"the world on turtle's back" is a creation myth because it

It explains how the Iroquois believe that the earth was created.

"The World on Turtle's Back" is a creation myth that explains how the Iroquois believe that the earth was created. Creation myths are a common feature of all cultures everywhere in the world, as they respond to common concerns of all peoples: "who created the Earth?" and "why are we here?" Creation myths have been passed down for generations, whether orally or in writing, and remain an important feature of culture.