Cao Cao's skulldnaCan't get the test?
1.DNA study of Cao Cao's family: An interdisciplinary team at Fudan University collected venous blood samples from the Cao family across the country and used the full sequence of Y-chromosome DNA to find that the gene types of six families matched the age in which Cao Cao lived.
2.Fudan University Research: A joint research group of history and anthropology at Fudan University began research on the DNA of the Cao Cao family in 2009.
They collected venous blood samples from 280 males from 79 families with the surname Cao and 446 male volunteers with surnames such as Xiahou and Cao, and found that the genotypes of the six families matched the age in which Cao Cao lived through the full sequence of DNA on the Y chromosome.
3.Using DNA technology to study the Cao Cao family: Han Sheng, professor of the Department of History of Fudan University and vice president of the Chinese Society of Wei, Jin, Southern and Northern Dynasties, and Professor Li Hui, Key Laboratory of Modern Anthropology of the Ministry of Education of Fudan University, joined forces to find that the gene types of the six families were consistent with the age in which Cao Cao lived by extrapolating the ancestors from the genes of the modern Cao family.
O2*—M268 is a rare chromosome type, accounting for only 5% of the Chinese population. The possibility of counterfeiting of these Cao families is very small, with a probability of only 3 in 10 million.
Therefore, forensic science determined that they were the real descendants of Cao Cao. Through the full spectrum analysis of the Y chromosome of these six families, it was found that the mutation rate and change rate were stable, and a point of difference would occur every 140 years.
To this day, the difference between the descendants of Cao Pi and Cao Zhi is about 13 points, which is basically the same as the time they lived. The research group has successfully reversed the DNA of the Cao Cao family based on the genes of the descendants of the modern Cao surname, but the research is still ongoing for further confirmation.
In early 2011, Han Sheng and Li Hui traveled to Bozhou, Anhui Province, where Cao Cao's hometown and Cao clan's tomb were located. With the active support of the local cultural relics department, they found two teeth from the Cao clan tomb "Yuanbaokeng No. 1 Tomb" in the 70s of the last century.
Among them, a well-preserved tooth with a hard surface was brought back to the laboratory, where a small hole was made in the side and ancient DNA was extracted. After 6 rigorous tests, each with an interval of one month, the memory of time and space hidden in this tooth was revealed—the type of Y chromosome in its ancient DNA was the previously found O2*—M268.
Through the double verification of modern genes and ancient DNA, experts from Fudan University confirmed that Cao Cao's Y chromosome type is O2*-M268. Cao Zuyi, a member of the Red Society and a self-proclaimed descendant of Cao Cao, deduced that Cao Xueqin's ancestral home might be in Rushan after studying The Dream of Red Mansions, Cao's genealogy and related historical materials.
Based on this evidence and the available DNA data of the surname Cao, Fudan University supports the "Rushan theory", which states that Cao Xueqin's ancestral home is in Rushan. Although there are many debates about Cao Xueqin's ancestral hometown, including the "Fengrun theory" and the "Liaoyang theory", the current DNA evidence from Fudan University and Cao Zuyi's research results are inclined to the "Rushan theory".
According to the latest reports, the Y-chromosome DNA detected by Fudan University with a second-generation sequencer belongs to nuclear DNA, a result that has raised doubts in the archaeological community.
Deng Yajun, director of the Forensic Forensic Evidence Appraisal Center of Beijing BGI Fangrui, said that although nuclear DNA can be detected by second-generation sequencers, it needs to be spliced later, and the difficulty of detecting ancient and obsolete DNA will increase with age.
Deng Yajun also pointed out that mitochondrial DNA is easier to detect than nuclear DNA, and the mitochondrial DNA structure is relatively stable, and there are many examples of archaeological success that have been completed by measuring mitochondrial DNA.
In addition, Deng Yajun emphasized that the removal of contamination and the exclusion of microbial erosion and external DNA retention are the key steps in the detection of ancient DNA, because the skull is very thin, cannot be repeated after destruction, and its degree of degradation is too high, the organic matter DNA is minimal, and the bones currently unearthed are not enough for effective DNA extraction.
Therefore, the successful detection of ancient DNA requires a high level of information analysis and the ability to stitch together biological information, as well as specialized techniques to decontaminate them.
Wang Minghui, an expert in physical anthropology, said that the current DNA technology needs to preserve well-preserved teeth or limb bones as samples, and the samples of male individuals in Cao Cao's tomb - two teeth and one limb bone cannot meet this requirement, and due to various historical circumstances, such as dating breaks, accession, and surnames, etc., may affect Cao's lineage and Y chromosome, so it is not appropriate to test Cao Cao's DNA at present.
In addition, Wang Minghui also said that Cao Cao's background is controversial, and the identity of his descendants cannot be determined by genealogy alone. Deng Yajun also questioned this.
Faced with a dozen or dozens of different subtypes, how to determine Cao Cao's descendants? There are many social and ethical issues involved behind this. If the frame of reference is incorrect, no further work can be carried out. "
Deng Yajun said"While testing the offspring's Y chromosome can determine that they belong to the Cao Cao family, it is not possible to determine whether they are descendants of Cao Cao himself, his brother, or his uncle.
It was very difficult to confirm Cao Cao's identity. "Wang Minghui added:"Theoretically, even if all the problems are solved, the DNA identified by the offspring is extracted, and the ancient DNA is extracted for comparison, the results, even if they are very similar, can only prove the existence of a common paternal genetic relationship. "
In view of this, the archaeological community has doubts about the authority of DNA identification. Jia Lianmin, deputy director of the Henan Provincial Institute of Cultural Relics and Archaeology and who participated in the archaeological work of Cao Cao's Gaoling, said"We are also following this news.
The identification of the Cao Cao family by DNA is a new way of thinking and method, but this method is still controversial. "Jia Lianmin believes that DNA identification of ancient people is an emerging archaeological research method, but the authority of this method has not been fully recognized by the academic community.
He pointed out that DNA can also be contaminated, for example, when modern people come into contact with human remains, which may contaminate the DNA of modern people. "At present, this is still a kind of research in development and development, and it cannot be said to have been qualitative. "
Jia Lianmin believes that DNA identification is not as authoritative as carbon-14 archaeological methods, nor is it fully recognized in practice.
Although DNA identification has a scientific basis, it is not possible to assert the correctness of Cao Cao's family DNA identification because it is not yet widely recognized by the academic community and our knowledge of this field is still limited.
Despite this, paleoDNA research has advanced by leaps and bounds in the past decade, entering the era of genomics, which provides an important tool for archaeology. However, paleogenomics is informative but overly simplistic in explaining the problem, creating conflicts with archaeologists and leading to tensions between archaeologists and genomicists.
The concern of many archaeologists about this new research direction and the uneasiness of certain research practices once again remind us of the difficulty of interdisciplinary collaborative research and the need for in-depth collaboration.