By
1800, four years after the elephant paper, Cuvier’s fossil zoo had
expanded to include twenty-three species that he deemed to be extinct.
Among these were a pygmy hippopotamus, whose remains he found in a
storeroom at the Paris museum; an elk with enormous antlers, whose bones
had been found in Ireland; and a large bear—what now would be known as a
cave bear—from Germany. The Montmartre animal had, by this point,
divided, or multiplied, into six separate species. (Even today, little
is known about these species except that they were ungulates and lived
some thirty to forty million years ago.) “If so many lost species have
been restored in so little time, how many must be supposed to exist
still in the depths of the earth?” Cuvier asked.
Cuvier had a
showman’s flair and, long before the museum employed public-relations
professionals, knew how to grab attention. (“He was a man who could have
been a star on television today,” Tassy told me.) At one point, the
gypsum quarries around Paris yielded a fossil of a rabbit-size creature
with a narrow body and a squarish head. Cuvier hypothesized, based on
the shape of its teeth, that the fossil belonged to a marsupial. This
was a bold claim, as there were no known marsupials in the Old World. To
heighten the drama, Cuvier announced that he would put his
identification to a public test. Marsupials have a distinctive pair of
bones, now known as epipubic bones, that extend from their pelvis.
Though these bones were not visible in the fossil as it was presented to
Cuvier, he predicted that, if he scratched around, the missing bones
would be revealed. He invited Paris’s scientific élite to gather and
watch as he picked away at the fossil with a fine needle. Voilà, the
bones appeared. (A cast of the marsupial fossil is on display in Paris
in the paleontology hall, but the original is deemed too valuable to be
exhibited and is kept in a special vault.)
Cuvier
staged a similar bit of paleontological performance art during a trip
to the Netherlands. In a museum in Haarlem, he examined a specimen that
consisted of a large semicircular skull attached to part of a spinal
column. The fossil, three feet long, had been discovered nearly a
century earlier and had been attributed—rather curiously, given the
shape of the head—to a human. (It had even been assigned a scientific
name:
Homo diluvii testis, or “man who was witness to
the Flood.”) To rebut this identification, Cuvier first found an
ordinary salamander skeleton. Then, as Rudwick relates it, he began
chipping away at the rock around the deluge man’s spine. When he
uncovered the fossil animal’s forelimbs, they were, just as he had
predicted, shaped like a salamander’s. The creature was not an
antediluvian human but something far weirder: a giant amphibian.
The
more extinct species Cuvier turned up, the more the nature of the
beasts seemed to change. Cave bears, giant sloths, even giant
salamanders—all these bore some relation to species that were still
alive. But what to make of a bizarre fossil that had been found in a
limestone formation in Bavaria? Cuvier received an engraving of this
fossil from one of his many correspondents. It showed a tangle of bones,
including what looked to be extremely long arms, skinny fingers, and a
narrow beak. The first naturalist to examine it speculated that its
owner had been a sea animal and had used its elongated arms as paddles.
Cuvier, on the basis of the engraving, determined—shockingly—that the
animal was actually a flying reptile. He called it a
ptero-dactyle, meaning “wing-fingered.”
Cuvier’s
proof of extinction—of “a world previous to ours”—was a sensational
event, and news of it soon spread across the Atlantic. When a nearly
complete giant skeleton was unearthed by some farmhands in Newburgh, New
York, it was recognized as a find of great significance. Vice-President
Thomas Jefferson made several attempts to get his hands on the bones.
He failed. But a friend, the artist Charles Willson Peale, who’d
recently established the nation’s first natural-history museum, in
Philadelphia, succeeded.
Peale, perhaps an even more accomplished
showman than Cuvier, spent months fitting together the bones he acquired
from Newburgh, fashioning the missing pieces out of wood and
papier-mâché. He presented the skeleton to the public on Christmas Eve,
1801. To publicize the exhibition, Peale had his black servant, Moses
Williams, don an Indian headdress and ride through the streets of
Philadelphia on a white horse. The reconstructed beast
stood eleven feet high at the shoulder and more than seventeen feet
long from tusks to tail, a somewhat exaggerated size. Visitors were
charged fifty cents—quite a considerable sum at the time—for a viewing.
The beast, an American mastodon, at this point still lacked an
agreed-upon name, and was variously referred to as an incognitum,
an Ohio animal, and, most confusing of all, a mammoth. It became
America’s first blockbuster exhibit, and set off a wave of “mammoth
fever.” The town of Cheshire, Massachusetts, produced a
twelve-hundred-and-thirty-pound “mammoth cheese”; a Philadelphia baker
produced a “mammoth bread”; and the newspapers reported on a “mammoth
parsnip,” a “mammoth peach tree,” and a mammoth eater, who “swallowed 42
eggs in ten minutes.” Peale also managed to piece together a second
mastodon, out of additional bones found in Newburgh and a nearby town in
the Hudson Valley. After a celebratory dinner held underneath the
animal’s capacious rib cage, he dispatched this second skeleton to
Europe with two of his sons, Rembrandt and Rubens. The skeleton was
exhibited for several months in London, during which time the younger
Peales decided that the animal’s tusks must have pointed downward, like a
walrus’s. Their plan was to take the skeleton on to Paris and sell it
to Cuvier. But while they were in London war broke out between Britain
and France, making travel between the two countries impossible.
Cuvier finally gave the mastodonte
its name in a paper published in Paris in 1806. The peculiar
designation comes from the Greek, meaning “breast tooth”; the cusps on
the animal’s molars apparently reminded him of nipples.
Despite
the ongoing hostilities between the British and the French, Cuvier
managed to obtain detailed drawings of the skeleton that Peale’s sons
had taken to London, and these gave him a much better picture of the
animal’s anatomy. He realized that the mastodon was far more distant
from modern elephants than the mammoth was, and assigned it to a new
genus. (Today, mastodons are given not only their own genus but their
own family.) In addition to the American mastodon, Cuvier identified
four other mastodon species, all “equally strange” to the earth today.
Peale didn’t learn of Cuvier’s new name until 1809, and when he did he
immediately seized on it. He wrote to Jefferson proposing a
“christening” for the mastodon skeleton in his Philadelphia museum.
Jefferson was lukewarm about the name Cuvier had come up with—it “may be
as good as any other,” he replied—and didn’t deign to respond to the
idea of a christening.
In
1812, Cuvier published a four-volume compendium of his work on fossil
animals—“Recherches sur les Ossemens Fossiles de Quadrupèdes.” Before he
began his “researches,” there had been zero vertebrates classified as
extinct. Thanks for the most part to his own efforts, there were now at
least forty-nine.
As Cuvier’s list grew, so did his renown. Few
naturalists dared to announce their findings in public until he had
vetted them. “Is not Cuvier the greatest poet of our century?” Balzac
asked. “Our immortal naturalist has reconstructed worlds from a whitened
bone; rebuilt, like Cadmus, cities from a tooth.” Cuvier was honored by
Napoleon and, once the Napoleonic Wars finally ended, was invited to
Britain, where he was presented at court.
The English were eager
converts to Cuvier’s project. In the early years of the nineteenth
century, fossil collecting became so popular among the upper classes
that a whole new vocation sprang up. A “fossilist” was someone who made a
living hunting up specimens for rich patrons. The year Cuvier published
his “Recherches,” one such fossilist, a young woman named Mary Anning,
discovered a particularly outlandish specimen. The creature’s skull,
found in the limestone cliffs of Dorset, was nearly four feet long, with
a jaw shaped like a pair of needle-nose pliers. Its eye sockets,
peculiarly large, were covered with bony plates.
The fossil ended
up in London at the Egyptian Hall, a privately owned museum not unlike
Peale’s. It was put on exhibit as a fish and then as a relative of a
platypus before being recognized as a new kind of reptile—an
ichthyosaur, or “fish-lizard.” A few years later, other specimens
collected by Anning yielded pieces of another, even wilder creature,
dubbed a plesiosaur, or “almost-lizard.” Oxford’s geology expert, the
Reverend William Buckland, described the plesiosaur as having a
lizardlike head joined to a neck “resembling the body of a Serpent,” the
“ribs of a Chameleon, and the paddles of a Whale.” Apprised of the
find, Cuvier found the account of the plesiosaur so outrageous that he
questioned whether the specimen had been doctored. When Anning uncovered
another, nearly complete plesiosaur fossil, Cuvier had to acknowledge
that he’d been wrong. “One shouldn’t anticipate anything more monstrous
to emerge,” he wrote to one of his British correspondents. During
Cuvier’s trip to England, he visited Oxford, where Buckland showed him
yet another astonishing fossil—an enormous jaw with one curved tooth
sticking up out of it like a scimitar. Cuvier recognized this animal,
too, as some sort of lizard. A couple of decades later, the jaw was
identified as belonging to a dinosaur.
The study of stratigraphy
was in its infancy at this point, but it was already understood that
different layers of rocks had been formed during different periods. The
plesiosaur, the ichthyosaur, and the as yet unnamed dinosaur had all
been found in limestone deposits that were attributed to what was then called the Secondary and is now known as the Mesozoic era. So, too, had the ptero-dactyle
and the Maastricht animal. This pattern led Cuvier to another
extraordinary insight about the history of life: it had a direction.
Lost species whose remains could be found near the surface of the earth,
like mastodons and cave bears, belonged to orders of creatures that
were still alive. Dig back further and one found creatures, like the
animals from Montmartre, that had no obvious modern counterparts. Keep
digging, and mammals disappeared altogether from the fossil record.
Eventually, one reached not just a world previous to ours but a world
previous to that, dominated by giant reptiles.
Cuvier’s
ideas about this history of life—that it was long, mutable, and full of
fantastic creatures that no longer existed—would seem to have made him a
natural advocate for evolution. But he opposed the concept of
evolution, or
transformisme, as it was known in Paris
at the time, and he tried—generally, it seems, successfully—to humiliate
any colleagues who advanced the theory. Curiously, it was the same
skills that led him to discover extinction that made evolution appear to
him preposterous, an affair as unlikely as alchemy.
As Cuvier
liked to point out, he put his faith in anatomy; this was what had
allowed him to distinguish the bones of a mammoth from those of an
elephant and to recognize as a giant salamander what others took to be a
man. At the heart of his understanding of anatomy was a notion that he
termed “correlation of parts.” By this, he meant that the components of
an animal all fit together and are optimally designed for its particular
way of life; thus, a carnivore will have an intestinal system suited to
digesting flesh. Its jaws will be “constructed for devouring prey; the
claws, for seizing and tearing it; the teeth, for cutting and dividing
its flesh; the entire system of its locomotive organs, for pursuing and
catching it; its sense organs for detecting it from afar.”
Conversely,
an animal with hooves must be an herbivore, since it has “no means of
seizing prey.” It will have “teeth with a flat crown, to grind seeds and
grasses,” and a jaw capable of lateral motion. Were any one of these
parts to be altered, the functional integrity of the whole would be
destroyed. An animal that was born with, say, teeth or sense organs that
were somehow different from its parents’ would not be able to survive,
let alone give rise to an entirely new kind of creature.
In Cuvier’s day, the most prominent proponent of
transformisme
was his senior colleague at the National Museum of Natural History,
Jean-Baptiste Lamarck. According to Lamarck, there was a force—the
“power of life”—that pushed organisms to become increasingly complex. At
the same time, animals and also plants often had to cope with changes
in their environment. They did so by adjusting their habits; these new
habits, in turn, produced physical modifications that were then passed
down to their offspring. Birds that sought prey in lakes spread out
their toes when they hit the water, and eventually developed webbed feet
and became ducks. Moles, having moved underground, stopped using their
sight, and so over generations their eyes became small and weak. Lamarck
adamantly opposed Cuvier’s idea of extinction; there was no process he
could imagine that was capable of wiping an organism out entirely.
(Interestingly, the only exception he entertained was humanity, which,
Lamarck allowed, might be able to exterminate certain large and
slow-to-reproduce animals.) What Cuvier interpreted as
espèces perdues Lamarck claimed were simply those that had been most completely transformed.
The
notion that animals could change their body types when convenient
Cuvier found absurd. He lampooned the idea that “ducks by dint of diving
became pikes; pikes by dint of happening upon dry land changed into
ducks; hens searching for their food at the water’s edge, and striving
not to get their thighs wet, succeeded so well in elongating their legs
that they became herons or storks.” He discovered what was, to his mind
at least, definitive proof against
transformisme in a collection of mummies.
When
Napoleon invaded Egypt, the French, as usual, seized whatever
interested them. Among the crates of loot shipped back to Paris was an
embalmed cat. Cuvier examined the mummy, looking for signs of
transformation. He found none. The ancient Egyptian cat was,
anatomically speaking, indistinguishable from a Parisian alley cat. This
proved that species were fixed. Lamarck objected that the few thousand
years that had elapsed since the Egyptian cat was embalmed represented
“an infinitely small duration” relative to the vastness of time.
“I
know that some naturalists rely a lot on the thousands of centuries
that they pile up with a stroke of the pen,” Cuvier responded
dismissively. Eventually, he was called upon to compose a eulogy for
Lamarck, which he did very much in the spirit of burying rather than
praising. Lamarck, according to Cuvier, was a fantasist. Like the
“enchanted palaces of our old romances,” his theories were built on
“imaginary foundations,” so that, while they might “amuse the
imagination of a poet,” they could not “for a moment bear the
examination of anyone who has dissected a hand, a viscus, or even a
feather.”
Having dismissed
transformisme, Cuvier was left with a gaping hole.
He had no account of how new organisms could appear, or any explanation
for how the world could have come to be populated by different groups
of animals at different times. This doesn’t seem to have bothered him.
His interest, after all, was not in the origin of species but in their
demise.
The
very first time he spoke about the subject, Cuvier intimated that he
knew the driving force behind extinction, if not the exact mechanism. In
his lecture on elephants, he proposed that the mastodon, the mammoth,
and the Megatherium had all been wiped out “by some kind of
catastrophe.” Cuvier hesitated to speculate about the precise nature of
the calamity—“It is not for us to involve ourselves in the vast field of
conjectures that these questions open up”—but, at that point, he seems
to have believed that one disaster would have sufficed.
Later, as
his list of extinct species grew, his position changed. There had, he
decided, been multiple cataclysms. “Life on earth has often been
disturbed by terrible events,” he wrote. “Living organisms without
number have been the victims of these catastrophes.”
Like his view of
transformisme,
Cuvier’s belief in cataclysm fit with—indeed, could be said to follow
from—his convictions about anatomy. Since animals were functional units,
ideally suited to their circumstances, there was no reason, in the
ordinary course of events, that they should die out. Not even the most
devastating events known to occur in the contemporary world—volcanic
eruptions, say, or forest fires—were sufficient to explain extinction;
confronted with such changes, organisms simply moved on and survived.
The changes that had caused extinctions must therefore have been of a
much greater magnitude—so great that animals had been unable to cope
with them. That such extreme events had never been observed by him or
any other naturalist was another indication of nature’s mutability: in
the past, it had operated differently—more intensely and more
savagely—than it did at present.
“The thread of operations is
broken,” Cuvier wrote. “Nature has changed course, and none of the
agents she employs today would have been sufficient to produce her
former works.” Cuvier spent several years studying the rock formations
around Paris—together with a mineralogist friend, he produced the first
stratigraphic map of the Paris Basin—and here, too, he saw signs of
cataclysmic change. The rocks showed that, at various points, the region
had been submerged. The shifts from one environment to another—from
marine to terrestrial, or, at some points, from marine to
freshwater—had, Cuvier decided, “not been slow at all”; rather, they had
been brought about by those sudden “revolutions” on the surface of the
earth. The latest of these revolutions must have occurred relatively
recently, for traces of it were still everywhere apparent. This event,
Cuvier believed, lay just beyond the edge of recorded history; he
observed that many ancient myths and texts, including the Old Testament,
allude to some sort of crisis—usually a deluge—that preceded the
present order.
Cuvier’s ideas about a globe wracked periodically
by cataclysm proved to be nearly as influential as his original
discoveries. His major essay on the subject, which was published in
Paris in 1812, was almost immediately reprinted in English and exported
to America. It also appeared in German, Swedish, Italian, and Russian.
But a good deal was lost, or, at least, misinterpreted in translation.
Cuvier’s essay was pointedly secular. He cited the Bible as merely one
of many ancient texts, alongside the Hindu Vedas and the Shujing. This
sort of ecumenism was unacceptable to the Anglican clergy who made up
the faculty at institutions like Oxford, and when the essay was
translated into English it was construed by Buckland and others as
offering proof of Noah’s flood.
By now, the empirical grounds of
Cuvier’s theory have largely been disproved. The physical evidence that
convinced him of a “revolution” just prior to recorded history (and that
the English interpreted as proof of the Deluge) was in reality debris
left behind by the last glaciation. The stratigraphy of the Paris Basin
reflects not sudden “irruptions” of water but, rather, gradual changes
in sea level and the effects of plate tectonics. On all these matters,
Cuvier was, we now know, wrong.
Yet his wildest-sounding claims
have turned out to be surprisingly accurate. Cataclysms happen. Nature
does, on occasion, “change course,” and at such moments it is as if the
“thread of operations” has been broken. The contemporary term for these
cataclysms is “mass extinctions,” and the geological record suggests
that, in the past half billion years, there have been five major ones
and a dozen or more lesser ones. In the most severe of the so-called Big
Five, at the end of the Permian period, some two hundred and fifty
million years ago, something like ninety per cent of all species died
off, and multicellular life came perilously close to being obliterated
altogether. In the most recent, at the end of the Cretaceous, the
dinosaurs were wiped out, along with the mosasaurs, the pterosaurs, the
plesiosaurs, the ammonites, and two-thirds of all families of mammals,
all in what, geologically speaking, amounted to an instant.
Meanwhile,
as far as the American mastodon is concerned, Cuvier was to an almost
uncanny extent correct. He decided that the beast had disappeared five
or six thousand years ago, in the same “revolution” that had killed off
the mammoth and the Megatherium. Actually, the American mastodon
vanished
around thirteen thousand
years ago, in a wave of disappearances that has become known as the
megafauna extinction. This wave coincided with the spread of modern
humans, and, increasingly, is understood to have been a result of it.
Humans are now so rapidly transforming the planet—changing the
atmosphere, altering the chemistry of the oceans, reshuffling the
biosphere—that many scientists argue that we’ve entered a whole new
geological epoch: the Anthropocene. In this sense, the crisis that
Cuvier discerned just beyond the edge of recorded history was us. ♦
(This is the first part of a two-part article.)
