Nature's Boswell

Article excerpt

Life: A Natural History of the First Four Billion Years of Life on Earth, by Richard Fortey; Alfred A. Knopf, Inc.; $30; 416 pp.


There is much poetry in this tale of life's four-billion-year history on Earth. It is a beautifully written and structured work, autobiographical yet packed with lucid expositions of science. The personal elements are crucial to the story, for Fortey-a senior paleontologist in London's Natural History Museumhas been at the center of paleontological research for more than two decades.

Fortey begins with an account of a 1967 expedition to Norway's Arctic island of Spitsbergen, where he and a fellow Cambridge student spent two months discovering a wealth of Ordovician fossils. Fortey was the younger, but positions were reversed when letters from Cambridge arrived with their exam results, and he alone had done well enough to continue to a higher degree. The honesty with which this socially delicate tale is told is striking, but what impressed me was the way in which Fortey interweaves it with apparently effortless explanations of the origin of the universe and the depth of evolutionary time.

"The Earth was born from debris that circled the nascent sun," writes Fortey in describing the astronomical events that shaped our world and the solar system. Stressing what he sees as randomness in Earth's origin, he points out that a slight variation in size, position, or spin of Earth might have precluded the possibility of life. Then, too, he notes how improbable it was that life was generated out of the poisonous brew of cyanide and oxides of carbon. He moves on to describe the first photosynthesizing prokaryotic bacteria and stromatolites-fossilized in Precambrian rocks-which pumped oxygen into the atmosphere and paved the way for multicellular organisms.

This far back, the division between animals and plants is murky, but as Fortey writes, "animals are the spongers on the hard work of photosynthesizers." He employs an imaginative mixture of natural history, paleontology, and even selections from Disney's Fantasia to get his points across and picks a rock sequence in Newfoundland to trace the first flourishing of Ediacara fauna through to the Cambrian radiation. The ancient assemblages of fossil animals in the Burgess Shale are also discussed, and Fortey presents an analysis of Stephen Jay Gould's book on the Burgess animals, Wonderful Life. Fortey says of Gould: "If palaeontology has a priesthood, then Steve Gould is the pontiff. The Burgess Shale, however, is one case where he has, I think, been fallible." Where Gould sees a world of dead-end oddities in the shale, Fortey sees ancestors for many extant life-forms.

We learn from Fortey about the plethora of paleontological techniques and how the slow, laborious, and sometimes dangerous work of this science is done. For example, hydrofluoric acid, used to remove fossils from their matrix, can also remove "almost everything, including the fingernails of the investigators if they fail to take the most stringent of precautions." He also describes paleontologists who tease "details out with a pin by gently flaking off little pieces of the covering rock, preparing drawings of every limb under a camera lucida, testing reconstructions until they made sense in three dimensions."

Other paleontologists are drawn in brief biography, such as the eccentric nautiloid authority Rousseau H. Flower, who carried a bullwhip around his New Mexico field site and used it on rocky outcrops that refused to yield his beloved fossils. While the expert on Ediacara fauna, Dolf Seilacher, of the University of Tubingen, contradicted everyone and everything, he inspired Fortey with his conviction that the best place to be was somewhere nobody had been before. …