Eight Little Piggies
Thus, if we must convene a court more than 150 years after the event—a rather foolish notion in any case, though we seem driven to such anachronism—I think that Darwin will pass through the pearly gates, with perhaps a short stay in purgatory to think about paternalism. What then is the antidote to paternalism and its modern versions of insufficient appreciation for human differences (combined with too easy an equation of one’s own particular and largely accidental way with universal righteousness)? What else but the direct and sympathetic study of cultural diversity—the world’s most fascinating subject in any case, whatever its virtues in moral education. This is the genuine theme behind our valuable modern movement for pluralism in the study of literature and history—for knowing the works and cultures of minorities and despised groups rendered invisible by traditional scholarship.
I don’t deny that occasional abuses have been perpetrated by people with strong emotional commitments to this good cause; what else is new? But the attempt by even more zealous conservatives to distort and caricature this movement as a leftist fascism of “political correctness” ranks as a cynical smokescreen spread to cover a power struggle for control of the curriculum. Yes, Shakespeare foremost and forever (Darwin too). But also teach about the excellence of pygmy bushcraft and Fuegian survival in the world’s harshest climate. Dignity and inspiration come in many guises. Would anyone choose the tinhorn patriotism of George Armstrong Custer over the eloquence of Chief Joseph in defeat?
Finally, think about one more Darwinian line—perhaps the greatest—from the slavery chapter in the Voyage of the Beagle. We learn about diversity in order to understand, not simply to accept:
If the misery of our poor be caused not by the laws of nature, but by our institutions, great is our sin.
19 | Ten Thousand Acts of Kindness
THE VISITOR’S CENTER at Petrified Forest National Park, in Arizona, houses an exhibit both heartwarming and depressing. Signs throughout the park beg, exhort, order, and plead with visitors not to collect and keep any fossil wood, lest the park be denuded on less than a geological time scale. The exhibit contains pieces of wood stolen from the park, but returned in guilt—the heartwarming side.
The depressing side resides in the notes written to explain decisions to send the contraband back to its natural place. No note from an adult cites any moral principle or even a personal sense of guilt. All tell tales of bad luck, usually trivial rather than catastrophic, that occurred soon after the theft—Uncle Joe’s broken hip or three hundred bucks worth of fender bending. The wood, as an evil talisman, must be returned. Apparently, these penitents understand neither principles of conservation nor laws of probability. A single exception—restoring one’s faith in primal feeling—lies in the only letter from a child:
Dear Mr. Ranger, I took this and felt bad later. I’m sending it back. I’m sorry.
I have often wondered why so many people feel compelled to take such a souvenir in the face of so many good reasons for abstaining. I know that the motives are varied and complex, but I believe that for many people a primary impetus arises from a common misunderstanding about fossils.
Many people think that fossils, almost by definition, are rare and precious. (Some are, of course—the six specimens of Archaeopteryx and our limited evidence of human ancestry, for example.) The urge to own something both uncommon and unusual must inspire many of the thefts. But most ordinary fossils, including petrified wood, are not single jewels on vast beaches of common sand, but intrinsic and abundant parts of their geological strata. Why purloin a piece from a national park, thereby committing both an illegal and an immoral act, when petrified wood can be found in abundance at so many places right outside the park boundaries? The fossils are beautiful, and they are tempting. But they are also plentiful.
Fossils are, for the most part, not comparable with single archeological sites—limited to one spot and easily exhausted without hope of replenishment. Destroy Troy by careless collecting, and that’s that forever. (On this point, two tangential and contentious comments deserve essays in themselves, but shall have to pass by in epitome. First, most fossil localities should not be regulated like unique archeological sites. Fossils in the ground, wrapped in red tape, are worthless, and fossils exposed in an outcrop will quickly be weathered and destroyed if not collected. I abhor both careless collecting and commercial exploitation of fossils with scientific value, but misplaced regulation, based on a false taxonomy that equates paleontology with archeology, can be just as harmful. Second, paleontological expeditions are not called digs, because we so rarely go to a single spot and excavate. Since specimens are usually intrinsic to strata and spread throughout wide areas of outcrop, digging in one place would be a very foolish way to collect most fossils. But the archeologists’ term dig has permeated pop culture, where it lurks as a snare for the unwary bluffer. If you wish to prove the opposite of your intention to impress, then ask a paleontologist, as I have been asked perhaps a thousand times, “Have you been on any interesting digs lately?” Sorry for those petty explosions, but grant me the catharsis of getting some parochial issues off my chest.)
Many fossils, then, are abundant components of their strata, exposed over miles of outcrop: Just consider the clam shells exposed by the millions on polished marble surfaces in the bathrooms of New York’s finest art deco skyscrapers, or the thousands of Turitella shells weathering out of the limestone in older parts of Quasimodo’s bailiwick at Notre Dame de Paris.
The Big Badlands of South Dakota replay the tale of the Petrified Forest. Fossil vertebrates can be outstandingly abundant, and these beds have been collected by professionals for more than a century. In much of the Brule Formation, source of the “worst” terrain, fossils are so common that every tiny pinnacle and elevation has a bone on top. (The fossils are harder than the enclosing sediments. Bones and teeth therefore weather out to form tops of tiny promontories, capping and protecting a column of sediment below, while surrounding rock crumbles away on all sides.) Yet visitors think they are seeing precious and tempting rarities on the official trails—and the stealing begins again. On the major nature trail, park officials covered the best specimens with plastic boxes. But people broke the boxes and took the bones underneath. So naturalists replaced the real fossils with casts and then put the plastic boxes back for good measure!
This extraordinary abundance of some fossils illustrates something important about the history of life. Evolution is a theory about change through time—“descent with modification,” in Darwin’s words. Yet when fossils are most abundant during substantial stretches of time, well-represented species are usually stable throughout their temporal range or alter so little and in such superficial ways (usually in size alone) that an extrapolation of observed change into longer periods of geological time could not possibly yield the extensive modifications that mark general pathways of evolution in larger groups. Most of the time, when the evidence is best, nothing much happens to most species.
Niles Eldredge and I have tried to resolve this paradox with our theory of punctuated equilibrium. We hold that most evolution is concentrated in events of speciation, the separation and splitting off of an isolated population from a persisting ancestral stock. These events of splitting are glacially slow when measured on the scale of a human life—usually thousands of years. But slow in our terms can be instantaneous in geological perspective. A thousand years is one-tenth of one percent of a million years, and a million years is a good deal less than average for the duration of most fossil species. Thus, if species tend to arise in a few thousand years and then persist unchanged for more than a million, we will rarely find evidence for their momentary origin, and our fossil record will only tap the long periods of prosperity and stability. Since fossil deposits of overwhelming abundance record such periods of success for widespread species living in stasis, we can resolve the apparent paradox that when fossils are most common, evolution is most rarely observed.
The abundant fossils of the cl
assic Big Badlands strata provide an excellent illustration of this paradox. My colleague Donald Prothero has been studying all well-preserved mammalian species in these deposits. He finds that none change gradually during their residence in Big Badlands strata. New species enter with geological abruptness, either because they have evolved in situ as the theory of punctuated equilibrium predicts or because they have simply migrated into the area.
One of my graduate students, Tim Heaton, recently completed a thesis on the most common genus of rodents (themselves the most diverse group of mammals) from Oligocene sediments throughout western North America, prominently including the Big Badlands. Paleontologists divide the Oligocene into three “land mammal ages” called Chadronian, Orellan, and Whitneyan. Heaton’s genus, Ischyromys, is relatively rare in the Chadronian, but fantastically abundant in the Orellan, where thousands of jaws have been collected (and nearly all—in an extended fit of admirable activity—photographed, measured, and statistically analyzed by Heaton).
The Orellan Ischyromys has a traditional interpretation consistent with conventional views of evolutionary gradualism. The Orellan sequence has been read as a tale of steady increase in size within a single species. But Heaton’s statistical work on several thousand specimens has disproved this old idea in favor of an opposite interpretation. Heaton finds two separate species, one small and one large, in the lower Orellan; the small species then becomes extinct and only the large form persists into the upper Orellan. Neither species shows much, if any, change throughout its range (the large form may undergo a slight size increase in the upper beds). The old impression of gradual increase results from mixing the two species together and falsely treating the complex as a single form. As the small species decreases in abundance and finally dies off, average size of the whole complex increases because more and more (and finally all) specimens represent the stable large form—not because any gradual evolution is occurring.
On the other hand, in the older Chadronian beds, where Ischyromys is relatively rare, Heaton has discovered a previously unrecognized richness of taxonomic diversity: several species of Ischyromys and a related genus, Titanotheriomys. Although none of these species shows any change after its origin (most are too rare to provide much evidence for anything beyond simple existence), this diversity illustrates marked evolutionary activity for Ischyromys in the Chadronian, while Heaton has shown that nothing happens (beyond the extinction of the small species) in the overlying Orellan, where Ischyromys is so abundant. The small, isolated, and rapidly speciating populations that produced so much evolution among Chadronian Ischyromys did not often leave their calling cards in the fossil record.
Again, we note the paradox: Nothing much happens for most of the time when evidence abounds; everything happens in largely unrecorded geological moments. We could attribute this pattern to a devious or humorous God, out to confuse us or merely to chuckle at our frustration. But I choose to look upon this phenomenon in a positive light. There is a lesson, not merely frustration, in the message that change occurs in infrequent bursts and that stability is the usual nature of species and systems at any moment.
Being human, I love to toot my own horn in support of punctuated equilibrium. But I am writing this essay for another reason. What’s past (in this essay), as the Bard says, is prologue—a prologue to make a point by analogy about the real subject of this essay: the vexatious issue of human nature.
Let us return to the irony of Ischyromys in the Chadronian and Orellan, and of punctuated equilibrium in general. Evolution has constructed the tree of life; yet, at almost any moment for any species, change is not occurring and stasis prevails. If we then ask, What is the normal nature of a species? the only possible reply is, stability. Yet exquisitely rare change has built the tree of life and made history on a broad scale. We now come to the nub of my argument: The defining property of a species, its normal state, its nature, its appearance at almost any time stands contrary to the process that makes history (and new species). If we tried to infer the nature of species from the process that constructs the history of life, we would get everything precisely backward!—for events of great rarity (but with extensive consequences) make history.
The same separation should be enforced between human nature and the events that construct our history. We have committed an enormous error in assuming that the behavioral traits involved in history-making events must define the ordinary properties of human nature. Must we not link the causes of our history, or so the false argument goes, to the nature of our being?
But if my analogy holds, precisely the opposite might be true. If rare behaviors make history, then our usual nature must be defined by our general actions in an everyday world that engulfs us nearly all the time, but does not set the fate of nations. The causes of history may be opposed to the ordinary forces that prevail at almost every moment—just as the processes that construct the tree of life are invisible and inactive nearly all the time within stable species.
History is made by warfare, greed, lust for power, hatred, and xenophobia (with some other, more admirable motives thrown in here and there). We therefore often assume that these obviously human traits define our essential nature. How often have we been told that “man” is, by nature, aggressive and selfishly acquisitive?
Such claims make no sense to me—in a purely empirical way, not as a statement about hope or preferred morality. What do we see on any ordinary day on the streets or in the homes of any American city—even in the subways of New York? Thousands of tiny and insignificant acts of kindness and consideration. We step aside to let someone pass, smile at a child, chat aimlessly with an acquaintance or even with a stranger. At most moments, on most days, in most places, what do you ever see of the dark side—perhaps a parent slapping a child or a teenager on a skateboard cutting off an old lady? Look, I’m no ivory-tower Pollyanna, and I did grow up on the streets of New York. I understand the unpleasantness and danger of crowded cities. I’m only trying to make a statistical point.
Nothing is more unfamiliar or uncongenial to the human mind than thinking correctly about probabilities. Many of us have the impression that daily life is an unending series of unpleasantnesses—that 50 percent or more of human encounters are stressful or aggressive. But think about it seriously for a moment. Such levels of nastiness cannot possibly be sustained. Society would devolve to anarchy in an instant if half our overtures to another human being were met with a punch in the nose.
No, nearly every encounter with another person is at least neutral and usually pleasant enough. Homo sapiens is a remarkably genial species. Ethologists consider other animals relatively peaceful if they see but one or two aggressive encounters while observing an organism for, say, tens of hours. But think of how many millions of hours we can log for most people on most days without noting anything more threatening than a raised third finger once a week or so.
Why, then, do most of us have the impression that people are so aggressive, and intrinsically so? The answer, I think, lies in the asymmetry of effects—the truly tragic side of human existence. Unfortunately, one incident of violence can undo ten thousand acts of kindness, and we easily forget the predominance of kindness over aggression by confusing effect with frequency. One racially motivated beating can wipe out years of patient education for respect and toleration in a school or community. One murder can convert a friendly town, replete with trust, into a nexus of fear with people behind barred doors, suspicious of everyone and afraid to go out at night. Kindness is so fragile, so easy to efface; violence is so powerful.
This crushing and tragic asymmetry of kindness and violence is infinitely magnified when we consider the causes of history in the large. One fire in the library of Alexandria can wipe out the accumulated wisdom of antiquity. One supposed insult, one crazed act of assassination, can undo decades of patient diplomacy, cultural exchanges, peace corps, pen pals—small acts of kindness involving millions of citizens—and bring two nations to a war that no one wants, but tha
t kills millions and irrevocably changes the paths of history.
Yes, I fully admit that the dark side of human possibility makes most of our history. But this tragic fact does not imply that behavioral traits of the dark side define the essence of human nature. On the contrary, I would argue, by analogy to the ordinary versus the history-making in evolution, that the reality of human interactions at almost any moment of our daily lives runs contrary, and must in any stable society, to the rare and disruptive events that construct history. If you want to understand human nature, defined as our usual propensities in ordinary situations, then find out what traits make history and identify human nature with the opposite sources of stability—the predictable behaviors of nonaggression that prevail for 99.9 percent of our lives. The real tragedy of human existence is not that we are nasty by nature, but that a cruel structural asymmetry grants to rare events of meanness such power to shape our history.
An obvious argument against my thesis holds that I have confused a social possibility of basically democratic societies with a more general human propensity. This alternative view might grant my claims that stability must rule at nearly all moments and that much rare events make history. But perhaps this stability reflects the behaviors of geniality only in relatively free and democratic societies. Perhaps the stability of most cultures has been achieved by the same “dark” forces that make history when they break out of balance—fear, aggression, terror, and domination of rich over poor, men over women, adults over children, and armed over defenseless. I allow that dark forces have often kept balances, but still strongly assert that we fail to count the ten thousand ordinary acts of nonaggression that overwhelm each overt show of strength even in societies structured by domination and even if nonaggression prevails only because people know their places and do not usually challenge the sources of order. To base daily stability on anything other than our natural geniality requires a perverted social structure explicitly dedicated to breaking the human soul—the Auschwitz model, if you will. I am not, by the way, asserting that humans are either genial or aggressive by inborn biological necessity. Obviously, both kindness and violence lie within the bounds of our nature because we perpetuate both, in spades. I only advance a structural claim that social stability rules nearly all the time and must be based on an overwhelmingly predominant (but tragically ignored) frequency of genial acts, and that geniality is therefore our usual and preferred response nearly all the time.