Answer: They explain how people came to live on the earth.
Explanation:
Myths, fables, and folk tales have for millennia served as mediums for passing historical knowledge for times when records could not be made.
They quite often attempt to explain the age old question of how humans came to be and quite often, they paint a different scenario than the one science does by ascribing it to some supernatural occurrence or being such as Zeus or Ra having created humans like in Greek and Egyptian mythology respectively.