The World Without Us

and started usurping neighboring Petexbatun 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 Rio Pasion’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 Petexbatun 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 Petexbatun, 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