Literary Theme with Biological Variations

In his short story "Pierre Menard, Author of Don Quixote" the Argentinian writer Jorge Luis Borges recounts the story of a symbolist author in turn-of-the-(last)century France who endeavors to rewrite Miguel de Cervantes’ celebrated work. Pierre Menard, however, is no mere parasite intending to copy or paraphrase Cervantes. His intent is to write a verbally identical book based on his own experience. Menard, alas, dies after completing only two chapters. But how fascinating those two chapters can be! Read as the work of a twentieth-century writer, Menard’s Don Quixote is a completely different book.

This, of course, is only possible in Borges’ brilliant fantasy world. In real life, if you hold two books in your hand --for example, Cervantes’ Don Quijote de la Mancha and Menard’s Don Quijote de la Mancha--, and the books correspond word by word, or almost, you immediately smell a rat. The books must --to say the very least-- have a common ancestor. They can’t really be independent.

Odoriferous rodents of the same kind assail the discerning noses of biologists when they compare organisms from the present and from the past using the tools of old and new biological disciplines such as embryology, anatomy, genetics, and biochemistry. Charles Darwin’s original treatise was a steamroller of evidence for “descent with modification.” Today, evolutionists possess further detailed and consistent proof of the fact of biological evolution.

Consider the backbone in humans. Humans, as you probably know, walk upright most of the time. Our backbones are placed in the back (duh). But look at the famous roof at the Museo de Antropología, in Mexico City. Here it is: 

A hypothetical Cosmic Engineer designing humans from scratch would have endowed us with sturdier “backbones” passing through the center of the torso, not along the back. As things are, we are well adapted to an upright posture, but not perfectly adapted, because we have only recently evolved from ancestors that went about on all fours. Imperfections such as are manifest in anatomical studies argue for evolution and against design.

Anatomy, physiology, embryology and other tools that were already available in Darwin’s time can probe only so deep into the similarities of organisms, and go only so far back in time. It is the more recently developed field of molecular biology that provides the most detailed and convincing evidence that we are all, from human to bacterium, ultimately related by descent from common ancestors.

The organic compounds known as aminoacids can be numbered in the hundreds, yet all bacteria, plants, animals and fungi synthesize all their proteins based on just 20 aminoacids, the same 20 for all living beings. Further, for all its staggering diversity, all life on Earth depends on the same few chemical pathways (fermentation, photosynthesis, respiration) to produce energy and build cell components. The molecular and chemical uniformity of life can only be accounted for by evolution.
Molecular biology is unique as a tool for comparative analysis of species in that it allows scientists to precisely quantify the degree of similarity of different organisms. The protein cytochrome c of humans is identical to that of chimpanzees. It differs by one aminoacid from that of rhesus monkeys, by 12 from that of horses, and by 21 aminoacids from that of tuna fish. Comparing the DNA of two species, molecular biologists can now even determine approximately how far back in time the species’ most recent common ancestor lived in the same way that linguists can tell how recently two languages diverged from a parent language by analyzing their similarities.

This is only a paltry sample of facts that can only be explained by evolution. Darwin himself provides many more in The Origin of Species. Today all scientists agree that, as Theodosius Dobzhansky, a leading evolutionist, once said: “Nothing in biology makes sense except in the light of evolution.”

Quality Control

Lawyers, politicians and scientists love a good argument. As a scientist, however, I wouldn’t want to argue with neither a lawyer nor a politician. For, you see, while we all may love debate, a lawyer’s, a politician’s, and a scientist’s aim in debating are entirely different.

        Lawyers argue to win. That’s what they get paid for. Whether they are right or not is immaterial. Even when he knows his client is guilty a lawyer must defend the client’s innocence. Truth is not the lawyer’s main concern.

        A politician’s job --whatever Plato, Aristotle, and others may have said in the past-- is to attain office and to remain in office. Sad to say, but that’s the way it is, as you know. A politician argues to win or, failing that, to make people believe he has won. Politicians employ every trick in the rhetorician’s repertoire to defend even the wobbliest ideas.

        Scientists don’t argue to win. They enjoy victory  as much as the next guy, but winning is not so important. What’s important is the clash of ideas. In scientific debate only the fittest ideas survive. Flimsy notions perish. What you want as a scientist is not to be proven right, but to be proven, period. Sir Karl Popper, a contemporary philosopher of science, wrote: “The wrong view of science betrays itself in the craving to be right, for it is not his possession of knowledge, of irrefutable truth, that makes the man of science, but his persistent and recklessly critical quest for truth.”

        Popper also wrote: “Those among us who are unwilling to expose their ideas to the hazard of refutation do not take part in the scientific game.”  Wolfgang Pauli, one of the founders of quantum mechanics, once hired an assistant whose job it was to constantly refute his employer’s ideas with the strongest arguments he could muster. Like the warriors of yore, scientists value a worthy opponent.

        An earthquake that leaves one building standing among others in ruins proves the sturdiness of that building. It is in the interest of science to constantly submit its constructs to conceptual earthquakes in order to test their sturdiness. Here is Popper again: “Once put forward, none of our hypotheses are dogmatically upheld. Our method of research is not to defend them in order to prove how right we are. On the contrary, we try to overthrow them.”

        Karl Popper is the creator of the idea of “falsability” of scientific hypotheses. He contends that, in order to be considered scientific, a hypothesis must be formulated in such a way that, if false, it can easily be proven false. This contrasts with the old idea of verfiability of scientific theories, but it makes for more solid foundations to the scientific edifice.

        For example: “Energy is conserved” is a valid scientific statement in Popper’s sense because it is easily refutable --finding one single instance of its not being true would suffice to topple it. The principle of conservation of energy was first formulated more than one hundred years ago. So far, scientists have not found a single case in which it is violated. You see, then, how Popperian “falsability” can yield sturdy scientific principles: energy conservation is easy to disprove, yet it hasn’t been disproven. The more tests it survives, the more confident we are that energy is conserved even in situations in which we have not explicitly shown this to be the case.

        When you buy a car you kick the tires and slam the doors to guarantee that you are making a sound investment. A scientist invests much more than money in the ideas he accepts as true. What’s on the line is his ability to do useful work in the future, his worldview, and his inner equilibrium. So when it comes to selecting our truths --our cars and buildings-- we scientists are extremely picky. It is painstaking work but in reward we, more than lawyers or politicians, can feel truly safe in the cars we choose to drive and the buildings we decide to inhabit.

A Path to Greater Wonderment

What is a violin made of? Bits of wood and bits of sheep’s intestine. Does its construction demean and banalize the music? On the contrary, it exalts the music further.

--Julian Barnes

 

The story is told that Hans Bethe, the man who finally unveiled the mystery of nuclear fusion in stars, was out with his girlfriend, sitting by a cliff and gazing at the night sky.

       “How beautiful they are,” said the girl at a loss for better words to describe the stars.

       “Yes,” Bethe replied, “and right now I am the only person in the world who knows why they shine.”

       You might be tempted to rebuke Bethe for spoiling a romantic moment, but before you do, allow me to plead his cause.

       Does scientific explanation spoil beauty? Consider what Bethe’s discovery led up to. We now know that all the atoms in the universe other than hydrogen --the simplest possible atom, with a proton for a nucleus and an orbiting electron-- were created in the interiors of stars that later exploded as supernovas. The stuff our planet is made of, and the stuff we ourselves are made of, was cooked in a stellar oven billions of years ago. So what Bethe and other astrophysicists have discovered is, in effect, a link between us and the cosmos. Those bright points of light that stud the night sky are even now brewing the substance of new life.

       As for poetry and romance, consider this: Where Bethe’s companion saw little pinpoints of faintly-colored brightness her physicist friend saw mighty suns, their incandescent atmospheres roiling with nuclear fury, their colors revealing their temperature, age and composition.

       In other words, it is with nature as it is with good books and good movies --you take more from it the more you bring to it. It is simply not true that the scientist is insensitive to the beauty of nature because he can understand part of that beauty. On the contrary, science is a path to greater wonderment. The play of forces and quantum effects that allows the stars to shine and later enrich the universe with heavy elements is so subtle it makes you dream. The deductive chain linking the Big Bang with the present-day structure of the universe --though still riddled with gaps-- is nothing less than awe-inspiring. But only, I’m afraid, to the trained eye and mind --as it is with good movies.

       Consider the movie Shakespeare in Love. At the screening I attended with my wife, Magali, several years ago, there were people from all walks of life, young, old, and even a few little kids. The plot plays on many levels. On the very surface, if the name Shakespeare doesn’t ring a bell (hard to imagine but not impossible), it is a love story with some vague comedy to it.

       On the next level, you can laugh at the idea of an uninspired Shakespeare intending to write a crowd-pleaser titled Romeo and Ethel, the Pirate’s Daughter. You know he eventually wrote a tragedy, Romeo and Juliet, which is widely considered a masterpiece.

       Going deeper still, you even catch a few snippets of actual Shakespeare diaglogue being uttered in the background as an oblivious Will goes by. Later he uses those very phrases in Romeo and Ethel. You may also appreciate the piquancy in the screenwriter’s ploy of having Christopher Marlowe, Shakespeare’s real-life rival, suggest a better plot for Romeo. This is as far as my Shakespearean experience (such as it is) will take me, but there are deeper layers to Shakespeare in Love. How much more delightful the film must be for the lucky ones who can understand it in full.

       On the opposite side of the spectrum, the little kids only laughed when a character said “boobies.”

       So don’t be too harsh on Hans Bethe, the physicist who helped explain the stars. His intent was not to spoil a moment of romance, but to share with his sweetheart the poetry of a great discovery.

Einstein Confesses his "Biggest Blunder"

In 1917 Albert Einstein began to explore the cosmological implications of his recently published general theory of relativiy. General relativity is a theory of gravitation, the only force acting between stars and galaxies, so it stood to reason that it should have something to say about the structure of the universe.

Einstein wrote his equations, gave them a nudge and watched them soar. To his astonishment, they revealed that under general relativity the universe could not be static, but must be either expanding or contracting. There was, at the time, no observational evidence for this, and Einstein was forced to conclude, much to his chagrin, that there must be something wrong with the theory. He did not discard it. Instead, he modified the equations adding an artificial term containing what he called the “cosmological constant.” The cosmological constant, he thought, would hold the universe in check.

He was wrong. The Russian mathematician Aleksandr Friedmann found that Einstein had made an algebraic error, upon correction of which the universe happily took wing again. Einstein was puzzled. The equations of general relativity were simple and elegant. They had the kind of mathematical beauty in which the insightful physicist discerns physical thruth even before the equations are tested experimentally. But the astronomers he consulted told him that the stars wander more or less randomly through space, showing no concerted motion. Nature, it appeared to Einstein, had spoken, and against nature´s last word no physicist in his right mind --least of all Einstein-- ought to rise.

At the time many astronomers still believed that the stars in the Milky Way galaxy were more or less the whole universe. The spiral nebulae had not yet been recognized as galaxies in their own right. Many scientists thought they were solar systems in the process of formation, so when the astronomer Vesto Slipher of Lowell Observatory discovered that several spiral nebulae seemed to be receding from the earth at speeds much greater than the typical velocities of stars, nobody knew what to make of his data. He had in fact found the first observational indication that the universe is expanding.

But Slipher did not know that his spiral nebulae were faraway galaxies. Only after Edwin Hubble discovered Cepheid variable stars in the spiral nebulae were they identified as such. Moreover, the presence of Cepheid variables in the spirals allowed astronomers to determine their distances. In 1929 Hubble plotted the distances of 25 galaxies against their velocities of recession from the earth as measured by the “redshift” in their spectra. If the velocities were random, if the observation that most spirals seemed to be receding from the earth were just a coincidence, the graph would show a swarm of points scattered every which way. Instead, Hubble found a straight line.

Hubble was no theorist, and he was completely innocent of general relativity. He was wary of this “redshift-distance relation,” as he cautiously called it, and did not draw conlcusions from his discovery. But his graph was a message in the handwriting of the powers that be. To all who had eyes it read: “Behold, the universe is expanding.”

Einstein later called the cosmological constant his "biggest blunder". However, watch this for later developments in the fate of  this strange antigravity force:

Sticks and Shadows to Measure the Earth

The size of the Earth was determined for the first time some 2,200 years ago. At the time it was already known that our world is a sphere, but nobody had as yet come up with a way of accurately measuring its circumference.

That the earth is round was clear from several easily observable facts: when ships put out to sea their hulls always sink below the horizon before their masts; during a lunar eclipse the Earth’s shadow on the moon is always round. And so on.

One day the mathematician Erathostenes, head of the famed Alexandria library, learned about a curious fact while “leafing through” a papyrus book (presumably part of the library’s huge collection). Every year at noon on June 21 the columns of the temples in the distant city of Syene (present day Aswan), in Egypt, ceased to cast a shadow. As Erathostenes later verified, this was not the case in Alexandria, where vertical columns cast definite shadows at noon on the summer solstice.

Erathostenes knew that on a round Earth columns in Alexandria and columns in Syene do not point in the same direction. He reasoned that at noon on June 21 the sun came directly overhead in Syene so that temple columns were parallel to its rays, while at the same time vertical columns in Alexandria (or vertical sticks, or vertical whatever) were at an angle to the sun’s rays. Erathostenes saw how he could use this fact to determine the Earth’s circumference.



He planted a vertical stick on the ground in Alexandria and waited for the summer solstice. He then computed the angle formed by his stick and the sun’s rays by measuring the length of the stick’s shadow and comparing it to its height, a method involving math taught in highschool today. Erathostenes hired someone to walk all the way from Alexandria to Syene (located exactly due south from Alexandria, near the first cataract of the Nile) and measure the distance between the two cities. It is not too hard to see that the angle formed by the sun’s rays and the stick in Alexandria must be the same as the angle that the vertical of Syene and the vertical of Alexandria would form if extended to the center of the earth. So the clever mathematician now had an angle and the length of arc it traced on the surface of the earth. The angle turned out to be one fifitieth of 360 degrees, so the distance between Alexandria and Syene must equal one fiftieth of the Earth’s circumference. The figure Erathostenes came up with is equivalent to some 40,000 kilometers --remarkably close to present-day measurements.





Many centuries later a Genoese seaman by the name of Cristoforo Colombo was trying to prove that the Earth was small enough for him to reach China by sailing westward from Europe in a reasonably short time. His critics, who were probably aware of Erathostenes’s figure, claimed that the ocean separating Europe from Asia to the west was too vast, that Columbus’s proposed voyage could not be done. And they were on to something. In his eagerness to prove himself right the studious future Admiral of the Ocean Sea had rejected all ancient measurements which were incompatible with his claim, including Erathostenes’s. Had our continent not been in the way, Columbus would have sailed from Palos into oblivion.

Galileo's New Toy

The night of 7 January, 1610, in Padua, Venetian Republic, a 45-year-old mathematics professor opened his window and peered at the sky through an optical instrument he had built some six months earlier. This professor´s name was Galileo Galilei and the instrument was the telescope, known at the time as a "spyglass."
By the time Galileo came across the spyglass in 1609 the instrument had been known for some time as a peculiar toy sold in marketplaces in the Netherlands, France and England. Nobody knows who invented it. It is most likely one of those inventions that "are in the air" and which several people hit upon serendipitously and almost simultaneously. One Hans Lippershey, spectacle-maker from Middelburg, had applied for a patent to the States General of the Netherlands and tried to sell the instrument to the government by pointing out its possible military applications.
Galileo was a skillful constructor of scientific instruments, and once he had seen a spyglass he was quick to grasp the principles involved. He immediately set to work on an instrument which made distant objects appear to be three times closer than they really were. Some time later, he pushed contemporary technology to the limit by building a telescope ten times as powerful as the first one.
Realizing, as Lippershey had, the strategic potential of the spyglass, Galileo subsequently arranged a demonstration for the Venetian authorities. Later he wrote:
"Very many were the patricians and senators who, although aged, have more than once climbed the stairs of the highest campanili of Venice, to detect sails and vessels on the sea, so far away that coming under full sail toward the harbor, two hours or more passed before they could be seen without my spyglass."
As a consequence of this demonstration, Galileo´s salary was doubled and he was granted a lifelong professorial appointment at Padua.
Six months later, Galileo took his best telescope and trained it on the night sky. It was a stroke of genius. Today, one can hardly think of anything more natural to do with a telescope than to point it at the sky, but we must remember that at the time, although Nicolaus Copernicus had published his views about a sun-centered cosmos more than 60 years before, the sky was still held to be divine and pristine, a place of purity as opposed to earthly corruption. Many centuries before, Aristotle claimed that the stars and planets, including the sun and moon, were celestial emmanations that moved around the earth attached to crystal spheres and surrounded by a transparent substance called aether. Looking at the sky, therefore, meant peering into the abode of God. Galileo was treading unchartered and dangerous territory.
What he saw with his telescope during the Winter of 1610 confirmed what he had known for a long time, but had been cautious not to maintain openly --that Aristotle had been dead wrong about the nature of the stars and planets. The moon did not have a polished surface, as the Greek philosopher had said, but was instead deeply scarred with craters, crevasses and mountains, like the earth. The telescope revealed countless stars that were not visible to the unaided eye, and showed that Venus has phases like the moon, which is only possible if it orbits the sun and not the earth. But what stunned him the most was the discovery of four previously undetected "stars" in the vicinity of Jupiter. It gradually became clear that they were circling the planet. This demolished an old objection to the Copernican system in which the earth moved around the sun like the wandering stars, namely, that the moon could not possibly revolve around the earth if the earth itself revolved around the sun.
Galileo´s telescopic findings, which he wasted no time in publishing, changed humankind´s picture of the universe.

Darwin's Nose

The course of history rarely hinges on the impact of a single individual...let alone an individual’s nose. Yet Charles Darwin’s nose --which one captain Robert FitzRoy disliked at first sight-- was a hair’s breadth from disqualifying its owner for the post of “naturalist” aboard HMS Beagle, departing on a voyage around the world. The young Darwin had been recommended for the job by his mentor, professor John Steves Henslow, after several candidates had turned down FitzRoy’s overtures.

Charles’ father, Dr. Robert Darwin II, was a respected physician, the son of another doctor Darwin, Erasmus, who at the close of the 18th century had proposed one of the many theories of evolution then in vogue. The ponderous and imposing doctor Robert wanted his son to follow in his footsteps, but Charles gave up medicine after witnessing an operation performed without the aid of anesthetics. In the wake of this incident, doctor Darwin had decided that his son should become a clergyman. This decision seemed to suit the indolent Charles, and so he set off to Cambridge University.

Charles Darwin had some time earlier began collecting insects spurred by his cousin William Darwin Fox. The new hobby soon became an obsession. “I am dying by inches, from not having anybody to talk to about insects,” he wrote to his cousin.

Charles sought after new beetle varieties. He was more interested in collecting as many different kinds as he could get his hands on than in dissecting and classifying them. “I will give proof of my zeal,” he wrote in his autobiography.
One day, tearing off some old bark, I saw two rare beetles and seized one in each hand, then I saw a third and new kind, which I could not bear to lose, so that I popped the one which I held in my right hand into my mouth. Alas! It ejected some intensely acrid fluid which burnt my tongue so that I was forced to spit the beetle out, which was lost, as was the third one.

It was at Cambridge that Darwin, aged 22, met the botanist J. S. Henslow. Henslow, a revered teacher, developed a great fondness for his pupil. “What a fellow that Darwin is for asking questions,” he once remarked. Chalres, his mind still set on a career in the Church of England, had finally found a passion.

One day, returning home from a walking tour of North Wales with the geologist Adam Sedgwick, Charles found a letter from Henslow waiting for him. Her Majesty’s Ship Beagle, commanded by captain Robert FitzRoy, was soon to set sail for South America on a scientific voyage that would eventually take her around the world. “Capt. F. wants a man (I understand) more as a companion than a mere collector and would not take any one, however good a naturalist, who was not recommended to him likewise as a gentleman,” wrote Henslow.

FitzRoy was rather cold on his first meeting with Darwin. Charles was a bourgeois from a liberal family, whereas the captain was an aristocrat and a headstrong conservative. FitzRoy felt particularly hostile toward the young man’s nose. It was not the nose of a man who could withstand the hardships of life at sea. But in the end Charles’ enthusiasm and good nature won the seaman over and he was given the position.

And so Charles Darwin embarked in what was to be a five year trip around the world, during which his early belief that species were immutable was to be shaken and eventually shattered, to be replaced by the conviction that they had evolved through the ages. Twenty-odd years after Darwin’s return to England, the naturalist poured the results of his musings in a beautiful book that changed the world --The Origin of Species.