Wonderful Life: The Burgess Shale and the Nature of History (12 page)

But how to establish chronology? The obvious method of simply asking the major players for their memories cannot suffice. Oh, I did my duty in this regard. I visited them all, pad and pencil in hand. The exercise made me feel rather foolish, for I know these men well, and we have been discussing the Burgess Shale over beer and coffee for nearly two decades.

Besides, the worst possible source for what Harry Whittington thought in 1971, when he published his first monograph on
Marrella
, is Harry Whittington in 1988. How can one possibly peel away an entire edifice of later thought to recover an embryonic state of mind unaffected by the daily intellectual struggles of nearly twenty subsequent years? The timing of events becomes jumbled in retrospect, for we arrange our thoughts in a logical or psychological order that makes sense to us, not in chronological sequence.
*

I call this the “my, how you’ve grown” phenomenon. No comment from relatives is more universally detested by children. But the relatives are correct; they haven’t visited for a long time and do accurately remember the last meeting long ago, while a child sees his past dimly through all the intervening events. Freud once remarked that the human mind is like a psychic Rome in violation of the physical law that two objects can’t occupy the same space at the same time. No buildings are demolished, and structures from the time of Romulus and Remus join the restored Sistine Chapel in a confusing jumble that also heaps the local trattoria upon the Roman bath. The recovery of chronological order requires contemporary documents.

I have therefore worked primarily from the published record. My procedure was simplicity itself. I read technical monographs in strictly chronological order, focusing almost entirely on the primary works of anatomical description, not the fewer articles of secondary interpretation. I may be a lousy reporter, but at least I can proceed as no journalist or “science writer” ever would, or could. The men who revised the Burgess Shale are my colleagues, not my subjects. Their writings are my literature, not the distant documents of another world. I read more than a thousand pages of anatomical description, loving every word—well, most of them at least—and knowing by personal practice exactly how the work had been done. I started with Whittington’s first monograph on
Marrella
(1971), and only stopped when I ran out at
Anomalocaris
(Whittington and Briggs, 1985),
Wiwaxia
(Conway Morris, 1985), and
Sanctacaris
(Briggs and Collins, 1988). I don’t know that I have ever had more fun, or experienced more appreciation for exquisite work beautifully done, than during the two months that I devoted to this exercise.

Does such a procedure distort or limit the description of science? Of course it does. Every scientist knows that most activities, particularly the mistakes and false starts, don’t enter the published record, and that conventions of scientific prose would impart false views of science as actually done, if we were foolish enough to read technical papers as chronicles of practice. Bearing this self-evident truth in mind, I shall call upon a variety of sources as I proceed. But I prefer to focus on the monographic record for a particular, and largely personal, reason.

The psychology of discovery is endlessly fascinating, and I shall not ignore that subject. But the logic of argument, as embodied in published work, has its own legitimate, internal appeal. You can pull an argument apart into its social, psychological, and empirical sources—but you can also cherish its integrity as a coherent work of art. I have great respect for the first strategy, the mainstay of scholarship, but I love to practice the second as well (as I did in my book
Time’s Arrow, Time’s Cycle
, an analysis of the central logic in three texts crucial for geology’s discovery of time). Chronological change in a succession of arguments, each coherent at its own moment, forms a primary record of intellectual development.

The revision of the Burgess Shale involves hundreds of people, from the helicopter pilots who flew supplies in and out of Burgess base camp, to the draftsmen and artists who prepared drawings for publication, to an international group of paleontologists who offered support, advice, and criticism. But the research program of monographic revision has centered on one coherent team. Three people have played the focal role in these efforts: the originator of the project and chief force throughout, Harry Whittington, professor of geology at Cambridge University (that is, in British terminology, senior figure and department head), and two men who began as graduate students under him in the early 1970s and have since built brilliant careers on their researches in the Burgess Shale—Simon Conway Morris (now also at Cambridge) and Derek Briggs (now at Bristol University). Whittington also collaborated with two junior colleagues, especially before his graduate students arrived—Chris Hughes and David Bruton.

The seeds of conventional drama lie with these people, particularly in the interaction between Whittington and Conway Morris, but I have no such story to tell. Whittington is meticulous and conservative, a man who follows the paleontological straight and narrow, eschewing speculation and sticking to the rocks—exactly the opposite of anyone’s image for an agent of intellectual transformation. Conway Morris, before the inevitable mellowing of ontogeny, was a fiery Young Turk, a social radical of the 1970s. He is, by temperament, a man of ideas, but happily possessed of the patience and
Sitzfleisch
needed to stare at blobs on rocks for hours on end. In legend, the Burgess reinterpretation would have emerged as a tense synergism between these men—Harry instructing, pleading caution, forcing attention to the rocks; Simon exhorting, pushing for intellectual freedom, nudging his reluctant old mentor toward a new light. One can imagine the discussions, the escalating arguments, the threats, the near fracturings, the break, the return of the prodigal son, the reconciliation.

I don’t think that any of this occurred, at least not overtly. And if you know the British university system, you will immediately understand why. British doctoral students study in nearly complete independence. They take no courses, but only work on their dissertation. They agree on a topic with their mentor, and then start their research. If they are lucky, they may meet with their adviser once every month or so; once a year would be more likely. Harry Whittington, a quiet, conservative, and inordinately busy man, was not about to challenge this peculiar tradition. Simon has told me that “Harry didn’t like being disturbed,” for he “grudged every moment that he couldn’t get on with his research.” But he was, Simon insists, “a splendid adviser; for he left us alone and he got us support.”

I have questioned Harry, Simon, and Derek many times, trying to probe through my initial disbelief. They all insist that they never viewed themselves as a team with a coherent purpose or a general attitude. They were not striving actively to develop a central interpretation together. They never met regularly; in fact, they insist that they never met as a group at all. They didn’t even encounter each other on the one certain gathering ground of any British academic department—the almost unmissable daily ritual of morning coffee—for Simon, the social radical, had formed a rump group in his office, and never came, while Harry, who could always see essence beneath externality (the key to deciphering the Burgess animals, after all), never insisted on conformity of any kind. Oh, they all engaged in complex cross-fertilization—but as much, I suspect, by reading each other’s papers as by any programmatic or regular discussion. The most I could wrest from any of the trio was an acknowledgement by Derek Briggs that they developed “some corporate perception, even if not by daily interaction.”

The drama I have to tell is intense and intellectual. It transcends these ephemeral themes of personality and the stock stage. The victory at stake is bigger and far more abstract than any material reward—a new interpretation of life’s history. This goal, once achieved, brings no particular earthly benefit. Paleontology has no Nobel prizes—though I would unhesitatingly award the first to Whittington, Briggs, and Conway Morris as a trio. And, as the old clichés go, you can’t fry an egg with your new view of life, or get on the subway, unless you also have a token. (I don’t think it even gets you any frequent-flyer miles, though almost everything else does.) You do get the gratitude of your fellow paleontologists, and it doesn’t harm your job prospects. But the main reward must be satisfaction—the privilege of working on something exciting, the internal peace of accomplishment, the rare pleasure of knowing that your life made a difference. What more can a person want than to hear, from whatever source he honors as absolute and permanent, the ultimate affirmation that life has been useful: “Well done, thou good and faithful servant”?

A common misconception holds that soft-bodied fossils are usually preserved as flat films of carbon on the surface of rocks. The Burgess organisms are, of course, strongly compressed—we cannot expect the preservation of much three-dimensional structure as the weight of water and sediment piles above an entombed body devoid of hard parts. But the Burgess fossils are not always completely flattened—and this discovery provided Whittington with the basis for a method that could reveal their structure. (Burgess soft parts, by the way, are not preserved as carbon. By a chemical process not yet understood, the original carbon was replaced by silicates of alumina and calcium, forming a dark reflective layer. This replacement did not compromise the exquisite preservation of anatomical detail.)

Walcott never recognized, or appreciated only dimly, that some three-dimensional architecture had been retained. He treated the Burgess fossils as flat sheets, and therefore worked by searching through his specimens for the ones preserved in the most revealing (or least confusing) orientation—usually, for bilaterally symmetrical animals, splayed out straight and flat (as in figure 3.1, a typical Walcott illustration). He ignored specimens in an oblique or frontal orientation, because he thought that the different parts and surfaces so encountered would be squashed together into a single uninterpretable film on the bedding plane; a top view, by contrast, would offer maximal resolution of separate features.

Walcott illustrated his specimens by photographs, often egregiously retouched. Whittington’s group has also used photography extensively, but mostly for publication, rather than as a primary research tool. The Burgess specimens do not photograph well (figure 3.2 is a magnificent exception), and little can be gained by working from prints, however enlarged or filtered, rather than from actual specimens. The aluminosilicate surfaces reflect light in various ways at different angles of illumination—and some resolution has been gained by comparing the dull images obtained at high angles of illumination with the bright reflections, obtained at low angles.

Whittington therefore used the oldest method of all as his primary mode of illustration—patient and detailed drawing of specimens. The basic item of machinery, the camera lucida, is no different now from the model that Walcott used, and not much improved from its original invention by the mineralogist W. H. Wollaston in 1807. A camera lucida is, basically, a set of mirrors that can focus the image of an object onto a flat surface. You can attach a camera lucida to a microscope and cast the image under the lens onto a piece of paper. By simultaneously viewing the specimen and its reflection on paper, you can draw the animal without moving your head from the eyepiece. Whittington and his team adopted the procedure of drawing every specimen, at very large scale, for any species under investigation. You can study a set of drawings together, but you cannot easily make simultaneous observations on numerous tiny specimens, all needing magnification.

Whittington applied his camera lucida and skill in drafting to a set of methods all linked to his central recognition that the Burgess fossils retained some three-dimensional structure, and were not just flattened sheets on bedding planes. I shall illustrate the power of these simple procedures by showing their usefulness in the study of the largest Burgess arthropod, the species that Walcott named
Sidneyia inexpectans
to honor his son, who had found the first specimen. (I choose
Sidneyia
because David Bruton’s 1981 monograph on this genus is, in my opinion, the most technically elegant and attractive publication of the entire series by Whittington and his associates.) Consider the three main operations:

3.1. An attractive plate of Burgess photographs from Walcott’s 1912 monograph on arthropods. The photographs are extensively retouched.
Canadaspis
is at top left;
Leanchoilia
at bottom.