Why do some people have long black hair in their ears?

If this person's ears are long and hairy, it is probably hirsutism of external auditory canal. Hirsutism of external auditory canal is a genetic symptom of Y sex recognized by scholars at present. This disease is common in Indians, but also in Caucasians, Australians, Japanese and Nigerians. Is hirsutism of external auditory canal a Y-linked genetic disease? The pathogenic genes of this kind of genetic diseases are located on the Y chromosome, and there is no corresponding gene on the X chromosome, so these genes can only be passed along with the Y chromosome, from generation to generation, from son to grandson, and so on. Therefore, it is called "all-male inheritance". So far, only a few genes of genetic traits or diseases are known to be located on the Y chromosome.