It is said that the little toe nail of Han nationality is made up of two pieces, one is big and the other is small. I remember when they were young, they became one when they grew up. Why?

Inheritance is recessive, or your little toenail is too small and has been cut off. Remember to cut it off when you see someone, because it's ugly.

This thing you are talking about seems to be a feature of Mongolian race. Some Han people do, but I remember many students don't. However, it seems that the dominant proportion of this thing is Han nationality, which may have been used to distinguish Manchu from Han nationality. The east-west ratio is estimated to be about half in the north and very small in the south.

Some people say that this characteristic is the characteristic of Shanxi immigrants between yuan and next year, and I doubt it.

Off-topic, I have always been skeptical about Hong Tong's theory of immigration, and there are many similar theories in the south. During the war, people were displaced, and after the war, they usually went home to rebuild their homes. But why are the genealogies of rebuilding homes mostly written by a clan in Hongdong, Shanxi? Perhaps immigrants have preferential policies, or perhaps Hongdong is just a "checkpoint" or "immigration bureau" to integrate the victims. . . . There are too many possibilities, and no one knows the truth, so we can only guess!