The Cambrian Explosion was one of the great mysteries of evolution. The sudden proliferation of life forms 550 million years ago baffled even Darwin, who, in The Origin of Species, admitted that such rapid diversification presented a valid argument against his theory. But now, a century and a half later, 34-year-old Oxford University researcher Andrew Parker advances a new explanation of the Cambrian Explosion so compelling that many prominent scientists have accepted its plausibility. Parker contends that it was the development of sight in animals that caused biology's Big Bang. His account of how he solved the problem of the origin of biodiversity unfolds with the excitement of a topnotch whodunit.