Mary Anning - III

Once while searching for fossils after a storm, Mary came across a winged creature unlike anything she had ever encountered. This fossil had a long tail with dozens of vertebrae, hints of claws and wings and an enormous skull, rounded jaw and long beak. The entire fossil was less than four feet long. It looked to be a cross between a vampire bat and some kind of reptile. Mary’s discovery would eventually be called a Dimorphodon, the earliest type of Jurassic pterosaur. But, like before, Mary was not given credit for the discovery. 

It was the first pterosaur — or “winged lizard” — ever discovered outside of Germany. First appearing about 200 million years ago — almost 70 million years before the first known bird — pterosaurs had existed alongside dinosaurs. A contemporary of Mary’s earlier finds, the ichthyosaur and the plesiosaur, the pterosaur was believed to be the biggest creature ever to fly. Over time, other pterosaur skeletons would be found. Although some were as small as today’s birds, others had wingspans of nearly 40 feet.

In March 1829, she uncovered the second complete skeleton of the long-necked plesiosaur. So magnificent was the skeleton that an international battle erupted between museums wishing to be the first to showcase it. Finally, the British Museum purchased it for £105 pounds. The Edinburgh Philosophical Journal made mention of her fossil finds that year in the first-ever published list of Britain’s greatest geological collections. 

In December 1829, Mary came across a fossil that wasn’t enormous in size but certainly was peculiar in appearance. A mere 18 inches long, it had a long snout and looked a bit like a fish, but not a regular one. In 1833, scientists agreed that the fossil was indeed a fish, a fish-eating chimaeroid with a body like an otter’s and a flat tail like a beaver’s. The name chimaeroid was derived from a fire breathing she-monster in Greek mythology that boasts a lion’s body and a serpent’s tail.

It was a fossil of a cartilaginous fish — a fish later lumped together with the likes of sharks, skates, rays, and other vertebrates with internal skeletons made entirely of cartilage. It was ancestor to both the shark and the ray. To the untrained eye, the importance of the find might have seemed somewhat contrived. But it was a significant find because it was a transitional creature between sharks and rays. Most important for Mary, it was her fourth major discovery, one that kept her in the spotlight for some time.

Mary ended 1830 on a high note unearthing that December yet another species of plesiosaur, a large-skulled creature with a neck at least three times as long as its head. What made it still more interesting was that resting on the bones of the pelvis was its Coprolite (fossilized feces) finely illustrated. Eventually this creature was deemed to be a new type of plesiosaur — one with more neck bones than other types. As usual it was never mentioned during the formal proceedings that it was Mary who originally found the plesiosaur.

One of the few scientists who had acknowledged her work was a Swiss-born American biologist and geologist Luis Agassiz. In 1841, he would pay Mary her official due by naming a species of fish after her: the Acrodus anningiae. In 1844 he named yet another species of fish after her: Belenostomus anningiae. Such acts of respect for women were unheard of among Mary’s British colleagues. Every one of her own finds had been named after men. In July 1846, Mary was paid some due locally when she was named the first honorary member of the new Dorset County Museum in Dorchester, established the same year. 

Lacking adequate treatment, Mary Anning finally succumbed to breast cancer, dying on Tuesday, March 9, 1847, after having endured serious pain for at least two years. Her body was buried in the yard outside St. Michael’s church that overlooks the sea, at the top of the eroding Church Cliffs she had combed so often. Members of the church and the Geological Society in London paid tribute to Mary with a stained-glass window at St. Michael’s that portrays six acts of mercy from the Bible. The window was dedicated “in commemoration of her usefulness in furthering the science of geology . . . her benevolence of heart, and integrity of life.” 

By the end of her life she had become one of the most recognized names in geological circles, working closely with many of Europe’s most famous learned gentlemen scientists. With them, she’d debated the meaning of fossils and resolved disagreements. Mary’s steady stream of discoveries, begun when she was 12, had laid the foundations for groundbreaking reports on a broad array of bizarre prehistoric creatures.

Even London’s literary giant, Charles Dickens knew of her life. He wrote about Mary in his weekly literary magazine. In it he praised her “good stubborn English perseverance,” her intuition, her courage, physical and mental, in the face of locals who initially mocked her eccentricity. In his article, Dickens highlighted the strange lack of appreciation and the overall disregard for Mary from those in her own town.

At scientific societies, such as the Royal Society and the Geological Society, men still held sway, as women were barred until 1919. Even in the 1830s, men still regarded women as mostly weak and frivolous, more of a hindrance than a help in the scientific arena. Mary complained how “these men of learning have sucked her brains, and made a great deal by publishing works of which she furnished the contents, while she derived none of the advantages." But what was even worse was the careless disregard of museums when handling her discoveries.

As for Mary’s actual discoveries, many aren’t there. Some are housed in various institutions across the country, but too many have been lost or misplaced. The skull of the first ichthyosaur found by Mary’s brother, Joseph, in 1811 is on display at the Natural History Museum in London. The rest of the 17-foot skeleton is nowhere to be found. Although the British Museum purchased the whole specimen in 1819, it either neglected to keep the body or else somehow lost track of it over the years. 

It was fossils like the ones Mary discovered that scientists relied on the most in helping them to decipher the global geologic record. It was Mary’s spectacular marine reptiles that pushed them into finally contemplating a different explanation for the world’s origin. Mary’s many finds also laid the groundwork for Charles Darwin’s theory of evolution, elucidated in his 1859 On the Origin of Species. Darwin drew on Mary’s fossilized creatures as irrefutable evidence that life in the past was nothing like life in the present. At the time, merely suggesting such an idea was considered outrageous and even downright blasphemous.

London’s Natural History Museum refers to Mary on its website as the “greatest fossil hunter ever known.” Stephen Jay Gould said, "Mary Anning [is] probably the most important unsung (or inadequately sung) collecting force in the history of paleontology."

Mary Anning - II

Between about 1815 and 1819, when Mary was not even 20, she unearthed several more complete specimens of ichthyosaurs. Some she uncovered were only the size of a trout; others, nearly as big as a baleen whale. For scientists, Mary’s skeletons provided a picture of the kind of creatures that inhabited the seas during the remote past. For geologists, the ichthyosaur specimens raised the possibility that a link once existed between fish and reptile.

In spite of her fossil finds, she was struggling to make ends meet but fortunately she somehow managed to draw the attention of a very important admirer. He had a fossil collection which he decided to sell. The sale brought in more than £400 — comparable to nearly $50,000 today — all of which he handed over to the Annings. For the first time in their lives, Mary and her family were financially secure. The event also delivered a much-needed publicity boost, and across Europe, an increasing number of fossil collectors began asking about this young woman from Lyme Regis named Mary Anning, the young recipient of the auction’s proceeds. 

A year after the auction, in early 1821, she discovered and excavated a beautifully preserved ichthyosaur only five feet long. That same month she spent days digging out another much larger ichthyosaur skeleton, this one a fearsome 20 feet long. Later that year she found another five-foot fossil that was eventually named Ichthyosaurus vulgaris. Early in 1822 she retrieved yet another large ichthyosaur, this one at least nine feet long. As before, these finds were credited not to her but to the monied gentlemen collectors who purchased them.

By 1823, when Mary was 24, the family’s financial situation was once again precarious. The fossil business was an unpredictable one and, as geology grew into a popular science, there were more people hunting for fossils, meaning more competition. Early in the year, Mary sold an exceptionally well- preserved ichthyosaur skeleton to a collection of geologists. But, as usual, during the presentation, the lecturer failed to mention the young woman who had found it.

This time, however, the oversight did not go unnoticed. Local geologist and fossil collector George Cumberland immediately fired off a letter to a Bristol newspaper praising the “persevering industry of a young female fossilist of the name of Hanning.” (He spelled her name the way local Dorset residents pronounced it.) He told readers how Mary had removed from the cliffs “relics of a former world . . . at the continual risk of being crushed by the suspended fragments they leave behind. . . . [T]o her exertions we owe nearly all the fine specimens of Ichthyosauri of the great collections."

Then she discovered a strange creature that resembled a turtle with a flat mouth and stubby short tail and, oddest of all, an abnormally long neck. It was named Plesiosaurus, meaning “near to reptile.” News of the find spread to the eminent Georges Cuvier who expressed suspicions that the new animal might be a sham. The length of the neck seemed unrealistic. To the scientific community, Cuvier was far too good at what he did to be wrong. If he was dubious, then everyone else would be too.

For Mary, Cuvier’s misgivings were a disaster. If he convinced others that the new fossil was a forgery, the Anning family’s reputation could be ruined forever. At a special meeting to arbitrate on the matter, many recognized that its features precisely matched all the earlier similar findings of parts of an animal. After a lengthy discussion, the society members were convinced that Mary’s skeleton wasn’t a fake. Perhaps for the first time, Cuvier was shown to be fallible. Later, after more careful study of Mary’s drawings and eventually the bones themselves, Cuvier admitted that he’d rushed to judgment and made a mistake. In The Fossil Hunter, Shelley Emling writes: 

It was Mary’s discovery of the plesiosaur that gave impetus to serious contemplations on evolution, which would years later feed into Darwin’s theories on evolution. Although the ichthyosaur was the first extinct animal known to science, it wasn’t completely unlike modern dolphins and tuna. But plesiosaurs were so different from any modern animal that they couldn’t be so easily dismissed as a variety of a known existing creature.

Mary continued digging up fossils that fit no blueprint previously imagined. She discovered several new species of ammonites and continued to master anatomy by cutting up and studying both the soft tissue of modern fish and the dried up bones of ancient ones, without ever stepping foot inside any museum or university. At a time when a woman did not walk in public with a man to whom she was not related, Mary was visited frequently by many great scholars, all of them men, in search of information as much as fossils. 

For years, while out searching for fossils, Mary had stumbled across twisted, rounded dark-gray pebbles, some with black spots. Often they were no more than four inches long and only an inch or so in diameter. But sometimes they were much larger. On at least a few occasions, Mary had found these stones inside the skeletons of ichthyosaurs, leading her to believe they might be fossilized clumps of undigested food that remained in the intestines, if not ejected at death.

To her, the reason these masses had taken on their puzzling shapes and spiral markings might have been obvious: They simply had passed in a soft form through the intestines of ancient animals. In 1828, a scientist who studied these pebbles that Mary had discovered, named the fossilized feces “coprolites”. The study of fossilized feces would turn out to be one of the most important techniques available to paleontologists. Years later, it was coprology that led scientists to determine that the Tyrannosaurus rex was a carnivore.

Mary Anning - I

Mary Anning is a name that most people would not have heard of. It was only after her death that she gained a group of determined fans researching how such a marginalized person - her sex, regional dialect, lack of formal education, and adherence to the Dissenter faith, a religious strain that didn’t conform to the teachings of the established Church of England - managed to hold her own in a male-dominated field. Even if her name is not familiar, many people would have heard this tongue-twister inspired by her: "She sells sea-shells sitting on the sea-shore."

Mary Anning was born in 1799 in Lyme Regis, in the southwest English county of Dorset. Mary's father, Richard, was a cabinetmaker and amateur fossil collector. By the time she was five or six, Mary was actively hunting for fossils with her father who taught her how to look for and clean the fossils they found on the beach. 

At this time, most people in the Christian world accepted the idea of an earth created in six days in 4004 BC. The land animals harmoniously shared the garden with Adam and Eve. During Noah’s time, the global flood decimated all life except for that which had been brought into his ark. Most people had absolute faith in the fact that species never changed or evolved, or became extinct. The world was pretty simple - there wasn’t any radioactivity or relativity, extinction or evolution, to complicate matters. 

Mary enjoyed one big advantage: the very good fortune of having been born in Lyme Regis alongside some of the most geologically unstable coastlines in the world. Its unstable cliffs held the remains of many ancient reptiles that used to roam the world hundreds of millions of years in the past. There were all sorts of fossils which used to baffle locals - what later were determined to be bivalves, ammonites, belemnites, and brachiopods. Scientists eventually discovered that the cliffs east and west of Lyme Regis portrayed an almost continuous sequence of rock formations spanning the entire Mesozoic Era, also known as the "Age of Reptiles," which spanned from approximately 252 to 66 million years ago. 

Mary's father died when she was eleven after which her schooling was neglected. In those days, most people thought that intellect in a woman was something to be avoided and that educating girls, especially lower class ones, was a waste of time. Only men with a certain amount of wealth or status could vote, attend university, or hold public office. But even at the age of 11, Mary was already very intelligent and articulate despite her rudimentary schooling and could easily converse with adults. 

Fossil hunting was dangerous work. She had often narrowly avoided disaster. Her father’s own spillon the rocks likely had contributed to his death. Whenever the weather became rough, which was quite often, the winds could kick up giant waves with the power to pin even stronger people against rocks and sheer cliff faces. But Mary would ignore the warnings and continue looking for fossils on cliffs that appeared ready to buckle at a moment’s notice. 

Shortly after Mary’s twelfth birthday, a few months after her father had died, her brother spotted an enormous fossil skull of a strange lizard-like creature. Mary searched patiently for nearly a year, working with her hammer, chipping away at the rock, before she found the rest of the skeleton. The creature looked like a mix of a  dolphin, a crocodile, a fish and a lizard. Mary realized that the skeleton was a much greater discovery than the skull had originally indicated. 

Eventually news spread far and wide that a young girl from Lyme Regis had made an incredible find: an entire connected skeleton of a creature never before seen. The creature was named ichthyosaur, or “fish lizard.” Even though the description turned out to be a misnomer, since the creature was neither a fish nor a lizard but rather a sea reptile that lived at the the time of dinosaurs, the name has stuck to this day.

The find was nothing short of a small miracle. No one in the world could recall seeing such a creature before. People started wondering: How could someone have found the remains of a creature that no longer existed when every single being in the world was designed at the same time and with a specific purpose by a loving and all-powerful God? During Mary’s time, it was inconceivable that a completely different world might have existed before humans became a part of it.

But Mary didn’t receive much recognition for her discovery. The Geological Society was becoming a highly influential body but it didn’t admit women, not even as a member’s guest. Britain’s leading anatomist made an address to scientists to describe the skeleton but never mentioned her when thanking those who brought the fossil to the world’s attention. He also incorrectly praised a museum for Mary’s careful cleaning of the fossil. 

By the time she was a teenager, Mary was a voracious reader. Within a few years, she became a self-taught expert in of anatomy, animal morphology, and science illustration. She had an unerring eye for a fossil’s best hiding places, developed through hours of on-the-spot training. Day after day, no matter what the weather, Mary toiled away amid the shaky cliffs prone to landslides. When she wasn’t strolling the beach, she was likely to be found studying not only long-gone animals but also modern ones, dissecting dead squid, cuttlefish, and other soft-bodied cephalopods to find out what they ate, how they lived, and in what ways they moved their bones and muscles.

Alexander Selkirk - III

Daniel Defoe was a failed businessman. At the time accounts of Selkirk's adventures came out in 1712 and 1713, he was in his early fifties. Short of money, he was trying to pay off debts, support a wife and children, and maintain a big house by writing books, pamphlets, and newspaper articles. Defoe had a sharp tongue and his political stories annoyed powerful men in the church and government. One of his pamphlets charged some members of Parliament with disrespect for the rights of Englishmen. They did not appreciate his views. A £50 reward was offered for his capture.

He was betrayed by an informer and was charged with sedition. Defoe was fined £135 and spent the next six months in prison. Even though he wrote a lot, by his sixtieth year Defoe was broke, partly because he made unwise investments in business ventures that didn't turn profits. He desperately needed a money-spinner. He remembered the accounts of Selkirk's marooning that he had read. The story of a man surviving alone on an uninhabited island was one that he could use.

In the early eighteenth century almost all books published were nonfiction. Histories, biographies, and travel books were popular subjects. Novels rarely appeared. Defoe spoke with his printer who  agreed that a book about a marooned seaman on a tropical island might sell, but only if it read like nonfiction. In order to achieve this, Defoe decided to write in such a way that it would seem that the hero was writing the book himself, make the story appear as though it had really happened.

In April 1719 the new book appeared in the shops of London booksellers. Defoe's name did not appear as author. The title page read: "The Life and Strange Surprizing Adventures of Robinson Crusoe, of York, Mariner. Written by Himself. It became the most famous adventure story ever told, the tale of the shipwrecked mariner who survived twenty-eight years on an island off Brazil. The book is still available today in bookstores and libraries almost three hundred years after it was first published.

Readers believed Crusoe's story was true. In the Preface, Defoe noted that the book was "a just history of fact; neither is there any appearance of fiction in it." The book was so popular that it was reprinted a month after its first print run of 1500 copies and thrice more by the end of the year. The story was serialized in The Original London Post for sixty-five weeks, an astonishing run. Defoe never named Selkirk as the model for his hero. 

But in a new edition of his novel he wrote: "There is a man alive, and well known too, the actions of whose life are [my] subject, and to whom all or most part of the story alludes: this may be depended upon for the truth, and to this I set my name. Defoe's notes for his story, still preserved in the Guildhall Library in London, read in part: "Goats plenty. Fish: abundance, split and salt.... The fat of young seals good as olive oil."

There is also mention of a visit with a Captain Thomas Bowry of the East India Company, a shipping firm who showed Defoe maps of Juan Fernández. Ten years after it was published, Defoe's story appeared in French, and by 1760 in German, Dutch, and Russian. Translations appear today in nearly all the world's languages. After the success of the first Crusoe story, Defoe wrote two more: "Further Adventures of Robinson Crusoe in 1719 and "Serious Reflections of Robinson Crusoe" the next year. 

In his lifetime, Defoe turned out an awesome amount of writing but only Crusoe and Moll Flanders (1722) remains in print today. Although he wrote a lot, Defoe never seemed to earn enough money to support his wife and seven children. In April 1731, he was hiding from people he owed money to in a shabby house in London where he died, some twelve years after his famous novel first appeared in which he created one of the most enduring characters in all fiction.

Did Selkirk ever read the story? Possibly. In April 1719, when the novel appeared, he was on leave from H.M.S. Enterprise and in London. On daily walks about the city he sometimes visited bookstores. At the end of his famous story, Defoe arranged for Crusoe to return to the island on which he had lived for twenty-eight years. But we know that was only fiction. Alexander Selkirk, the real-life Robinson Crusoe, never visited his island home again.

Alexander Selkirk - II

As he grew to know his island, he felt more comfortable. But there were days when the island's quiet grew heavy. He had no living soul to talk to. Moody and dispirited, he wondered what God had in mind, imprisoning him on this remote island. These melancholy periods, however, came about less and less as the weeks passed and his contentment continued to grow. He found his temper moderating. His angry outbursts at trees and sky for the injustice of his lot ceased. By the end of his second year on Juan Fernández, Selkirk was living comfortably. 

His life on Juan Fernández had become a daily joy, his days aboard ship and his home in Largo increasingly remote. The hut was warm, food plentiful. He was never bored. Knowledge of the island had replaced fear and ignorance. He had a sense of complete freedom, of fulfillment, of safe harbor. There was the solitude to endure, of course, and the lack of a mate or two to enjoy a drink and a chat. But in this he had no choice. He came to a decision. If fate decreed, he would be content to spend the rest of his days on his island kingdom, master of his own life and destiny.

(My reactions after becoming locked-in also followed a similar trajectory. When Time has done enough work, you find ways to deal with the new reality and eventually you get used to it. As soon as an imagined experience becomes an actual experience that cannot be changed, the brain looks for ways to analyse and explain it in a way that allows us to appreciate it. This happens even for regular, everyday events rather than just for terrible events like becoming a quadriplegic. Most people don’t realize how quickly the human mind gets adapted to new situations.)

One day he saw two ships heading for Juan Fernández. He saw their flags through his spyglass: English! Eight seamen came ashore and were bewildered by the sight of disheveled man who could only grunt and mutter words that sounded like "marooned ... marooned." One of the officers recognized Selkirk — "the best man on the Cinque Ports," he stated. Learning that Selkirk had been sailing master of the Cinque Ports and a veteran seaman "of great skill and conduct" he was appointed second mate of the ship.

On the way back home he had unexpected news about the crew of the Cinque Ports - it had run onto an underwater shelf, broke apart, and sank. Almost all the crew drowned, but the captain and six seamen made shore in a boat and were captured by waiting Spanish soldiers. Selkirk was stunned. What if he had not gone ashore on Juan Fernández? He might have drowned or still be wasting away in a Spanish prison. By choosing the island, he had escaped a dreadful fate.

Selkirk finally reached London on October 14,1711 eight years after he left. There had been days on a faraway island when he had expected never to see England again. Life must have seemed very good. Sometime in 1712, the captain of the ship published a book. Sections told about the rescue of Selkirk. The book became the most popular travel book of the year and was reprinted in French, Dutch, and German. Selkirk, the man who had survived four years alone on an island, became a celebrity. He was introduced to rich friends and invited to dinner parties. 

But he could never get used to this luxurious lifestyle. An article said, "[He] frequently bewailed his return to the world which could not ... with all its enjoyments, restore him to the tranquility of his solitude" on his island. He is quoted as saying, "I am now worth 800 pounds but shall never be so happy as when I was not worth a farthing." In late 1716 or early 1717 he enlisted in the Royal Navy. 

Sometime in November or December 1721, when in Africa, Selkirk became ill. Medicine at the time knew little about treating tropical diseases. He died a few days later. At a spot called Selkirk's Lookout on Juan Fernández today stands a bronze tablet placed in 1863. It reads:

In memory of Alexander Selkirk, mariner, a native of Largo, in the county of Fife, Scotland, who lived on this island in complete solitude for four years and four months. He was landed from the Cinque Ports galley, 96 tons, A.D. 1704, was taken off in the Duke, privateer, 12th Feb., 1709. He died Lieutenant of H.M.S. Weymouth A.D. 1728, aged 47 years.

The last date was incorrect. The Weymouth's logbook in the Public Records Office in London gives 1721 as the year of his passing. He was 41. Still, the tablet, erected nearly a century and a half after Selkirk's death, recognized the Scottish mariner's magnificent adventure — a salute to a fellow seaman who had survived four years alone on a remote island.

And by the time he died, he had become the role model for one of the most famous characters in fiction - Robinson Crusoe. 

Alexander Selkirk - I

Selkirk was a veteran seaman. At fifteen years of age, he had run away from home, the seaside village of Largo, Scotland. He sailed on merchant ships between the West Indies and England and learned navigation, which enabled him to become a ship's officer. He joined an English ship called the Cinque Ports. As sailing master in 1703, he had piloted the Cinque Ports from England south through the Atlantic Ocean, around stormy Cape Horn. 

The Cinque Ports reached the remote Spanish island of Juan Fernández off the West coast of South America. The island lies 360 miles due west of Valparaiso, Chile. Because England and Spain were at war, the island was not a safe place for an English ship. He knew from charts that the island was about twelve miles long and four miles wide. He was twenty-seven years old and strongly built. He also possessed a quick temper.

The island was the only anchorage and watering place that could be chanced along the Spanish-held South American coast. While water casks were being refilled from freshwater streams on shore and trees cut for the woodbin, Selkirk inspected the ship. After its long passage from England to Juan Fernández, many repairs were needed.

The captain, though, would hear none of it. Repairs could take days. Spanish warships could appear any time. He was determined that as soon as water and wood came aboard, they would leave. Selkirk argued that the captain was being overly cautious but the latter refused to yield. Selkirk stubbornly refused to accept the decision. Now his well-known temper began to rise. The captain decided to call Selkirk's bluff. He left Selkirk alone on the island and left. 

As the night came on, it's unlikely that he was deeply distressed. He believed that the whole episode had been an unfortunate fit of temper on both their parts. His marooning on the island would be temporary — maybe a day, a week, and the Cinque Ports would come back. He was navigator, the one man able to sail the poorly charted ocean and find the way back to England. He would just have to make the best of it until the ship returned.

He considered building a fire but decided against it. Savages might see the flames. He had heard of flesh eaters on South Pacific islands. His sea chest held a few linen shirts and wool stockings, flint and steel for making fire, cooking pot, brass spyglass, hatchet, knife, and his books on navigation and geometry. As the days went by, his hopes of the ship returning diminished. He found crabs, mussels, and clams for food. He managed to build a fire and used water from a stream. 

After weeks on the beach, Selkirk shifted to a cave whose hollow entrance offered an advantage: a high lookout over the bay, a place to watch for a ship. He slept whole days away. Sleep was his only escape. Awake, he whistled Scottish folk tunes, a human sound in the island's stillness. Sometime in May or June of 1705, after eight or nine months on the beach and in the cave, Selkirk admitted a hard truth - the Cinque Ports would not be returning to the island. It was possible that he would stay here for years, perhaps for the rest of his days.

He discovered waterfalls and streams and marveled at the island birds—hawks, owls, petrels, puffins, blackbirds, and hummingbirds. In one valley he came upon a field of turnips and stands of fig trees. He found patches of oats, pumpkins, radishes, parsnips, and parsley growing wild. Selkirk gathered the crops gratefully, but how they came to grow there he didn't know. (In 1591 Spanish settlers from the South American mainland had planted crops and grazed goats during a brief but unsuccessful attempt to farm and build homes on the island.)

He stacked dry grass and branches, ready to set on fire. The smoke would signal a passing ship. But a signal fire also meant taking a fearful risk. The waters between Juan Fernández and the coast of South America were patrolled by Spanish and French warships. A smoke signal might bring one or the other.  "[The Spanish] would murder him," he feared, "or make a slave of him in the [silver] mines." Despite his daily watch, no ship arrived to rescue him. He was alone, both master of the island and its prisoner.

Selkirk's days followed a regular routine. After a reading in the Bible, he prepared a light breakfast — fruit, a cabbage leaf, a drink of fresh water. Next a bath in the nearby stream, scrubbing himself with pumice, a soft volcanic stone. He mashed charcoal from the fire pit into powder, placed a line on a finger, scrubbed his teeth, then rinsed his mouth in the stream. A walk on the beach might reward him with the capture of a sea turtle. Sometimes he fished for snapper, bonito, sea bass, and yellowtails. 

The impact hypothesis - III

The Alvarezes wrote up the results from their tests and sent them, along with their proposed explanation, to Science. Their paper, “Extraterrestrial Cause for the Cretaceous-Tertiary Extinction,” was published in June 1980. An asteroid six miles wide collided with the earth sixty-five million years ago. (The date was later revised to 66 mya.) Exploding on contact, it released energy of more than a million of the most powerful H-bombs ever tested. Debris, including iridium from the pulverized asteroid, spread around the globe. 

Sunlight disappeared and temperatures plunged and a mass extinction ensued. The Alvarezes proposed that the main cause of the K-T mass extinction was not the impact itself or even the immediate aftermath. The truly catastrophic effect of the asteroid was the dust which spread around the globe and shut out the sunlight and blocked photosynthesis in plants. In the intervening decades, this account has been subjected to numerous refinements. 

It generated lots of excitement, much of it beyond the bounds of paleontology. In the context of “hard-core uniformitarianism,” the impact hypothesis was worse than wrong — it couldn’t have happened. A few years later, an informal survey was conducted among paleontologists. A majority thought some sort of cosmic collision might have taken place. But only one in twenty thought it had anything to do with the extinction of the dinosaurs. Among professional paleontologists, the Alvarezes’ idea and in many cases the Alvarezes themselves were reviled.

But evidence for the hypothesis continued to accumulate. First was tiny grains of rock known as “shocked quartz.” Under high magnification, shocked quartz exhibits what look like scratch marks caused by high pressure that deform the crystal structure. Shocked quartz was first noted at nuclear test sites and later found near impact craters. In 1984, grains of shocked quartz were discovered in a layer of clay from the K-T boundary in eastern Montana. 

It occurred to Walter Alvarez that if there had been a giant, impact-induced tsunami, it would have left behind a distinctive "fingerprint" in the sedimentary record. He scanned the records of thousands of sediment cores that had been drilled in the oceans, and found such a "fingerprint" in cores from the Gulf of Mexico (oops! Gulf of America). Finally, a hundred-mile-wide crater was discovered beneath the Yucatán Peninsula buried under half a mile of newer sediment. 

This crater had shown up in gravity surveys taken in the nineteen-fifties by Mexico’s state-run oil company. When Walter located the cores in 1991 and examined them, they were found to contain a layer of glass—rock that had melted, then rapidly cooled at the K-T boundary. To the Alvarez camp, this

was the conclusive proof that they required about there having been an asteroid impact.  It was enough to move many uncommitted scientists to support the impact hypothesis. By this time, Luis Alvarez had died of complications from esophageal cancer. The crater became more widely known, after the nearest town, as the Chicxulub crater.

When the Alvarezes had published their hypothesis, they knew of only three sites where the iridium layer was exposed. In the decades since, dozens more have been located. The confirmation of the impact hypothesis was a challenge to a uniformitarian viewpoint that basically every geologist and paleontologist had been trained in. 

On land, every animal larger than a cat seems to have died out. The event’s most famous victims, the dinosaurs — or, to be more precise, the non-avian dinosaurs — suffered a hundred percent losses. Around two-thirds of the mammalian families living at the end of the Cretaceous disappear at the boundary. Everything (and everyone) alive today is descended from an organism that somehow survived the impact. 

Change one detail, and we can imagine a completely different world. If the asteroid had hit a moment earlier or later, it would have hit deep ocean instead of shallow seas, releasing far less toxic gas, and killing many fewer species. If the asteroid had been delayed by just one minute, it might have missed Earth entirely. An astrophysicist has proposed that tiny oscillations of the sun's orbit flung the asteroid from the distant Oort cloud toward our planet. But for one small vibration in an unfathomably distant reach of deep space, dinosaurs might have survived — and humans might never have existed. 

Natural Selection is often presented as a relentless improvement from worse to better. Richard Dawkins once said that “Nature is a miserly accountant, grudging the pennies, watching the clock, punishing the smallest extravagance." But evolution at times proceeds in an unpredictable fashion. This is obvious when you consider that the evolution of mammals only happened because of an asteroid strike. But we mostly hear about survival of the fittest not survival of the luckiest.