The Moral Animal: Why We Are, the Way We Are: The New Science of Evolutionary Psychology (4 page)

Though Darwin's youth and life were in some ways eccentric, in this one sense they were typical of his era: he lived amid tremendous moral gravity. His world was a place where questions of right and
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wrong were seen at every turn. What's more, it was a place where these questions seemed answerable — absolutely answerable — though the answers were sometimes painful to bear. It was a world very different from ours, and Darwin's work would do much to make the difference.

The original career plan for Charles Darwin was to be a doctor. His father, he recalled, felt sure "that I should make a successful physician — meaning by this, one who got many patients." The senior Darwin, himself a successful physician, "maintained that the chief element of success was exciting confidence; but what he saw in me which convinced him that I should create confidence I know not." Nonetheless, Charles at age sixteen dutifully left the cozy family estate in Shrewsbury and, accompanied by his older brother, Erasmus, headed for the University of Edinburgh to study medicine.

Enthusiasm for this calling failed to materialize. At Edinburgh Darwin paid grudging attention to course work, avoided the operating theater (watching surgery, in the days before chloroform, wasn't his cup of tea), and spent much time on extracurricular pursuits: trawling with fishermen to gather oysters, which he then dissected; taking taxidermy lessons to complement his newfound love of hunting; walking and talking with a sponge expert named Robert Grant, who ardently believed in evolution — but didn't, of course, know how it works.

Darwin's father sensed a certain vocational drift and, Charles recalled, "was very properly vehement against my turning an idle sporting man, which then seemed my probable destination."
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Hence Plan B. Dr. Darwin proposed a career in the clergy.

This may seem strange guidance, coming from a man who didn't believe in God, given to a son who wasn't glaringly devout and who had a more obvious calling in zoology. But Darwin's father was a practical man. And in those days zoology and theology were two sides of one coin. If all living things were God's handiwork, then the study of their ingenious design was the study of God's genius. The most noted proponent of this view was William Paley, author of
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the 1802 book
Natural Theology; or, evidences of the existence and attributes of the Deity, collected from the appearances of nature.
In it Paley argued that, just as a watch implies a watchmaker, a world full of intricately designed organisms, precisely suited to their tasks, implies a designer.
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(He was right. The question is whether the designer is a farseeing God or an unconscious process.)

The workaday upshot of natural theology was that a country parson could, without guilt, spend much of his time studying and writing about nature. Hence, perhaps, Darwin's fairly favorable, if not especially spiritual, reaction to the prospect of donning the cloth. "I asked for some time to consider, as from what little I had heard and thought on the subject I had scruples about declaring my belief in all the dogmas of the Church of England; though otherwise I liked the thought of being a country clergyman." He did some reading on divinity and "as I did not then in the least doubt the strict and literal truth of every word in the Bible, I soon persuaded myself that our Creed must be fully accepted." To prepare for the clergy, Darwin went to Cambridge University, where he read his Paley and was "charmed and convinced by the long line of argumentation."
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Not for long. Just after finishing at Cambridge, Darwin encountered a strange opportunity: to serve as naturalist aboard the HMS Beagle. The rest, of course, is history. Though Darwin didn't conceive of natural selection aboard the Beagle, his study of wildlife around the world convinced him that evolution had taken place, and alerted him to some of its most suggestive properties. Two years after the end of the ship's five-year voyage, he saw how evolution works. Darwin's plans to enter the clergy would not survive this insight. As if to provide future biographers with ample symbolism, he had brought along on the voyage his favorite volume of verse,
Paradise Lost
.
¹¹

As Darwin left England's shores, there was no glaring reason to think people would be writing books about him a century and a half later. His youth, ventured one biographer, in a fairly common judgment, had been "unmarked by the slightest trace of genius."
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Of course, such claims are always suspect, as the early inauspiciousness of great minds makes for good reading. And this particular claim deserves special doubt, as it rests largely on Darwin's self-appraisals,
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which didn't tend toward inflation. Darwin reports that he couldn't master foreign languages, and struggled with mathematics, and "was considered by all my masters and by my Father as a very ordinary boy, rather below the common standard in intellect." Maybe, maybe not. Perhaps more stock should be placed in another of his appraisals, about his knack for winning the friendship of men "so much older than me and higher in academical position": "I infer that there must have been something in me a little superior to the common run of youths."
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Anyway, the absence of blinding intellectual flash isn't the only thing that has led some biographers to deem Darwin "an unlikely survivor in the immortality stakes."
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There is also the sense that he just wasn't a formidable man. He was so decent, so sweet, so lacking in untrammeled ambition. And he was something of a country boy, a bit insular and simple. One writer has asked, "Why was it given to Darwin, less ambitious, less imaginative, and less learned than many of his colleagues, to discover the theory sought after by others so assiduously? How did it come about that one so limited intellectually and insensitive culturally should have devised a theory so massive in structure and sweeping in significance?"
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One way to answer that question is by contesting its assessment of Darwin (an exercise we'll get to), but an easier way is to contest its assessment of his theory. The idea of natural selection, while indeed "sweeping in significance," is not really "massive in structure." It is a small and simple theory, and it didn't take a huge intellect to conceive it. Thomas Henry Huxley, Darwin's good friend, staunch defender, and fluent popularizer, supposedly chastised himself upon comprehending the theory, exclaiming, "How extremely stupid not to have thought of that!"
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All the theory of natural selection says is the following. If within a species there is variation among individuals in their hereditary traits, and some traits are more conducive to survival and reproduction than others, then those traits will (obviously) become more widespread within the population. The result (obviously) is that the species' aggregate pool of hereditary traits changes. And there you have it.

Of course, the change may seem negligible within any given generation. If long necks help animals reach precious leaves, and
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shorter-necked animals therefore die before reproducing, the species' average neck size barely grows. Still, if variation in neck size arises freshly with new generations (through sexual recombination or genetic mutation, we now know), so that natural selection continues to have a range of neck sizes to "choose" from, then average neck size will keep creeping upward. Eventually, a species that started out with horselike necks will have giraffe-like necks. It will, in other words, be a new species.

Darwin once summed up natural selection in ten words: "[M]ultiply, vary, let the strongest live and the weakest die."
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Here "strongest," as he well knew, means not just brawniest, but best adapted to the environment, whether through camouflage, cleverness, or anything else that aids survival and reproduction
^*
. The word "fittest" (a coinage Darwin didn't make but did accept) is typically used in place of strongest, signifying this broader conception — an organism's "fitness" to the task of transmitting its genes to the next generation, within its particular environment. "Fitness" is the thing that natural selection, in continually redesigning species, perpetually "seeks" to maximize. Fitness is what made us what we are today.

If this seems easy to believe, you probably aren't getting the picture. Your entire body — much more complexly harmonious than any product of human design — was created by hundreds of thousands of incremental advances, and each increment was an accident; each tiny step between your ancestral bacterium and you just happened to help some intermediate ancestor more profusely get its genes into the next generation. Creationists sometimes say that the odds of a person being produced through random genetic change are about equal to those of a monkey typing the works of Shakespeare. Well, yes. Not the complete works, maybe, but certainly some long, recognizable stretches.

Still, things this unlikely can, through the logic of natural selection,
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be rendered plausible. Suppose a single ape gets some lucky break — gene XL, say, which imbues parents with an ounce of extra love for their offspring, love that translates into slightly more assiduous nurturing. In the life of any one ape, that gene probably won't be crucial. But suppose that,
on average
, the offspring of apes with the XL gene are 1 percent more likely to survive to maturity than the offspring of apes without it. So long as this thin advantage holds, the fraction of apes with gene XL will tend to grow, and the fraction without it will tend to shrink, generation by generation by generation. The eventual culmination of this trend is a population in which all animals have the XL gene. The gene, at that point, will have reached "fixation"; a slightly higher degree of parental love will be "species typical" now than before.

Okay, so one lucky break thus flourishes. But how likely is it that the luck will persist — that the
next
random genetic change will
further
increase the amount of parental love? How likely is the "XL" mutation to be followed by an "XXL" mutation? Not at all likely in the case of any one ape. But within the population there are now scads of apes with the XL gene. If any one of them, or any one of their offspring, or grand-offspring, happens to luck out and get the XXL gene, the gene will have a good chance of spreading, if slowly, through the population. Of course, in the meantime, lots more apes will probably get various less auspicious genes, and some of those genes may extinguish the lineage in which they appear. Well, that's life.

Thus does natural selection beat the odds — by not really beating them. The thing that is massively more probable than the charmed lineages that populate the world today — an uncharmed lineage, which reaches a dead end through an unlucky break — happened a massively larger number of times. The dustbin of genetic history overflows with failed experiments, long strings of code that were as vibrant as Shakespearean verse
until
that fateful burst of gibberish. Their disposal is the price paid for design by trial and error. But so long as that price can be paid — so long as natural selection has enough generations to work on, and can cast aside scores of failed experiments for every one it preserves — its creations can be awesome. Natural selection is
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an inanimate process, devoid of consciousness, yet is a tireless refiner, an ingenious craftsman
^*
.

Every organ inside you is testament to its art — your heart, your lungs, your stomach. All these are "adaptations" — fine products of inadvertent design, mechanisms that are here because they have in the past contributed to your ancestors' fitness. And all are species-typical. Though one person's lungs may differ from another's, sometimes for genetic reasons, almost all the genes involved in lung construction are the same in you as in your next-door neighbor, as in an Eskimo, as in a pygmy. The evolutionary psychologists John Tooby and Leda Cosmides have noted that every page of
Gray's Anatomy
applies to all peoples in the world. Why, they have gone on to ask, should the anatomy of the mind be any different? The working thesis of evolutionary psychology is that the various "mental organs" constituting the human mind — such as an organ inclining people to love their offspring — are species-typical.
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Evolutionary psychologists are pursuing what is known in the trade as "the psychic unity of humankind."

Between us and the australopithecine, which walked upright but had an ape-sized brain, stand a few million years: 100,000, maybe 200,000 generations. That may not sound like much. But it has taken only around 5,000 generations to turn a wolf into a chihuahua — and, at the same time, along a separate line, into a Saint Bernard. Of course, dogs evolved by artificial, not natural, selection. But as Darwin stressed, the two are essentially the same; in both cases traits are weeded out of a population by criteria that persist for many generations. And in both cases, if the "selective pressure" is strong enough — if genes are weeded out fast enough — evolution can proceed briskly.

One might wonder how the selective pressure could have been
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very strong during recent human evolution. After all, what usually generates the pressure is a hostile environment — droughts, ice ages, tough predators, scarce prey — and as human evolution has proceeded, the relevance of these things has abated. The invention of tools, of fire, the advent of planning and cooperative hunting — these brought growing control over the environment, growing insulation from the whims of nature. How, then, did ape brains turn into human brains in a few million years?

Much of the answer seems to be that the environment of human evolution has been human (or prehuman) beings.
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The various members of a Stone Age society were each other's rivals in the contest to fill the next generation with genes. What's more, they were each other's tools in that contest. Spreading their genes depended on dealing with their neighbors: sometimes helping them, sometimes ignoring them, sometimes exploiting them, sometimes liking them, sometimes hating them — and having a sense for which people warrant which sort of treatment, and when they warrant it. The evolution of human beings has consisted largely of adaptation to one another.