The Human Age (20 page)
No clouds of starlings pepper the sky before turning on a knife-edge and circling round. The overuse of pesticides has silenced the wildlife they feed on, and now great flocks and swarms and slithers of animals have vanished. Ironically, as a result
of crops blanketing 70 percent of the United Kingdom’s land, more biodiversity has begun haunting the cities. Friends tell me London is askitter with red foxes.
I’m struck by the uniform, yielding, furrowed richness of the miles. Single crops parade past the window, along with clans of cattle and sheep. The same monotony of genes rules much of the planet, as wild and varied habitats give way to more prosperous if homogenous big farms. In the United States alone, twenty thousand square miles of land are covered by corn—an area twice the size of Massachusetts. We’re dabbling in eugenics all the time, breeding ideal crops to replace less aesthetic or nutritious or more perishable varieties, leveling forests to graze cattle or erect shopping malls and condos, planting groves of a few familiar trees homeowners and industries prefer. In the process, there’s the gradual eradication of genes, without fanfare, sometimes even driven by good motives.
We’re at a dangerous age in our evolution as a species: clever, headstrong, impulsive, and far better at tampering with nature than understanding it. Who knows what vanishing life forms—and their DNA—we may one day regret losing? Pollen from this sameness of crops will show up in the fossil record as a curiosity of our age; examining it, Olivine will wonder why we wiped out a beneficial smorgasbord of plants in favor of a few genetically modified, fruitless varieties. Will she guess that most of these were bred in the fields of avarice (forcing farmers to keep buying a company’s seeds)?
We’re in the midst of the planet’s sixth great extinction, losing between seventeen thousand and one hundred thousand species a year. It’s hypothesized that what caused the first great extinction, 440 million years ago, was radiation from the collapse of a massive supernova. During the second extinction, 245 million years ago, a possible meteor strike combined with volcanic eruptions killed off so many ocean species that coral reefs vanished for 10 million years. About 210 million years ago, some catastrophic event wiped out more than half of all life forms. The extinction that ravaged the planet 65 million years ago polished off the dinosaurs, sent temperatures soaring by nearly 60°F, and pushed sea levels up more than nine hundred feet. Today’s extinction event, the first during our reign, could end up being the most catastrophic of all. Many scientists predict that, at the pace we’re going, about half of all the world’s plants and animals will vanish by 2100. But, for a change, we know the exact causes of the extinction, having created them ourselves—climate change, habitat loss, pollution, invasive species, big agriculture, acidifying the oceans, urbanization, a growing population demanding more natural resources—and we’re in a position to stop them, if we set our collective mind to it.
So, as species dematerialize around us, worldwide efforts are under way to collect and protect the DNA of as many as possible before it’s too late. Two brave doomsday efforts have been leading the way. One is the Svalbard Global Seed Vault, a remote and heavily guarded underground cavern tucked four hundred feet inside a sandstone mountain on the Norwegian island of Spitsbergen, in the secluded Svalbard archipelago, which lies about eight hundred miles from the North Pole—a James Bond destination safe from both man-made
and natural disasters, even melting ice caps (it’s 430 feet above sea level), tectonic activity, or nuclear war.
In some climate scenarios, due to crop shrivel and shortage of fresh water, food becomes scarce. The vault’s mission is to preserve seed diversity, because one never knows what calamity might descend, which crops might fail, and what seeds—whether heirloom or genetically engineered—might offer a solution in the Anthropocene world. The key may be a relic from a bygone era. As Paula Bramel, assistant executive director of the seed vault, explains: “The environment is changing to the point where farmers can no longer maintain the seeds of the varieties that they always used. And that’s really a loss to everybody because that variety may have a trait that’s really critical in the future.”
If those seeds aren’t cached now, they won’t sprout later. Bramel points out this is a particular problem in Africa. We’ve abandoned many heirloom crops because they’re not as cheap to grow in our technological Valhalla, or as blemish-free as we demand. Some are no longer as hardy in our changing climes. We may one day wish we still had them. The vault is the Norwegian government’s farsighted gift to the world; there’s no charge to countries for storing, cataloging, and overseeing millions of backup seeds, which, for the most part, sleep at -0.4°F, in refrigeration naturally provided by the permafrost. Every decade or so, some of the Sleeping Beauty seeds must be awakened and allowed to bloom so that fresh seeds can be collected. Of course, in the best possible future, if such a state of grace exists, they won’t be needed. In the meantime, as a fail-safe treasury, the vault houses millions of specimens of over four thousand different species.
The second doomsday effort lives on the campus of Nottingham University, in the Frozen Ark, which stores the DNA of 48,000 individuals from 5,438 different animal species. It’s Noah’s Ark moored in Robin Hood’s backyard, and its logo is a blue sketch of an ark sailing on a double helix of ocean waves.
B
ryan loved snails, though not all snails equally. He was especially fascinated by one turban-shaped gastropod in the genus
Partula
. Among partulas, he had a thing for the species
Partula mooreana
. Just like Darwin’s finches, drifting colonies of partulas on tiny islands became cut off from their neighbors and rapidly diversified to a surprising degree in color, size, and shell motifs. Free of natural predators—except the Polynesians who strung ceremonial necklaces from their shells—the snails hoovered up algae on the undersides of caladium, plantain, dracaenas, turmeric, and other leaves in the understory of heavily forested volcanic slopes.
In Bryan’s pale-blue office, I’d seen an old book on his desk, opened to favorite pages of colorful plates. Some of the shells were straw yellow and girdled by two or three narrow reddish-chestnut bands, others light-brown-capped with darker whorls, or cream and purple. Despite their different patterns and hues, they were all partulas. Beside it, several snail-shell necklaces lay in casual loops of pink, brown, tan, and gray. Each tiny shell had been carefully matched for colors and size, and what makes this remarkable is that, according to Bryan, even in one valley shell patterns can vary about every
twenty yards. It was disturbing to see the remnants of so many tiny lives ghosting across his desk, their sticky inhabitants long extinct. Their spiraling interiors belong in a church designed by Gaudí; their eye-catching shells remain to delight and haunt us. But their empty beauty tugs at the mind.
Once, a hundred or so species of partulas inhabited French Polynesia, where the shells of the most attractive species, brown-and-green-striped, were prized. They bore such incantatory names as
Partula dolorosa
,
Partula mirabilis
,
Partula solitaria
, and
Partula diaphana
. In the 1880s an enterprising French customs officer, who enjoyed the taste of snails, decided to start a snail farm and flog snails to islanders. The snails he chose to breed were the plump, succulent giant African snail
Achatina fulica
. When his snails didn’t catch on as cuisine, he tossed them into the wild, where they began raiding the local crops and gardens and hitching rides to other islands. Faced with heavy crop damage, U.S. authorities on Guam introduced a particularly voracious predator, the carnivorous Florida rosy wolfsnail,
Euglandina rosea
, into one orange plantation in 1977. But even snails can be picky eaters, and unfortunately the rosy wolfsnail didn’t find giant African snails tasty. Instead it dashed into the adjoining forests, where it hunted down and feasted on the partulas, which for some reason it fancied. Online one can watch ghoulish footage of the carnivores at work, plunging into the shells of small, helpless partulas and gulping them down in mouthfuls with cannibalistic gusto. Ten years later, these rosy wolfsnails commanded the whole island and had devoured fifty species of partulas. Yet another tragic tale of invasive species (and human intervention) gone awry.
Volcanic archipelagos offer natural laboratories for studying how species evolve and reinvent themselves, and so, in the 1990s, Bryan Clarke, his wife, Ann, and their lab assistant, Chris Wade, traveled to French Polynesia to study the partulas. As it happens, I was there at almost exactly the same time; though I was not in pursuit of snails, I know the tapestry of sensations they would have worked among:
The spicy sweet smell of scorched sandalwood wafting through the air. Six-man outriggers pulling swiftly past, each with a piece of tusk-shaped wood tied to one side for balance. Dogs sleeping under overturned outriggers in a budget of shade. The sky everywhere full of seabirds, and on land pairs of fairy terns perching like small white angels among the tree limbs while balancing their single egg on a branch. Men heavily tattooed, women swaying as they sang traditional songs filled with baying and keening. Small houses lining the village roads. Here and there, in the foothills, house lights sparkling from the foliage, and beyond them, raincloud-wrapped mountains steaming like volcanoes. Elaborate designs everywhere one looked—on church stones, wooden carvings, and bark cloth—curving like vines and whorling like snail shells, worlds within worlds. It was as if the native artisans had looked through microscopes into the heart of cells.
As a tantrum of sun flashed across the cobalt-blue sea, they boarded a long red-and-white ferry, lashed to the dock by four thick ropes like a wild animal that might otherwise escape, and traveled among small islands with hillsides of bottle green and slate cliffs plunging straight into the sea. It was in this remote spell of thick foliage, light-years from the clipped lawns of England, that they desperately searched for the tiny, rare, beautifully ribboned tree snails.
They found a handful of live partulas on the island of Moorea, but Bryan had a hunch that the ancestor of all 126 partula species might live on the lone island of ’Eua, about two and a half hours from Tonga. Thirty or forty million years older than the other islands, ’Eua isn’t volcanic but a flat chunk of Gondwanaland shelf that broke off and plunked itself next to Tonga. Would they find there the ur-snails that populated all of the Pacific islands?
When they arrived, they discovered to their dismay that the ’Eua islanders had chopped down all of the rainforest in order to plant farms of manioc. Partula’s habitat was gone. Only one faint possibility remained. At the very bottom of ’Eua’s steep ravines, a thin line of trees nestled beside streams. Islanders didn’t risk the climb, and
neither did Bryan, but Ann and Chris had come too far to turn back. Pressing on, they slogged down the gorges into the island’s deep green pockets. After three weeks of scouring the plateau, beaches, and the last shreds of rainforest on the island, all they found was one midden of empty shells in a stream at the bottom of a crevasse. Picking up the small, round shells, and turning them gently like ancient coins, they realized that they were about twenty years too late, since snail shells last only twenty years in the wild. Grief-stricken, they held the remains of an extinction in their hands.
According to Ann, the combined loss felt too heavy to bear. Carefully packing a few of the live
Partula mooreana
they’d found into lunch boxes, they journeyed home to Nottingham. Most of these snails they shared with the London Zoo, which set up a captive breeding program, and Bryan and Ann began breeding the rest, aided by a technician who was a genius at caring for partulas and getting them to have babies. Unusually, even for snails, partulas don’t lay eggs, but have live babies, complete with shells on.
“Here’s a partula with young,” Ann says, opening a book to the startling image of a snail with a perfectly formed second snail emerging from behind its head (where the reproductive organs hide). “These get born just like that.”
“With a soft shell, surely.”
“No, with a
hard
shell. They’re born as complete adult snails.”
Curiouser and curiouser
, I think. The tiny necklace-worthy striped snails that haunted the trees in the kingdom of Tonga sprang from the sides of both hermaphroditic parents fully formed with (surely this birthing might hurt?) hard calcium shells. Not to mention, during courtship they stab each other in the head with calcium “love darts” pulled from their quiver.
Aghast at the pace of Partula’s extinction, a handful of zoos worldwide also began breeding the snails with some success, from a fenced-in partula preserve on Tahiti to the Snail Room at the London Zoo, where one can see them, small as a fingernail, slow-motion slime-skiing along the glass with their nether parts exposed.
But there’s no use releasing them back into the wild while hungry packs of rosy wolfsnails still rampage.
“When we came back with the partulas in lunch boxes we were very despondent,” Ann says wistfully, “and I think it was at that very moment Bryan and I thought of the Frozen Ark. Because we’d seen all these partulas dying out. We thought, well, we’re doing this for the snails, who else is doing it for other endangered species? We started to hunt about and we really couldn’t find anyone.”
The Clarkes set up the Frozen Ark Project in 1996 as a response to this crisis, with a single simple objective—to save samples of frozen cells containing DNA from endangered animals before they go extinct. Not as an alternative to preserving animals in their natural environments or to keeping them in zoos, she stresses, but as crucially important extra insurance.
Today a consortium of twenty-two of the world’s finest zoos, aquariums, museums, and research institutions have climbed aboard the Ark and are providing DNA. Only a tiny dab is needed, gathered painlessly from mouth swabs, feces, hair, feathers, or blood during routine veterinary visits. The samples are sent to Nottingham, where they’re cataloged and safely frozen, with backups stored at the home zoos. It’s convenient that DNA is thousands of times smaller than a gnat’s whisker; many individuals exist only as wispy smears on small white filter papers. A single-car garage could store a million; a briefcase could hide enough to repopulate a continent. At the Frozen Ark, specimens hover in liquid nitrogen at -196°F, ensuring viable DNA for hundreds of thousands of years, and hundreds of years for complete cells. Nothing moves at -196°F, but in time these cells could be resurrected and recultured.