How did death enter the world?

According to various religious and mythological beliefs, death entered the world as a consequence of disobedience or a fall from grace. In the Judeo-Christian tradition, the story of Adam and Eve describes how their transgression in the Garden of Eden brought sin and mortality into human experience. Philosophically, death is often viewed as a natural part of the life cycle, intrinsic to existence and evolution. Ultimately, interpretations vary widely across cultures and belief systems.