[...]... timeless "laws of nature. " This book is about the nature of history and the overwhelming improbability of human evolution under themes of contingency and the metaphor of replaying life' s tape It focuses upon the new interpretation of the Burgess Shale as our finest illustration of what contingency implies in our quest to understand the evolution of life I concentrate upon details of the Burgess Shale because... found them in the abundant deposits that contain the soft-bodied Ediacara fauna? Puzzles mount upon puzzles the more we consider details of the astounding 100-million-year period between the Ediacara fauna and the consolidation of modern body plans in the Burgess Shale The beginning of the Cambrian is not marked by the appearance of trilobites and the full range of modern anatomy identified as the Cambrian... are also the world's most important fossils, in part because they have revised our view of life, but also because they are objects of such exquisite beauty Their loveliness lies as much in the breadth of ideas that they embody, and in the magnitude of our struggle to interpret their anatomy, as in their elegance of form and preservation The animals of the Burgess Shale are holy objects in the unconventional... complexity, the 100 million years from Ediacara to Burgess may have witnessed three radically different Page 26 faunas the large pancake-flat soft-bodied Ediacara creatures, the tiny cups and caps of the Tommotian, and finally the modern fauna, culminating in the maximal anatomical range of the Burgess Nearly 2.5 billion years of prokaryotic cells and nothing else two-thirds of life' s history in stasis at the. .. chaperone with the improbable name of Anna Horsey, there to assuage grief and regain composure Helen, with the enthusiasm of late teen-aged years, did thrill to the monuments of Western history, but she saw nothing to match the beauty of a different West the setting of the Burgess Shale, where she had accompanied her father both during the discovery of 1909 and the first collecting season of 1910 From... the apex: "Higher on the evolutionary ladder," we learn, "the nematode, the fly and the frog have the advantage of complexity beyond the single cell, but represent far simpler species than mammals" (June 10, 1988) The fatuous idea of a single order amidst the multifarious diversity of modern life flows from our conventional iconographies and the prejudices that nurture them the ladder of life and the. .. object of nature thus participating in the legitimate sense of a great human adventure called "progress in scientific thought." But the animals of the Burgess Shale are somehow even more satisfying in their adamantine factuality We will argue forever about the meaning of life, but _Opabinia_ either did or did not have five eyes and we can know for certain one way or the other The animals of the Burgess Shale. .. see in the innumerable facets of the eye of the earliest crustacean, the same evidences of Omniscience as in the completion of the vertebrate form (1854, p 459) > Darwin, honest as always in exposing the difficulties of his theory, placed the Cambrian explosion at the pinnacle of his distress, and devoted an entire section to this subject in the _Origin of Species_ Darwin acknowledged the anti-evolutionary... potential source of evidence retains a chemical signature of organic activity Of the two common isotopes of carbon, ^12C and ^13C, photosynthesis differentially uses the lighter ^12C and therefore raises the ratio of isotopes-^12C/^13C-above the values that would be measured if all the sedimentary carbon had an inorganic source The Isua rocks show the enhanced values of ^12C that arise as a product of organic... intelligible by the hypothetical experiment of the tape, promotes a radical view of evolutionary pathways and predictability Rejection of ladder and cone does not throw us into the arms of a supposed opposite pure chance in the sense of coin tossing or of God playing dice with the universe Just as the ladder and the cone are limiting iconographies for life' s history, so too does the very idea of dichotomy . Burgess Shale -LIFE BEFORE THE BURGESS: THE CAMBRIAN EXPLOSION AND THE ORIGIN OF ANIMALS -LIFE AFTER THE BURGESS: soft-bodied FAUNAS AS WINDOWS INTO THE PAST the SETTING OF THE BURGESS SHALE WHERE . WORLD-WIDE FAUNA the TWO GREAT PROBLEMS OF THE BURGESS SHALE the ORIGIN OF THE BURGESS FAUNA the DECIMATION OF THE BURGESS FAUNA CHAPTER IV. Walcott's Vision and the Nature of History. VIEW OF LIFE& apos;S HISTORY AND EVOLUTION the BURGESS SHOEHORN AND WALCOTT'S STRUGGLE WITH THE CAMBRIAN EXPLOSION the BURGESS SHALE AND THE NATURE OF HISTORY -_ Inset_: A Plea for the High