Flower of an African violet Saintpaulia ionantha, which contains a transposon or transposable element (commonly known as a jumping gene"). Transposons are mobile pieces of DNA, which can move about within the genome (whole of the DNA of an organisms) and effect changes, depending on where they are at the time. Transposons are thought to be one mechanism by which rapid genetic change could occur, as is required by evolutionary theory. This normally double pink flowered plant has, as a result of a transposon, thrown up a normal single purple flower on the same plant."