How to treat scholars' painting of China's surname? Can you get anything from it?

When the same surname rate is plotted on the map, researchers also use it to calculate another pointer to reveal the password of population and surname. This "pointer" has an academic name called "Nestor distance", which is actually a genetic distance, revealing the size of the surname difference between any two different regions. The bigger this "pointer" is, the greater the difference in surnames between the two places. The researchers found an interesting phenomenon: compared with its neighboring cities, other cities in Xinjiang and Ningxia, the genetic distance of Shihezi in Xinjiang is very different. On the contrary, the genetic distance with some cities in Henan and Jiangsu is very small.

"The two places are far apart, but the difference in surnames is very small, indicating that there may be large-scale immigration between the two places. People from one place go to another place and reproduce according to normal laws, resulting in a similar population structure. " Chen Jiawei said, looking back at history, we can find the answer from aiding Xinjiang. Many local people moved to Shihezi from Henan, Shandong, Jiangsu, Anhui and other central plains areas.

Similar phenomena also occur in Shandong and Northeast provinces. Although the geographical distance is far, the genetic distance is very close. This is related to the "de-orientalization" in history. For a long time, the East Gate of Shanhaiguan City has defined the area outside Shanhaiguan and the Central Plains. /kloc-in the 0/9th century, the lower reaches of the Yellow River suffered from famine year after year, and local farmers ventured into the northeast despite the ban of the Qing government. During the hundreds of years from the Qing Dynasty to the Republic of China, countless Shandong people "ran here and there", and the population of Northeast China soared. During this period, it also experienced the lifting of the ban at the end of 19. This is an unprecedented migration in China's modern history. In this process, * * * 20 million people moved to the sparsely populated three northeastern provinces.

"The closer the historical age is, the more accurately we can find events with similar genetic distances. If the time is too long, you can draw a vague and regular trend; The long-term evolution can be traced back to nearly a thousand years. " Chen Jiawei said that an analysis being conducted by researchers hopes to further improve the genetic distance and see which people are related in two distant places.

An interesting phenomenon is that the genetic distance between Beijing and the surrounding cities within 800 kilometers is very small. Once it exceeds 800 kilometers, the surname difference suddenly increases sharply, and the farther the distance is, the faster it increases. But in the middle and lower reaches of the Yangtze River, it is another scene. Take some cities in Shanghai, Jiangsu and Zhejiang as examples. As long as there is a little geographical distance, the genetic distance will widen a lot. After increasing to a certain extent, the genetic distance will not change.

"This shows that within 800 kilometers of Fiona Fang, people have been completely integrated. Why is there such a big difference between North and South? We are also analyzing and have not found the exact reason. " Chen Jiawei guessed that this might be related to frequent wars in the history of the north, where people could move completely, but they didn't go far. "We are doing something to judge the formation process and life characteristics of each city according to the relationship between genetic distance and geographical distance between each city and its neighboring cities."