The Y chromosome helps detect nesting tools

Are conquests and concubines spreading the genes of a man throughout China?

XY chromosome pair
(Photo: futura-sciences)

According to a recent study based on genetic information from Y chromosome, about 1.5 million people in Mongolia and northern China share ancestors. Historical data suggests that their common ancestor was a man named Giocangga who lived in the middle of the 16th century and that his descendants founded the Qing Dynasty to rule China from 1644 to 1912.

This analysis is similar to a controversial study in 2003 that claimed that nearly 16 million Chinese men are now the descendants of Genghis Khan.

Similar to the descendants of Genghis Khan, the descendant of the Giocangga ruled a vast steppe that lived the king's life with many wives and frequency. This month's study published by American Journal of Human Genetics suggests that this is a very effective breeding strategy

"This kind of survival advantage is probably a genetic trait of more important people than we have identified," said Chris Tyler-Smith, at the Wellcome Trust Sanger Institute, Hinxton, UK, the leader. two works above.

Immutability of Y chromosome

To demonstrate the fertility of conquerors, scientists must perform both historical and genetic analysis. Most useful information is in the Y chromosome Y (exists in all men) and Y chromosome tends to be stable.

Other chromosomes are very easy to exchange genetic information with. However, during fertilization, the Y chromosome pairs with X (a very large chromosome compared to the Y chromosome) and this prevents the exchange of the passage between the two chromosomes. This means that the Y chromosome is very little changed over generations, which is very convenient if used as an ancestor traceability agent.

In the recent analysis Tyler-Smith's group in the UK and China examined the Y chromosome of 1000 Asians. The results after comparing the DNA sequence of the Y chromosome show a similarity of 3.3%. This equivalent genetic information could show that these people had the same ancestors about six centuries ago.

To identify the true owner of this Y chromosome, Tyler-Smith turned over historical evidence. They thought it was Giocangga.

An aristocracy inherited the gene from Giocangga during their reign until 1912. Even low aristocracy also had many concubines that could be the reason why Y's sex chromosome was The Giocangga is so widely dispersed.

In addition to Tyler-Smith's hypothesis, the Manchus of the military only married people in the tribe and today these groups have the highest proportion of Y sexually transmitted Y chromosomes.

Only Y YH Khan's Y chromosome is comparable to the Giocangga Y Y chromosome when the ratio is about 2.5%, according to Tyler-Smith.

The owner of the Y chromosome

According to geneticists, it is difficult to get accurate information about the origin of the chromosome and, depending on historical evidence, is more difficult to trust.

"But all geneticists know that we are living fossils," said Steve Jones of University College London, who claims the Jiangga hypothesis is not unreasonable. Martin Richards, a geneticist at the University of Leeds, UK, said that Tyler-Smith analysis showed that the origin of sex chromosomes is one of the most rational analyzes he has ever known.

However, others protested. It is too risky to claim that it is Giocangga's chromosome, like Stanford's Luca Cavalli-Sforza. He also said that even the study on Genghis Khan was overzealous!

Researchers can prove their hypothesis by experimenting on Giocangga's descendants. But it's easier said than done. Although the aristocracy had 80,000 people in 1912, however, the Cultural Revolution in the 1960s and 1970s caused everyone in the aristocracy to hide their identity for not being harmed, and many Supply information has been destroyed. Some men who are believed to be able to help back the ancestor of Giocangga do not want to provide DNA to researchers.