long been seen as natural curiosities. But, as clues to the past, their meaning was murky. The presence of plant and animal shapes found in solid rock, and especially the appearance of fossilized marine life on mountaintops around the world, had puzzled people for centuries. There were imaginative explanations—though not to the point of guessing the truth—that whole worlds of living organisms had come and gone in the eons before us. It was believed by some that ocean life—possibly seeds or spawn—had been carried up to the mountains during the biblical deluge. Speculation during the Middle Ages centered on some kind of geological hoax perpetrated within the earth’s mantle, where supposed “plastic forces” created rocky simulations of living things. Earlier, the Greeks had thought it possible that the sea had once covered the land where marine fossils turned up. Aristotle believed such fossils might be the residue of creatures trapped in crevices of formerly submerged rocks. Leonardo da Vinci thought the fossilized assemblages of corals and shells found in the mountains of Italy argued against a biblical interpretation. He noticed they were intact and arranged in the same way as in the ocean. Da Vinci concluded that it was impossible for such objects to have been transported to the mountains in a pristine condition—especially by way of a violent, forty-day flood. Linnaeus took a pragmatic view of fossils, naming them as if they were any other extant species.
All of this would have to be rethought, and soon, because people had begun finding large, unusual-looking bones on both sides of the Atlantic. The discoveries in America were particularly important because they pointed up the shortcomings of Linnaean taxonomy, and also because they sharpened the dispute between American naturalists and another European authority, the great French scientist and nature writer Georges-Louis Leclerc, comte de Buffon.
Count Buffon—or just Buffon, as he was usually called—was a contemporary of Linnaeus. Born in 1707 to a middle-class family in the small town of Montbard in Burgundy, Buffon was an unremarkable student. But he had a curious mind and was fascinated by mathematics and science—as well as money, power, fancy clothes, and beautiful women. Drawing on reserves of ego, ambition, and literary ability, Buffon launched an unlikely but meteoric career as a celebrity naturalist. In 1739, King Louis XV of France appointed Buffon keeper of the Royal Botanical Garden, a prestigious, essentially administrative position. The “garden” was much more than a royal arboretum. It was actually a well-organized academy that offered coursework in medicine and natural science, and which had a small faculty as well as many specimens of plants and animals from around the world. Buffon devoted himself to expanding and cataloguing the collection, called the King’s Cabinet of Natural History. This work morphed into one of the most important and all-encompassing scientific publications of the eighteenth century, the Histoire naturelle, générale et particulière, avec la description du Cabinet du roi—Buffon’s Natural History. The first three installments of this encyclopedic undertaking appeared in 1749. By the time of his death in 1788, Buffon had completed thirty-six volumes, including an edition illustrated with copper engravings of mammals from every corner of the world.
The subject of Buffon’s Natural History was everything. Buffon endeavored to explain all that was known about the physical world, including its origins. He covered geology and anthropology, the formation of the planets, reproduction, astronomy, meteorology, mineralogy. He wrote about the oceans and air and continents. He covered physics and botany and zoology and, of course, taxonomy. Buffon liked naming things every bit as much as Linnaeus did, though the two profoundly disagreed on how to catalogue the taxa. Buffon thought the Linnaean system was flawed and far too generous in the way it defined species. Buffon, for example, thought all quadrupeds were variants on just thirty-eight mammalian species. Buffon didn’t care for purely morphological analyses, and he poked fun at the way shared characteristics sometimes led Linnaeus into highly improbable groupings of animals that were obviously distant from one another. Buffon saw nature as more varied and more of a continuum. Nature, Buffon insisted, “works by insensible degrees.” Taxonomic associations based on one or a few physical traits inevitably produced arbitrary divisions.
Buffon based his definition of a species on reproductive compatibility instead. A species, Buffon decided, comprises those closely related organisms that can interbreed and produce fertile offspring—a definition still widely accepted. Buffon offered a classic example: “The ass resembles the horse more than the water spaniel the hound, but nonetheless the water spaniel and the hound are only one species, since they together produce individuals that can themselves produce others, whereas the horse and the ass are certainly from different species, since they together produce only defective and barren individuals.” In other words, the sterility of a mule, the hybrid that results from breeding an ass and a horse, is a dead end in nature. A species, Buffon said, was marked by the persistence of its generations through time—a “chain of successive existence.”
Buffon’s Natural History was massive, expensive, and despite Buffon’s nebulous background in many areas of natural history, widely read. Prior to writing the Natural History, Buffon’s interests had centered on physics and celestial mechanics. He worked on the “problem” of infinity, a troublesome concept useful in mathematics but perplexing as an aspect of reality. He also conducted experiments in optics and rocketry, including attempts to calculate the size and configuration of the propellant required to send a rocket into space. Intrigued by the story of Archimedes setting the Roman fleet ablaze at Syracuse by means of reflected sunlight, Buffon had invented a “burning mirror” that could melt iron at close range or set fire to buildings two hundred feet away.
Buffon understood nature as a process—one involving a multitude of fluid interactions and changes taking place over time. He believed the earth was much older than the biblical claim of a few thousand years, and also that conditions on the planet had varied throughout its history. Life, he proposed, was a cosmic accident made possible by affinities between organic molecules that cohered into organisms. Anticipating Darwinian evolution, Buffon stated that all life forms were influenced by environmental conditions and were subject to incremental variations that ultimately gave rise to the plants and animals as they appeared in the present.
These brilliant (and probably heretical) insights led Buffon to speculate a little too freely on some of the taxa that were distributed around the world and now had come to the attention of naturalists in Europe.
Buffon never went to America. He studied accounts of North American wildlife and examined specimens submitted to the king’s collection, measuring and comparing them closely with European species. Many of the ideas he formed about the New World were based on reports that were inaccurate, mean-spirited, or poorly translated. Buffon’s focus on North American fauna was also a notable departure from the existing interest in the natural history of the New World, which had focused on plants. European horticulturists saw the botanical wealth of America as a potentially important resource given the depleted plant stocks in Europe.
Buffon detected several things about American animals. For one, it was clear that some species in the New World were unique. There were no turkeys or rattlesnakes or bald eagles in Europe. These belonged to the exotica of America. But it was equally apparent that America was home to many animals—deer, bears, beavers, porcupines, foxes, wolves—that also lived in Europe or Asia. Buffon supposed that America must have been colonized by animals that long ago proceeded across a former land bridge to North America, presumably to escape hunting and crowding in the Old World. Once there, some maintained their original forms, while others diverged and gave rise to novel species. What was most remarkable to Buffon concerned the animals common to both the Old and New Worlds: Animals from America were smaller than their counterparts in Europe.
Buffon proposed an unorthodox explanation for this discrepancy. The differences between Old World and New World animals belonging to the same species, Buffon determined, must be the result of environmental differences between Europe and America—most important, the harshness of the North American climate. In the New World, wrote Buffon, “nature is always rude and sometimes deformed.” America, he said, was well suited to lower life forms like reptiles and bugs, but was otherwise a gloomy and disadvantaged environment for living things. “The air and the earth
