Reconstructing phylogenetic trees from DNA sequences has become a popular exercise in many branches of biology, and here the well-known geneticist John Avise explains why. Molecular phylogenies provide a genealogical backdrop for interpreting the evolutionary histories of many other types of biological traits (anatomical, behavioral, ecological, physiological, biochemical and even geographical). Guiding readers on a natural history tour along dozens of evolutionary pathways, the author describes how creatures ranging from microbes to elephants came to possess their current phenotypes. Essential reading for college students, professional biologists and anyone interested in natural history and biodiversity, this book is packed with fascinating examples of evolutionary puzzles from across the animal kingdom; how the toucan got its enormous bill, how reptiles grow back lost limbs and why Arctic fish don't freeze.