The Best American Science and Nature Writing Part 7

On the voyage home, we found time for reflection, and I understood why the blue whale's flukeprint so mesmerized me each time I saw it at the dome. That big, circular slick is the signature of the species, the John Hanc.o.c.k of flukeprints, outsize and insistent. It jumps out boldly from the parchment. Its uncanny persistence on the sea's surface, defying the choppiness, is a good omen. Appearing at the dome, this winter haven, it suggests that the blue whale might after all defy the chop of history.

"Still here!" the flukeprint says.

JANE GOODALL The Lazarus Effect.

FROM Discover.

IN 2008, DURING MY LECTURE TOUR in Australia, a very large, very black, very friendly Lord Howe Island stick insect (Dryococelus australis) crawled across my hands, my face, and my head. The encounter sent s.h.i.+vers up my spinea"knowing, as I did, the incredible story of how it came to be there.

The forests of Lord Howe Island, about three hundred miles off the coast of New South Wales, Australia, were the only known home of the Lord Howe Island phasmid, also called a stick insect or walking sticka"a creature about the size of a large cigar, four or five inches long and half an inch wide. In 1918 black rats arrived on the island after a s.h.i.+pwreck, relentlessly adapting to their new environment and probably finding easy and delicious prey in the giant phasmid, which lacked wings. At some point in the 1920s, the Lord Howe Island phasmid was presumed extinct.

Then, in 1964, rock climbers found the dried-out remains of a giant stick insect on Ball's Pyramid, an 1,800-foot-tall spire of volcanic rock fourteen miles from Lord Howe Island. Five years later, other rock climbers found two other dried bodies incorporated into a bird's nest on a remote pinnacle of the spire, a place almost entirely without vegetation. It seemed impossible that a large, forest-loving vegetarian insect could be surviving in such a bleak environment. And so biologists ignored these reports until, in February 2001, a small group of peoplea"David Priddel, the senior research scientist of the Department of Environment and Climate Change in New South Wales, his colleague Nicholas Carlile, and two other intrepid soulsa"decided to settle the matter once and for all.

The seas around Ball's Pyramid are rough, and the team of three men and one woman had to leap from their small boat onto the rocks. ("Swimming would have been much easier, but there are too many sharks," Carlile said.) They put up a small camp and set off to climb about 500 feet up the spire of rock where the main vegetative patches clung to life. They searched thoroughly but found nothing other than some big crickets, and eventually the heat and lack of water drove them back down. Then, in a crevice 225 feet above the sea, they came upon another tiny patch of comparatively lush vegetation, dominated by a single melaleuca bush. Here they found the fresh droppings of some large insect.

Back in camp, over supper, they discussed the situation. Priddel knew that stick insects were nocturnal and that the group would have a better chance of seeing them if they went back to that bush at night. Carlile and team member Dean Hisc.o.xa"a local ranger and expert rock climbera"volunteered to make the almost suicidal climb in the dark. Finally they reached the vegetated area and saw one and then two enormous, s.h.i.+ning, black-looking bodies spread out on the bush. "It felt like stepping back into the Jura.s.sic age, when insects ruled the world," Carlile said.

Early the next morning, the whole team climbed back up and made a thorough search. They found some fra.s.s (the proper terminology for insect poo) and about thirty eggs in the soil. They were all convinced that the only population in the world of Lord Howe Island's giant phasmid lived on that one melaleuca shrub.

How did the little colony get to that isolated pillar of rock? Perhaps a female, full of eggs, had made the fourteen-mile journey from Lord Howe Island clinging to the leg of some seabird or floating on some vegetation after a storm. And once there, she had found the one and only suitable habitat on the entire pyramid, that little bush. The point is, she got there somehow. How her descendants survived for eighty years in that desolate environment we shall never know.

As soon as they returned, the biologists got to work on a recovery plan for the stick insect. They faced many battles with bureaucracy, and two years elapsed before they had permission to returna"and they were allowed to catch only four individuals. When they arrived, they found that there had been a big rockslide on Ball's Pyramid. How easily the entire population could have been wiped out during those two frustrating years. However, on Valen tine's Day in 2003, they found the colony still thriving on its one bush. To transport the incredibly rare insects, a special container had been prepared, and this presented a problem when they arrived in Australia. It was not long after 9/11, and security was very tight, yet the scientists had to convince officials not to open the precious box! One pair of insects went to a private breeder in Sydney, and the other two, Adam and Eve, went to the Melbourne Zoo. To everyone's delight and relief, Eve soon began laying pea-size eggs.

Within two weeks of arriving in Australia, the pair in Sydney died and Eve became very, very sick. Patrick Honan, a member of the Invertebrate Conservation Breeding Group, worked every night for a month desperately trying to cure her. He scoured the Internet for help, but no one knew anything about the veterinary care of giant stick insects! Eventually, based on gut instinct, Patrick concocted a mixture that included calcium and nectar and fed it to his patient, drop by drop, as she lay curled up in his hand. To his joy, she seemed to get better, and she laid eggs for a further eighteen months. But the only ones that hatched were the thirty or so that she had laid before she fell sick.

In 2008, when I visited the Melbourne Zoo, Patrick showed me his rows of incubating eggs: 11,376 at the last count, with about 700 adults in the captive population. He showed me a photo of how they sleep at night, in pairs, the male with three of his legs protectively over the female beside him. As further insurance for the survival of the species, eggs are now being sent to other zoos and private breeders in Australia and overseas. The 200 eggs that were sent to the San Antonio Zoo in Texas have already begun to hatch.

My second story is about a very small and very beautiful breed of horse and an American woman, Louise Firouz, who "discovered" and rescued the animals from obscurity in Iran. Louise had married a young man from the Iranian royal family, Narcy Firouz, and had become a princess. In 1957 the young couple established the Norouzabad Equestrian Center, where the wealthier Iranian families sent their children to learn to ride. But the horses were typically too big for the smaller children, including their own three. And so when, in 1965, Louise heard rumors of a small pony in the Elburz Mountains near the Caspian Sea, she determined to investigate. She set out on horseback with a few women friends, and she found the "ponies." They were being used as work animals, pulling carts, malnourished and covered with ticks.

Almost at once Louise realized that these were not ponies at alla"they had the distinctive gait, temperament, and facial bone structure of horses. Very small, narrow horses to be sure, standing just over forty inches, but horses for all that.

As she pondered the nature of this little horse, Louise suddenly remembered seeing, on the walls of the ancient palace in Persepolis, relief carvings of a horse that looked very much like the one she had just found. The Lydian horse depicted in those carvings had the same small, prominent skull formation. With a sense of excitement, Louise began to wonder whether, hidden beneath the matted coats of these work animals, there was a true representative of the ancient lost breed of the royals, considered extinct for a thousand years. She found that there were still five purebred horses in the village, and she bought three of them. After extensive DNA testing, archaeozoologists and genetic specialists agreed with Louise that these animals were indeed Caspian horses, the ancestral form of the Arabian horse. What an incredible find!

At first Louise and Narcy financed the breeding themselves, but then in 1970 a Royal Horse Society was formed in Iran. The society's mission was to protect Iran's native breeds, and it bought all of Louise's Caspian horses, which by then numbered twenty-three. Louise and Narcy then started a second, private herd near the Turkmenistan border. When two mares and a foal were killed by wolves, Louise, wanting to ensure that some of the horses would be kept safe, arranged for eight of them to be exported to Britain in 1977. The Royal Horse Society was angered, presumably because it had not been consulted. The society immediately banned all further exports of Caspian horses and began collecting all of the animals that remained in Iran, including all but one of the Firouzes' second herd.

Then came the 1979 Islamic revolution. Because of their connections with the royal family, the Firouzes were imprisoned. Narcy was jailed for six months, but Louise for only a few weeks, for she remembered advice given to her by a friend: that if she went to prison, she should go on a hunger strike. This worked, but during that time most of the Caspian horses were auctioned for use as beasts of burden or slaughtered for meat.

Still pa.s.sionate about saving her beloved Caspian horses, Louise managed to rescue some of those that remained from starvation and slaughter and established, for the third time, a small herd in Iran. And once again she managed to export some of them to safety.

The last such effort was in the early 1990s, when Louise sent seven horses on a dangerous journey to the United Kingdom. They had to pa.s.s through the Belarus war zone, where bandits attacked and robbed the convoy. The horses arrived safely, but it had been a costly business. Soon after, in 1994, Louise's husband died, and she could no longer afford her breeding program.

With Iran's many political upheavalsa"the overthrow of the shah, the Iran-Iraq war, the very real threat of faminea"as well as the Caspian's former a.s.sociation with royaltya"the fate of these horses was ever in the balance. One moment they were considered a national treasure, the next they were seized as wartime food. But thanks to Louise Firouz, who had exported a total of nine stallions and seventeen mares, the future of this ancient line has been ensured. Today they can be found in England, France, Australia, Scandinavia, New Zealand, and the United States.

DAVID QUAMMEN Darwin's First Clues.

FROM National Geographic.

THE JOURNEY OF YOUNG CHARLES DARWIN aboard His Majesty's s.h.i.+p Beagle, during the years 1831a"36, is one of the best known and most neatly mythologized episodes in the history of science. As the legend goes, Darwin sailed as s.h.i.+p's naturalist on the Beagle, visited the Galpagos archipelago in the eastern Pacific Ocean, and there beheld giant tortoises and finches. The finches, many species of them, were distinguishable by differently shaped beaks, suggesting adaptations to particular diets. The tortoises, island by island, carried differently shaped sh.e.l.ls.

These clues from the Galpagos led Darwin (immediately? long afterward? here the mythic story is vague) to conclude that Earth's living diversity has arisen by an organic process of descent with modificationa"evolution, as it's now knowna"and that natural selection is the mechanism. He wrote a book called The Origin of Species and persuaded everyone, except the Anglican Church establishment, that it was so.

Well, yes and no. This cartoonish account of the Beagle voyage and its consequences contains a fair bit of truth, but it also confuses, distorts, and omits much. For instance, the finches weren't as illuminating as the diversity of the islands' mockingbirds, at least initially, and Darwin couldn't make sense of them until a bird expert back in England helped. The Galpagos stopover was a brief anomaly near the end of an expedition devoted mostly to surveying the South American coastline. Darwin hadn't signed on to the Beagle as its official naturalist; he was a twenty-two-year-old Cambridge graduate pointed rather indifferently toward a career as a country clergyman, invited on the voyage as a dining companion for the captain, a mercurial young aristocrat named Robert Fitzroy. Darwin did a.s.sume the role of naturalist, and thought of himself that way, as time went on. But his theory developed slowly, secretively, and The Origin of Species (full t.i.tle: On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life) didn't appear until 1859. Many scientists, along with some Victorian clergymen, resisted its evidence and arguments for decades afterward. The reality of evolution became widely accepted during Darwin's lifetime, but his particular theorya"with natural selection as prime causea"didn't triumph until about 1940, after it had been successfully integrated with genetics.

Apart from those clarifications, the most interesting point missed by the simplified tale is this: Darwin's first real clue toward evolution came not in the Galpagos but three years before, on a bl.u.s.tery beach along the north coast of Argentina. And it didn't take the form of a bird's beak. It wasn't even a living creature. It was a trove of fossils. Never mind the notion of Darwin's finches. For a fresh view of the Beagle voyage, start with Darwin's armadillos and giant sloths.

In September 1832, during the first year of its mission, the Beagle anch.o.r.ed near Baha Blanca, a settlement at the head of a bay about four hundred miles southwest of Buenos Aires. A certain General Rosas was waging a genocidal war against the Indians, and Baha Blanca stood as a fortified outpost, occupied mostly by soldiers. For more than a month the Beagle remained in that area, some of its crew occupied with surveying, others a.s.signed to sh.o.r.e dutiesa"digging a well, gathering firewood, hunting for meat. The landscape round about was cla.s.sic Argentine Pampas, fertile gra.s.sland, giving way to gra.s.s-anch.o.r.ed sand dunes along the coast. The hunters brought back deer, agoutis, and other game, including several armadillos and a large flightless bird Darwin loosely called an "ostrich." Of course it wasn't an ostrich (which is native to Africa and, formerly, the Middle East); it was a rhea, specifically Rhea americana, ostrichlike in appearance but endemic to South America and the heaviest bird on the continent.

"What we had for dinner to day would sound very odd in England," Darwin wrote in his diary on September 18, reveling in the exoticism of his new regimen: "Ostrich dumpling & Armadilloes." He was out for a romping adventure, not just a natural history field trip, and his s.h.i.+pboard diary (later transformed into a travel book that came to be known as The Voyage of the Beagle) reflects his attention to cultures, peoples, and politics as well as to science. The red meat of the big bird resembled beef, he recorded. The armadillos, peeled out of their sh.e.l.ls, tasted and looked like ducks. His culinary experiences here on the Pampas, and later in Patagonia, besides being part of his voracious tour of discovery, would eventually play a role in his evolutionary thinking.

A few days afterward, on September 22, 1832, Darwin and Fitzroy took a small boat to visit a site called Punta Alta, ten miles from their anchorage, where they found some rocky outcrops overlooking the water. "These are the first I have seen," Darwin wrote, "& are very interesting from containing numerous sh.e.l.ls & the bones of large animals."

Despite the name, Punta Alta ("high point") was not very high, its reddish mudstone cliff rising only about twenty feet. But if the headland wasn't dramatic, the exposed fossils were: big shapes, unusual shapes, and abundant. Darwin and a helper went to work on the soft rock with pickaxes. Between that session and later efforts, he harvested from Punta Alta the remains of nine great mammals, all unknown or barely known to science. They were extinct Pleistocene giants, unique to the Americas in an age sometime before 12,000 years ago.

The most famous of them was Megatherium, an elephant-size ground sloth that had already been named and described by the French anatomist Georges Cuvier on the basis of one set of fossils found in Paraguay. Living sloths are native to Central and South America, and only there; Megatherium shared many of their anatomical traits but was far too large for climbing trees. Darwin's finds also included at least three other giant ground sloths, an extinct form of horse, and a protective carapace of small bony scutes fitted closely together, remnant from some big beast that must have strongly resembled an armadillo. He was already familiar with flesh-and-blood armadillos, having eaten those shucked, ducky ones with his ostrich dumplings. He had also watched local gauchos kill armadillos and roast them in the sh.e.l.ls. Of the twenty species of living armadillo, all are confined to the Americas and several are common on the Pampas; the roasted animals may have been six-banded armadillos (Euphractus s.e.xcinctus), plentiful there abouts and reputed to taste terrible, which might not have dissuaded those unfussy gauchos, who sometimes lived off the land for weeks. "Like to snails, all their property is on their backs & their food around them," Darwin wrote, referring to the cowboys, not the armadillos.

A month later, thirty miles up the coast from Punta Alta, Darwin discovered another fossil-rich sea cliff, this one rising 120 feet and marking a place called Monte Hermoso. There he unearthed the stony remains of several gnawing creatures, which variously put him in mind of an agouti, a capybara, and a smaller South American rodent, the tuco-tuco, except that again, in each case, the match between fossil and living species was close but not identical. Still later and farther south on the Argentine coast, he excavated a third set of mammal bones, which, to an anatomist who eventually examined them, suggested an extinct form of camel. That creature became known as Macrauchenia. The camel family includes two wild South American species, the guanaco and the vicua, as well as their domesticated forms, the llama and the alpaca. Darwin was well aware that living guanacos inhabited that area, having shot one himself just days earlier.

These discoveries, a.n.a.logies, and juxtapositions went into his memory and imagination, to ferment there as the voyage continued and for years afterward. Meanwhile the fossils themselves were crated up for s.h.i.+pping back to England, mostly to the care of John Stevens Henslow, the gentle botanist who had been Darwin's mentor at Cambridge.

"I have been lucky with fossil bones," he told Henslow in a letter. He mentioned the giant rodent, the ground sloths, and the section of bony polygonal scutes, commenting on the last: "Immediately I saw them I thought they must belong to an enormous Armadillo, living species of which genus are so abundant here." And he added: "If it interests you sufficiently to unpack them, I shall be very curious to hear something about them."

It's important not to overstate how clearly Darwin could even identify, let alone interpret, what he had found. Most of his fossils, apart from the Megatherium, represented species not yet familiar to experts, and he was no expert. He wasn't a comparative anatomist, like the great Cuvier; he wasn't especially knowledgeable about mammals; and the very word "paleontologist" hadn't yet come into use. Darwin entrusted the description and identification of his fos sils to a brilliant young anatomist back in London named Richard Owen, an up-and-coming authority on extinct mammals. It was Owen who gave names to the unknown sloths, and Owen who suggested (mistakenly, later correcting himself) the affinity between Macrauchenia and a camel.

Darwin himself was no Owen. He was just a highly attentive field man, greedy for specimens, learning as he went. The Beagle invitation had rescued him from an unsuitable future as a country pastor, and since his first days aboard s.h.i.+p he had applied himself diligently, maturing fast to a.s.sume (and then transcend) the role of s.h.i.+p's naturalist. His best qualifications for interpreting the fossils were his intense curiosity, his talent for close observation, and his instinctive sense that everything in the natural world is somehow connected with everything else. Also, he wasn't afraid to speculate boldlya"so long as he could do it in private.

Another small but suggestive datum reached him months later, while the Beagle lingered off northern Patagonia and Darwin spent time ash.o.r.e among another congenial group of gauchos. First it was hearsay: the gauchos mentioned a rare form of ostrich, smaller than the common one, with shorter legs, and more easily killed using their bolas, but otherwise similar. The possibility of finding that bird slipped Darwin's mind until one of his s.h.i.+pmates shot such a smaller "ostrich" (another rhea) for its meat. Darwin paid little attention, a.s.suming it was a juvenile. "The bird was skinned and cooked before my memory returned," he wrote, in a pa.s.sage so candid you can almost see him smacking his forehead with a palm. "But the head, neck, legs, wings, many of the larger feathers, and a large part of the skin, had been preserved." He rescued those sc.r.a.ps and sent them to England, where they were st.i.tched into a presentable specimen for the museum of the Zoological Society. The ornithologist John Gould, to whom Darwin would consign his Galpagos finches and mockingbirds for identification, also got a first look at this creature. Gould confirmed that it was a distinct species and called it Rhea darwinii (a name later changed because of taxonomic technicalities) for the man who had rescued it from the midden.

What intrigued Darwin most about the two rhea species was that, similar as they were, they overlapped very little in geographic distribution. The greater rhea inhabited the Pampas and northern Patagonia as far south as Argentina's Ro Negro, which drained to the coast at about 41 degrees south lat.i.tude; the lesser rhea replaced it beyond the Ro Negro and occupied southern Patagonia. Together with the evidence of extinct South American mammals, the implications of rhea diversity and distribution would prove almost as suggestive to Darwin as the patterns he would later find among the finches and mockingbirds of the Galpagos.

How do species originate, and how do they come to be where they are? The orthodox story, still firmly embraced by European science at the time of the Beagle voyage, was that G.o.d had created species independently, in sequential batches (to compensate for extinctions), and had chosen to place them, almost arbitrarily, in their particular localesa"kangaroos in Australia, giraffes and zebras in Africa, rheas and sloths and armadillos in South America, extinct and living forms cl.u.s.tered closely in s.p.a.ce and time. But to Darwin, both the extinct mammals (along with their living counterparts among sloths and armadillos) and the two rheas (occupying adjacent regions of habitat) suggested something more rational: the ideas of relatedness and succession among closely allied species. The living tree sloths and armadillos seemed to have succeeded earlier such forms in time, inhabiting roughly the same terrain during different epochs of Earth's history. (Those earlier forms of sloth were true sloths; the earlier armored creatures are now known as glyptodonts, a family distinct from but closely related to living armadillos.) The two rheas, similar but not identical, likewise seemed to succeed each othera"but in s.p.a.ce, across the horizontal dimension of landscape. The cl.u.s.tering in time and in s.p.a.ce thus hinted that each group had descended, with modification, from common ancestors: rheas from rheas, sloths from earlier sloths, armadillos from an armadilloish or glyptodontish precursor, possibly far larger than armadillos living today. That's the explanation to which Darwin felt drawn, because it seemed more economical, more inductive, and more persuasive than the creationist scenario.

How important were the South American data in shaking his faith in the orthodox viewa"persuading him that evolution was a reality for which he should seek a material explanation? Darwin himself would give several answers to that question over the length of his lifetime. His answers ranged, in essence, from very important, but less so than the Galpagos birds, to crucially important, period.

He hinted at the subject in 1845, in the second edition of his Beagle narrative, revised by him to include coy hints about the theory he was still unprepared to publish. The relations.h.i.+ps between fossil and living forms among the rodents, the sloths, the camels, and the armadillos were "most interesting facts," he noted. Further work by other investigators had meantime revealed the same kind of pattern in Brazila"fossil and living forms of anteater, of tapir, of monkey and peccary and possum. "This wonderful relations.h.i.+p in the same continent between the dead and the living," Darwin wrote, would "throw more light on the appearance of organic beings on our earth, and their disappearance from it, than any other cla.s.s of facts." But what sort of light? What would that light reveal? Throwing light was one of his favorite metaphors, and it would return, but not for a decade and a halfa"not until he was ready to s.h.i.+ne the blinding beam of his theory in public.

There's another intriguing question about the South American fossils and rheas: When did this evidence register on Darwin, tipping him toward the idea of evolution? The widely accepted view is that he returned from the Beagle voyage not yet an evolutionist, merely puzzled by what he had seen, and that he made the big leap to evolutionary thinking after his consultations in London with John Gould and Richard Owen about the bird and fossil specimens he had consigned to them. (Soon after that he began using a new term for the process: "trans.m.u.tation.") But not everyone agrees.

"I think he was personally converted much earlier," a historian of paleontology named Paul D. Brinkman told me. We were sitting in his office at the North Carolina Museum of Natural Sciences in Raleigh, amid a portrait of young Darwin, a Jura.s.sic Park poster, and photos of old ground sloth and glyptodont specimens. "Why would there be this resemblance between the fossil fauna and the extant fauna of this area? Why would they be so similar?" he asked, repostulating questions that Darwin must have framed. The ancient rodents and the living agoutis, the glyptodonts and the armadillosa"why? "I think one of the possible explanations he was mulling over, even as early as 1832, was that one begat the other. Trans.m.u.tation." But even Brinkman admits that there is only tenu ous evidence, "no smoking gun," for his hypothesis about Darwin having converted to evolutionism long before ever striding ash.o.r.e in the Galpagos.

One cryptic piece of testimony came from Darwin himself, near the end of his life, in the private autobiography he wrote for his family. "During the voyage of the Beagle," he reminisced, "I had been deeply impressed by discovering in the Pampean formation great fossil animals covered with armour like that on the existing armadillos." He alluded also to the rheas and to the Galpagos species, differing island by island. "It was evident," Darwin wrote, "that such facts as these, as well as many others, could be explained on the supposition that species gradually become modified; and the subject haunted me." In years since, it has also haunted scholars.

The Beagle, having completed its South American survey work, then spent a year circ.u.mnavigating the world; it reached England in October 1836. Darwin, then twenty-seven and a seasoned naturalist, weary of travel, eager for home, was a changed man in other ways too. He no longer saw himself serving time in a country parsonage; he was committed to a life of science. And he had at least started to lose his belief in the immutability of species. It's not possible to know with certainty, but he seems by then to have identified the great question, though not yet the great answer, that would dominate the rest of his working life.

With his specimens outsourced for expert identificationa"the birds to Gould, the fossil mammals to Owen, the reptiles to a zoologist named Thomas Bella"he set about putting his thoughts in order and following out his suspicions. He brainstormed in his most private notebook about ostriches, guanacos, and whether "one species does change into another." If so, how might such trans.m.u.tation occur? About a year and a half later, after adding one crucial piece to his thinking (the idea of excess reproduction and struggle for existence, adopted from an essay on human population by Thomas Malthus), Darwin hit upon his theory: natural selection, whereby the best adapted individuals of each population survive to leave offspring and others don't. Then he nurtured, refined, developed, and concealed that theory for twenty years, until a younger man named Alfred Russel Wallace struck upon the same idea, forcing Darwin to rush to get his own ready for print.

That was in 1858. By then Darwin had begun writing a long, detailed, heavily footnoted treatise on natural selection, but it was only half finished. Panicked, feeling proprietary, yet also reawakened to the wondrous immediacy of the story he had to tell, he shoved the big book aside and quickly composed a more streamlined account. This shorter, slapdash version would be merely an "abstract" of the theory and its supporting data, he claimed. He called it "my abominable volume" because, after decades of cogitation and delay, the writing process was so hurried and painful. He wanted to t.i.tle it An Abstract of an Essay on the Origin of Species and Varieties Through Natural Selection, but his publisher persuaded him to accept something at least marginally more snappy. It appeared in November 1859, t.i.tled On the Origin of Species by Means of Natural Selection et cetera, and was a sellout success immediately.

Five more editions went to print during Darwin's lifetime. Almost inarguably, it's the most significant single scientific book ever published. After 150 years, people still venerate it, people still deplore it, and The Origin of Species continues to exert an extraordinary influencea"though, unfortunately, not many people actually read it.

And the forgotten clues that led him to his theory are still largely forgotten. Anyway, they're omitted from the mythic account. Scholars still dispute the significance of those extinct and living Argentine creatures, especially the ground sloths and glyptodonts, the tree sloths and armadillos and rheas. Evidence is mixed, even among the various comments on the matter left behind by Darwin himself. The most telling of those comments, in my view, is one so conspicuously placed that it tends to get overlooked. It comprises the first two sentences of The Origin of Species, beginning the book on a nostalgic note. It says: "When on board H.M.S. 'Beagle,' as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to me to throw some light on the origin of species..."

The finches of the Galpagos make their appearance about four hundred pages later.

PART FOUR.

The Environment: Gloom and Doom.

JIM CARRIER All You Can Eat.

FROM Orion.

THE GREEN DUMPSTER behind Red Lobster was nearly empty when I lifted the lid. Through the effluvium of yesterday's supper, way down, sat a couple of pretty blue boxes. I hitched myself over the rim, leaned in, and took one.

I am not a regular dumpster diver. I was driven by a hunger for knowledge. Inside the restaurant, where the dcor, ambience, soundtracka"all but the smella"reeked of the sea, I asked the server who laid before me the first plate of Red Lobster's "endless shrimp" where they came from.

"Farms," she said.

"Where are these farms?" I asked.

"Different places." She gave a shrug. "Do you want another beer?"

I ate only eight grilled shrimp from Red Lobster's "endless" supply. Something was stuck in my craw. An hour before, I had been in a community hall in Brownsville, Texas, with forty-three angry, tearful American shrimpers. In a country awash in shrimp, they were going bankrupt. They had gathered to hear more bad news: severe new rules limiting what they could catch.

"What about Red Lobster?" I asked the group.

"Red Lobster!" one man shouted. "They're our enemy. They haven't bought a shrimp since the 1980s."

The restaurant walls were covered with shrimp boatsa"striking photos of trawlers at docks, at sea, in sunset silhouettes. The Gulf of Mexico was a mile away. Yet while I sat eating, real shrimp boats sat rusting, their outriggers raised as if surrendering.

The box from the dumpster gave me a clue: "Product of Ecuador. Farm Raised."

I am farm raised. I nurse a nostalgia for what those words used to mean. Holding that fetid box, I began to question my own clueless consumption. From a springboard both pure and naive, I dove into all-you-can-eat shrimp.

Shrimp, in my youth in upstate New York, were rare and pricey. I remember a 1960s shrimp c.o.c.ktail at the Rainbow Room atop Rockefeller Center. I don't remember my date's face, but I do recall a scent of privilege. Thirty years would pa.s.s before another shrimp scene would be as sharply etched on my mind. It was late October in the Carolinas. I had tied my sailboat to an old wood dock in front of a village on the Intracoastal Waterway. Around me marsh gra.s.s tinted gold by the sunset was slowly emerging from ebbing waters. Barely a month into living aboard, I'd opened a beer to toast my good fortune when a man from the village walked onto the dock with a bucket and a ball of netting.

With a practiced arabesque he threw the net. It blossomed into a ten-foot parachute that dappled a circle and sank. In a few seconds, he pulled the line, and wet flopping creatures spilled onto the dock. He sorted through them, discarded several, and repeated the motion. Half a dozen throws later the bucket held two handfuls of shrimp.

"Supper," he said, and walked off.

The scene was magical, almost biblical: its grace and bounty, its sense of proportiona"one man, one meala"evoked a sustaining ocean. As I sailed farther south I began to see shrimp everywhere. Shrimp boats seining night and day. Roadside stands selling shrimp from coolers. All-you-can-eat shrimp buffets for a few dollars. These waters, a federal survey reported in 1884, contained "immense schools" of shrimp, so many that a man could catch bushels on a "pleasant evening." It appeared that nothing had changed. In fact, everything had changed during a century in which shrimp had gone from lowly regional fare, caught by hand, to America's favorite seafood.

In 1913, one hundred miles down the coast from where I had watched the man cast his net, Billy Cork.u.m, a Ma.s.sachusetts fis.h.i.+ng captain, introduced the otter trawl to Amelia Island, Florida. An ungainly contraption of ropes, cables, wooden doors, and nets, the trawl was dragged through the water just above the ocean floor, its mouth open like a whale's. Modified with a drooping chain to "tickle" mud-dwelling shrimp into jumping into the maw, diesel-pulled trawls scooped shrimp by the billions.

"We never had so darned many shrimp," old-timer Anthony Taranto told the Southern Foodways Alliance, a University of Mississippi inst.i.tute that studies southern food culture. "You couldn't hardly sell them and couldn't hardly do nothing with them."

Shrimp are a perfect protein delivery system, built with a head and carapace that twist off easily, revealing a muscle that can be cooked in three minutes. The Chinese and Greeks loved them. Apicius included shrimp in his Roman cookbook. But it took decades for shrimp to whet appet.i.tes outside the American South. Packed in barrels of ice and s.h.i.+pped by rail, shrimp were served in tulip gla.s.ses as "c.o.c.ktails" in upstate New York in 1914. As cookbooks added Low Country recipes, canning and, in 1943, a shrimp-peeling machinea"invented by a teenager, J. M. Lapeyre, in Houma, Louisiana, who noticed how easily shrimp meat could be squished out of its sh.e.l.l by his rubber boota"made shrimp available nationwide.

Trawls soon emptied the shallows of southern waters and moved deeper. For seventy years growing fleets of bigger boats galloped from one gold strike to another as veins of shrimp were discovered off Louisiana (white, 1933), Mexico (brown, 1940), Dry Tortugas (pink, 1949), and Key West, where in 1957 huge, royal red shrimp were discovered a thousand feet down.

"Greater riches are being brought up than all the gold ever sunk off the Spanish Main," gushed National Geographic in 1957. Many shrimpers became millionaires.

"We were outlaws," Wallace Beaudreaux, of Brownsville, Texas, eighty-one, told me, describing raids into Mexican waters. It was not unusual for boats to gross $10,000 to $25,000 on a single trip.

I felt rich in 1998, buying a pound of shrimp for a mere three dollars right off the boats near where I anch.o.r.ed in Key West. I had only one question: with thousands of boats endlessly trawling and millions like me endlessly gobbling, how could there be any shrimp left in the sea?

"Shrimp are a crop, like wheat," shrimpers replied. 'You can't overfish them."

I was asking the wrong question. I should have wondered where all these shrimp were coming from and how they could cost three dollars a pound. I happened to sail into the Deep South in time to witness the crash of a culture bound to, and blinded by, endless shrimp dreams.

Shrimp have been around since Gondwana. Their tracks are found alongside dinosaurs', which explains their astounding diversitya"more than two thousand species in every body of water in the world. They are a major food source for Salt Lake gulls, ocean whales, gulf red snappera"virtually every marine critter, which makes them ideal bait.

But the shrimp's life cycle was understood only in the 1960s. Shrimp don't ascend rivers to sp.a.w.n, as once thought, but reverse the process in a complicated and delicate cycle. Adult shrimp mate in deep water, holding each other feet-to-feet. He inserts a capsule of sperm, and she spews half a million microscopic eggs that resemble milk spilled in water. These babies molt through a dozen stages as tiny, spiderlike creatures, finally emerging shrimplike in a month.

With mysterious instinct they move up and down in the water column, catching waves, currents, and winds that sweep them into shallow bays. In the gulf this cycle coincides with a s.h.i.+ft from northerly to southerly winds, a warming of bay waters, and an increase in freshwater runoff from rivers, which reduces salinity. In these brackish, rich estuaries, protected by reeds and organic muck, they begin devouring one-celled algae called diatoms and growing at the rate of one inch a month. In two or three months, triggered apparently by increased salinity, they begin to walka"literallya"and flick their tails back to the sea, traveling as far as two hundred miles. Left alone, a shrimp grows to a length of six to eight inches, developing a tail as big around as a man's thumb. At this stage they are in deep water, ready to sp.a.w.n before dying or being eaten by a predator.

I learned all this aboard Leslie Hartman's runabout one May day in Mobile Bay. She was out there, as she is every week of the year, her long brown ponytail swinging like a pendulum as she heaved a miniature trawl off the stern. As Alabama's shrimp biologist, Hartman's job is to constantly sample the size of shrimp returning to the sea and determine when they are large enough to open the state's shrimp season.

After fifteen minutes, she stopped the boat, hauled in the net, and dumped the catch into a white bucket. She knelt and fingered through glistening life. Little rays, horned blowfish, baby snapper, and a bunch of crabs were thrown back. Left in the bottom were a set of creatures that ranged from transparent globules half an inch long to juvenile shrimp up to two inches. She counted, measured, and logged the sample and sped off for another drag elsewhere.

The threshold for legal shrimp in Alabama is 68 shrimp per pound. A "68" shrimp is pretty small, often canned, tossed into macaroni salad, or breaded and fried as "popcorn" shrimp. Shrimp c.o.c.ktails use a minimum size of 40 to 50 per pound. When I look at shrimp in a grocer's case I usually choose "20a"25," the size of my little finger. Hartman's task was to calculate when the average of her samples reached 68. She was always anxious to reach that point, for she considered herself a friend of the industry.