Do we understand how evolution works? In this book Steven Hawkins outlines various possible mechanisms of biological evolution - the Neo-Darwinian Modern Synthesis, Symbiogenesis and Developmental Systems Theory. He contrasts and compares these various theories and proposes a view of evolution in which all three mechanisms have a role to play. In this schema 'natural selection' only has a minor role to play in biological evolution. In the final chapter Hawkins considers non-biological evolution and is drawn to conclude that we are unable to understand the fundamental nature of both non-biological evolution and biological evolution.