Werewolves in Antiquity

When we see that a myth lasts not only centuries, but millennia, undoubtedly, we are facing an enigma. The case I wish to address is especially intriguing: the myth of the werewolf. From the werewolves described by Herodotus in the fifth century BC to the lycanthropy in twentieth-century cinema, the same myth, in different forms, has apparently continued for thousands of years. How has it spread so extensively throughout time and space? How can this amazing continuity be explained? Is it really the same myth? Is it associated with some kind of ritual?