BOOKS

Prehistoric monsters

Did evolution change course in the Rockies?

DON CUMMING November 27 1989
BOOKS

Prehistoric monsters

Did evolution change course in the Rockies?

DON CUMMING November 27 1989

Prehistoric monsters

BOOKS

Did evolution change course in the Rockies?

WONDERFUL LIFE: THE BURGESS SHALE AND THE NATURE OF HISTORY By Stephen Jay Gould

(.Penguin, 347 pages, $27.95)

As both a serious scientist and a popularizer, Stephen Jay Gould delights in making provocative statements. His latest is that the most important

animal fossils on earth are found, not in Africa, but in the Rocky Mountains of Canada. Gould, a Harvard University professor whose previous works include The Flamingo’s Smile and An Urchin in the Storm, declares in his new book that fossils found in the Burgess Shale quarry in British Columbia’s Yoho National Park hold the key to the history of life, including human evolution. Gould sets out his claim in Wonderful Life: The Burgess Shale and the Nature of History, which is based on recent examinations of 530-million-year-old fossils found in 1909 at the site, near the Alberta border. The Burgess Shale is the remains of an ancient sea. Less than a city block long, it contains more varieties of life, now in fossil form, than all five modern oceans combined. The fossils lay misunderstood and neglected in drawers at the Smithsonian Institution in Washington, D.C., for more than 40 years—until scientists, not including the author, began to re-evaluate them. With his highly readable and superbly illustrated book, Gould examines the new evidence and uses it to challenge some of the most widely held notions of evolution, including Darwin’s theory of natural selection, also called survival of the fittest.

With boyish glee, Gould describes the fossilized sea creatures found in the Burgess Shale as “weird.” One, called Opabinia, had five eyes and fed itself with a segmented, flexible, frontal appendage much like a vacuum-cleaner hose. Two others that particularly fascinate Gould are Hallucigenia, “which had an anatomy to match its name,” and Anomalocaris, the largest animal of its time at up to seven inches in length and “a fearsome predator with a circular jaw.” Their original discoverer, paleontologist Charles Doolittle Walcott, longtime head of the Smithsonian, arbitrarily classified the creatures as oddball ancestors of present-day organisms and assigned them a place on the evolutionary ladder as it was then understood. But in the 1970s, paleontologist Harry B. Whittington of Cambridge University and two of his graduate students discovered that there was more to the fossils than imprints on the surface of the rock. Dissecting the rock with dentists’ tools, they uncovered the full three-

dimensional structure of the animals and concluded that many of them comprised separate phyla, or major divisions of animal life—and had no evolutionary connection to present-day life forms.

That, to Gould, was a revolutionary discovery. He suggests that those creatures were wiped out in an environmental catastrophe. The ones found by scientists were likely preserved by a mud slide. The creatures became extinct, Gould says, not because they were less fit than

surviving species, but be-

cause they happened to be in the wrong place at the wrong time. Indeed, he argues repeatedly that a different calamity—or even a slight variation in events—would have led evolution

along another path, in which case humans might not have evolved at all. Evolution, he argues, cannot be described in terms of timeless laws or with the traditional ladder model, showing inevitable progress upward. There are evolutionary rules, says Gould, but they operate in the background. The rest is chance or, as he puts it, contingency.

Wonderful Life is refreshingly free of jargon. But in paleontology, truth is to be found in the details, says Gould, and he does not spare the anatomical and historical particulars. Subtly

shaded drawings by Marianne Collins of Toronto’s Royal Ontario Museum (ROM) greatly assist in the understanding and appreciation of the animals.

Further work on the Burgess finds is to be spearheaded by paleontologist Desmond Collins of the ROM. Gould credits him with some of the best of recent discoveries, including the slightly lobster-like Sanctacaris, nicknamed “Santa Claws.” It will be up to Collins and others to determine the acceptance of Gould’s evolutionary theories. Meanwhile, with Won-

derful Life, Gould demonstrates that he has few, if any, peers as a scientific storyteller.

DON CUMMING