By far the most provocative evolutionary work since Charles Darwin's Origin of Species, James Graham, a self-taught amateur, claims that animal evolution must have involved something more than can be explained by the old theory of evolution. With a weight of scientific evidence, he methodically shows that lethal cancer in juveniles - cancer selection, is the only plausible candidate for the missing mechanism. He goes on to use this astonishing theory to propose solutions to problems that have confounded natural selectionists. The small size of insects, the sudden origin of the human brain, the functions of ageing, sleep and even the very origin of animals are all, he maintains, incisively explained by cancer selection.