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 overloaded with humid and noxious vapors are unable either to purify themselves or to profit by the influence of the sun, who darts in vain his most enlivening rays upon this frigid mass.”
Buffon described a kind of ecological withering that was the reverse of evolution, in which animals responded over time to an oppressive climate by becoming less fit. America was a land of stunted, less vigorous survivors. Buffon called this process “degeneration,” and he claimed it as an example of the kind of morphological changes wrought by nature over long periods. “These changes are made only slowly, imperceptibly,” Buffon wrote. “The great worker of Nature is Time; as it always moves with an equal, uniform, and regulated pace, it does everything; and these changes, at first imperceptible, become noticeable little by little, and finally leave results about which one cannot be mistaken.”
The idea caught on. Europeans were already convinced of the inhospitable environment in America. From the time they first set foot in the New World, European explorers had reported its many unpleasantries. There were frightening snakes, tormenting insects, sour fens, and forbidding forests shrouded in fogs and poisonous airs. The land, unlike Europe, had not been improved through the industry of its native people. Although much of the continent was near the same latitudes as Europe, North America was much colder in the winter and endured awful heat and humidity in the summer.
Buffon argued that the degenerative effects of the North American climate could be seen even in livestock brought over from Europe—which he insisted also grew smaller than their ancestors. He stopped short of claiming that the same thing happened to the human colonists, though some of Buffon’s adherents said as much. What finally brought a response to Buffon from America was what he said about the New World’s aboriginal people—judgments again made without any direct observation to back them up. Indians, he said, were no different from the animals of America. They were a degenerate species. Because Indians were about the same size as Europeans, Buffon defended his theory with a wildly racist assessment of their many other deficiencies:
Although the savage of the new world is about the same height as man in our world, this does not suffice for him to constitute an exception to the general fact that all living nature has become smaller on that continent. The savage is feeble, and has small organs of generation; he has neither hair nor beard, and no ardor whatever for his female; although swifter than the European because he is better accustomed to running, he is, on the other hand, less strong in body; he is also less sensitive, and yet more timid and cowardly; he has no vivacity, no activity of mind; the activity of his body is less an exercise, a voluntary motion, than a necessary action caused by want; relieve him of hunger and thirst, and you deprive him of the active principle of all his movements; he will rest stupidly upon his legs or lying down entire days.
An answer to these brutal words—and to the whole theory of degeneration—would be offered, and when it came it would mark the beginning of American science.
In 1705, a farmer mucking about on the banks of the Hudson River near Albany, New York, found something odd. Spring floods had eroded the riverbank, exposing a foreign object. It was a gigantic tooth, about the size of a fist and weighing almost five pounds. Further excavation at the site unearthed the remains of a large animal that had presumably owned the tooth, including what appeared to be a thighbone approximately seventeen feet long. These additional parts were so badly decomposed that they crumbled instantly upon being dug up and could not be identified. The tooth, meanwhile, went on a journey.
It was sent to the Royal Society in London, in a box labeled “tooth of a Giant.” The society was arguably the most respected scientific institution in the world. Its president at the time was Sir Isaac Newton. Everyone there agreed that it was a very big tooth indeed. Beyond that, things got hazy. For a while the prevailing