Book excerpt: "Inspired by a GSA Penrose Conference held in Lander, Wyoming, June 14-18, 2006, this volume discusses the beginning and evolution of plate tectonics on Earth, and gives readers an introduction to some of the uncertainties and controversies related to the evolution of the planet. In the first three sections of the book, which cover isotopic, geochemical, metamorphic, mineralization, and mantle geodynamic constraints, a variety of papers address the question of when "modern-style" plate tectonics began on planet Earth. The next set of papers focuses on the geodynamic or geophysical constraints for the beginning of plate tectonics. The volume's final section synthesizes a broad range of evidence, from planetary analogues and geodynamic modeling, to Earth's preserved geologic record. This work provides an excellent graduate level text summarizing the current state of knowledge and will be of interest to a wide range of earth and planetary scientists."--Publisher's website.