* A small and little-known molluscan group called the Aplacophora does seem more similar in its elongate, wormlike body, sometimes covered with plates or spicules, but Conway Morris enumerates an impressive list of detailed differences in his monograph.
* If I wished to play devil’s advocate against my own framework, I would argue that the criterion by which we make the claim of twenty losers and only four winners is falsely retrospective. By patterns of tagmosis, modern arthropods are surely strikingly less disparate than Burgess forebears. But why use patterns of tagmosis as a basis for higher-level classification of arthropods? A nearly microscopic ostracode, a terrestrial isopod, a planktonic copepod, a Maine lobster, and a Japanese king crab span more variety in size and ecological specialization than all the Burgess arthropods put together—though all these modern creatures are called Crustacea, and display the stereotyped tagmosis of this class. A paleontologist living during the Burgess might consider the arthropods as less varied because he had no reason to regard patterns of tagmosis as a particularly important character (for the utility of tagmosis in distinguishing major genealogical lines only became apparent later, after most alternatives were decimated and stereotypy set in among the few surviving and highly disparate lines).
I regard this argument as a poor case. If you wish to reject tagmosis as too retrospective then what other criterion will suggest less disparity in the Burgess? We use basic anatomical designs, not ecological diversification, as our criterion of higher-level classification (bats and whales are both mammals). Nearly every Burgess genus represents a design unto itself by any anatomical criterion. Tagmosis does stabilize in post-Burgess times, as do arrangement and forms of appendages-while no major feature of arthropod design can distinguish broad and stable groups in the Burgess.
* Many of Walcott’s cruder errors, on the other hand—confusing the sclerites of Wiwaxia with setae of polychaetes, and the lateral Haps of Opabinia with arthropod segments represented a more basic failure to distinguish analogy from homology.
* Thus, we can take some steps to resolving the genealogy of Burgess organisms. We can eliminate some resemblances based on analogy-setae of polychaetes and sclerites of Wiwaxia, for example. We can also eliminate some shared-but-primitive characters that do not define genealogical groups-bivalved carapaces and “merostomoid” body form. But the identification of shared-and-derived characters has been largely unsuccessful so far. Homology of shared-and-derived frontal appendages may unite Leanchoilia with Actaeus (and perhaps also with Alalcomenaeus). The lateral Raps with gills above may be shared-andderived characters in Opabinia and Anomalocaris, thus constituting the only genealogical linkage between two of the weird wonders.
* Technical footnote: Several efforts have been made to construct a cladogram for the Burgess arthropods (Briggs, 1983, and in press). These have, so far, been conspicuously unsuccessful, as the different possibilities do not satisfactorily converge. If the grabbag model is correct, and each maior feature of each new lineage arises separately from a suite of latent possibilities common to all, then genealogical connectivity of phenotypes is broken, and the problem may be intractable by ordinary cladistic methods. Of course, some continuity in some genuinely nested sets of characters may well exist, but the appropriate features will be difficult to identify.
† I exaggerate to make a point. Rules of construction and order pervade nature. Not all conceivable combinations can work, nor can all amalgams be constructed within the developmental constraints of metazoan embryology. I use this metaphor only to express the vastly expanded range of Burgess possibilities.
* Biology textbooks often speak of variation as “random.” This is not strictly true. Variations are not random in the literal sense of equally likely in all directions; elephants have no genetic variation for wings. But the sense that “random” means to convey is crucial: nothing about genetics predisposes organisms to vary in adaptive directions. If the environment changes to favor smaller organisms, genetic mutation does not begin to produce biased variation toward diminished size. In other words, variation itself supplies no directional component. Natural selection is the cause of evolutionary change; organic variation is raw material only.
* I retranslate here, hoping not to repeat one of the greatest absurdities I ever encountered—Milton’s Paradise Lost translated into German as part of the libretto for Haydn’s Creation, then retranslated as doggerel for a performance in English that could not use Milton’s actual words and still retain Haydn’s musical values.
Chapter IV
* Perhaps the most touching document in the Walcott archives at the Smithsonian Institution is the highly personal note of condolence written to Walcott by Roosevelt upon the accidental death of Walcott’s second wife.
* Yes, this is William Howard Taft, then ex-president, and acting chief justice of the United States, who introduced this memorial meeting for Walcott.
* I do not like to discuss intellectual issues as abstract generalities. I believe that conceptions are best appreciated and understood through their illustration in a person’s idea, or in a natural object. Thus, I am charmed and fascinated by Walcott. I have rarely “met” a man so out of tune with my own view of life—and I do feel that I know him after so much intimacy from the archives. Yet 1 have gained enormous respect for Walcott’s integrity and demoniacal energy in research and administration. I do not particularly like him (as if my opinion mattered a damn), but I am mighty glad that he graced my profession.
* Walcott is identified on this manuscript as “of the Geological Survey and Honorary Curator of Paleozoic Fossils in the National Museum.” He held the honorary curatorial post from 1892 until he became secretary of the Smithsonian in 1907. I assume that he had not yet been appointed director of the Survey, for he would have been so identified. Since he became director in 1894, the date of the lecture must be between 1892 and 1894.
* One tangential point before leaving this rare example of a public address by such a private and imperious man. Walcott was a clear but uninspired writer. So many professionals make the mistake of assuming that popular presentations of science—particularly writing about nature—must abandon clarity for overblown, rapturous description. A Wordsworth or a Thoreau can pull it off; the great majority of naturalists, however great their emotional love for the outdoors, cannot—and should not try, lest the ultimate in unintended parody arise. Besides, audiences do not need such a crutch. The “intelligent layperson” exists in abundance and need not be coddled. Nature shines by herself. But, in any case, and with some embarrassment, I give you Charles Doolittle Walcott on the Grand Canyon at sunset:
The Western sky is all aflame. The scattered banks of clouds and wavy cirrus have caught the warring splendor, and shine with orange and crimson. Broad slant beams of yellow light, shot through the glory-rifts, fall on turret and tower, on pinnacled crest and wending ledge, suffusing through with a radiance less fulsome, but akin to that which flames in western clouds. The summit band is brilliant yellow, the next below is pale rose. But the grand expanse within is deep, luminous, resplendid [sic] red. The climax has now come; the blaze of sunlight poured over an illimitable surface of glowing red is flung back into the gulf, and, commingling with the blue haze, turns it into a sea of purple of most imperial hue. However vast the magnitudes, however majestic the forms or sumptuous the decoration, it is in these kingly colors that the highest glory of the Grand Canyon is revealed.
* Our agreement on the theme, if not the terminology, provides hope that even the most implacable differences in style and morality may find a common meeting ground on this most important of intellectual turfs—for Steve is the most fanatical Red Sox booster in New England, while my heart remains with the Yankees.
* “Holotype” is taxonomic jargon for the specimen designated to bear the name of a species. Holotypes are chosen because concepts of the species may change later and biologists must have a criterion for assigning the original name. (If, for example, later taxonomi
sts decide that two species were mistakenly mixed together in the first description, the original name will go to the group including the holotype specimen.)
Chapter V
* Mass extinctions do not negate the principle of natural selection, for environments can change too fast and too profoundly for organic response; but coordinated dyings do run counter to Darwin’s preference for seeing the large in the small, and for viewing organic competition, group by separate group, as the primary source of life’s overall pattern.
* The repetition of the Burgess pattern by conventional groups with hard parts is very fortunate and favorable for testing the main issue presented by the phenomenon of decimation: Do losers disappear by inferiority in competition, or by lottery? Unfortunately, we can learn little about this key question from the Burgess Shale itself, for this soft-bodied fauna is only a spot in time, and we have virtually no evidence about the pattern of later decimation. (One Devonian arthropod, Mimetaster from the Hunsrückschiefer, is probably a surviving relative of Marrella; most other Burgess anatomies disappear without issue, and we have no evidence at all for how or when.) But patterns of extinction in groups with hard parts can be traced. Paradoxically, therefore, the best and most operational way to test for sources of decimation in the Burgess would be to study the parallel and tractable situation in echinoderms. My first question: do echinoderm “failures” tend to disappear at full abundance during mass extinctions, or to peter out gradually at different uncoordinated times? The former situation would be strong evidence for a substantial component of lottery in decimation. We do not know the answer to this question, but the solution is obtainable in principle.
* Geographic range is a property of populations, not of individual clams or snails. Hence, even if survival is correlated with geographic range, a species’fate may be random with respect to the anatomical virtues of its individuals.
OTHER TITLES BY STEPHEN JAY GOULD PUBLISHED BY W. W. NORTON & COMPANY
Ever Since Darwin: Reflections in Natural History
The Panda’s Thumb: More Reflections in Natural History Hen’s Teeth and Horse’s Toes: Further Reflections in Natural History The Flamingo’s Smile: Reflections in Natural History Finders, Keepers: Eight Collectors (with R. W. Purcell) An Urchin in the Storm: Essays about Books and Ideas Bully for Brontosaurus: Reflections in Natural History Eight Little Piggies: Reflections in Natural History The Mismeasure of Man
The Book of Life (editor)
Illuminations (with R. W. Purcell)
Triumph and Tragedy in Mudville: My Lifelong Passion for Baseball
OTHER TITLES BY STEPHEN JAY GOULD
Ontogeny and Phylogeny
Time’s Arrow, Time’s Cycle: Myth and Metaphor in the Discovery of Geological Time Dinosaur in a Haystack: Reflections in Natural History Full House: The Spread of Excellence from Plato to Darwin Questioning the Millennium: A Rationalist’s Guide to a Precisely Arbitrary Countdown
Leonardo’s Mountain of Clams and the Diet of Worms:
Essays on Natural History
Rock of Ages: Science and Religion in the Fullness of Life The Lying Stones of Marrakech: Penultimate Reflections in Natural History
Crossing Over: Where Art and Science Meet (with R. W. Purcell) The Structure of Evolutionary Theory
I Have Landed: The End of a Beginning in Evolutionary History
Copyright © 1989 by Stephen Jay Gould All rights reserved
First published as a Norton paperback 1990; reissued 2007
Book design by Antonina Krass
“Design” copyright 1936 by Robert Frost and renewed 1964 by Lesley Frost Ballantine. Reprinted from The Poetry of Robert Frost, edited by Edward Connery Lathem, by permission of Henry Holt and Company, Inc.
Library of Congress Cataloging-in-Publication Data Gould, Stephen Jay.
Wonderful life: the Burgess Shale and the nature of history / Stephen Jay Gould.
p. cm. Bibliography: p. Includes index.
1. Evolution–History. 2. Invertebrates, Fossil. 3. Paleontology–Cambrian. 4. Paleontology–British Columbia–Yoho National Park (B.C.) I. Title.
QE770.G67 1989
560’.9–dc l988–37469
ISBN 978-0-393-30700-9
ISBN 978-0-393-24520-2 (e-book) W. W. Norton & Company, Inc.
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Wonderful Life: The Burgess Shale and the Nature of History Page 39