The Chinese surname has a very big characteristic, that is, it is the same Han surname, but it is likely to have a very big difference in consanguinity. Generally speaking, taking Wuyishan-Nanling as the boundary, the consanguinity of Chinese surnames is obviously divided into two branches: the north and the south.The consanguinity of the Han nationality between the two places is quite different, even greater than that between the Han nationality in the north and south and the local ethnic minorities. This shows that with the expansion of the population, the Han nationality continued to go south and crossed the Yangtze River into Huguang more than 2000 years ago, and finally crossed the strait to Hainan Island. During this process, the Han people who moved south continued to integrate with many ethnic minorities who spoke Dong-Tai, South Asian and Miao languages, thus diluting the consanguinity of the Han nationality in the north.
The statement 'The north and south branches with the same surname may not come from the same ancestor' can best refute the above argument if it is true.