Book excerpt: The field of developmental instability has generated a large amount of controversy recently, mostly because of fierce disagreement over the genetic basis of fluctuating asymmetry and its role in mate selection. This book is a timely and innovative critical evaluation of a burgeoning field. The book explores the premise that complex organismal, ecological and evolutionary processes can be understood as emergent properties of the "epigenetic machine," that is, the mechanisms fundamental to all organisms responsible for building and organizing phenotypes from information translated from DNA.