Approximately 5% of people on the planet are born with a small hole above one or both ears. Interestingly, in the USA, such people constitute less than 1% of the population, while in Asia this distinction is diagnosed in approximately 10% of newborns. Scientists are yet to reach a conclusion about the causes of this feature’s formation and the role it plays in the body, but some believe that the holes could be an evolutionary remnant of fish gills.