Mitochondrial DNA is one of the most explored genetic systems because of what it can tell us about the human past. This volume takes a unique perspective, presenting the disparate strands that must be tied together to exploit this system. From molecular biology to anthropology, statistics to ancient DNA, this first volume of three presents the global picture of human mitochondrial DNA variation. It takes a critical look at the field, flagging the problems, as well as the successes, and always placing the mitochondrial phylogeny centre stage.