Wonderful Life: The Burgess Shale and the Nature of History Read Online Free PDF Page B

mental powers, then the eventual origin of self-conscious intelligence may be implicit in all that came before. In short, I cannot understand our continued allegiance to the manifestly false iconographies of ladder and cone except as a desperate finger in the dike of cosmically justified hope and arrogance.
    I leave the last word on this subject to Mark Twain, who grasped so graphically, when the Eiffel Tower was the world’s tallest building, the implications of geology’s most frightening fact:
    Man has been here 32,000 years. That it took a hundred million years to prepare the world for him * is proof that that is what it was done for. I suppose it is. I dunno. If the Eiffel Tower were now representing the world’s age, the skin of paint on the pinnacle knob at its summit would represent man’s share of that age; and anybody would perceive that the skin was what the tower was built for. I reckon they would, I dunno.
    R EPLAYING L IFE’S T APE : T HE C RUCIAL E XPERIMENT
    The iconography of the cone made Walcott’s original interpretation of the Burgess fauna inevitable. Animals so close in time to the origin of multicellular life would have to lie in the narrow neck of the funnel. Burgess animals therefore could not stray beyond a strictly limited diversity and a basic anatomical simplicity. In short, they had to be classified either as primitive forms within modern groups, or as ancestral animals that might, with increased complexity, progress to some familiar form of the modern seas. Small wonder, then, that Walcott interpreted every organism in the Burgess Shale as a primitive member of a prominent branch on life’s later tree.

    1.17. The false but still conventional iconography of the cone of increasing diversity, and the revised model of diversification and decimation, suggested by the proper reconstruction of the Burgess Shale.
    I know no greater challenge to the iconography of the cone—and hence no more important case for a fundamentally revised view of life—than the radical reconstructions of Burgess anatomy presented by Whittington and his colleagues. They have literally followed our most venerable metaphor for revolution: they have turned the traditional interpretation on its head. By recognizing so many unique anatomies in the Burgess, and by showing that familiar groups were then experimenting with designs so far beyond the modern range, they have inverted the cone. The sweep of anatomical variety reached a maximum right after the initial diversification of multicellular animals. The later history of life proceeded by elimination, not expansion. The current earth may hold more species than ever before, but most are iterations upon a few basic anatomical designs. (Taxonomists have described more than a half million species of beetles, but nearly all are minimally altered Xeroxes of a single ground plan.) In fact, the probable increase in number of species through time merely underscores the puzzle and paradox. Compared with the Burgess seas, today’s oceans contain many more species based upon many fewer anatomical plans.
    Figure 1.17 presents a revised iconography reflecting the lessons of the Burgess Shale. The maximum range of anatomical possibilities arises with the first rush of diversification. Later history is a tale of restriction, as most of these early experiments succumb and life settles down to generating endless variants upon a few surviving models. *
    This inverted iconography, however interesting and radical in itself, need not imply a revised view of evolutionary predictability and direction. We can abandon the cone, and accept the inverted iconography, yet still maintain full allegiance to tradition if we adopt the following interpretation: all but a small percentage of Burgess possibilities succumbed, but the losers were chaff, and predictably doomed. Survivors won for cause—and cause includes a crucial edge in anatomical complexity and competitive ability.
    But the Burgess