The World Without Us - Alan Weisman (2007)

Part III

Chapter 16. Our Geologic Record

1. Holes

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NE OF THE largest, and probably longest-lasting, relics of human existence after we’re gone is also one of the youngest. As the gyrfalcon flies, it lies 180 miles northeast of Yellowknife, Northwest Territories, Canada. If you flew over it today, it would be the very round hole half a mile wide and 1,000 feet deep. There are many huge holes here. This is the dry one.

Though, within a century, the rest may be, too. North of the 60th parallel, Canada contains more lakes than the rest of the world combined. Nearly half of Northwest Territories isn’t land at all, but water. Here, ice ages gouged cavities into which icebergs dropped when the glaciers retreated. When they melted, these earthen kettles filled with fossil water, leaving countless mirrors that sequin the tundra. Yet the resemblance to an immense sponge is misleading: because evaporation slows in cold climates, little more precipitation falls here than in the Sahara. Now, as the permafrost thaws around these kettles, glacial water held in place by frozen soil for thousands of years is seeping away.

Should northern Canada’s sponge dry out, that would also be a human legacy. For now, the hole in question and two recent smaller ones nearby comprise Ekati, Canada’s first diamond mine. Since 1998, a parade of 240-ton trucks with 11-foot tires, owned by BHP Billiton Diamonds, Inc., has lugged more than 10,000 tons of ore to a crusher 24 hours a day, 365 days a year, even at —60°F. The daily yield is a handful of gem-quality diamonds, worth well over $1 million.

They’re found in volcanic tubes that formed more than 50 million years ago, when magma bearing pure, crystallized carbon pushed up from deep below the surrounding granite. Even rarer than these diamonds, however, is what fell into the craters left by these lava pipes. This was the Eocene, when today’s lichen-covered tundra was a coniferous forest. The first trees that toppled in must have burned, but as everything cooled, others were buried in fine ash. Sealed away from air, then preserved by cold Arctic dryness, the fir and redwood trunks that diamond miners discovered weren’t even fossilized, but simply wood: intact, 52-million-year-old lignin and cellulose, dating back to when mammals were just expanding into niches vacated by dinosaurs.

One of the oldest mammal species on Earth still lives there, a Pleistocene relic that managed to survive because it was extraordinarily equipped to brave weather that ice-age humans preferred to escape. The chestnut pelage of the musk ox is the warmest organic fiber known, with eight times the insulating factor of sheep’s wool. Known in Inuit as qiviut, it renders musk oxen so impervious to cold that they’re literally invisible to infrared satellite cameras used to track caribou herds. Yet qiviut was nearly their downfall in the early 20th century, when they were all but exterminated by hunters who sold their hides in Europe for carriage robes.

Today, the few thousand that remain are protected, and the only legally harvested wild qiviut comes from wisps found clinging to tundra vegetation, a laborious undertaking that contributes to the $400 price a sweater made from ultrasoft musk ox fleece can command. If the Arctic becomes progressively balmier, however, qiviut may again be this species’ undoing—although, if humans (or at least their noisy carbon emitters) vanished, the musk ox might still get a break from the heat.

If too much of the permafrost itself is undone, it would thaw deeply buried ice that forms crystalline cages around methane molecules. An estimated 400 billion tons of these frozen methane deposits, known as clathrates, lie a few thousand feet beneath the tundra, and even more are found beneath the world’s oceans. All that very-deep-freeze natural gas, estimated to at least equal all known conventional gas and oil reserves, is both enticing and frightening. Because it’s so dispersed, no one has come up with an economical way to mine it. Because there’s so much of it, if it all floats away once the ice cages melt, that much methane might ratchet global warming to levels unknown since the Permian extinction, 250 million years ago.

For now, until something cheaper and cleaner comes along, the only other still-abundant source of fossil fuel we can count on will leave an even bigger signature on the surface than a mere open-pit diamond mine—or copper, iron, or uranium mines, for that matter. Long after those fill with water or with their own windblown tailings, this one is good to endure a few more million years.

2. Heights

“It can only be appreciated—if that’s the word—from above,” says Susan Lapis, a cheerful redheaded pilot who volunteers for the North Carolina-based nonprofit organization SouthWings. From the window of her single-engine, red, white, and blue Cessna 182, you look down at a world sliced as flat as any mile-high ice sheet ever managed. Only this time, the glacier was us, and the world was once West Virginia.

Or Virginia, Kentucky, or Tennessee, because several million acres of Appalachia in all those states now look identically amputated, sheared away by coal companies that, in the 1970s, discovered a trick cheaper than tunneling or even strip-mining: just pulverize the entire top third of a mountain, sluice out the coal with a few million gallons of water, push what’s left over the side, and blast again.

Not even the Amazon laid bare rivals the shock of this planar void. In every direction, it’s simply gone. Grids of white dots—the next round of dynamite charges—provide the only remaining texture on naked plateaus that were once vertical, verdant heights. Demand for coal has been so ferocious—100 tons extracted every two seconds—that often there hasn’t even been time to log here: oaks, hickories, magnolias, and black cherry hardwoods have been bulldozed into the hollows, to be buried by a former Allegheny mountain of rubble—“the overburden.”

In West Virginia alone, 1,000 miles of streams flowing through those hollows have been buried as well. Water finds a way, of course, but as it pushes through tailings for the next several thousand years, it will emerge with more than the normal concentration of heavy metals. Yet even given projected world energy demand, industry geologists—and industry opponents—believe that deposits in the United States, China, and Australia contain about 600 years’ worth of coal. By mining this way, they can get at much more of it, much faster.

Mountaintop removal, West Virginia.

PHOTO BY V. STOCKMAN, OVEC/SOUTHWINGS.

If energy-drunk humans were gone tomorrow, all that coal would remain in the ground until the end of time on Earth. If we’re around at least a few more decades, however, a lot of it won’t, because we’ll dig it up and burn it. But if an unlikely plan goes extremely well, one of coal power’s most problematic by-products may end up sealed away once more beneath the surface, creating yet another human legacy to the far future.

The by-product is carbon dioxide, which a burgeoning consensus of humanity agrees probably should not be stored in the atmosphere. The plan, which is attracting growing attention—especially from industry boosters of an oxymoron born of recombinant public relations: “clean coal”—is to capture CO2 before it leaves the smokestack of coal-fired electrical plants, stuff it underground, and keep it there. Forever.

It would work like this: Pressurized CO2 would be injected into saline aquifers that, in much of the world, lie under impermeable caprock at depths of 1,000 to 8,000 feet. There, supposedly, the CO2 would go into solution, forming mild carbonic acid—like salty Perrier. Gradually, the carbonic acid would react with surrounding rocks, which would dissolve and slowly precipitate out as dolomite and limestone, locking the greenhouse gas in stone.

Each year since 1996, Norway’s Statoil has sequestered 1 million tons of carbon dioxide in a saline formation under the North Sea. In Alberta, CO2 is being sequestered in abandoned gas wells. Back in the 1970s, then federal attorney David Hawkins joined in discussions with semioticians about how people 10,000 years hence might be alerted to buried nuclear wastes at what today is New Mexico’s WIPP site. Now, as director of the Climate Center of the Natural Resources Defense Council, he contemplates how to tell the future not to drill into sequestered reservoirs of invisible gases we might sweep under the rug, lest they unexpectedly burp to the surface.

Aside from the expense of drilling enough holes to capture, pressurize, and inject the CO2 from every industrial and power plant on Earth, a big concern is that hard-to-detect leaks of even  of 1 percent would eventually add up to the amount we’re pumping into the air today—and the future wouldn’t realize it. But given the choice, Hawkins would rather try containing carbon than plutonium.

“We know that nature can engineer leak-free gas storage: there’s been methane trapped for millions of years. The question is, can humans?”

3. Archaeological Interlude

We tear down mountains, and unwittingly build hills.

Forty minutes northeast of the city of Flores on northern Guatemala’s Lake Petén Ixta, a paved tourist road arrives at the ruins of Tikal, the largest Classic Mayan site, its white temples rising 230 feet above the jungle floor.

In the opposite direction, until recent improvements halved travel time, the rutted road southwest from Flores took three miserable hours, ending at the scruffy outpost of Sayaxché, where an army machine gun placement perched atop a Mayan pyramid.

Sayaxché is on the Río Pasión—the Passion River—which lolls through the western Petén province to the confluence of the rivers Usamacinta and Salinas, together forming Guatemala’s border with Mexico. The Pasión was once a major trade route for jade, fine pottery, quetzal feathers, and jaguar skins. More recently, commerce includes contraband mahogany and cedar logs, opium from Guatemalan highland poppies, and looted Mayan artifacts. During the early 1990s, motor-driven wooden launches on a sluggish Pasión tributary, the Riochuelo Petexbatún, also carried quantities of two modest items that in the Petén are veritable luxuries: corrugated zinc roofing and cases of Spam.

Both were destined for the base camp that Vanderbilt University’s Arthur Demarest built in a jungle clearing out of mahogany planks for one of the biggest archaeological excavations in history, to solve one of our biggest mysteries: the disappearance of Mayan civilization.

How can we even contemplate a world without us? Fantasies of space aliens with death rays are, well, fantasies. To imagine our big, overwhelming civilization really ending—and ending up forgotten under layers of dirt and earthworms—is as hard for us as picturing the edge of the universe.

The Maya, however, were real. Their world had seemed destined to thrive forever, and, at its zenith, it was far more entrenched than ours. For at least 1,600 years, about 6 million Maya lived in what in some ways resembled southern California—a flourishing megalopolis of city-states, with few breaks between overlapping suburbs across a lowland that today comprises northern Guatemala, Belize, and Mexico’s Yucatan Peninsula. Their commanding architecture, and their astronomy, mathematics, and literature, would have humbled the achievements of contemporaries in Europe. Equally striking, and far less understood, is how so many could inhabit a tropical rain forest. For centuries, they raised their food and families in the same fragile environment that today is quickly being devastated by relatively few hungry squatters.

What has baffled archaeologists even more, however, is the Maya’s spectacular, sudden collapse. Beginning in the eighth century AD, within just 100 years lowland Mayan civilization vanished. In most of the Yucatan, only scattered remnants of the population remained. Northern Guatemala’s Petén province was virtually a world without people. Rainforest vegetation soon overran the ball courts and plazas, enshrouding tall pyramids. Not for 1,000 years would the world again be aware of their existence.

But the Earth holds ghosts, even of entire nations. Archaeologist Arthur Demarest, a stocky, thick-moustached Louisiana Cajun, declined a Harvard chair because Vanderbilt offered him a chance to exhume this one. During his graduate fieldwork in El Salvador, Demarest raced to salvage a bit of the ancient record from a forthcoming dam that displaced thousands, converting many of them to guerrillas. When three of his workers were accused of being terrorists, he pleaded to officials who let them go, but they were assassinated anyway.

In his first years in Guatemala, guerrillas and the army stalked each other within a few kilometers of his digs, catching in their crossfire people who still speak languages derived from the hieroglyphics his team was decoding.

“Indiana Jones swashbuckled through a mythical, generic Third World of swarthy people with threatening, incomprehensible ways, defeating them with American heroics and seizing their treasures,” he says, mopping his thick black hair. “He would have lasted five seconds here. Archaeology isn’t about glittery objects—it’s about their context. We’re part of the context. It’s our workers whose fields are burning, it’s their children who have malaria. We come to study ancient civilization, but we end up learning about now.”

By Coleman lantern, he writes through the humid night to the rumble of howler monkeys, piecing together how, over nearly two millennia, the Maya evolved a means of resolving discord between nations without destroying each other’s societies in the process. But then something went wrong. Famine, drought, epidemics, overpopulation, and environmental plunder have been blamed for the Maya’s downfall—yet for each, arguments exist against liquidation on such a massive scale. No relics reveal an alien invasion. Often extolled as an exemplary stable and peaceable people, the Maya seemed least likely to overreach and be devoured by their own greed.

However, in the steamy Petén, it appears that is exactly what happened—and that the path to their catastrophe seems familiar.

_________

The trek from the Riochuelo Petexbatún to Dos Pilas, the first of seven major sites that Demarest’s team uncovered, passes for hours through mosquito-rich stretches of strangler vines and palmilla thickets, then finally climbs a steep escarpment. In remaining groves still unplundered by timber poachers, giant cedars, ceibas, chicle-bearing sapodillas, mahoganies, and breadnut trees rise from the thin tropical soils capping the Petén limestone. Along the escarpment’s ragged edge, the Maya built cities that Arthur Demarest’s archaeologists have determined once formed an interlocking kingdom called Petexbatún. Today, what appear to be hills and ridges are actually pyramids and walls, built from chunks of local limestone hewn with chert adzes, now disguised by soil and a mature rain forest.

The jungle surrounding Dos Pilas, filled with clacking toucans and parrots, was so dense that after it was discovered in the 1950s, 17 years passed before anyone noticed that a nearby hill was actually a 220-foot pyramid. In fact, to the Maya, pyramids re-created mountains, and their carved monoliths, called stelae, were stone representations of trees. The dot-and-bar code glyphs carved into the stelae unearthed around Dos Pilas tell that, about AD 700, its k’uhul ajaw—divine lord—began to break the rules of restrained conflict and started usurping neighboring Petexbatún city-states.

A mossy stela shows him in full headdress, holding a shield, standing on the back of a bound human captive. Before society began unraveling, Classic Mayan wars were often keyed to astrological cycles, and at first impression they might seem singularly grisly. A male of an opposing royal family would be captured and paraded in humiliation, sometimes for years. Eventually, his heart would be ripped out, or he would be decapitated, or tortured to death—at Dos Pilas, one victim was tightly rolled and bound, and then used for a game on the ceremonial ball court until his back was broken.

“And yet,” Demarest notes, “there was relatively no societal trauma, no destruction of fields or buildings, or territories taken. The cost of Classic Mayan ritual war was minimal. It was a way of maintaining peace through constant, low-grade warfare that released tensions between leaders without endangering the landscape.”

The landscape was a working equilibrium between wilderness and artifice. On hillsides, Mayan walls of tightly packed cobbles trapped rich humus from runoff water for cultivation terraces, now lost beneath a millennium of alluvium. Along lakes and rivers, Mayas dug ditches to drain swamps, and by heaping the soil they removed, they created fertile raised fields. Mostly, though, they mimicked the rain forest, providing layered shade for diverse crops. Rows of corn and beans would shelter a ground cover of melons and squash; fruit trees, in turn, shielded them, and protective patches of the forest itself would be left among fields. Partly, it was a happy accident: without chain saws, they had to leave the biggest trees.

That is exactly what hasn’t happened in nearby modern squatter villages, along logging roads where flatbed trailers carry away cedar and mahogany. The settlers, Mayan-Kekchi-speaking refugees from the highlands, fled counterinsurgency attacks that killed thousands of Guatemalan peasants during the 1980s. Because slash-and-burn rotations used in volcanic mountains prove calamitous in rain forests, these people were soon surrounded by expanding wastelands yielding only stunted ears of maize. To keep them from looting all his sites, Demarest budgets for doctors and jobs for locals.

The Maya’s political and agricultural system functioned for centuries throughout the lowlands, until it began to break down at Dos Pilas. During the eighth century, new stelae began appearing, with the creative flair of individual sculptors supplanted by uniform, military social realism. Gaudy hieroglyphics incised on each tier of an elaborate temple staircase record victories over Tikal and other centers, whose glyphs were replaced by those of Dos Pilas. For the first time, land was being conquered.

Strategically parlaying alliances with other rival Mayan city-states, Dos Pilas metastasized into an aggressive international power whose influence advanced up the Río Pasión’s valley to today’s Mexican border. Its artisans planted stelae portraying a Dos Pilas k’uhul ajaw resplendent in jaguar-skin boots, with a naked, vanquished king crushed under his feet. Dos Pilas’s rulers amassed fabulous wealth. In caves where no human had been for 1,000 years, Demarest and his colleagues found where they hoarded hundreds of ornate polychromed pots containing jade, flint, and the remains of sacrificed humans. In tombs the archaeologists exhumed, royalty were buried with their mouths full of jade.

By AD 760, the domain they and their allies controlled encompassed more than three times a normal Classic Mayan kingdom. But they now barricaded their cities with palisades, spending much of their reign behind walls. A remarkable discovery bears witness to the end of Dos Pilas itself. Following an unexpected defeat, no more self-aggrandizing monuments were built. Instead, peasants who lived in concentric rings of fields around the city fled their houses, erecting a squatters’ village in the middle of the ceremonial plaza. The degree of their panic is preserved in the bulwark they threw up around their compound, made from facing materials ripped from a k’uhul ajaw’s tomb and from the principal palace, whose corbeled temple was demolished and added to the rubble. It was the equivalent of tearing down the Washington Monument and Lincoln Memorial to fortify a tent city on the Capitol Mall. The desecration heightened as the wall ran right over the top of structures, including the triumphant hieroglyphic staircase.

Had these crude placements possibly occurred much later? That question was answered by the facing stones they found in direct contact with the stairs, with no intervening soil. The citizens of Dos Pilas, either beyond reverence for, or thoroughly outraged by, the memory of their greedy former rulers, did this themselves. They buried the magnificent carved hieroglyphic staircase so deeply that no one knew it existed until a Vanderbilt graduate student uncovered it 1,200 years later.

Did mounting population exhaust the land, tempting Petexbatún rulers to seize their neighbors’ property, leading to a cycle of response that spiraled into cataclysmic war? If anything, Demarest believes, it was the other way around: An unleashed lust for wealth and power turned them into aggressors, resulting in reprisals that required their cities to abandon vulnerable outlying fields and intensify production closer to home, eventually pushing land beyond its tolerance.

“Society had evolved too many elites, all demanding exotic baubles.” He describes a culture wobbling under the weight of an excess of nobles, all needing quetzal feathers, jade, obsidian, fine chert, custom polychrome, fancy corbeled roofs, and animal furs. Nobility is expensive, nonproductive, and parasitic, siphoning away too much of society’s energy to satisfy its frivolous cravings.

“Too many heirs wanted thrones, or needed some ritual bloodletting to confirm their stature. So dynastic warfare heightened.” As more temples need building, the higher caloric demand on workers requires more food production, he explains. Population rises to insure enough food-producers. War itself often increases population—as it did in the Aztec, Incan, and Chinese empires—because rulers require cannon fodder.

Stakes rise, trade is disrupted, and population concentrates—lethal in a rain forest. There is dwindling investment in long-term crops that maintain diversity. Refugees living behind defensive walls farm only adjacent areas, inviting ecological disaster. Their confidence in leaders who once seemed all-knowing, but are obsessed with selfish, short-term goals, declines with the quality of life. People lose faith. Ritual activity ceases. They abandon centers.

A ruin at nearby Lake Petexbatún, on a peninsula called Punta de Chimino, turned out to be the fortress city of the last Dos Pilas k’uhul ajaw. The peninsula had been severed from the mainland by three moats, one cutting so deeply into bedrock that approximately three times the energy required to build the city itself was expended to dig it. “That’s the equivalent,” Demarest observes, “of spending 75 percent of a nation’s budget on defense.”

It was a desperate society that had lost control. The spear points the archaeologists discovered embedded in the fortress walls—including on the inside—testify to the fate of whoever ended up cornered on Punta de Chimino. Its monuments were soon eaten by the forest: in a world relieved of its humans, man’s attempts to make his own mountains quickly melt back into the ground.

“When you examine societies just as self-confident as ours that unraveled and were eventually swallowed by the jungle,” says Arthur Demarest, “you see that the balance between ecology and society is exquisitely delicate. If something throws that off, it all can end.”

He stoops, picks up a sherd from the moist ground. “Two thousand years later, someone will be squinting over the fragments, trying to find out what went wrong.”

4. Metamorphosis

From a wooden crate on the floor of his office at the Smithsonian’s National Museum of Natural History, paleobiology curator Doug Erwin pulls an eight-inch chunk of limestone he found in a phosphate mine between Nanjing and Shanghai, south of China’s Yangtze River. He shows the blackish bottom half, replete with fossilized protozoa, plankton, univalves, bivalves, cephalopods, and corals. “Life here was good.” He points to the faint whitish line of ash that separates it from the dull gray upper half. “Life here got really bad.” He shrugs.

“It then took a long time for life to get better.”

It took dozens of Chinese paleontologists 20 years of examining such rocks to determine that the faint white line represents the Permian Extinction. By analyzing zircon crystals infused in tiny glassy and metallic globules embedded in it, Erwin and MIT geologist Sam Bowring precisely dated that line to 252 million years ago. The black limestone lying below it is a frozen snapshot of the rich coastal life that had surrounded a single giant continent filled with trees, crawling and flying insects, amphibians, and early carnivorous reptiles.

“Then,” says Erwin, nodding, “95 percent of everything alive on the planet was wiped out. It was actually a thoroughly good idea.”

Sandy-haired Doug Erwin looks improbably boyish for so distinguished a scientist. When he dismisses life-on-Earth’s closest brush with total annihilation, however, his smile isn’t flippant but thoughtful—the result of decades of poring over West Texas mountains, old Chinese quarries, and ravines in Namibia and South Africa to puzzle out what exactly happened. He still doesn’t know for sure. A million-year-long volcanic eruption through enormous coal deposits in Siberia (then part of Pangea, the single supercontinent) flooded the land with so much basalt magma— in places, it was more than three miles thick—that CO2from vaporized coal may have glutted the atmosphere and sulfuric acid may have rained from the skies. The coup de grâce may have been an asteroid even bigger than the one that did in the dinosaurs much later; it apparently collided with the piece of Pangea we now call Antarctica.

Whatever it was, over the next few million years, the most common vertebrate was a microscopic-toothed worm. Even insects suffered a mass collapse. This was a good idea?

“Sure. It made way for the Mesozoic Era. The Paleozoic had been around for nearly 400 million years. It was fine, but it was time to try something new.”

Following the Permian’s fiery end, the few survivors had little competition. One of them, a half-dollar-sized, scalloplike clam called claraia, became so abundant that its fossils today literally pave rocks in China, southern Utah, and northern Italy. But within 4 million years, they and most other bivalves and snails that boomed after the mass extinction died out themselves. They were victims of more mobile opportunists such as crabs, who’d had minor roles in the old ecosystem, but suddenly—at least by the geologic clock—had a chance at creating new niches in a fresh new system. All it took was evolving a claw to crack open mollusks that couldn’t flee.

The world took off in a different direction—one characterized by active predators—that went from near nothingness to the lush kingdom of dinosaurs. While that was happening, the supercontinent split into pieces that gradually dispersed around the globe. When, after 150 million more years, that other asteroid hit what is now Mexico’s Yucatan Peninsula, and dinosaurs proved too big to hide or adapt, it was time to start over yet again. This time, another agile minor character, a vertebrate called Mammalia, saw a chance to make its move.

Might the current explosion of extinctions—invariably pointing to a sole cause, and not an asteroid this time—suggest that a certain dominant mammal’s turn may be coming to an end? Is geologic history striking again? Doug Erwin, the extinction expert, works on such a vast timescale that the few million years of our Homo species’ life span is almost too short for him to contemplate. Again, he shrugs.

“Humans are going extinct eventually. Everything has, so far. It’s like death: there’s no reason to think we’re any different. But life will continue. It may be microbial life at first. Or centipedes running around. Then life will get better and go on, whether we’re here or not. I figure it’s interesting to be here now,” he says. “I’m not going to get all upset about it.”

If humans do stick around, University of Washington paleontologist Peter Ward predicts that agricultural land will become the biggest habitat on Earth. The future world, he believes, will be dominated by whatever evolves from the handful of plants and animals we’ve domesticated for food, work, raw materials, and companionship.

But if humans were to go tomorrow, enough wild predators currently remain to out-compete or gobble most of our domestic animals, though a few feral exceptions have proved impressively resilient. The escaped wild horses and burros of the American Great Basin and Sonoran Desert essentially have replaced equine species lost at the end of the Pleistocene. Dingoes, which polished off Australia’s last marsupial carnivores, have been that country’s top predator for so long that many down under don’t realize that these canines were originally companions to Southeast Asian traders.

With no large predators around other than descendants of pet dogs, cows and pigs will probably own Hawaii. Elsewhere, dogs may even help livestock survive: sheep ranchers in Tierra del Fuego often swear that the shepherding instinct is so deeply bred in their kelpie dogs that their own absence would be immaterial.

If, however, we humans do remain at the top of the planetary pecking order, in such numbers that ever more wilderness is sacrificed to food production, Peter Ward’s scenario is conceivable, although total human dominion over nature won’t ever happen. Small, fast-reproducing animals like rodents and snakes adapt to anything short of glaciers, and both will be continually selected for fitness by feral cats, highly fertile themselves. In his book Future Evolution, Ward imagines rats that evolve into kangaroo-sized hoppers with saber tusks, and snakes that learn to soar.

Frightening or entertaining, at least for now that vision is fanciful. The lesson of every extinction, says the Smithsonian’s Doug Erwin, is that we can’t predict what the world will be 5 million years later by looking at the survivors.

“There will be plenty of surprises. Let’s face it: who would’ve predicted the existence of turtles? Who would ever have imagined that an organism would essentially turn itself inside out, pulling its shoulder girdle inside its ribs to form a carapace? If turtles didn’t exist, no vertebrate biologist would’ve suggested that anything would do that: he’d have been laughed out of town. The only real prediction you can make is that life will go on. And that it will be interesting.”