A book about wonder and a wonderful book. The story of the Burgess Shale — from its initial misinterpretation to its reassessment 50 years later — is mind blowing. This limestone outcropping high in the Canadian Rockies near British Columbia — which was once a near equatorial climate at sea level 530 million years ago but now sits at an altitude of 8,000 feet — has revealed about 150 previously unknown arthropod genera and entirely new species with anatomies that would be unimaginable to us today had Charles Doolittle Walcott not discovered them in 1909.
Gould calls these animals with their diverse anatomies "weird wonders" and explains that their broad proliferation was possible because the middle Cambrian was a time of filling the so-called "ecological barrel." In other words, it was a time of low ecological competition among animals which ultimately permitted unsuccessful anatomies to flourish for a few million years before the full panoply of evolutionary pressures (natural selection) began to eliminate the less successful designs.
Another thing learned from the Burgess Shale is the imprecision of "survival of the fittest." Certainly, adapting to environmental change is vital, but it's not the whole ballgame. The adapted animal also needs luck on its side, luck that it cannot possibly have any direct role in affecting. I refer to the importance of contingency. Gould calls it "decimation by lottery," and given its sway religious adherence solely to classic evolutionary principles such as gradualism, etc., becomes short sighted.
Finally, if you will accept my argument that contingency is not only resolvable and important, but also fascinating in a special sort of way, then the Burgess not only reverses our general ideas about the source of pattern – it also fills us with a new kind of amazement (also a frisson for the improbability of the event) at the fact that humans ever evolved at all. We came this close (put your thumb about a millimeter away from your index finger), thousands and thousands of times, to erasure by the veering of history down another sensible channel. Replay the tape a million times from a Burgess beginning, and I doubt that anything like Homo sapiens would ever evolve again. It is, indeed, a wonderful life. (p. 289)
If you're like me, one who wonders why we were set down on a speck of interstellar dust in the midst of a universe so vast we daily fail to comprehend its age and scale, this book is for you. Gould is a fabulous writer. He writes with a minimum of jargon, and concepts of any complexity he is careful to explain. But he does this without being tedious; he does it, in fact, while sharing his own boundless sense of fascination. Gould was a brilliant man, a rare amalgam of top-flight scientist, science writer, and teacher. When he died 10 years ago he left a great hole in the landscape of writers who could engagingly write for the general reader about evolutionary biology and paleontology. There is simply no one else like him working today. I'min the process of reading all of his books. There are about 20. Highly recommended for those with an interest in science, particularly the life sciences.