The Next Species: The Future of Evolution in the Aftermath of Man (22 page)

Barren land free of all vegetation gradually began to disappear. As the search for space grew more competitive, plants began to move into the lowlands, forming swamps, which led to coals reappearing. But it was not until the late Triassic that the earth was covered with
green again.

In the wake of the Permian extinction, plants and animals went through similar successions. Hans-Dieter Sues led me into a back room in the Smithsonian Institution one spring day to show me some important animal fossils that thrived in the world of changes that occurred in the aftermath of the Permian extinction. The room was filled with boxes stacked on metal shelves. Sues, smiling, reached into one box and pulled out a skull. “This is
Lystrosaurus
,” he said, as if it were a friend. “They were the most dominant group of animals of the early Triassic era, even if they were rather ugly.” The skull is round, with a pug nose and sockets where the tusks had once been. It wouldn’t sell beer or toothpaste.

The return of animals during that time mimics the return of plants. In the early Triassic there were few species of animals, but those that survived spread throughout the world. Fossils of
Lystrosaurus
are the most numerous remains from the Permian extinction. It was a relative of early mammals. Its skin was smooth like a hippo. A horny beak may have covered the upper and lower jaws. Some cousins of
Lystrosaurus
reached body weights in excess of 2,200 pounds (1,000 kilograms). Still, he got around. He was the
dominant vertebrate animal in the early Triassic in South America, India, Antarctica, China, and Russia.

There were few predators in the early Triassic. Most animals were dead and there wasn’t enough for a good predator to eat. The only real consumption going on was by fungi that were attracted to all the dead bodies. Sues pulled another fossil out of the box. This was the skull of a gorgonopsid, a nasty predator with huge canine teeth. He was the dominant predator of the late Permian. Some of his relatives attained the size of a lion. But the gorgonopsids didn’t make it across the Permian-Triassic extinction line.

The sheer intensity of the extinction, plus a decrease in oxygen, warming, and other crises that continued in lethal bursts for five to six million years after the Permian extinction, delayed the resurrection in the early Triassic. Even ten million years after the Permian extinction things were bleak. River drainage patterns confirm a catastrophic loss of vegetation, which didn’t bode well for plant eaters. Global warming,
acid rain, ocean acidification, and ocean anoxia (the absence of oxygen) continued for a while, as did the greenhouse gases that precipitated them. Greenhouse gases don’t vanish quickly. There was life then, but it was meager. Then, 240 to 230 million years ago, things started to change.

This is when the crocodylomorphs (crocodile-like animals) and the first dinosaurs started to form. In the seas, ancestral crabs and lobsters as well as the first marine reptiles were creating some of the first ecosystems, but the crocodylomorphs weren’t semiaquatic beasts like their modern-day progeny—crocodiles, alligators, caimans, gharials—they were terrestrial beasts. And
they weren’t the second-best predator of the day. They ruled the lands, the most vicious predators on earth.

There is a rendering in Hans-Dieter Sues and Nicholas C. Fraser’s book
Triassic Life on Land: The Great Transition
that gives you an inkling of the ferocity of the crocodile-like animals during the late Triassic. It is a scene from western North America.
A colossal phytosaur, looking like a diesel truck only with a long thick tail and a mammoth gaping crocodile mouth, is standing in a shallow area of water, surrounded by animals with tall spindly legs, looking like a pack of dogs but with that same crocodile-like face. There’s five of them, and although the figure of the phytosaur is scary even as a drawing, the crocodylomorph reptiles have completely surrounded him and are not as impressed with his size.

For the most part these were dry-land creatures. The shape and musculature of the jaw distinguished them from other animals. During the Triassic, crocodylomorphs spread across the lands, evolving into different forms, from slender, long-legged, wolflike animals to huge, fearsome animals that were the apex predators of the food web (formerly food chain).

At the end of the Triassic, about 200 million years ago, more volcanic activity in the Central Atlantic elevated CO
₂
in the atmosphere
with some of the same results that had occurred in the Permian, and the crocodylomorphs lost their advantage to the dinosaurs as many of the largest croc species died out. With the land cleared of competitors, the dinosaurs expanded their dominion, evolved into different species, and took over.

But the crocodylomorphs didn’t lose all their ferocity. Paul Sereno, a paleontologist at the University of Chicago, discovered a number of prehistoric crocodylomorphs living alongside the dinosaurs in the wetlands of the ancient Sahara 100 million years later. They were still fearsome creatures.

Sarcosuchus imperator
, nicknamed SuperCroc, was some forty feet long and weighed eight tons. What Sereno refers to as BoarCroc was twenty feet long and had three rows of fangs, what Sereno refers to as a “dinosaur slicer.” But it also had long, agile legs rather than the squat, close-to-the-ground legs our present-day crocodiles possess. While modern crocodiles wait by the water and leap out to grab their prey, BoarCroc could have leapt out of the water and charged up the bank after dinosaurs.

Crocodile-like animals were the dominant predator to evolve during the 50 million years of the Triassic that followed the Permian extinction. The defenses of the plant eaters grew stronger, as did the attack mechanisms of the new creatures that preyed on them. Crocodiles ruled for a while, but then came the dinosaurs, perhaps the most successful creatures to evolve over the last 600 million years. Even during their reign, mammals were hiding out in the bushes, waiting their turn to take over.

The litany of these creatures proves two things: that even the strongest of animals are vulnerable; and that, though the characters, or the species, may change, life goes on.

A mass extinction may have grave consequences for some species, ours included, but it will not stop life. In the form of plants, animals, birds, reptiles, fish, fungi, and bacteria, life will find a way to exist, and
will eventually adapt to survive any conditions thrown at it by man, natural selection, or the universe. Evolution has proven for over the last three billion years to be unstoppable. Nature survives even in war zones. If you give nature space, it finds a way to persist.

On a crisp winter afternoon, Dave Choate, a researcher from the Orange County Cooperative Mountain Lion Study, and I stood at the top of a high hill in the Santa Ana Mountains in California listening for beeps on his tracking mechanism that told Choate
there were mountain lions from his study nearby. We were surrounded by the Camp Pendleton Marine Corps base, where 175,000 men and women train each year. Overhead, a squadron of fighter jets streaked toward the bombing range. At various times we heard the sounds of mortars, machine guns, and exploding rockets.

Yet, in spite of the noise, about 75 percent of Camp Pendleton is a de facto wildlife refuge—a huge military reservation comparable in size to the state of Rhode Island. The military needs open space to train service personnel, just as artillery and planes need buffer zones around the ranges where they direct their shells and bombs. If we were to fly overhead, we would see an area pockmarked by military activities, but we would also see a checkerboard pattern of civilian housing and shopping malls that virtually surround the base.

Mountain lions, bobcats, coyotes, and badgers hunt deer, rabbits, and rodents in areas where hawks, falcons, and eagles fill the air along with a multitude of ducks and shore birds. The base even has a herd of buffalo. Military lands are well patrolled, so there’s little poaching. Military laws deal out harsher punishments for violators. Says one US Air Force colonel, “We’re kind of mean SOBs if you break the rules.”

Driving south past Camp Pendleton on Interstate 5, the coastal highway, you leave urban sprawl and enter an area that, for all its failings, is open mountains shrouded in golden grasses and coastal shrubs confronting long sandy beaches. Big oak trees with branches that fall to the ground, the result of a paucity of grazing animals, punctuate the many fields of herbs and flowers. If it were not for the marines, this could all be houses, gas stations, and mini-malls.

The Korean demilitarized zone is another example of how nature can hang on under the worst circumstances. The zone is a 148-mile (238-kilometer) line that bisects the Korean Peninsula at the 38th parallel. It represents the armistice boundary between North and South Korea that was established in 1953, after several years of war between the two states. A ten-foot (three-meter) chain-link fence topped with razor wire prevents combatants from going at each other.

The armistice stopped the carnage (almost 900,000 soldiers and 2 million civilians killed or wounded as of July 27, 1953) but not the conflict, as the two states are technically still at war. Hundreds of thousands of troops from two large armies and more than 30,000 US troops stationed in South Korea patrol the area armed with live bullets, backed up by tanks, artillery, and ballistic missiles, all on alert.

But this brandishing of weapons can’t take away from the value that this no-man’s-land provides for nature. Wetlands created by five rivers, and the steep, forested Taebaek Mountains, make this place
the perfect wildlife sanctuary.

The DMZ’s roughly four hundred square miles are home to musk deer, black bears, and lynx. About one-third of the world’s population of red-crowned cranes depends on the DMZ for habitat. Ninety percent of the planet’s black-faced spoonbill population breeds on islands located here. And approximately 1,500 of the earth’s largest vulture species, the black vulture, winter here as well.

The loss of the DMZ would bring ruin to populations of goatlike Amur gorals, Siberian musk deer, and other Korean animals, according to Ke Chung Kim, of Pennsylvania State University and cofounder of DMZ Forum, which advocates for the protection of the DMZ as a peace park. Right now nature is being protected by one of the largest and most well-armed military guards in the world. Other such zones have been created during past conflicts, including the United Nations buffer zone between Iraq and Kuwait, and the Vietnamese demilitarized
zone between North and South Vietnam, all fine examples of what nature can do in the absence of man.

Perhaps the primary example of nature’s long-term survivability is the exclusion zone around the former Chernobyl nuclear power plant in Ukraine. It has been more than a quarter century since the Number Four reactor exploded at the plant. Then dangerous radioactive material spread over vast areas of Ukraine, Belarus, and Russia. Today whole towns are still abandoned. Cancer rates from people in the surrounding areas are high. But the 1,100-square-mile (2,850-square-kilometer) exclusion zone created around the failed reactors is home to a surprising number and variety of wildlife.

Roe deer and wild boar wander among the deserted villages, while bats fly in and out of vacant houses. Wild boars have also taken a liking to the villages. Rare species such as lynx, Przewalski’s horses, and eagle owls are thriving in areas that people have abandoned. Even wolves have made a comeback here.

It’s not that all is peachy, no problems, nothing to worry about. James Morris, a University of South Carolina biologist, works in the “Red Forest” (so named because the pine needles all turned red after the reactors went down). He’s seen trees with weird, twisted forms, the result of radiation destroying the trees’ ability to know which way is up and which is down.

A study in the
Journal of Animal Ecology
shows that
reproductive rates are much lower in the Chernobyl birds than in control populations. Another study in PLOS (Public Library of Science) says that the
brains of the local birds are 5 percent smaller than average and that this may inhibit their survival. Around 40 percent of the barn swallows return each year in other areas, but the annual return rate at Chernobyl is 15 percent or less.

Yet a recent study by Professor Jim Smith at the University of Portsmouth, UK, says that most wildlife has recovered from the
initial radiation problems, and that they are doing better than before simply because the human population has been removed. Kiev ecologists believe
radiation effects will diminish over time, but that the real story is how Chernobyl has burst into life. They hope one day the area can be turned into a national park.

Chernobyl is not our only nuclear problem. On March 11, 2011, the T
hoku earthquake and resulting tsunami swamped the Fukushima Daiichi nuclear power plant, located 149 miles (240 kilometers) north of Tokyo, in Fukushima prefecture (province), and cut the power to vital cooling systems for three reactors in use. The result was the second-worst nuclear accident in history. The facility remains toxic to this day.