This book presents coverage of the principles and practice of molecular clocks, which have provided fascinating and unprecedented insights into the evolutionary timescale of life on earth. It begins by following the early development of the molecular evolutionary clock in the 1960s, and leads to the complex statistical approaches that are now used to analyse genome sequences. The chapters of this book have been contributed by leading experts in the field and address the important issues of evolutionary rates, molecular dating, and phylogenomic analysis. This is the first time that these different aspects of the molecular clock have been brought together in a single, comprehensive volume. It is an invaluable reference for students and researchers interested in evolutionary biology, genetic analysis, and genomic evolution.