Wonderful Life: The Burgess Shale and the Nature of History
This requirement applies in exactly the same way to the Burgess fauna. If we wish to assert that Burgess extinctions preserved the best designs and eliminated predictable losers, then we cannot use mere survival as evidence for superiority. We must, in principle, be able to identify winners by recognizing their anatomical excellence, or their competitive edge. Ideally, we should be able to “visit” the Burgess fauna in its heyday, while all its elements flourished, and pick out the species destined for success by some definable, structural advantage.
But if we face the Burgess fauna honestly, we must admit that we have no evidence whatsoever—not a shred—that losers in the great decimation were systematically inferior in adaptive design to those that survived. Anyone can invent a plausible story after the fact. For example, Anomalocaris, though the largest of Cambrian predators, did not come up a winner. So I could argue that its unique nutcracker jaw, incapable of closing entirely, and probably working by constriction rather than tearing apart of prey, really wasn’t as adaptive as a more conventional jaw made of two pieces clamping together. Perhaps. But I must honestly face the counterfactual situation. Suppose that Anomalocaris had lived and flourished. Would I not then have been tempted to say, without any additional evidence, that Anomalocaris had survived because its unique jaw worked so well? If so, then I have no reason to identify Anomalocaris as destined for failure. I only know that this creature died—and so, eventually, do we all.
As the monographic revisions of Burgess genera continued, and as Harry, Derek, and Simon became more adept at reconstructing such unconventional creatures as functioning organisms, their respect grew for the anatomical integrity and efficient feeding and locomotion of the Burgess oddballs. They talked less and less about “primitive” designs, and labored more and more to identify the functional specializations of Burgess animals—see Briggs (1981a) on the tail of Odaraia, Conway Morris (1985) on the protective spines of Wiwaxia, Whittington and Briggs (1985) on the inferred mode of swimming for Anomalocaris. They wrote less about predictable, ill-adapted losers, and began to acknowledge that we do not know why Sanctacaris is cousin to a major living group, while Opabinia is a memory frozen into stone. The later articles talk more and more about good fortune. Briggs tacked a proviso onto his claim, quoted earlier, about survival due to superior adaptation: “… and also, without doubt, because certain species were luckier than others” (1985, p. 348).
All three scientists also begin to emphasize—as a positive note of interest, not an admission of defeat in the struggle to rank Burgess organisms by adaptive worth—the theme that a contemporary observer could not have selected the organisms destined for success. Whittington wrote of Aysheaia as a potential cousin to insects, the greatest of all multicellular success stories:
Looking forward from the Burgess Shale, it would have been difficult to predict which [the survivors] would have been. Aysheaia, slow-moving around sponge colonies, hardly would have looked to be the ancestors of those formidable conquerors of the land, myriapods and insects (1980, p. 145).
Conway Morris wrote that “a hypothetical observer in the Cambrian would presumably have had no means of predicting which of the early metazoans were destined for phylogenetic success as established body plans and which were doomed to extinction” (1985, p. 572). He then commented explicitly on the dangers of circular reasoning. Suppose that the jaw of Wiwaxia is homologous with the molluscan radula and that the two groups, as closest cousins, represent alternative Burgess possibilities. Since wiwaxiids died and mollusks lived to diversify, one might be tempted to argue that the wiwaxiid molting cycle was less efficient than the continuous accretionary growth of mollusks. But Conway Morris acknowledged that if wiwaxiids had lived and mollusks died, we could have ginned up just as good an argument about the benefits of molting:
Nevertheless, molting as a mode of growth is widely used in a number of phyla including arthropods and nematodes, these latter two groups being arguably the most successful of all metazoan phyla. In conclusion, if the clock was turned back so metazoan diversification was allowed to rerun across the Precambrian–Cambrian boundary, it seems possible that the successful body plans emerging from this initial burst of evolution may have included wiwaxiids rather than mollusks (1985, p. 572).
Thus, all three architects of the Burgess revision began with the conventional view that winners conquered by dint of superior adaptation, but eventually concluded that we have no evidence at all to link success with predictably better design. On the contrary, all three developed a strong intuition that Burgess observers would not have been able to pick the winners. The Burgess decimation may have been a true lottery, not the predictable outcome of a war between the United States and Grenada or a world series pitting the 1927 New York Yankees against the Hoboken Has-Beens.
We can now fully appreciate the force of so much patient work in documenting the Burgess arthropods. Whittington and colleagues reconstructed some twenty-five basic body plans. Four led to enormously successful groups, including the dominant animals of our world today; all the others died without issue. Yet, except for the trilobites, each surviving group had only one or two representatives in the Burgess. These animals were not marked for success in any known way. They were not more abundant, more efficient, or more flexible than the others. How could a Burgess observer ever have singled out Sanctacaris, an animal known from only half a dozen specimens? How, as Whittington argued, could the Burgess handicapper ever have given the nod to Aysheaia, a rare and odd creature crawling about on sponges? Why not bet on the sleek and common Marrella, with sweeping spines on its head shield? Why not on Odaraia, with its subtle and efficient tail flukes? Why not on Leanchoilia, with its complex frontal appendage? Why not on sturdy Sidneyia, with nothing fancy but everything in order? If we could wind the tape of life back to the Burgess, why should we not have a different set of winners on a replay? Perhaps, this time, all surviving lineages would be locked into a developmental pattern of biramous limbs, well suited for life in the water but not for successful invasion of the land. Perhaps, therefore, this alternative world would have no cockroaches, no mosquitoes, and no black flies—but also no bees and, ultimately, no pretty flowers.
Extend this theme beyond arthropods to the weird wonders of the Burgess. Why not Opabinia and Wiwaxia? Why not a world of grazing marine herbivores bearing sclerites, not snail shells? Why not Anomalocaris, and a world of marine predators with grasping limbs up front and a jaw like a nutcracker? Why not a Steven Spielberg film with a crusty seaman sucked into the cylindrical mouth of a sea monster, and slowly crushed to death by multiple layers of teeth lining a circular mouth and extending well down into the gullet?
We do not know for sure that the Burgess decimation was a lottery. But we have no evidence that the winners enjoyed adaptive superiority, or that a contemporary handicapper could have designated the survivors. All that we have learned from the finest and most detailed anatomical monographs in twentieth-century paleontology portrays the Burgess losers as adequately specialized and eminently capable.
The idea of decimation as a lottery converts the new iconography of the Burgess Shale into a radical view about the pathways of life and the nature of history. I dedicate this book to exploring the consequences of this view. May our poor and improbable species find joy in its new-found fragility and good fortune! Wouldn’t anyone with the slightest sense of adventure, or the most weakly flickering respect for intellect, gladly exchange the old cosmic comfort for a look at something so weird and wonderful—yet so real—as Opabinia?
CHAPTER IV
Walcott’s Vision and the Nature of History
THE BASIS FOR WALCOTT’S ALLEGIANCE TO THE CONE OF DIVERSITY
A BIOGRAPHICAL NOTE
If Charles Doolittle Walcott had been an ordinary man, his shadow would not loom so large over the Burgess Shale and his fundamental error of the shoehorn might merit no more than a footnote. But Walcott was one of the most extraordinary and powerful scientists that America has
ever produced. Moreover, his influence rested squarely upon his deeply conservative and traditional perspective upon life and morality. Therefore, if we can grasp the complex reasons for his firm commitment to the Burgess shoehorn, we may win some general insight into the social and conceptual locks upon scientific innovation.
To be sure, Walcott’s name is not well known, even to people generally familiar with the history of American science. But his eclipse from public consciousness only reflects our curiously biased view of the history of science, an attitude virtually guaranteed to miscalculate the importance of people in their own time. We value innovation and discovery—quite rightly, of course. Therefore, our genealogy of intellectual progress becomes a chronological list of precursors, people with hot ideas validated by later judgment—even if these scientists enjoyed no influence whatever during their lifetime, and had no palpable impact upon the practice of their profession. For example, we remember Gregor Mendel for the brilliance of his insights, but one can argue that his work scarcely influenced the history of genetics—except ultimately as a beacon and a symbol. His conclusions were ignored in their time, and became influential only when rediscovered by others.
This curiously prospective style of assessment excludes from later consciousness those powerful scientists who in their own time dominated a field, and may have shaped a hundred careers or a thousand concepts, in the service of conventional views later judged incorrect. But how can we grasp science as a social dynamic if we forget these people? How can we sharpen our proper focus upon lonely innovators if we ignore the dominating context of their opposition? Charles Doolittle Walcott is a premier example of such an overlooked man—a great geologist, an indefatigable worker, a noted synthesizer, a central source of power in the social hierarchy of American science, but not, fundamentally, an intellectual innovator.
Walcott’s erasure from memory also has another cause, centered upon a paradox. Many scholars, myself among them, loathe administration (while bearing no animus against administrators). This is, of course, a selfish attitude, but life is short and should not be spent wallowing in unhappiness and incompetence—the twin consequences experienced by most scholars who attempt administration. Since scholars write history, skill in management gets short shrift. But where would science be without its institutions? Isolated genius, despite the romantic myths, usually does little by itself.
To make matters worse, great administrators are doubly expunged from history—first, because scholars rarely choose to write about scientific governance; second, because administrative skill breeds invisibility. Bad or dishonest administrators go down in copiously noted shame. The mark of a well-run institution is a smooth flow that appears effortless, nonconstraining, almost automatic. (How many of you know the name of your local bank’s president, unless he has been indicted for embezzlement?) Administrators, of course, are well known to their subordinates and beneficiaries—for we must approach the boss to seek those favors of space and money that define the daily business of academia. But a good administrator’s name dies with his passage from power.
Charles Doolittle Walcott was a fine geologist, but he was an even greater administrator. During the last two decades of his life, including the entire period of his work with the Burgess Shale, Walcott was the most powerful scientific administrator in America. He not only ran the Smithsonian Institution from 1907 until his death in 1927; he also had his finger—or rather, his fist—in every important scientific pot in Washington. He knew every president from Theodore Roosevelt to Calvin Coolidge, some intimately.* He played a key role in persuading Andrew Carnegie to found the Carnegie Institution of Washington, and worked with Woodrow Wilson to establish the National Research Council. He served as president of the National Academy of Sciences and the American Association for the Advancement of Science. He was a pioneer, booster, and facilitator in the development of American aviation.
Walcott occupied all these roles with grace and consummate skill. Among those who know the Smithsonian’s history, I note a virtual consensus in identifying Walcott as the finest secretary between founder Joseph Henry and that recently retired genius of administration, S. Dillon Ripley. Walcott’s terse summary at the end of his diary for 1920 provides a good sense of his life at age seventy, at the apex of his power:
I am now Secretary of Smithsonian Institution, President National Academy of Sciences, Vice Chairman National Research Council, Chairman Executive Committee Carnegie Institute of Washington, Chairman National Advisory Committee for Aeronautics.… Too much but it is difficult to get out when once thoroughly immersed in the work of any organization.
Walcott’s biography is an American success story. He was born in 1850 and raised near Utica, New York, in a family of barely adequate means. He attended the Utica public schools, but never earned an advanced degree (though numerous honorary doctorates graced his later career). While working on a local farm, he collected trilobites, and took his first step toward a professional career in science by selling his specimens to Louis Agassiz, America’s greatest natural historian. (This tale includes a precious irony with respect to later work on the Burgess. Agassiz praised Walcott and bought his collection because Walcott had found trilobite appendages for the first time. Walcott was able to make his discovery because he had recognized the three-dimensional preservation of his fossils, and had noted legs under the carapace. Yet Walcott’s principal failure with the Burgess lay in his treatment of these fossils as fiat sheets, while Whittington sparked the modern revision by revealing their three-dimensional structure.)
Agassiz’s death in 1873 derailed Walcott’s hope for formal study in paleontology at Harvard. In 1876, he began his scientific career as assistant to the official New York State geologist, James Hall. He joined the United States Geological Survey in 1879 at the lowest rank of field geologist. By 1894, he had risen to director, firmly guiding the institution through its worst period of financial crisis to a conspicuous rebuilding. He served in this role until his appointment as head of the Smithsonian in 1907.
All this time, Walcott maintained an active and distinguished program of field research and publication on the geology and paleontology of Cambrian strata. He was obsessed with the problem of the Cambrian explosion, and studied Precambrian and Cambrian rocks throughout the world, hoping to achieve some empirical solution. When he found the Burgess Shale in 1909, Walcott was not only the most powerful scientist in Washington but also one of the world’s foremost experts on fossil trilobites and Cambrian geology. Charles Doolittle Walcott was no ordinary man.
THE MUNDANE REASON FOR WALCOTT’S FAILURE
As a meticulous and conservative administrator, Walcott left an unintended but priceless gift to future historians. He copied every letter, saved every scrap of correspondence, never missed a day of writing in his diary, and threw nothing out. Even at the very worst moment of his life, when his second wife died in a train crash on July 11, 1911, Walcott wrote a crisply factual entry in his diary: “Helena killed at Bridgeport, Conn. by train being smashed up at 2:30 A.M. Did not hear of it until 3 P.M. Left for Bridgeport 5:35 P.M.…” (Walcott may have been meticulous, but please do not think him callous. On July 12, overcome with grief, he wrote: “She was killed by blow on temple (right).… I went home where Helena lives in everything about it. My love—my wife—my comrade for 24 years. I thank God that I had her for that time. Her untimely fate I cannot now understand.”)
All this material is now housed in eighty-eight large boxes, occupying, as the official report tells us (Massa, 1984, p. 1), “11.51 linear meters of shelf space plus oversize material” in the archives of the Smithsonian Institution. No set of documents can capture the elusive (and mythical) “essence” of a person, for each source tells a piece of the story in yet another way. But the Walcott material is rich and diverse—field notebooks, diaries, private jottings, formal correspondence, business accounts, panoramic photographs, an unpublished “official” biography commissioned by his third wife, tax receipts, dipl
omas for honorary degrees, letters to his daughter’s chaperone and to the custodians of his son’s wartime grave in France—and it enables us to construct a revealing picture of this intensely private man who lived in the corridors of public power.
I did not approach the Walcott archives with any general biographical intent. I had but one goal, which became something of an obsession: I wanted to know why Walcott had committed his cardinal error of the shoehorn. I felt that the answer to this question could complete the larger story told by the Burgess Shale—for if Walcott’s reasons were rooted not in personal idiosyncrasy, but in his allegiance to traditional attitudes and values, then I could show how Whittington’s revision, with its theme of decimation by lottery, overturned something old and central to our culture. I searched through box after box and found numerous clues to a complex set of factors, all clearly indicating that Walcott had been driven to the shoehorn from the core of his being and beliefs. Walcott imposed his well-formulated view of life upon the Burgess fossils; they did not talk back to him in any innovative or independent terms. The shoehorn was a conventional device that preserved both the traditional iconography of the cone of diversity, and its underlying conceptual apparatus of progress and the predictable evolution of consciousness.
My claim may strike many readers as odd and cynical, especially as applied to a scientific theory. Most of us are not naive enough to believe the old myth that scientists are paragons of unprejudiced objectivity, equally open to all possibilities, and reaching conclusions only by the weight of evidence and logic of argument. We understand that biases, preferences, social values, and psychological attitudes all play a strong role in the process of discovery. However, we should not be driven to the opposite extreme of complete cynicism—the view that objective evidence plays no role, that perceptions of truth are entirely relative, and that scientific conclusions are just another form of aesthetic preference. Science, as actually practiced, is a complex dialogue between data and preconceptions. Yet I am arguing that Walcott’s shoehorn operated virtually without constraint from Burgess data, and am thus denying that the usual dialogue occurred in this case. Moreover, I make this claim about the greatest discovery of a first-rank scientist, not about a minor episode in the life of a peripheral actor. Can such an unusual one-way flow from preconception to evidence really occur?