The Universe Within (21 page)

To see things Dave’s way, you need to think about the 3.5-billion-year history of life as one big survival game, where the creatures that live longest and produce the most fertile offspring win. Then think about the features that help species survive and reproduce. For animals, you’d likely make a list that includes traits like the abilities to run faster than predators, to jump high, to climb efficiently, and to have jaws specialized for particular foods. It might mean being big at some times and small at others. You could measure how well creatures do certain activities, such as feed, reproduce, and move about. You could use these measurements to make predictions of winners and losers: faster animals would out-survive slower ones, faster breeders would do the same to slower ones, and so on. And for large chunks of
geological time, tens or hundreds of millions of years, these features would seem to relate to the success of different species. Then you’d look to see how these features help animals at the biggest catastrophes in the history of life. You’d guess these features would be keys to long-term success. And you’d be dead wrong.

What is the holy grail of paleontologists, the feature that predicts success during cataclysm? In the immense history of Earth, on many continents, over billions of years, through extinctions caused by asteroids, sea level change, and
volcanic eruption, there seem to be rules about what happens to living things during cataclysms. One trait—among all those that life has ever had—seems to give us the ability to predict whether a species is likely to live or die at a
catastrophe. The best survival tip for a species is to be widely spread around the globe. Species that have individuals spread about, preferably on different continents, fare better than those that are found in only one spot.

For millions of years, survival and reproduction depend on how well creatures feed, move about, reproduce, and so on. Then, every so often, a catastrophe happens, and those traits become virtually meaningless. What matters is the happenstance of where they live. Rare events wipe the slate clean and briefly change the rules of the game. The creatures that survive catastrophe aren’t always “better” at any ecological trick. If the ultimate victory is surviving a catastrophe, then the winners are those that are
globally distributed.

If creative destruction is good for economies, so too is it for the biosphere. Survivors of global calamities inherit a new Earth—a planet with fewer competitors. Imagine a game of
king of the hill. A huge, mean playground bully sits at the top of the hill and, with the advantages of his elevation and size, simply owns it. Nothing you do can get you up there. What is the best gift you can be given in this game? Maybe some random event, perhaps his mom calling him home for dinner, leaving the hill open for you. With the bully gone, you can simply scamper up the hill and gain the advantage of elevation to use when others come up.

The king-of-the-hill idea may also hold for species. If a successful species occupies some niche, perhaps lives in a particular zone of the
ocean, others cannot easily occupy that ecological
space. Now, if a cataclysm removes that ecological version of king of the hill, the
survivors can occupy the prize position without so much as a fight.

From our perspective, as one species sitting on top of 3.5 billion years of life’s history, we ask: What has this meant for us?

Most of our
fossil
hunts are spectacularly unsuccessful, and my work in the 1990s with Farish
Jenkins in Africa was no exception. We spent a fruitless month looking for
mammals in
200-million-year-old rocks in Namibia, and at the finale Farish wanted to boost morale by taking us up north on a safari. After a few days’ drive, we found ourselves in
Etosha National Park, a vast desert along the border with Angola. The desert plain is dotted with small water holes that are magnets for life. Every day we’d haul out of bed at sunrise, park our cars next to a quiet water hole, and sit for hours, simply watching the panoply of life come and go. First the birds arrive. Then come the zebras and buffalo. A pack of hyenas might wander about. Everybody scatters as a lion circles, then, when things seem safe, the whole crew settles back to a normal rhythm of feeding and drinking.

Here we were in a glorious world of large mammals and birds of all kinds, but my brain was still locked inside the patterns of rocks of 200 million years ago. At that time, reptiles of every imaginable description roamed Earth; mammals were tiny shrew-sized creatures, and birds were nonexistent. Daily life at the water hole contains the imprint of
catastrophes millions of years ago. The water holes before that time were loaded with a different creature, a very successful one.
Dinosaurs, large and small, plant eating and carnivorous, occupied these niches. Instead of elephants and large plant-eating mammals, in the
Cretaceous there were herds of ceratopsians and hadrosaurs. In place of large lions, there were tyrannosaurs and other large dinosaurian and crocodilian carnivores. The dinosaurs and their cousins were the
kings of the hill for eons until they got knocked out by catastrophe. Only then did the descendants of a little mouselike creature, with teeth as small as grains of sand—whom dinosaurs trampled under their feet—grow to become the new kings of the hill.

A
rctic bush pilots are a special breed. Years of solo flying endow them with a crusty independence and deep familiarity with the landscape. After countless hours looking down on terrain, pilots’ eyes can discern patterns hidden from the rest of us. During one flight in 2002, our pilot suddenly pushed the plane into a steep dive and veered into a tight bank, a maneuver that dropped us from ten thousand feet to about two hundred over the water in a small fjord. While I was seeing my life flash before my eyes, he saw a school of fish and, being a fisherman in his spare time, wanted to get a closer view. Even if my eyes
weren’t closed, there was no way I could have perceived swimming
arctic char from such an altitude.

During one chopper run in 1985, a pilot named
Paul Tudge was shuttling supplies between distant camps on
Canada’s
Axel Heiberg Island and
Eureka Sound, two of the North’s most spectacular places. When the air is clear and the ground free from snow, the colors and images are so sharp that tiny details can be visible miles in the distance. In this part of the Arctic, barren mountain ranges border gentle valleys. The enduring action of ice, wind, and intense cold sculpts the bedrock into a range of obelisks, sheer walls, and potholes that almost seem unnatural. The sensation of otherworldliness is magnified by the lack of large
plants: there are no standing trees, shrubs, or even grass in this area.

Scanning brown, gray, and red vistas below his chopper, Tudge noticed something odd on the bedrock floor. Wind had winnowed a depression, out of which poked objects that looked like tree stumps. Not believing that there are trees in the Arctic, let alone ones that grew out of rock, Tudge set the chopper down. Lying in wait for him were not only tree stumps but piles of branches, logs, and other tree parts jutting from the ground. He dutifully collected samples and shipped them to one of the Arctic’s leading
fossil plant experts,
James Basinger of the University of Saskatchewan. Basinger dropped everything and mounted an expedition as soon as money and permits could allow; of course, in the Arctic this process can take a year or more.

Awaiting Basinger’s spade was an entire buried forest mummified in eroding rock. The cold dry air left fine anatomical details of the leaves and wood intact, including their original cellular structure. The wood of these trees even burns. There is a big difference between these logs and a Duraflame; the Arctic ones come from a forest over 40 million years old.

The stumps that jut from this frozen landscape expose redwood trees that would have reached heights of 150 feet or more.
In the past, this place was no barren wasteland; it was alive with
plants much like Northern California is today. Of course, nowadays the tallest tree up north is a little
willow that rises mere inches off the ground. It is almost as difficult to see
Arctic willows from six feet as Tudge’s
fossil forest from the air.

About twenty years before
Paul Tudge’s flight, the eminent paleontologist
Edwin Colbert received a box in his office at the
American Museum of Natural History in New York City. Sent by a famed geologist from the Ohio State University, it contained a sheet of official letterhead wrapped around an isolated bone the size of a human finger. The colleague had collected this fragment in the field and wanted Colbert’s expert opinion.

From his many years on expedition to the American Southwest, Colbert was able to identify the bone in a split second: it had the distinctive texture and shape of a jaw from an ancient
amphibian that lived over 200 million years ago. Looking somewhat like fat crocodiles, these creatures were widespread throughout the globe for a good chunk of
geological time. But this ordinary-looking fragment was very special: it came from the
Transantarctic
Mountains, a range two hundred miles from the
South Pole.