Exactly one hundred years ago leading American paleontologist Charles Doolittle Walcott (right) was hiking along Burgess Pass in the Canadian Rockies when he found a slab of shale containing fossil crustaceans. His interest piqued, Wolcott made return trips to the Burgess Shale in the following years where he ultimately collected tens of thousands of fossils. Many of these fossils were extraordinarily well-preserved, and they were mysterious. They included strange forms like Anomalocaris, Opabinia, Wiwaxia, and Hallucigenia. These fossils revealed a mystery: like other Cambrian fauna, these strange soft-bodied fossils appeared in the fossil record abruptly, without evolutionary precursors.
Darwin himself was aware of this problem in his own day, writing that the lack of fossil evidence for the evolution of Cambrian trilobites “must at present remain inexplicable; and may be truely urged as a valid argument against the views here entertained.” Nearly 150 years after Darwin penned those words, biology textbooks are still observing things like, “Most of the animal phyla that are represented in the fossil record first appear, ‘fully formed,’ in the Cambrian.” Indeed, the striking appearance of animals in the Cambrian explosion is captured in a recent article in Nature article commemorating the 100th anniversary of Wolcott’s discovery, stating that “virtually all animal groups alive today were present in Cambrian seas.”
The Cambrian seas are now being brought back to life in a new video from Illustra Media titled “Darwin’s Dilemma: The Mystery of the Cambrian Fossil Record,” set to be released next month. With all the stunning animation and computer graphics we’ve grown accustomed to enjoying from Illustra, the film tells the story of Wolcott’s discovery of the Burgess shale and both the beauty and scientific importance of the fossils he found. It also recounts attempts by paleontologists to explain away the abrupt appearance of major animal groups in the Cambrian explosion and offers the views of scientists who feel the best explanation for the bioinformational explosion recorded in Cambrian rocks is intelligent design.
We’ll have more on this film in the next few weeks, but it’s a good time to remember Wolcott’s important discovery 100 years ago and the challenge it has brought to Darwinian thinking.