Creation myths may be etiological, attempting to provide explanations for the origin of the universe. For instance, Eridu Genesis, the oldest known creation myth, contains an account of the creation of the world in which the universe was created out of a primeval sea (Abzu). Creation myths vary, but they may share similar deities or symbols. For instance, the ruler of the gods in Greek mythology, Zeus, is similar to the ruler of the gods in Roman mythology, Jupiter. Another example is the ruler of the gods in Tagalog mythology, Bathala, who is similar to various rulers of certain pantheons within Philippine mythology such as the Bisaya's Kaptan.