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The Next Species: The Future of Evolution in the Aftermath of Man - Softcover

Tennesen, Michael

 
9781451677522: The Next Species: The Future of Evolution in the Aftermath of Man
Softcover
ISBN 10: 1451677529 ISBN 13: 9781451677522
Verlag: Simon & Schuster, 2016

Inhaltsangabe

“Simultaneously sobering and exhilarating, Michael Tennesen’s wide-ranging survey of disasters highlights both life’s fragility and its metamorphosing persistence” (Booklist) and describes what life on earth could look like after the next mass extinction.

A growing number of scientists agree we are headed toward a mass extinction, perhaps in as little as 300 years. Already there have been five mass extinctions in the last 600 million years, including the Cretaceous Extinction, during which an asteroid knocked out the dinosaurs. Though these events were initially destructive, they were also prime movers of evolutionary change in nature. And we can see some of the warning signs of another extinction event coming, as our oceans lose both fish and oxygen, and our lands lose both predators and prey. In The Next Species, Michael Tennesen questions what life might be like after it happens.

In thoughtful, provocative ways, Tennesen discusses the future of nature and whether humans will make it through the bottleneck of extinction. Could life suddenly get very big as it did before the arrival of humans? Could the conquest of Mars lead to another form of human? Could we upload our minds into a computer and live in a virtual reality? How would we recognize the next humans? Are they with us now?

Tennesen delves into the history of the planet and travels to rainforests, canyons, craters, and caves all over the world to explore the potential winners and losers of the next era of evolution. His predictions, based on reports and interviews with top scientists, have vital implications for life on earth today. The Next Species is “an engrossing history of life, the dismal changes wrought by man, and a forecast of life after the sixth mass extinction” (Kirkus Reviews).

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Über die Autorin bzw. den Autor

Michael Tennesen is a science writer who has written more than 300 stories in such journals as Discover, Scientific American, New Scientist, National Wildlife, Audubon, Science, Smithsonian, and others. He was a Media Fellow at the Nicholas School of the Environment and Earth Sciences, Duke University, and a Writer in Residence at the Cary Institute of Ecosystem Studies in Millbrook, New York. He lives in the California desert near Joshua Tree National Park with Maggie, his wife.

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Next Species 1 A MASS EXTINCTION: THE CRIME SCENE
IF YOU’RE CURIOUS as to what a mass extinction looks like, you might want to visit the remains of the Capitan Reef at Guadalupe Mountains National Park, the highest mountains in Texas. Life abounded in the seas back then, but the dinosaurs had yet to appear. The creatures that walked the dry land were not as enormous, nor as diversified, as they would become later. The continents were bound together in a single landmass, but as it broke up and drifted apart, the movement provided the isolation necessary for new species to evolve. Still, life had to sidestep the Permian extinction before it could truly flourish. The story of life’s decimation at this point, followed by its resurrection, has multiple lessons for our own predicament.

The Capitan Reef, though long dead, once thrived between 272 and 260 million years ago in the middle of the Permian period, just before the greatest mass extinction the world has ever known. The International Union of Geological Sciences has selected three points within the park as “golden spikes,” the standard against which all other rocks of the Middle Permian period are compared. (The actual markers that indicate these points are brass plaques.)

At the bottom of the trail up to the reef one day, I met Guadalupe Mountains National Park geologist Jonena Hearst. After she patiently answered questions from a park visitor and showed me some maps and geological charts, a process that took twenty minutes, she loaded up her day pack and lifted it onto her back. With a big broad smile she signaled it was time to get going. I followed after her. It was fall, a transitional time in West Texas weather, when mornings bore the chill of impending winter, yet the afternoons carried a remembrance of summer heat. McKittrick Canyon before us cut a slash through the Guadalupe Range, exposing the backbone of the Capitan Reef—one of the most extensive fossil reef formations on earth.

The surrounding terrain was dry, open desert, with cactus and creosote brush sheltering an assortment of rabbits, snakes, and lizards—a marked contrast from the tropical rain forests of Vilcabamba. Whereas the rain forest is full of moisture and life, the desert is bashful about any display of exuberance. Farther up McKittrick Canyon, cottonwoods surrounded a portion of the stream that surfaced intermittently. The trees were full of inviting autumn colors, but our path quickly pulled away from the stream and veered up a steep embankment toward the Capitan Reef above us.

What we saw of the reef exposed here displayed the calcified remains of an enormous formation of shelled creatures and sponges that once lay beneath an ancient sea, not unlike the coral reefs of today. A huge fault lifted a section of the reef high into the air, brandishing the dark rock for all to see. The trail was steep—a gauntlet of narrow switchback turns, full of slippery boulders that tested one’s stamina and balance. Yet the site was still quite popular, particularly with geologists and paleontologists, for it led into the fossil remains of an ancient world.

Park geologist Hearst was the keeper of this treasure, and was astute and knowledgeable about its intricate secrets. But she was as exuberant as she was scholarly. She told me she had last hiked up this reef just two weeks earlier, yet she wore a big smile despite some heavy breathing. “It’s a geological Disneyland,” she proclaimed. “Every time I go up there, I learn something new. How many times have I been on that ride, you ask?” She shook her finger toward the reef. “Don’t know, but I want to do it again!”

The hike began at the bottom of an enormous depression known as the Delaware Basin, which spread out into Texas. The reef had formed over a distance stretching many miles around the lip of the basin, the horseshoe mouth of which once pointed out to an ancient sea. A quarter of a billion years ago, this reef was still glowing with a halo of life formed by millions of juvenile fish and other marine creatures that once used the nooks and crevices of the reef to avoid large predators.

Back then, two enormous continents—Laurentia (made up of North America, Europe, and Asia) and Gondwana (made up of South America, Africa, Antarctica, and Australia)—formed the terrestrial landscape at the surface of the planet. These two landmasses were on a collision course, soon to form Pangaea, the single continent that would take the world through the Permian extinction, an event that came the closest to ending life on earth than at any other time in the last 600 million years.

Our trail told the grand story of life before that event. We scrambled up the loose rock beneath the slopes of the giant reef head. We gained altitude quickly as the trail rose above the desert landscape. This was a deepwater reef, different from the shallower coral reefs most recreational divers are familiar with today. In Permian times, we would have been walking 5,000 feet (1,500 meters) below the surface of the ocean. “A very long snorkel to get to the top,” said Hearst.

As we rose upward, larger boulders and layered outcrops gradually displaced the loose, rocky slopes. Hearst stopped before a large boulder that reached our height and stared at the markings on it. At first I didn’t see anything special; it was just a big boulder. But then she pointed out the many fossils contained in the rock. It turned out that we weren’t staring at a plain rock—we were gazing on the calcified remains of ancient reef animals that had once been bound together in a mass of life.

During the Permian period this gallery of life included flowerlike crinoids, which sat atop stalks attached to the seafloor, their numerous tentacles coated with mucus extended out to capture prey, and you could see the fossil remains of these creatures in this rock. There were also bryozoans, small animals that superficially resembled corals, which grew in tightly packed colonies resembling intricate fans, lacy fronds, or fruitlike displays that accumulated into massive stony buttresses. Also here were clamlike creatures called brachiopods, which were filled with a tangle of filaments that helped the animal sift food from the water but which would have made a poor clam chowder. There were numerous species of sponges as well as nautilus-like creatures housed in large spiral shells. The boulder was filled with such animals, surrounded by algae, which acted as cement to hold everything together. As she pointed to other rocks nearby, my astonishment grew. All the boulders housed similar amazing displays.

From the base of the reef we pressed on up the trail. As we approached the part of the reef formerly within the reach of sunlight and the energy of the waves, the reef fauna began to change from marine communities dominated by sponges and bryozoans to those dominated by algae and large clamlike gastropods.

Toward what was once sea level, the sponges disappeared. We entered the intertidal zone where outgoing tides would have periodically exposed the reef to sunlight and air, and this produced still more shifts in the animal communities. Ahead we could see the remains of limestone barrier islands. Behind the barrier islands were sand and gravel bars cut through by tidal channels, and beyond that the dry remains of a large lagoon facing a shoreline of salt flats.

The Permian period stretched from 298 million to 251 million years ago, the reef thriving across the West Texas terrain along the margins of what was once a warm tropical sea. In its prime, it would have been about four hundred miles in length.

Reefs are among the most biologically diverse of any ecosystems. They are the rain forests of the sea. Yet they...

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Verlag
Simon & Schuster
Erscheinungsdatum
2016
Sprache
Englisch
ISBN 10 
1451677529
ISBN 13 
9781451677522
Einband
Taschenbuch
Anzahl der Seiten
336
Kontakt zum Hersteller
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