According to the author, much of the selective breeding that led to the fleece types known today took place in prehistory. Sometimes innovations in technology led to selective breeding for particular coat characateristics; in other cases particular features of the sheep's coat inspired new ways to use it. Primitive types of sheep, which have coarse kemps that molt annually and fine hairs that grow continuously, are contrasted with the Merino breed, developed in Spain during the Middle Ages, with a uniformly fine white wool coat that does not molt. -- AATA