Vestigial organs is a term used for organs which are degenerated, underdeveloped or useless for an organism. Usually, with the changes in the outer environment, the organs undergo a gradual change in order to cope up with those changes. Presence of vestigial organs is an indication that they were useful for our ancestors but as we evolved with the changing surroundings, these structures lost their functionality but our still found in our bodies. It is not compulsory that if an organ is vestigial for humans, so will it be for other organisms too.