Spirals are also a symbol of hypnosis. This most likely comes from the cliché of people and cartoon characters being hypnotized by staring into a spinning spiral (One example being Kaa in Disney's "The Jungle Book"). They are also used as a symbol of dizziness, where the eyes of a cartoon character, especially in anime and manga, will turn into spirals to show they are dizzy or dazed. The spiral symbolizes the double helix structure of DNA, representing biological evolution, and the spiral structure of a galaxy.