A short history of nearly everything - Bill Bryson [162]
For one thing, 500-million-plus years ago when the Burgess Shale was formed it wasn't at the top of a mountain but at the foot of one. Specifically it was a shallow ocean basin at the bottom of a steep cliff. The seas of that time teemed with life, but normally the animals left no record because they were soft-bodied and decayed upon dying. But at Burgess the cliff collapsed, and the creatures below, entombed in a mudslide, were pressed like flowers in a book, their features preserved in wondrous detail.
In annual summer trips from 1910 to 1925 (by which time he was seventy-five years old), Walcott excavated tens of thousands of specimens (Gould says 80,000; the normally unimpeachable fact checkers of National Georgraphic say 60,000), which he brought back to Washington for further study. In both sheer numbers and diversity the collection was unparalleled. Some of the Burgess fossils had shells; many others did not. Some were sighted, others blind. The variety was enormous, consisting of 140 species by one count. “The Burgess Shale included a range of disparity in anatomical designs never again equaled, and not matched today by all the creatures in the world's oceans,” Gould wrote.
Unfortunately, according to Gould, Walcott failed to discern the significance of what he had found. “Snatching defeat from the jaws of victory,” Gould wrote in another work, Eight Little Piggies, “Walcott then proceeded to misinterpret these magnificent fossils in the deepest possible way.” He placed them into modern groups, making them ancestral to today's worms, jellyfish, and other creatures, and thus failed to appreciate their distinctness. “Under such an interpretation,” Gould sighed, “life began in primordial simplicity and moved inexorably, predictably onward to more and better.”
Walcott died in 1927 and the Burgess fossils were largely forgotten. For nearly half a century they stayed shut away in drawers in the American Museum of Natural History in Washington, seldom consulted and never questioned. Then in 1973 a graduate student from Cambridge University named Simon Conway Morris paid a visit to the collection. He was astonished by what he found. The fossils were far more varied and magnificent than Walcott had indicated in his writings. In taxonomy the category that describes the basic body plans of all organisms is the phylum, and here, Conway Morris concluded, were drawer after drawer of such anatomical singularities—all amazingly and unaccountably unrecognized by the man who had found them.
With his supervisor, Harry Whittington, and fellow graduate student Derek Briggs, Conway Morris spent the next several years making a systematic revision of the entire collection, and cranking out one exciting monograph after another as discovery piled upon discovery. Many of the creatures employed body plans that were not simply unlike anything seen before or since, but were bizarrely different. One, Opabinia, had five eyes and a nozzle-like snout with claws on the end. Another, a disc-shaped being called Peytoia, looked almost comically like a pineapple slice. A third had evidently tottered about on rows of stilt-like legs, and was so odd that they named it Hallucigenia. There was so much unrecognized novelty in the collection that at one point upon opening a new drawer Conway Morris famously was heard to mutter, “Oh fuck, not another phylum.”
The English team's revisions showed that the Cambrian had been a time of unparalleled innovation and experimentation in body designs. For almost four billion years life had dawdled along without any detectable ambitions in the direction of complexity, and then suddenly, in the space of just five or ten million years, it had created all the basic body designs still in use today. Name a creature, from a nematode worm to Cameron Diaz, and they all use architecture first created in the Cambrian party.
What was most surprising, however, was that there were so many body designs that had failed