Gould never ceases to astound me with his talents. Not only does he have fascinating insights into science, but each of his books is a literary event of exceptional clarity, with elegant yet distinctively quirky prose and humor. Reading his books, I think, is like drinking truly fine wine, each sip to savor and each vintage subtly different. His early death is a great loss.
This book covers a revolution that Gould argues was hidden from the public, that is, the complete reinterpretation of the Burgess Shale, which is the most important Cambrian fossil bed ever to have been found. In my reading, there were two fundamental ideas Gould wanted to get across: 1) that, with explosions of new forms of life that follow grand extinctions or leaps in evolutionary development, there is actually more rather than less diversity in basic forms; 2) this fact flatly contradicts our assumptions that life "progresses" by becoming ever more complex (and to some, evolutionarily superior, culminating in man). What Gould says is that, if you rewound the tape of life through all the contingencies that led to homo sapiens, it is more likely than not that we would never have existed. He would, in other words, remove us from the inevitability of occupying the apex of life's hierarchy.
For anyone familiar with Gould's essays, which I believe rank as works of genius in the genre of science popularization, will recognize these themes. What sets this book apart is his systematic, highly technical argument from the evidence of the re-interpretation. Much of the revolution depends on the numbers of joints in fossil legs, rendering them different than all the insect species that evolved from different ancestors, and other minutiae that Gould describes with peerless elegance. As such, I believe, he has succeeded in producing that most difficult of books: hard science for specialists that is also intended for the interested (and persistent) lay reader. This is a true virtuoso performance that is an incredible pleasure to read. As always, the persona he presents in the book is wonderfully companionable and open-minded.
As a reporter of science, I was surprised to learn that Gould was disdained by many of his colleagues at Harvard and the wider Cambridge area as having fallen behind the more mathematical and progressist-evolutionary approaches that have taken over the field of paleontology and biology. As I understood it - and this does not fully do justice to the objections of these scholars to Gould - they seemed to feel that he was wrong when he argued that many attributes did not have meaning or evolutionary significance and hence all should not be treated as such (i.e. catalogued ad infinitum in a scholastic manner that ignores certain assumptions). Instead, in my reading, Gould argued that, when catastrophic changes in the environment killed off huge numbers of species, the traits that allowed some to survive were usually evolved for other reasons and were perhaps redundant or useless at the time of the event. This book makes the most detailed case for Gould's position on these issues. I happen to believe that Gould is correct and that the vogue may one day shift back in his direction, i.e. become less determinist.