Top Quotes: “A Short History of Nearly Everything” — Bill Bryson
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The Origins of Earth
“What would you find beyond? The answer, disappointingly, is that you can never get to the edge of the universe. That’s not because it would take too long to get there-though of course it would — but because even if you traveled outward and outward in a straight line, indefinitely and pugnaciously, you would never arrive at an outer boundary. Instead, you would come back to where you began (at which point, presumably, you would rather lose heart in the exercise and give up). The reason for this is that the universe bends, in a way we can’t adequately imagine.”
“Surprisingly little of the universe is visible to us when we incline our heads to the sky. Only about 6,000 stars are visible to the naked eye from Earth, and only about 2,000 can be seen from any one spot.”
“About 4.6 billion years ago, a great swirl of gas and dust some 15 billion miles across accumulated in space where we are now and began to aggregate. Virtually all of it — 99.9 percent of the mass of the solar system — went to make the Sun. Out of the floating material that was left over, two microscopic grains floated close enough together to be joined by electrostatic forces. This was the moment of conception for our planet. All over the inchoate solar system, the same was happening. Colliding dust grains formed larger and larger clumps. Eventually the clumps grew large enough to be called planetesimals. As these endlessly bumped and collided, they fractured or split or recombined in endless random permutations, but in every encounter there was a winner, and some of the winners grew big enough to dominate the orbit around which they traveled. It all happened remarkably quickly.”
“At this point, about 4.5 billion years ago, an object the size of Mars crashed into Earth, blowing out enough material to form a companion sphere, the Moon. Within weeks, it is thought, the flung material had reassembled itself into a single clump, and within a year it had formed into the spherical rock that companions us yet. Most of the lunar material, it is thought, came from the Earth’s crust, not its core, which is why the Moon has so little iron while we have a lot.”
Science
“Before Owen, museums were designed primarily for the use and edification of the elite, and even then it was difficult to gain access. In the early days of the British Museum, prospective visitors had to make a written application and undergo a brief interview to determine if they were fit to be admitted at all. They then had to return a second time to pick up a ticket and finally come back a third time to view the museum’s treasures. Even then they were whisked through in groups and not allowed to linger. Owen’s plan was to welcome everyone, even to the point of encouraging workingmen to visit in the evening, and to devote most of the museum’s space to public displays. He even proposed, very radically, to put informative labels on each display so that people could appreciate what they were viewing.
In this, somewhat unexpectedly, he was opposed by T. H. Huxley, who believed that museums should be primarily research institutes.”
“In the early 1800s there arose in England a fashion for inhaling nitrous oxide, or laughing gas, after it was discovered that its use “was attended by a highly pleasurable thrilling.” For the next half century it would be the drug of choice for young people. One learned body, the Askesian Society, was for a time devoted to little else. Theaters put on “laughing gas evenings” where volunteers could refresh themselves with a robust inhalation and then entertain the audience with their comical staggerings.”
“Mendeleyev was said to have been inspired by solitaire. Using a broadly similar concept, he arranged the elements in horizontal rows called periods and vertical columns called groups. This instantly showed one set of relationships when read up and down and another when read side to side. Specifically, the vertical columns put together chemicals that have similar properties. Thus copper sits on top of silver and silver sits on top of gold because of their chemical affinities as metals, while helium, neon, and argon are in a column made up of gases. The horizontal rows, meanwhile, arrange the chemicals in ascending order by the number of protons in their nuclei — what is known as their atomic number.”
“For a long time it was assumed that anything so miraculously energetic as radioactivity must be beneficial. For years, manufacturers of toothpaste and laxatives put radioactive thorium in their products, and at least until the late 1920s the Glen Springs Hotel in the Finger Lakes region of New York (and doubtless others as well) featured with pride the therapeutic effects of its “Radioactive mineral springs.” Radioactivity wasn’t banned in consumer products until 1938.”
“Working with her new husband, Pierre, Curie found that certain kinds of rocks poured out constant and extraordinary amounts of energy, yet without diminishing in size or changing in any detectable way. What she and her husband couldn’t know — what no one could know until
Einstein explained things the following decade — was that the rocks were converting mass into energy in an exceedingly efficient wav. Marie Curie dubbed the effect “radioactivity.””
“As you will recall from school days, E in the equation stands for energy, m for mass, and o for the speed of light squared.
In simplest terms, what the equation says is that mass and energy have an equivalence. They are two forms of the same thing: energy is liberated matter; matter is energy waiting to happen. Since c2 (the speed of light times itself) is a truly enormous number, what the equation is saying is that there is a huge amount — a really huge amount-of energy bound up in every material things.
You may not feel outstandingly robust, but if you are an average-sized adult you will contain within your modest frame no less than 7x 1018 joules of potential energy — enough to explode with the force of thirty very large hydrogen bombs, assuming you knew how to liberate it and really wished to make a point. Everything has this kind of energy trapped within it. We’re just not very good at getting it out. Even a uranium bomb — the most energetic thing we have produced yet — releases less than 1 percent of the energy it could release if only we were more cunning.
Among much else, Einstein’s theory explained how radiation worked: how a lump of uranium could throw out constant streams of high-level energy without melting away like an ice cube. (It could do it by converting mass to energy extremely efficiently à la E=mc?.) It explained how stars could burn for billions of years without racing through their fuel. (Ditto.) At a stroke, in a simple formula, Einstein endowed geologists and astronomers with the luxury of billions of years. Above all, the special theory showed that the speed of light was constant and supreme. Nothing could overtake it.”
“This was truly startling. The universe was expanding, swiftly and evenly in all directions. It didn’t take a huge amount of imagination to read backwards from this and realize that it must therefore have started from some central point. Far from being the stable, fixed, eternal void that everyone had always assumed, this was a universe that had a beginning. It might therefore also have an end.”
“Atoms are very abundant. They’re also fantastically durable. Because they’re so long-lived, atoms really get around. Every atom you possess has almost certainly passed through several stars and been part of millions of organisms on its way to becoming you. We are each so anatomically numerous and vigorously recycled at death that a significant number of our atoms — up to a billion for each of us — probably once belonged to Shakespeare.”
“Every atom is made from three kinds of elementary particles: protons, which have a positive electrical charge; electrons, which have a negative electrical charge; and neutrons, which have no charge. Protons and neutrons are packed into the nucleus, while electrons spin around outside. The number of protons is what gives an atom its chemical identity. An atom with one proton is an atom of hydrogen, one with two protons is helium, with three protons is lithium, and so on up the scale. Each time you add a proton you get a new element.”
“Neutrons don’t influence an atom’s identity, but they do add to its mass. The number of neutrons is generally about the same as the number of protons, but they can vary up and down slightly. Add a neutron or two and you get an isotope. The terms you hear in reference to dating techniques in archeology refer to isotopes-carbon-14, for instance, which is an atom of carbon with six protons and eight neutrons (the fourteen being the sum of the two).
Neutrons and protons occupy the atom’s nucleus. The nucleus of an atom is tiny — only one millionth of a billionth of the full volume of the atom — but fantastically dense, since it contains virtually all the atom’s mass.”
“It is still a fairly astounding notion to consider that atoms are mostly empty space, and that the solidity we experience all around us is an illusion. When two objects come together in the real world — billiard balls are most often used for illustration — they don’t actually strike each other. “Rather,” as Timothy Ferris explains, “the negatively charged fields of the two balls repel each other … were it not for their electrical charges they could, like galaxies, pass right through each other unscathed.” When you sit in a chair, you are not actually sitting there, but levitating above it at a height of one angstrom (a hundred millionth of a centimeter), your electrons and its electrons implacably opposed to any closer intimacy.”
“Mastery of the neutron was essential to the development of the atomic bomb. (Because neutrons have no charge, they aren’t repelled by the electrical fields at the heart of an atom and thus could be fired like tiny torpedoes into an atomic nucleus, setting off the destructive process known as fission.) Had the neutron been isolated in the 1920s, they note, it is “very likely the atomic bomb would have been developed first in Europe, undoubtedly by the Germans.””
“All living things have within them an isotope of carbon called carbon-14, which begins to decay at a measurable rate at the instant they die. Carbon-14 has a half life — that is, the time it takes for half of any sample to disappear — of about 5,600 years, so by working out how much of a given sample of carbon has decayed, Libby could get a good fix on the age of an object — though only up to a point. After 8 half-lives, only 1/256 of the original radioactive carbon remains, which is too little to make a reliable measurement, so radiocarbon dating works only for objects up to 40k or so years old.”
“To his great credit, Patterson never wavered or buckled. Eventually his efforts led to the introduction of the Clean Air Act of 1970 and finally to the removal from sale of all leaded gasoline in the United States in 1986. Almost immediately lead levels in the blood of Americans fell by 80 percent. But because lead is forever, those of us alive today have about 625 times more lead in our blood than people did a century ago. The amount of lead in the. atmosphere also continues to grow, quite legally, by about a hundred thousand metric tons a year, mostly from mining, smelting, and industrial activities. The United States also banned lead in indoor paint, “forty-four years after most of Europe,” as McGrayne notes. Remarkably, considering its startling toxicity, lead solder was not removed from American food containers until 1993.”
Plate Tectonics
“Throughout the 1950s oceanographers were undertaking more and more sophisticated surveys of the ocean floors. In so doing, they found an even bigger surprise: the mightiest and most extensive mountain range on Earth was — mostly — underwater. It traced a continuous path along the world’s seabeds, rather like the stitching on a baseball. If you began at Iceland, you could follow it down the center of the Atlantic Ocean, around the bottom of Africa, and across the Indian and Southern Oceans, below tralia; there it angled across the Pacific as if making for Baja California before shooting up the west coast of the United States to Alaska. Occasionally its higher peaks poked above the water as an island or archipelago — the Azores and Canaries in the Atlantic, Hawaii in the Pacific, for instance — but mostly it was buried under thousands of fathoms of salty sea, unknown and unsuspected. When all its branches were added together, the network extended to 46,600 miles.
A very little of this had been known for some time. People laying ocean-floor cables in the nineteenth century had realized that there was some kind of mountainous intrusion in the mid-Atlantic from the way the cables ran, but the continuous nature and overall scale of the chain was a stunning surprise.
Moreover, it contained physical anomalies that couldn’t be explained. Down the middle of the mid-Atlantic ridge was a canyon — a rift-up to a dozen miles wide for its entire 12,000-mile length. This seemed to suggest that the Earth was splitting apart at the seams, like a nut bursting out of its shell. It was an absurd and unnerving notion, but the evidence couldn’t be denied.
Then in 1960 core samples showed that the ocean floor was quite young at the mid-Atlantic ridge but grew progressively older as you moved away from it to the east or west. Harry Hess considered the matter and realized that this could mean only one thing: new ocean crust was being formed on either side of the central rift, then being pushed away from it as new crust came along behind. The Atlantic floor was effectively two large conveyor belts, one carrying crust toward North America, the other carrying crust toward Europe. The process became known as seafloor spreading.
When the crust reached the end of its journey at the boundary with continents, it plunged back into the Earth in a process known as subduction. That explained where all the sediment went. It was being returned to the bowels of the Earth. It also explained why ocean floors everywhere were so comparatively youthful. None had ever been found to be older than about 175 million years, which was a puzzle because continental rocks were often billions of years old. Now Hess could see why. Ocean rocks lasted only as long as it took them to travel to shore.”
“There are also many surface features that tectonics can’t explain. Take Denver. It is, as everyone knows, a mile high, but that rise is comparatively recent. When dinosaurs roamed the Earth, Denver was part of an ocean bottom, many thousands of feet lower. Yet the rocks on which Denver sits are not fractured or deformed in the way they would be if Denver had been pushed up by colliding plates, and anyway Denver was too far from the plate edges to be susceptible to their actions. It would be as if you pushed against the edge of a rug hoping to raise a ruck at the opposite end. Mysteriously and over millions of years, it appears that Denver has been rising, like baking bread. So, too, has much of southern Africa; a portion of it a thousand miles across has risen nearly a mile in 100 million years without any known associated tectonic activity. Australia, meanwhile, has been tilting and sinking. Over the past 100 million years as it has drifted north toward Asia, its leading edge has sunk by some six hundred feet. It appears that Indonesia is very slowly drowning, and dragging Australia down with it. Nothing in the theories of tectonics can explain any of this.”
“A 7.3 quake is 50 times more powerful than a 6.3 earthquake and 2,500 times more powerful than a 5.3 earthquake.
At least theoretically, there is no upper limit for an earthquake — nor, come to that, a lower limit. The scale is a simple measure of force, but says nothing about damage. A magnitude 7 quake happening deep in the mantle — say, four hundred miles down — might cause no surface damage at all, while a significantly smaller one happening just four miles under the surface could wreak widespread devastation. Much, too, depends on the nature of the subsoil, the quake’s duration, the frequency and severity of aftershocks, and the physical setting of the affected area. All this means that the most fearsome quakes are not necessarily the most forceful, though force obviously counts for a lot.”
“For pure, focused, devastation, however, probably the most intense earthquake in recorded history was one that struck — and essentially shook to pieces — Lisbon, Portugal, on All Saints Day (November 1), 1755. Just before ten in the morning, the city was hit by a sudden sideways lurch now estimated at magnitude 9.0 and shaken ferociously for seven full minutes. The convulsive force was so great that the water rushed out of the city’s harbor and returned in a wave fifty feet high, adding to the destruction. When at last the motion ceased, survivors enjoyed just three minutes of calm before a second shock came, only slightly less severe than the first. A third and final shock followed two hours later. At the end of it all, sixty thousand people were dead and virtually every building for miles reduced to rubble. The San Francisco earthquake of 1906, for comparison, measured an estimated 7.8 on the Richter scale and lasted less than thirty seconds.”
Volcanos
“At 8:32 A.M. on a Sunday morning, May 18, the north side of the volcano collapsed, sending an enormous avalanche of dirt and rock rushing down the mountain slope at 150 miles an hour. It was the biggest landslide in human history and carried enough material to bury the whole of Manhattan to a depth of four hundred feet. A minute later, its flank severely weakened, St. Helens exploded with the force of five hundred Hiroshima-sized atomic bombs, shooting out a murderous hot cloud at up to 650 miles an hour — much too fast, clearly, for anyone nearby to outrace. Many people who were thought to be in safe areas, often far out of sight of the volcano, were overtaken. Fifty-seven people were killed. Twenty-three of the bodies were never found. The toll would have been much higher except that it was a Sunday. Had it been a weekday many lumber workers would have been working within the death zone. As it was, people were killed eighteen miles away.”
“Ninety minutes after the blast, ash began to rain down on Yakima, Washington, a community of fifty thousand people about eighty miles away. As you would expect, the ash turned day to night and got into everything, clogging motors, generators, and electrical switching equipment, choking pedestrians, blocking filtration systems, and generally bringing things to a halt. The airport shut down and highways in and out of the city were closed.
All this was happening, you will note, just downwind of a volcano that had been rumbling menacingly for two months. Yet Yakima had no volcano emergency procedures. The city’s emergency broadcast system, which was supposed to swing into action during a crisis, did not go on the air because “the Sunday morning staff did not know how to operate the equipment.” For three days, Yakima was paralyzed and cut off from the world, its airport closed, its approach roads impassable.”
“In 1943, at Parícutin in Mexico, a farmer was startled to see smoke rising from a patch on his land. In one week he was the bemused owner of a cone five hundred feet high. Within two years it had topped out at almost fourteen hundred feet and was more than half a mile across. Altogether there are some ten thousand of these intrusively visible volcanoes on Earth.”
“Virtually the whole park — 2.2 million acres — was caldera. The explosion had left a crater more than forty miles across — much too huge to be perceived from anywhere at ground level. At some time in the past Yellowstone must have blown up with a violence far beyond the scale of anything known to humans.
Yellowstone, it turns out, is a supervolcano. It sits on top of an enormous hot spot, a reservoir of molten rock that rises from at least 125 miles down in the Earth. The heat from the hot spot is what powers all of Yellowstone’s vents, geysers, hot springs, and popping mud pots. Beneath the surface is a magma chamber that is about forty-five miles across — roughly the same dimensions as the park — and about eight miles thick at its thickest point. Imagine a pile of TNT about the size of Rhode Island and reaching eight miles into the sky, to about the height of the highest cirrus clouds.”
“The last supervolcano eruption on Earth was at Toba, in northern Sumatra, seventy-four thousand years ago. No one knows quite how big it was other than that it was a whopper. Greenland ice cores show that the Toba blast was followed by at least six years of “volcanic winter” and goodness knows how many poor growing seasons after that. The event, it is thought, may have carried humans right to the brink of extinction, reducing the global population to no more than a few thousand individuals. That means that all modern humans arose from a very small population base, which would explain our lack of genetic diversity. At all events, there is some evidence to suggest that for the next twenty thousand years the total number of people on Earth was never more than a few thousand at any time. That is, needless to say, a long time to recover from a single volcanic blast.”
“The cycle of Yellowstone’s eruptions averaged one massive blow every 600,000 years. The last one, interestingly enough, was 630,000 years ago. Yellowstone, it appears, is due.”
“There are more geysers and hot springs at Yellowstone than in all the rest of the world combined.”
Climate
“Without the Moon’s steadying influence, the Earth would wobble like a dying top, with goodness knows what consequences for climate and weather. The Moon’s steady gravitational influence keeps the Earth spinning at the right speed and angle to provide the sort of stability necessary for the long and successful development of life. This won’t go on forever.”
“The first, much thinner edition of that atlas, produced in 1896, divided clouds into ten basic types, of which the plumpest and most cushiony-looking was number nine, cumulonimbus. That seems to have been the source of the expression “to be on cloud nine.”
For all the heft and fury of the occasional anvil-headed storm cloud, the average cloud is actually a benign and surprisingly insubstantial thing. A fluffy summer cumulus several hundred yards to a side may contain no more than twenty-five or thirty gallons of water — ”about enough to fill a bathtub,” as James Trefil has noted. You can get some sense of the immaterial quality of clouds by strolling through fog — which is, after all, nothing more than a cloud that lacks the will to fly. To quote Trefil again: “If you walk 100 yards through a typical fog, you will come into contact with only about half a cubic inch of water — not enough to give you a decent drink.” In consequence, clouds are not great reservoirs of water. Only about 0.035 percent of the Earth’s fresh water is floating around above us at any moment.
Depending on where it falls, the prognosis for a water molecule varies widely. If it lands in fertile soil it will be soaked up by plants or reevaporated directly within hours or days. If it finds its way down to the groundwater, however, it may not see sunlight again for many years — thousands if it gets really deep. When you look at a lake, you are looking at a collection of molecules that have been there on average for about a decade. In the ocean the residence time is thought to be more like a hundred years. Altogether about 60 percent of water molecules in a rainfall are returned to the atmosphere within a day or two. Once evaporated, they spend no more than a week or so — Drury says twelve days — in the sky before falling again as rain.”
“Oceans are the real powerhouse of the planet’s surface behavior. Indeed, meteorologists increasingly treat oceans and atmosphere as a single system, which is why we must give them a little of our attention here. Water is marvelous at holding and transporting heat. Every day, the Gulf Stream carries an amount of heat to Europe equivalent to the world’s output of coal for ten years, which is why Britain and Ireland have such mild winters compared with Canada and Russia.
But water also warms slowly, which is why lakes and swimming pools are cold even on the hottest days. For that reason there tends to be a lag in the official, astronomical start of a season and the actual feeling that that season has started. So spring may officially start in the northern hemisphere in March, but it doesn’t feel like it in most places until April at the very earliest.
The oceans are not one uniform mass of water. Their differences in temperature, salinity, depth, density, and so on have huge effects on how they move heat around, which in turn affects climate. The Atlantic, for instance, is saltier than the Pacific, and a good thing too. The saltier water is the denser it is, and dense water sinks. Without its extra burden of salt, the Atlantic currents would proceed up to the Arctic, warming the North Pole but depriving Europe of all that kindly warmth. The main agent of heat transfer on Earth is what is known as thermohaline circulation, which originates in slow, deep currents far below the surface — a process first detected by the scientist-adventurer Count von Rumford in 1797. What happens is that surface waters, as they get to the vicinity of Europe, grow dense and sink to great depths and begin a slow trip back to the southern hemisphere. When they reach Antarctica, they are caught up in the Antarctic Circumpolar Current, where they are driven onward into the Pacific. The process is very slow — it can take 1,500 years for water to travel from the North Atlantic to the mid-Pacific — but the volumes of heat and water they move are very considerable, and the influence on the climate is enormous.”
“One of the oddities of our solar system is that the Sun burns about 25 percent more brightly now than when the solar system was young. This should have resulted in a much warmer Earth. Indeed, as the English geologist Aubrey Manning has put it, “This colossal change should have had an absolutely catastrophic effect on the Earth and yet it appears that our world has hardly been affected.”
So what keeps the world stable and cool?
Life does. Trillions upon trillions of tiny marine organisms that most of us have never heard of — foraminiferans and coccoliths and calcareous algae — capture atmospheric carbon, in the form of carbon dioxide, when it falls as rain and use it (in combination with other things) to make their tiny shells. By locking the carbon up in their shells, they keep it from being reevaporated into the atmosphere, where it would build up dangerously as a greenhouse gas. Eventually all the tiny foraminiferans and coccoliths and so on die and fall to the bottom of the sea, where they are compressed into limestone. It is remarkable, when you behold an extraordinary natural feature like the White Cliffs of Dover in England, to reflect that it is made up of nothing but tiny deceased marine organisms, but even more remarkable when you realize how much carbon they cumulatively sequester. A six-inch cube of Dover chalk will contain well over a thousand liters of compressed carbon dioxide that would otherwise be doing us no good at all. Altogether there is about twenty thousand times as much carbon locked away in the Earth’s rocks as in the atmosphere. Eventually much of that limestone will end up feeding volcanoes, and the carbon will return to the atmosphere and fall to the Earth in rain, which is why the whole is called the long-term carbon cycle. The process takes a very long time — about half a million years for a typical carbon atom — but in the absence of any other disturbance it works remarkably well at keeping the climate stable.”
“Water is everywhere. A potato is 80 percent water, a cow 74 percent, a bacterium 75 percent. A tomato, at 95 percent, is little but water. Even humans are 65 percent water, making us more liquid than solid by a margin of almost two to one.”
The Ocean
“The water realm is known as the hydrosphere and it is overwhelmingly oceanic. Ninety-seven percent of all the water on Earth is in the seas, the greater part of it in the Pacific, which covers half the planet and is bigger than all the landmasses put together. Altogether the Pacific holds just over half of all the ocean water (51.6 percent to be precise); the Atlantic has 23.6 percent and the Indian Ocean 21.2 percent, leaving just 3.6 percent to be accounted for by all the other seas. The average depth of the ocean is 2.4 miles.”
“Even the most substantial ocean creatures are often remarkably little known to us — including the most mighty of them all, the great blue whale, a creature of such leviathan proportions that (to quote David Attenborough) its “tongue weighs as much as an elephant, its heart is the size of a car and some of its blood vessels are so wide that you could swim down them.” It is the most gargantuan beast that Earth has yet produced, bigger even than the most cumbrous dinosaurs. Yet the lives of blue whales are largely a mystery to us. Much of the time we have no idea where they are — where they go to breed, for instance, or what routes they follow to get there. What little we know of them comes almost entirely from eavesdropping on their songs, but even these are a mystery. Blue whales will sometimes break off a song, then pick it up again at the same spot six months later. Sometimes they strike up with a new song, which no member can have heard before but which each already knows. How they do this is not remotely understood. And these are animals that must routinely come to the surface to breathe.
For animals that need never surface, obscurity can be even more tantalizing. Consider the fabled giant squid. Though nothing on the scale of the blue whale, it is a decidedly substantial animal, with eyes the size of soccer balls and trailing tentacles that can reach lengths of sixty feet. It weighs nearly a ton and is Earth’s largest invertebrate. If you dumped one in a normal household swimming pool, there wouldn’t be much room for anything else. Yet no scientist — no person as far as we know has ever seen a giant squid alive. Zoologists have devoted careers to trying to capture, or just glimpse, living giant squid and have always failed. They are known mostly from being washed up on beaches — particularly, for unknown reasons, the beaches of the South Island of New Zealand. They must exist in large numbers because they form a central part of the sperm whale’s diet, and sperm whales take a lot of feeding.”
“Elsewhere, the oceans aren’t nearly so rich. Take Australia. With over 20,000 miles of coastline and almost nine million square miles of territorial waters, it has more sea lapping its shores than any other country, yet, as Tim Flannery notes, it doesn’t even make it into the top fifty among fishing nations. Indeed, Australia is a large net importer of seafood. This is because much of Australia’s waters are, like much of Australia itself, essentially desert. (A notable exception is the Great Barrier Reef off Queensland, which is sumptuously fecund.) Because the soil is poor, it produces little in the way of nutrient-rich runoff.
Even where life thrives, it is often extremely sensitive to disturbance. In the 1970s, fishermen from Australia and, to a lesser extent, New Zealand discovered shoals of a little-known fish living at a depth of about half a mile on their continental shelves. They were known as orange roughy, they were delicious, and they existed in huge numbers. In no time at all, fishing fleets were hauling in forty thousand metric tons of roughy a year. Then marine biologists made some alarming discoveries. Roughy are extremely long lived and slow maturing. Some may be 150 years old; any roughy you have eaten may well have been born when Victoria was Queen. Roughy have adopted this exceedingly unhurried lifestyle because the waters they live in are so resource-poor. In such waters, some fish spawn just once in a lifetime.”
“A bowl of shark fin soup retailed in Tokyo for $100. The World Wildlife Fund estimated in 1994 that the number of sharks killed each year was between 40 million and 70 million.”
“As of 1995, some 37,000 industrial-sized fishing ships, plus about a million smaller boats, were between them taking twice as many fish from the sea as they had just twenty-five years earlier. Trawlers are sometimes now as big as cruise ships and haul behind them nets big enough to hold a dozen jumbo jets. Some even use spotter planes to locate shoals of fish from the air.
It is estimated that about a quarter of every fishing net hauled up contains “by-catch” — fish that can’t be landed because they are too small or of the wrong type or caught in the wrong season. As one observer told the Economist: “We’re still in the Dark Ages. We just drop a net down and see what comes up.” Perhaps as much as twenty-two million metric tons of such unwanted fish are dumped back in the sea each year, mostly in the form of corpses. For every pound of shrimp harvested, about four pounds of fish and other marine creatures are destroyed.
Large areas of the North Sea floor are dragged clean by beam trawlers as many as seven times a year, a degree of disturbance that no ecosystem can withstand.”
“In the New England fisheries off Rhode Island, it was once routine to haul in lobsters weighing twenty pounds. Sometimes they reached thirty pounds. Left unmolested, lobsters can live for decades — as much as seventy years, it is thought — and they never stop growing. Nowadays few lobsters weigh more than two pounds on capture. “Biologists,” according to the New York Times, “estimate that 90 percent of lobsters are caught within a year after they reach the legal minimum size at about age six.” Despite declining catches, New England fishermen continue to receive state and federal tax incentives that encourage them--in some cases all but compel them — to acquire bigger boats and to harvest the seas more intensively.”
“While marine life is poorer than it ought to be in areas that have been overfished, in some naturally impoverished waters there is far more life than there ought to be. The southern oceans around Antarctica produce only about 3 percent of the world’s phytoplankton — far too little, it would seem, to support a complex ecosystem, and yet it does. Crab-eater seals are not a species of animal that most of us have heard of, but they may actually be the second most numerous large species of animal on Earth, after humans. As many as fifteen million of them may live on the pack ice around Antarctica. There are also perhaps two million Weddel seals, at least half a million emperor penguins, and maybe as many as four million Adélie penguins. The food chain is thus hopelessly top heavy, but somehow it works. Remarkably no one knows how.”
Cells
“A protein to be of use must not only assemble amino acids in the right sequence, but then must engage in a kind of chemical origami and fold itself into a very specific shape. Even having achieved this structural complexity, a protein is no good to you if it can’t reproduce itself, and proteins can’t. For this you need DNA. DNA is a whiz at replicating — it can make a copy of itself in seconds — but can do virtually nothing else. So we have a paradoxical situation. Proteins can’t exist without DNA, and DNA has no purpose without proteins. Are we to assume then that they arose simultaneously with the purpose of supporting each other? If so: wow.
And there is more still. DNA, proteins, and the other components of life couldn’t prosper without some sort of membrane to contain them. No atom or molecule has ever achieved life independently. Pluck any atom from your body, and it is no more alive than is a grain of sand. It is only when they come together within the nurturing refuge of a cell that these diverse materials can take part in the amazing dance that we call life. Without the cell, they are nothing more than interesting chemicals. But without the chemicals, the cell has no purpose. As the physicist Paul Davies puts it, “If everything needs everything else, how did the community of molecules ever arise in the first place?” It is rather as if all the ingredients in your kitchen somehow got together and baked themselves into a cake — but a cake that could moreover divide when necessary to produce more cakes. It is little wonder that we call it the miracle of life.”
“Our white cells actually use oxygen to kill invading bacteria. That oxygen is fundamentally toxic often comes as a surprise to those of us who find it so convivial to our well-being, but that is only because we have evolved to exploit it. To other things it is a terror. It is what turns butter rancid and makes iron rust. Even we can tolerate it only up to a point. The oxygen level in our cells is only about a tenth the level found in the atmosphere.”
Bacteria and Viruses
“If you are in good health and averagely diligent about hygiene, you will have a herd of about one trillion bacteria grazing on your fleshy plains — about a hundred thousand of them on every square centimeter of skin. They are there to dine off the ten billion or so flakes of skin you shed every day, plus all the tasty oils and fortifying minerals that seep out from every pore and fissure. You are for them the ultimate food court, with the convenience of warmth and constant mobility thrown in. By way of thanks, they give you B.O.
And those are just the bacteria that inhabit your skin. There are trillions more tucked away in your gut and nasal passages, clinging to your hair and eyelashes, swimming over the surface.”
“Bacteria, never forget, got along for billions of years without us. We couldn’t survive a day without them. They process our wastes and make them usable again; without their diligent munching nothing would rot. They purify our water and keep our soils productive. Bacteria synthesize vitamins in our gut, convert the things we eat into useful sugars and polysaccharides, and go to war on alien microbes that slip down our gullet.
We depend totally on bacteria to pluck nitrogen from the air and convert it into useful nucleotides and amino acids for us.”
“Flu normally is hardest on infants and the elderly, but in the 1918 outbreak deaths were overwhelmingly among people in their twenties and thirties. Older people may have benefited from resistance gained from an earlier exposure to the same strain, but why the very young were similarly spared is unknown. The greatest mystery of all is why the 1918 flu was so ferociously deadly when most flus are not. We still have no idea.”
Fossils
“Only about one bone in a billion, it is thought, ever becomes fossilized. If that is so, it means that the complete fossil legacy of all the Americans alive today — that’s 270 million people with 206 bones each — will only be about fifty bones, one quarter of a complete skeleton. That’s not to say of course that any of these bones will actually be found. Bearing in mind that they can be buried anywhere within an area of slightly over 3.6 mil-lion square miles, little of which will ever be turned over, much less examined, it would be something of a miracle if they were. Fossils are in every sense vanishingly rare. Most of what has lived on Earth has left behind no record at all. It has been estimated that less than one species in ten thousand has made it into the fossil record.”
“About 95 percent of all the fossils we possess are of animals that once lived under water, mostly in shallow seas.”
Fungi
“Closer inspection showed that lichens were more interesting than magical. They are in fact a partnership between fungi and algae. The fungi excrete acids that dissolve the surface of the rock, freeing minerals that the algae convert into food sufficient to sustain both.”
“Like most things that thrive in harsh environments, lichens are slow-growing. It may take a lichen more than half a century to attain the dimensions of a shirt button. Those the size of dinner plates, writes David Attenborough, are therefore “likely to be hundreds if not thousands of years old.””
Mammals
“There was a powerful incentive to leave the water: it was getting dangerous down there. The slow fusion of the continents into a single landmass, Pangaea, meant there was much, much less coastline than formerly and thus much less coastal habitat. So competition was fierce. There was also an omnivorous and unsettling new type of predator on the scene, one so perfectly designed for attack that it has scarcely changed in all the long eons since its emergence: the shark.”
“Once they got going, mammals expanded prodigiously sometimes to an almost preposterous degree. For a time, there were guinea pigs the size of rhinos and rhinos the size of a two-story house. Wherever there was a vacancy in the predatory chain, mammals rose (often literally) to fill it. Early members of the raccoon family migrated to South America, discovered a vacancy, and evolved into creatures the size and ferocity of bears. Birds, too, prospered disproportionately. For millions of years, a gigantic, flightless, carnivorous bird called Titanis was possibly the most ferocious creature in North America. Certainly it was the most daunting bird that ever lived. It stood ten feet high, weighed over eight hundred pounds, and had a beak that could tear the head off pretty much anything that irked it.”
“Go back just eight generations to about the time that Charles Darwin and Abraham Lincoln were born, and already there are over 250 people on whose timely couplings your existence depends. Continue further, to the time of Shakespeare and the Mayflower Pilgrims, and you have no fewer than 16,384 ancestors earnestly exchanging genetic material in a way that would, eventually and miraculously, result in you. At twenty generations ago, the number of people procreating on your behalf has risen to 1,048,576. Five generations before that, and there are no fewer than 33,554,432 men and women on whose devoted couplings your existence depends. By thirty generations ago, your total number of forebears--remember, these aren’t cousins and aunts and other incidental relatives, but only parents and parents of parents in a line leading ineluctably to you — is over one billion (1,073,741,824, to be precise). If you go back sixty-four generations, to the time of ti. Romans, the number of people on whose cooperative efforts your eventual existence depends has risen to approximately 1,000,000,000,000,000,000, which is several thousand times the total number of people who have ever lived.
Clearly something has gone wrong with our math here. The answer, it may interest you to learn, is that your line is not pure. You couldn’t be here without a little incest — actually quite a lot of incest — albeit at a genetically discreet remove. With so many millions of ancestors in your background, there will have been many occasions when a relative from your mother’s side of the family procreated with some distant cousin from your father’s side of the ledger. In fact, if you are in a partnership now with someone from your own race and country, the chances are excellent that you are at some level related. Indeed, if you look around you on a bus or in a park or café or any crowded place, most of the people you see are very probably relatives.”
“If all your DNA were woven into a single fine strand, there would be enough of it to stretch from the Earth to the Moon and back not once or twice but again and again. Altogether, according to one calculation, you may have as much as twenty million kilometers of DNA bundled up inside you.”
“So it was for the longest time with genes. The idea that you could pluck one from your body and take it away for study was as absurd to many of Morgan’s peers as the idea that scientists today might capture a stray thought and examine it under a microscope.”
“Most of the time our DNA replicates with dutiful accuracy, but just occasionally-about one time in a million — a letter gets into the wrong place. This is known as a single nucleotide polymorphism, or SP, familiarly known to biochemists as a “Snip.” Generally these Snips are buried in stretches of noncoding DNA and have no detectable consequence for the body. But occasionally they make a difference. They might leave you predisposed to some disease, but equally they might confer some slight advantage — more protective pigmentation, for instance, or increased production of red blood cells for someone living at altitude. Over time, these slight modifications accumulate in both individuals and in populations, contributing to the distinctiveness of both.
The balance between accuracy and errors in replication is a fine one. Too many errors and the organism can’t function, but too few and it sacrifices adaptability. A similar balance must exist between stability in an organism and innovation. An increase in red blood cells can help a person or group living at high elevations to move and breathe more easily because more red cells can carry more oxygen. But additional red cells also thicken the blood. Add too many, and “it’s like pumping oil,” in the words of Temple University anthropologist Charles Weitz. That’s hard on the heart. Thus those designed to live at high altitude get increased breathing efficiency, but pay for it with higher-risk hearts.”
“First in Germany and then in Switzerland researchers performed some rather bizarre experiments that produced curiously unbizarre outcomes. In one they took the gene that controlled the development of a mouse’s eye and inserted it into the larva of a fruit fly. The thought was that it might produce something interestingly grotesque. In fact, the mouse-eye gene not only made a viable eye in the fruit fly, it made a fly’s eye. Here were two creatures that hadn’t shared a common ancestor for 500 million years, yet could swap genetic material as if they were sisters.
The story was the same wherever researchers looked. They found that they could insert human DNA into certain cells of flies, and the flies would accept it as if it were their own. Over 60 percent of human genes, it turns out, are fundamentally the same as those found in fruit flies. At least 90 percent correlate at some level to those found in mice. (We even have the same genes for making a tail, if only they would switch on.) In field after field, researchers found that whatever organism they were working on — whether nematode worms or human beings they were often studying essentially the same genes. Life, it appeared, was drawn up from a single set of blueprints.”
“Until recently it was thought that humans had at least 100,000 genes, possibly a good many more, but that number was drastically reduced by the first results of the Human Genome Project, which suggested a figure more like 35,000 or 40,000 genes — about the same number as are found in grass.”
“Even thinking, it turns out, affects the ways genes work. How fast a man’s beard grows, for instance, is partly a function of how much he thinks about sex (because thinking about sex produces a testosterone surge).”
“Modern human beings show remarkably little genetic variability — there’s more diversity in one social group of fifty-five chimps than in the entire human population.”
