Darwin made a powerful argument for evolution in the Origin of Species, based on all the evidence available to him. But a few things puzzled him. One was how inheritance works - he did not know about genes. This book concerns another of Darwin's Dilemmas, and the efforts of modern palaeontologists to solve it.What puzzled Darwin is that the most very ancient rocks, before the Cambrian, seemed to be barren, when he would expect them to be teeming with...