I have been a science journalist for more than 30 years and have been involved in the world of horses for much of my life. I can remember reading about Eohippus when I was five years old and studying the O.C. Marsh-generated “horse clock” that presented such a reassuring “best of all possible worlds” view of evolution. I have owned several horses, one of which you’ll meet when you read the prologue to the book. I have ridden in the back country of Africa, annoyed buffalo and elk from the back of my horse in Yellowstone country, played polo, competed in horse shows, and been dumped on the ground too many times to count. I’ve never been a professional horseman, but until recently horses took up a great deal of my time.