Miyakma

This is the story of the first human, Miyakma, and how she gave birth to a thorny plant, a tiger, a bear, a monkey and a boy and a girl. Because there are no other humans around, the sister and brother eventually mate, bringing upon themselves the wrath of Khomda, the god who is their father. As a punishment, he sends them down into the bowels of the earth, and after many generations, they attempt to return above ground. They manage to escape by performing a human sacrifice, and realize that they need to dispose of the body of the victim. This leads them to create a "death culture", dealing with corpses differently according to whether the person died by accident or of old age. This "death culture" survives to this day.