Storytelling

Natural History, Dec, 1998 by Bruce Stutz

Just as Einstein changed the way we understand time and space, and Freud changed the way we understand the workings of the human psyche, Charles Darwin changed forever the way we look at natural forms. The shapes of bodies, of finches' beaks and fishes' fins, were not fixed at some moment of creation; rather, forms evolved and were altered by circumstance. Life on earth is a great collection of individual stories, natural histories that, while sounding Kiplingesque--how the snail got its shell, how the bacterium got its DNA--give us a deeper appreciation of the world and our place in it. This issue's section on evolution shows how scientists continue to interpret the narratives embodied in natural forms.

Some interpretations were just too good to be true. Ernst Haeckel, an early disciple of Darwin's, an artist, and an ideological hero of the National Socialist Workers' Party, maintained that the story of each species' evolution was retold in the stages of its prenatal development. This theory, commonly known as "ontogeny recapitulates phylogeny," was influential for a time but wrong: it depended more on Haeckel's artful imagination than on actual observation.

Some stories are fiercely argued. In his recent book, paleontologist Simon Conway Morris challenges Natural History columnist Stephen Jay Gould's understanding of the tales told by the fossils of Canada's Burgess Shale. Many of these life-forms no longer exist. For Gould, these species represent evolutionary dead ends, and at one time, Conway Morris agreed. In Gould's view, the story of a species' evolution does not unwind in continuous narrative but moves in fits and starts, driven by environmental change and even cataclysmic happenstance. The vagaries of evolution are such that if the tale were to begin again, it would never follow the same story line. This also applies to humans--intelligent life, by Gould's reading of the fossil record, is neither ultimate nor inevitable.

Conway Morris weaves a different story from the diverse strands of the Burgess fossil record. The species that Gould and Conway Morris once agreed were evolutionary dead ends, Conway Morris now believes to he primitive progenitors of present-day groups: the life-forms that look so fantastical to us today eventually evolved into the familiar. Conway Morris further asserts that intelligent life was inevitable, the inescapable denouement to evolution's long narrative. Gould disagrees. This "Showdown on the Burgess Shale" begins on page 48.

Some stories are only now being revealed. How the echinoderms--starfish and sea urchins, for example--came to have five sides and no head is a half-billion-year-old tale that gene research is just beginning to tell.