The late John Maynard Smith, Professor Emeritus,, and David Harper, School of Biological Sciences, University of Sussex at Brighton, UK

"This book is essential reading for anyone studying animal signals ... the book is well laid out, and its emphasis on clear definition and logic is without parallel in books on animal communication ... We think this book marks a significant contribution by Maynard Smith and Harper, a keystone in the communication literature, and a fitting legacy for John as it will speak discussions long after his death." - ISBE Newsletter

"[The Late] Maynard Smith has inspired generations of biologists with his writing, and he certainly will continue to do so with this work with Harper. Through their admirable assessment of the current status of the field of animal signal evolution, the authors have developed a platform for consensus ... Their fascinating and intriguing empirical examples and natural histories are excellently suited to illustrate the theoretical problems they address." - Science

"Reading the book is a great pleasure, and anyone interested in animal communication will find it both useful and inspiring." - Science

"It is an ideal text for the undergraduate new to the field. Part of the problem is the lack of a basic set of agreed concepts and definitions (signals?!) for workers in the field. This makes it an ideal starting place for ecological discussions where school students can try out different ideas as they try to understand ecology. There's even a case to be made for this as a way of doing fieldwork. Overall, worth reading for the insights it gives us." - TEG News