Wonderful Life
Stephen Jay Gould
347 pages, including index
published in 1989
Most of Stephen Jay Gould's books are collections of his columns for Natural History but every now and again he writes a book on a specific subject. In the case of Wonderful Life, he takes the amazing Burgess Shale fossils as his subject, using the story of their discovery and the 1970ties reevaluation of their importance to examine the history of evolution on Earth.
The fossils found in the Burgess Shale were discovered by Charles D. Walcott in 1909 and date back to a time just after the socalled Cambriam Explosion of 570 million years ago, which is the time when all the major groups of modern animals got started (or at least the oldest fossils we've found of them date back to this era.) The Burgess Shale fauna dates back to a time just after this event and thus contains the full diversity of it. However, at the time of their discovery, these fossils were still take for slightly odd representatives of conventional species, not the truly unique creators they later turned out to be.
In the heart of the book, Gould tells the story of how the Burgess Shale fossils were rediscovered and reevaluated by Henry Whittington and his graduate students Simon Conway Morris and Derek Briggs, examining each of the major fossils in turn. This I found to be the most interesting part of the book. I like this sort of scientific detective story and Gould is very good at writing about them.
But this is not just a history of the Burgess Shale animals, Gould has a far bigger and important point to make about evolution in general, which is what the rest of Wonderful Life is about. After Whittington, Morris and Brigss were done with the Burgess Shale, it turned out that its fossils contained a huge variety of bodyplans, both familiar and unfamiliar. It seemed that, unlike the traditional view of evolution's history of going from simple to complex, maximum variety existed shortly after the explosion of multicellar life upon the Earth. This has severe consequences for our view of evolution, according to Gould.
Traditionally, evolution is a clear cut process of progress with modern animals in general and us in specific the automatic obvious and correct outcome: evolution as a ladder. However, says Gould, what if we turned backt he clock to just after the Cambriam explosion: would the same species and phyla still become dominant, or is evolution far more dependent on chance then we're comfortable assuming? Gould thinks so. In his view, while evolution does have general rules guiding it, it is not determistic: accidents do happen. Evolution is a contigent process in other words, guided by accidents and incidents.
Quite interesting.
