Vestigiality describes those similar characters of organisms that have seemingly lost all or most of their original function in a species through evolution. A structure or organ or even a function is vestigial if it has diminished in size or usefulness in the course of evolution. Vestigial structures are markers of evolutionary descent. These may take various forms such as anatomical structures, behaviors and biochemical pathways. Some of these disappear early in embryonic development, but others are retained in adulthood. The idea that we are carrying around useless relics of our evolutionary past has long fascinated scientists and laypeople alike. Although some researches show nothing is rudimentary at all but having them is not a necessity.