PURSUING LIFE OVER 4 BILLION YEARS

Author: By Chet Raymo

Date: SUNDAY, April 12, 1998

Page: M3

Section: Books

Richard Fortey is senior paleontologist at the Natural History Museum, with a speciality in trilobites, and his book reminds me of those long-ago Saturdays in his host institution. Like the museum of those days (the displays have been jazzed up a bit since), his book ``Life: A Natural History of the First Four Billion Years of Life on Earth'' is capacious, jammed with marvelous treasures, and thoroughly Victorian in its wide-eyed wonder at the diversity and prodigiousness of life. He is a worthy successor to such Victorian masters of natural-history writing as Thomas Huxley and John Tyndall.

The story of life has been told many times before, but seldom with such wit and grace. Fortey is a gifted stylist who spices his narrative with personal experiences, historical anecdotes, and illuminating asides on the practice of science. He doesn't just describe ancient landscapes, he walks us though them, as if we were there, in a Carboniferous forest, say, or on the shore of a Devonian sea, with Fortey as our amiable and unfailingly interesting guide.

Consider the zest of the following passage: ``In the last twenty years I have devoted much thought trying to imagine the geography of the Ordovician [Era], piecing together the shadows of vanished worlds. This is like completing a jigsaw puzzle fabricated of scraps and dreams. The fossils have been my guide. I have chased them through jungles and across deserts. I have tracked them along Arctic shores and behind abandoned barns in Wales. This fieldwork has kept my feet on the ground and my hands on the rocks. Theories come out of pounding hammer on shale and limestone, conjuring visions of the ancestral faces of continents.''

As its subtitle suggests, ``Life'' sweeps across 4 billion years of evolution, from the first self-reproducing organisms in the primeval slime to the dawn of recorded history. Such a story could hardly be encompassed in a hundred volumes this size, but Fortey focuses our attention on pivotal moments in the fossil record when the capricious stream of natural selection lurched into new channels, gathering force and volume, fingering its way into the world we know today.

As subjects of the final chapters of the book, it is almost inevitable that we will imagine ourselves as the foregone outcome of all that went before. But so might it have seemed for the trilobites, the ammonites, or the dinosaurs had they been capable of conscious thought, so conspicuous is their representation among the fossils, so long their dominance of their habitats. Each of these great families came into being with the roll of the cosmic dice. With the roll of the dice each was laid low.

It is illuminating to know that the vast majority of plants and animals that ever lived have become extinct, and to most of these Fortey gives but a passing glance. And still what wonders he pulls from his bag of fossils! Fur, feather, eye, egg, backbone, blossom. He reveals each of these enduring adaptations in the context of a particular geography, as if it were the object of a wonderful Easter egg hunt. His childlike enthusiasm for discovery is infectious; the reader will want to sign on for Fortey's next fossil-hunting expedition to the trilobite-filled shores of Spitsbergen or the glacier-scratched rocks of the Arabian desert.

There is more to this book than the story of life. There is also the story of how we come to know the story of life: the patient picking over of hundreds of thousands of rocks; the expeditions to some of the planet's most inhospitable places; the controversies, the squabbles, the Golden Rule (``You must not fake your results'') -- not to mention the chastening realization that no matter how many fossils you have found, the next stone turned over might contain the evidence that will refute your most cherished assumption. Fortey expresses appropriate caution: ``Facts may be slippery things, but one thing we know is that we do not have enough of them.''

A 1993 Gallup poll indicated that about half of Americans believe the world is less than 10,000 years old, created as described in Genesis. The other half believe the world is more than 4 billion years old, as described by science. This is like the difference between the thickness of a single playing card and a pile of cards as high as a city skyscraper -- nothing in between, no shades of gray. Perhaps on no other issue are we so starkly divided.

What Young Earthers will make of Fortey's tale I don't know; for them, I suppose, it is a tissue of delusions. Old Earthers will find in this book an inspiring and marvelous context in which to understand ourselves -- creatures embedded in a cosmic flow of matter and energy in whom the universe has become conscious of itself. ``A review of the history of life should provoke awe, above all else,'' Fortey writes.

He asks for humility in the face of facts. Our history is not something we can make up, as we write novels or compose music. Our history is written in the layered rocks. ``Ultimately,'' Fortey says, ``it all boils down to bones.''