Ears can be used for identification of humans and have been found to have an accuracy rate of 99.6%. The human ear is thought to be an accurate biometric, or unique anatomic characteristic used for automated recognition, because it is less prone to changes caused by aging than are fingerprints, which can change over time. An algorithm known as image ray transform is used for identifying a person through the shape of his or her outer ear. Critics of using ears as identification point out that there are potential factors that could cause inaccurate readings, such as poor lighting and viewing angles, as well as hair obstructing the outer ear.
More about identification:
The first person to develop a system for identifying humans through fingerprints was Francis Galton, a cousin of Charles Darwin, in 1888.
It is estimated that the average human can recognize 1,500 other human faces.
India is the country with the largest biometrics database in the world, with about 200 million of its citizens’ fingerprints having been voluntarily added into a system for recognition with the goal of having the entire population in the database as a means of national ID.