'This is such a marvelous accomplishment that I would recommend to all, with even the slightest interest in evolution, buying the hardcover version to keep for a long time as standard reference to a phylogenetic understanding of structure and function in living organisms. I would especially recommend it to medical geneticists grappling daily with the (self-evident) fact that everything that develops, whether normal or abnormal, has evolved, and that nothing can occur in development that evolution has not made possible … [the book] is an extraordinarily effective means to learn about and to understand evolutionary relationships. It is one of the best-written and most comprehensive books on the subject.' American Journal of Medical Genetics