During the last twenty years or so there has been a radical change in the understanding of the processes that led to life on earth. Wonderful Life documents this "revolution in understanding" which easily ranks among the great intellectual accomplishments of all time. The author is a professor at Harvard University and is the best science writer I have ever read. This book should particularly fascinate anyone interested in how scientific discoveries are made as well as anyone interested in biology or paleontology.
The story Gould tells is of how a tiny outcrop of limestone in the Canadian Rockies, the Burgess Shale, changed biologists' view of the nature of history. The fossil bearing stratum there is only about 10 feet thick and a few hundred feet long. What is unique about the site is that the conditions in the seas which formed the limestone were such that the plants and animals were preserved as three-dimensional fossils.
Although there are two or three other sites in the world where three-dimensional fossils formed, this is the only one that occurred shortly after the most critical period in the development of life on earth -- the Cambrian Explosion. Prior to the Cambrian era (about 530 million years ago) life was predominately single celled. After the Cambrian era, plants and animals thrived in the Earth's oceans. This transition is therefore termed the Cambrian Explosion.
The early chapters of the book define the biological concepts that are subsequently utilized. Of these, the biological "cone of progress" is among the most important. The "cone" refers to the view of how life evolved on Earth which prevailed until the late 1960's. The theory postulates that there was a constant progression of primitive to more advanced organisms on earth, and was changed little from the time that Darwin first proposed the theory in the mid-nineteenth century. Diagrams showing the relationships between successive epochs of life were drawn as an increasingly wider branching tree, which invariably resembled a cone.
The fossils in the Burgess Shale shattered that view. Scientists found that of the twenty-four types (phyla) of arthropods (essentially insects) discovered there, only four exist today. Not only were there more types of creatures then, the differences between them were far greater than the differences between the plants and animals alive today. Thus, the cone of progress was completely contradicted. The graphics and photographs in the book of the creatures from the Burgess Shale show animals that are almost unbelievably strange. They make it very clear how vastly different the world was then.
The people involved in this scientific discovery are also as interesting as the fossils that they studied. The Burgess Shale was discovered in 1907 by the preeminent Cambrian Paleontologist of the era, Charles Walcott. At the time, he was Secretary of the Smithsonian Institution, a position he was awarded after a long career with the United States Geological Society, thus making him one of the most powerful people in American science of the era. Amazingly, he completely misinterpreted the Burgess fossils by steadfastly adhering to the "cone of progress." Walcott methodically ignored obvious indications of the uniqueness of each organism he studied, and misidentified each as predecessor of one of the existing four families of arthropods. This mistake is termed "The Burgess Shoehorn" by the author, and is considered one of the greatest scientific blunders of all time.
It took almost forty years for the influence of Walcott to subside to the point that a new interpretation of the 40,000 fossils that reside in the collection at the Smithsonian Institution was possible. Starting in 1971, Dr. Harry Whittington, a professor of geology at Cambridge, and ultimately two of his graduate students, Simon Conway Morris (now also of Cambridge), and Derek Briggs (now at Bristol University), spent fourteen years slowly unraveling the true story of these unique fossils.
The middle portion of the book is a highly detailed but readable chronicle of how each successive discovery that Walcott incorrectly assigned to an existing phylum slowly eroded the Burgess Shoehorn. Ultimately, this process led to the intellectual breakthrough which recognized the history of life as a succession of epochs in which life prospered and diversified, followed by events which annihilated nearly all life. Gould refers to this as "disparity followed by decimation." Although these chapters are somewhat technical, they are extremely interesting from both the standpoint of showing how scientists are able to glean information by dissecting fossils, and how a long series of small advances in the understanding of these remains led to a monumental breakthrough in knowledge.
In the final chapters, Gould describes the implications of "disparity followed by decimation." In particular, the last 40 to 50 pages contain a wonderful analysis that illuminates subtle concepts by drawing on examples from popular literature and movies. The most interesting concept is termed (biological) contingency. The name of the book is derived from one of the movies Gould uses to illustrate the concept: the Capra classic It's a Wonderful Life. The movie is about a character who wishes he had never lived, and is given the opportunity to see how his absence results in a radically different (and bleak) world. As in the movie, Gould explains how even a small change in our history would have probably prevented life from ever evolving. He thus shows how miraculous it is that we are here at all. Although this material could stand alone as a highly engaging description of modern biology, the final chapters tie together all of the material covered in the book.
As enjoyable an experience as this book was to read, I have to admit that I found the book distinctly unsettling. The raw data that led to this incredible discovery of our heritage was a very small number of fossils that came from an almost imperceptibly small percentage of the fossil bearing rock in the world. As a collector who has bashed many fossils looking for a really good specimen, I now wonder how many unique specimens I have discarded or destroyed. It will be clear to anyone who reads this book that scientists as brilliant as the group described on these pages deserve the chance to advance their research with as many specimens as possible.
I have no intention to proffer the opinion that all digging of fossils should stop. Gould himself states that "fossils in the ground don't do anyone much good"; however, I believe that I should know what to expect before digging into a fossil bearing site -- and stop immediately if things are not what I anticipate. It doesn't seem like too much of a burden to bear. Although the fossils in this story were far more primitive than vertebrates, I now understand more than ever the need for the moratorium on excavating vertebrate fossils from public lands.
It's been a long time since I have read a book that I found so illuminating. The writing is clear and the way that Gould explores the geological, biological, scientific, sociological, and historical (or bibliographic) elements of the Burgess Shale story make the book extremely interesting reading. The graphics and photographs are stunning. I strongly recommend this book.
Wonderful Life: The Burgess Shale and the Nature of History
by Stephen Jay Gould; W. W. Norton; 1989; ISBN 0-393-02705-8; $27.95.
Copyright © 1994 by Fallbrook Gem and Mineral Society, Inc.
The preceding article was originally published in the January 1994 issue of Lithosphere, the official bulletin of the Fallbrook [California] Gem and Mineral Society, Inc; Richard Busch (Editor).
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Last updated: 18 September 2002