The Canon (27 page)

Seated at his desk amid the biologist's customary organic habitat of rakishly piled printed matter and pantheistic bric-a-brac—a clock with frogs instead of numbers, a lively collection of genuinely fake reptile and amphibian statuettes, an old oven brick embossed with the word
SALAMANDER
, pictures of Charles Darwin, Ernst Haeckel, Richard Owen, and Homer Simpson—David Wake talked about his professional passions and his personal mission. He talked about tree frogs, skinks and sticklebacks, salamanders and their slingshot tongues. He described his atypical biography, a familial emulsion of two mindsets, the theological and the scientific, which normally carp at each other like Montagues and Capulets, red states and blue; and he talked of how his hybrid background informs the rigorous zeal of his teaching. Wake reminded me of a Methodist minister I knew in grade school, the father of one of my best friends—the same whitening hair and bespectacled, gentle blue eyes, the same open, loving-kindness kind of charm. But where Mr. Hill was an evangelist for revelation and the Gospel, David Wake prefers evidence and a really good fossil.

"I was raised in a conservative Christian community," Wake told me. "My grandfather was a Lutheran pastor, my parents were very religious. I myself went to Pacific Lutheran College. Two of my cousins have doctorates in theology. One served as the president of a Lutheran college in Alberta, and another was a bishop in Canada. So, you see, my family is filled with religious people and theologians.

"At the same time, my family also has a lot of scientists to its credit. One cousin was a curator at the Field Museum in Chicago. Another relative is a curator of the Natural History Museum in Oslo. My grandfather, the pastor, was an amateur naturalist. He lived in our home for a while, and he lived to the age of ninety-nine, so I knew him well. And he never, in his long, rich life, felt any conflict between his religion and his scientific knowledge. Nobody in my family did. My grandfather was the one who first taught me about evolution. He taught me to respect evidence and to remember that religion must always accommodate reality. We live in the real world, he said, and we must understand the world on its own empirical terms."

Wake has a message to share, and it is one that virtually all the scientists I spoke with, no matter their field, ranked at or near the top of their list of things they wish the public understood about science. The message is the alpha and omega, lox and bagels, of the life sciences.
Theodosius Dobzhansky, the great Russian geneticist, said it pithiest: "Nothing in biology makes sense, except in the light of evolution."

Evolution.
Evolution.
EVOLUTION! It doesn't matter whether you're an atheist, a churchgoer, a craven Faust in a foxhole. You may be Catholic, Muslim, Hindu, Jewish, Druid, a born-again Baptist, a born-again-and-again Buddhist. It doesn't matter what you believe to be our purpose here on Earth or hope to find in the hereafter, or whether you have faith in a Supreme Being or prefer the Ronettes. It doesn't matter what disk you insert in the mental module marked "God." None of it will suffer if you see the principle underlying and interlocking all earthly life. The life that we see around us, the life that we call our own, evolved from previous life forms, and they in turn descended from ancestral species before them. Newer species evolved from prior species through the majestic might of natural selection, a force so nearly omnipotent in its scope and skill that it needs no qualification, supplementation, ballast, or apologist. Evolution by natural selection, which also goes by the name of Darwinian evolution or Darwinism (darwinism on "casual Fridays"), explains life on Earth in its outrageous entirety, all the 30 million or 100 million species here today—many that have yet to be counted and classified, let alone inspire the next blockbuster tie-in—and all the many hundreds of millions of creatures that have arisen and vanished in the several billion years since life first appeared. For many biologists, evolution is part of the definition of life. "What is life?" one researcher put it. "That which eats, that which breeds, that which is squishy, and that which evolves."

Darwinism is so essential to understanding the slightest attogram of biomass that even physicists agree it should be granted equal protection in the eyes of the law. "People like to think of physics as being the source of the fundamental laws of science," said the MIT physicist Robert Jaffe. "But there's one fundamental law that comes from the life sciences, and it's just as deep and all-pervasive and universal as anything in the pantheon of physics. Evolution by natural selection is an absolute principle of nature, it operates everywhere, and it is astonishing. But evolution is underappreciated, and, what hurts me far more, it is under assault."

Darwinism is by no means universally despised or rejected. To the contrary, evolutionary theory has a rather large fan base, and as David Denby wrote in
The New Yorker
several years ago, evolutionary biology has replaced Freudianism at dinner parties as a preferred source of speculation for why this or that friend is behaving so badly. Charles Darwin's distinctive profile, the long white beard, the Victorian frock
coat, may be second only to Einstein's as a scientific face recognizable to a good chunk of the lay public. In many parts of Europe, Asia, and Latin America, evolutionary science is a staple of science education, and has no more currency as a source of sociocultural angst and spitting than might Copernican ideas about heliocentricity. Nevertheless, in America, home to many of the greatest research universities in the world and to more Nobel laureates of science than any other nation, the battle against evolution madly, militantly, proptosically, soldiers on. It may be wearing a moth-eaten uniform and carrying a musket, and its side may have lost the evidentiary war more than a century ago, but drat it all to hell, the gun still shoots: a guerrilla war against the monkey huggers!

Again and again, the opponents of evolution have managed to keep evolution from being taught in our schools or have demanded that biology textbooks also present "alternative viewpoints" to evolutionary theory, including nonscientific, data-deprived ideologies like creationism and intelligent design. The campaign against Darwinism has been successful enough to plant kernels of doubt in many minds. In one recent poll, which echoed survey results from the last couple of decades, only 35 percent of American adults agreed with the statement that "evolution is a scientific theory well supported by the evidence." As years of education mounted, so, too, did support for Darwin: 52 percent of college graduates and 65 percent of those with postgraduate training expressed acceptance of the theory of evolution. Still, that leaves 35 percent of the most scholastically saturated Americans looking askance at one of the bedrock concepts of modern science.

I'm always surprised at how often I encounter resistance toward or doubts about Darwinism among otherwise rational people. When I was thinking of writing a children's book about evolution, for example, and I asked my cousin, an artist, if she might illustrate it for me, she said she would—even though she didn't really believe the whole ape-to-human storyline. Another time, while I was standing around talking to a perfectly pleasant couple at a friend's wedding near Sacramento—he a lawyer, she a businesswoman—I mentioned evolution as a jumping-off point to another subject I had in mind. My conversation partners stopped me right there. "So," said the lawyer, "I take it this means you have no doubt that evolution is for real?"

"Um," I replied, staring into the crystal depths of my champagne glass, which was, tragically, empty at the moment. "About as much doubt as I have that, if I were to let go of this glass, gravity would pull it to the floor, it would shatter to pieces, and the bride would be pretty upset because it's a Waterford."

The couple chuckled weakly and then realized that a dear friend on the other side of the room was either calling their names or should be.

So maybe I don't get invited to many parties. Nevertheless, among scientists, the matter is as settled and straightforward as I made it sound. You release your glass, it falls to the ground. You gaze out at nature, evolution all around.

"The evidence for evolution?" said Tim White, a paleoanthropologist at the University of California, Berkeley. "Overwhelming and incontrovertible."

David Wake, who for thirty years has taught a course at Berkeley in advanced evolution, said, "The evidence is rock-solid, firm, and unassailable." Whenever you take medicine, he pointed out, chances are it was first tested on laboratory animals before being approved for use in humans. You may believe the Earth to be only six thousand years old and every creature installed as is by the Lord thereon; yet still you'd feel a tad safer knowing your sacrificial guinea pig had been a rodent rather than, say, a spider or a snail. "Why do experiments on mice more than on spiders, if not for the reason, as we all innately understand it, that mice are more like us than spiders are?" said Wake. "Hmm. Could that have something to do with evolution?"

Richard Dawkins, an evolutionary scientist at Oxford University, indefatigable defender of Darwinism, and author of
The Selfish Gene, The Blind Watchmaker,
and other lucid splendors, made the eloquent evolutionary case yet again, in an interview with a reporter from
Salon.com
. "It's often said that because evolution happened in the past, and we didn't see it happen, there is no direct evidence for it," he said. "That, of course, is nonsense. It's rather like a detective coming on the scene of a crime, obviously after the crime has been committed, and working out what must have happened by looking at the clues that remain. In the story of evolution, the clues are a billionfold."

There are clues from the distribution of genes throughout the animal and plant kingdoms, he said, and from detailed comparative analyses of a broad sweep of physical and biochemical characteristics. "The distribution of species on islands and continents throughout the world is exactly what you'd expect if evolution was a fact," he continued. "The distribution of fossils in space and in time are exactly what you would expect if evolution was a fact. There are millions of facts all pointing in the same direction, and no facts pointing in the wrong direction. The British scientist J.B.S. Haldane, when asked what would constitute evidence against evolution, famously said, 'Fossil rabbits in the Precambrian.' They've never been found. Nothing like that has ever been
found. Evolution could be disproved by such facts. But all the fossils that have been found are in the right place."

You can't pull Bugs Bunny from a billion-year-old hat, and pterodactyls never tugged on Raquel Welch's thong. "You have to be diabolically blinded," said Wake, "not to see evolution in everything that we do."

A good part of the problem stems from one little word: "theory." That Darwinism is called "the
theory
of evolution by natural selection" invites popular confusion and leaves the science vulnerable to determined adversaries. Will you look at that? say the critics. Scientists themselves call evolution a theory, rather than a fact. Obviously they must have doubts. And if they have so many doubts, why shouldn't the rest of us? For that matter, why should we believe their theory, their "creation myth," rather than somebody else's? As a bumper sticker I saw recently put it:
THE THEORY OF EVOLUTION: A FAIRY TALE FOR GROWNUPS
. In some states, antievolutionists have demanded that stickers be put on high school biology textbooks to point out that evolution is "just a theory," not a "fact."

Fie, fie to scientists here, for using a word like "theory," which has the common connotation of "conjecture," "speculation," or "guess." A pretty good guess, maybe even an educated guess, but still, a theory is a "could be" and not a "proven fact." Normally, I'm no promoter of technical jargon, but in this case, I wish scientists had a word of their own, to mean what a theory means to them. A solid, pompous, unflinchingly scientific term, in the style of "ribosome" or "igneous." A phrase resistant to casual or calculated misapprehension and to the juggernaut of justs.

Sometimes a cigar is just a cigar, and a trip to the moon on gossamer wings can easily be just one of those things. But a scientific theory is never just a Just So story. In science, an idea that has yet to be put to the test or burnished by evidence is called a hypothesis. You notice something about the world, and you propose a possible mechanism to explain the observation. There's your hypothesis. The hypothesis could be the result of simple reasoning by analogy, an extension of previous findings onto your similar though not identical case study; or it could be sheer heliospheric speculation. However sensible or sensational the conjecture may be, it's not your theory, it's your hypothesis. It's
just
your hypothesis. To test the hypothesis, you design an experiment, or you gather a generous sample of data points from the field, and you become a freak for control groups. You analyze your results and needle them with statistics. Now you have a result. If the result vindicates your initial hypothesis, go ahead and crow. If not, go ahead and dream up a
new and improved hypothesis to explain retroactively the findings you found; that's what the discussion section of a scientific paper is for. Either way, the verifiable, irrefutable fact remains, you don't yet have a theory to bear your name.

A scientific theory, like Einstein's theory of general relativity, like the theory of plate tectonics, like Darwin's theory of evolution, is a coherent set of principles or statements that explains a large set of observations or findings. Those constituent findings are the product of scientific research and experimentation; those findings, in other words, already have been verified, often many times over, and are as close to being "facts" as science cares to characterize them. To take a simple example: entomologists are always discovering previously unknown species of insects. You hike in the Adirondacks, they say, you poke around in the Great Lawn of Central Park, and you, too, might unearth a new type of beetle, which you can then offer to name after the police officer threatening to fine you for defacing city property. There are tens of millions of insects waiting to be discovered, of a staggering medley of sizes, disguises, noises, and knacks. Yet for all the diversity, entomologists know that any new insect they stumble on will display the following characteristics: three body segments—a head, thorax, and abdomen; three sets of legs; and a hard outer shell, or exoskeleton. These facts of insecthood are so robustly established that they're part of a Spanish song my daughter learned in kindergarten: "
¡Soy insecto, a veces pequeñito! ¡Seis piernas para caminar, cabeza, tórax, abdomen, abdomen, abdomen!
" The traits are the shared, taxonomically defining characteristics of the insect class, and they are the result of all insects having descended from a common ancestor. Here, then, is a modest factlet, one among legions, that is best regarded and understood beneath the vast climax canopy, the grand explanatory framework called the theory of evolution. Why do so many of earth's creatures have six legs, three body bays, and a stiff outer coat? Because the 30 million or so insect species alive today descended from an ancestral specimen bearing that winning combination, a real
pequeñito
of a progenitor that lived some time during the Devonian period, around 400 million years ago. But why do crickets, dung beetles, dragonflies, head lice, hornets, termites, praying mantises, and the rest of the teeming clade look so different from one another? It's descent with modification. As the insects radiated outward and began inhabiting a range of niches, they evolved to suit their station. Natural selection stepped in, brandishing a fly swatter, and, Whoa, it sure is a good thing I happen, through random mutational change, to resemble the leaf I'm sitting on.
Either fact you focus on, the diversity among insects or the traits that bind them, makes sense only in the light of evolution. The
theory
of evolution.