortal Linnaeus.”) tion just as the age of discovery was revealing the overwhelming richness of plant and animal life. But does Buffon deserve to be forgotten? His relative obscurity, like the immortality of Linnaeus, uffon, meanwhile, proposed no alternative way also turns out to be largely a matter of luck. Bof coming to grips with the abundance of new species. He made the mistake, as absurd as anything From Montbard, I walked along a canal to a in Linnaeus, of putting human beings at the center collection of handsome stone buildings with red tile of the animal world, and his Histoire naturelle paid roofs, just outside Buffon’s namesake village. It’s inordinate attention to species that were useful and an old forge where, late in life, Buffon conducted a familiar to us. Perhaps Linnaeus was a mere collec- series of remarkable experiments. He had his work- tor and classifier, as Buffon argued. And maybe he ers take molten balls of iron of various size and lacked Buffon’s insight into ecology and animal composition from the smelter and carefully measure behavior. But Buffon somehow missed a point all how long it took them to cool down. His theory was modern scientists understand: Classification is the that the Earth originated as a fireball, gradually essential first step. You need to know what species solidifying as it cooled. By scaling up from iron you are looking at, before you can begin to talk balls to the size of the planet, he hoped to estimate about how they behave. the age of the Earth. His numbers ranged from 10 million years to as little as 75,000 years, the esti- The attack on Linnaeus mainly hurt Buffon mate he published when his “Epochs of Nature” himself. According to Phillip R. Sloan, a historian finally appeared in 1778. of science at the University of Notre Dame, the Histoire naturelle was quickly translated into most Geologists now know that the Earth is billions major European languages. But it was twenty-five of years old. But Buffon’s work was the beginning years before the first translation appeared in of the end for the biblical belief that all creation Happy Birthday Linnaeus 7 dated back just 6,000 years. According to the late stood the value of Buffon’s work well enough to Stephen Jay Gould, “Epochs of Nature” was “the found the Museum national d’Histoire naturelle on most important scientific document ever written in the collections he had largely assembled. But one of promoting the transition to a fully historical view of the early zoologists there, Georges Cuvier, set out to nature.” turn natural history into a scientific discipline. And clearing the path to professionalism meant pushing The forge is now a museum, but amazingly, the Buffon and the kind of amateur naturalists he had exhibits make no reference whatever to the experi- inspired into the dustbin. ments Buffon conducted there. And that seems to be Buffon’s fate in history. His ideas, though essential But even Cuvier later conceded that Linnaeus in their day to the advancement of science, were and Buffon together possessed the essential tools consigned thereafter to oblivion. for rapidly advancing the scientific study of nature: “Linnaeus knew with precision the distinctive traits hierry Hoquet, the author of a recent book about of creatures; Buffon comprehended in a glance TBuffon, credits him with four important ideas in some of their most remote relations.” Without both, the history of science: the understanding of geolog- natural science as we know it would not exist. ic time, the definition of species on biological terms, the role of habitat in shaping species, and the At the Jardin des Plantes, a bronze statue of conviction that species can transform over time. Buffon presides in casual splendor over the gardens Those ideas all stand up to modern scrutiny. But and the natural history museums he helped make they are relatively complex, and buried in a prodi- great. One day this past summer, a worker—an gious stream of other ideas. unwitting agent of the cult of Linnaeus—set up a sprinkler directly in front of the statue, so that it Buffon’s reputation also suffered for political seemed to be spitting indifferently onto Buffon’s reasons. He died in 1788, a year before the French ruffled blouse. But then the pressure went off, and Revolution, which, unsurprisingly, had little regard for a little while, the image of Buffon glistened for such a close ally of the king. Buffon’s son went again under the Paris sun. to the guillotine. At least the revolutionaries under-