Molecular markers have opened exciting new windows through which to view the natural biological world. In this book, John Avise addresses the many applications for genetic markers (from polymorphic proteins and DNA) from the perspectives of population biology, behavioural ecology, organismal evolution and phylogeny. The book is taxonomically balanced with numerous examples from plants, animals, and microbes. It is also temporally balanced with examples ranging from assessments of genetic parentage and kinship in the most recent generations to phylogenetic assessments deep in the Tree of Life (and nearly everything in-between). This seminal work brings the reader up-to-date with the many dramatic advances and insights made over the last decade. Furthermore, by retaining descriptions of many pioneering works, it also traces the empirical and conceptual roots of each subject, thereby providing a rich sense of the field's history.