This book is about the mapping cultures of twentieth-century genetics. From Molecular Genetics to Genomics is the second volume of a collection of papers resulting from a conference that was held at the Max Planck Institute for the History of Science in Berlin in March 2001. It covers the mapping procedures developed in the era of molecular biology, gene technology, and genomics, that is, roughly, in the second part of the twentieth century. The accompanying first volumeClassical Genetic Research and its Legacy-covers the first part of the twentieth century. We felt that a detailed history of genetic mapping was timely, if not overdue, in view of the recent developments in genomics epitomized by the announcement of a first draft of the structure of the human genome in the summer of 2000, which was eventually made public in February 2001, a month before the workshop from whose deliberations this book took shape.