2020-10-31

Ancient human DNA found 100,000 years ago on the Qinghai-Tibet Plateau

By yqqlm yqqlm

Source:Guangming Daily

Beijing, October 30th, by reporter Li Yun

30th, At the important progress meeting of the”Archaeological China” major project held by the State Administration of Cultural Heritage in Beijing, the reporter was informed that the major achievements made by the Baishiya karst cave site in Xiahe, Gansu were published online in the top international academic journal Science at 2 am on the 30th.

Baishiya is located in the northeastern part of the Qinghai-Tibet Plateau. A human mandible fossil was discovered here decades ago. A research team composed of scholars from Lanzhou University and the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences named him”Xiahe People”. After research, the team used ancient protein analysis methods to identify him as Denisovan, and used uranium dating methods to determine his age as at least 160,000 years ago. The latest result of this release is that the research team successfully obtained the mitochondrial gene sequence of the Denisovan from the sediments of the Baishiya cave. Ancient DNA research revealed that the Denisovan lived on the Qinghai-Tibet Plateau for a long time in the late Pleistocene.

The Denisovans, named after their earliest fossil specimens discovered in Denisovan Cave, Siberia in 2008, are”new races”. It belongs to the ancient type Homo sapiens. It is between Homo erectus and modern people. It has also coexisted with modern people for some time. The indigenous populations of Oceania, East Asia, South Asia and the Americas have genetic contributions and have become a research hotspot of widespread international concern.

The Xiahe mandibular fossil found in the Baishiya cave is the first Denisovan fossil found outside the Denisovan Cave. This discovery extends the spatial distribution of Denisovans from Siberia to the Tibetan Plateau for the first time. It is the study of Denisovans and the Tibetan Plateauprehistoric humans Double major breakthrough in activity research. This research result was published in the top international academic journal Nature in 2019, which caused a sensation in the international and domestic paleoanthropological and archeological circles, and was widely recognized and supported by domestic and foreign experts. Although the latest results were published in Science at two o’clock in the evening Beijing time, they still received widespread attention at home and abroad.

In an interview with reporters, Chen Fahu, academician of the Chinese Academy of Sciences and director of the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences, introduced that Beijingers lived between 700,000 and 200,000 years ago. What relationship they have with modern people has never been clear. The evidence is clear. The Denisovans, who lived at least 160,000 years ago, are just one of them. Therefore, the results of this research fill an important gap in the history of human origin.

On the other hand, previous studies have shown that modern Homo sapiens reached the Qinghai-Tibet Plateau between 30,000 and 40,000 years ago. This study shows that the Denisovans, who may carry genes adapted to the high-cold and hypoxic environment, came to the Qinghai-Tibet Plateau before modern Homo sapiens, and successfully lived in cold and hypoxic high-altitude areas during the maximum glacial period of the Quaternary. This result provides new clues for further revealing the source of genes for adaptation to high altitude environments in modern Tibetans and Sherpas. As Wang Youping, a professor at Peking University’s School of Archaeology, Culture and Science, said:“This subverts our cognition and rewrites the archaeological history of the Paleolithic Age in China.”

Although through research, we know that the Xiahe people are Denisova People, but little is known about the people represented by this fossil living on the Qinghai-Tibet Plateau. To this end, the team used a new technical means-sediment DNA analysis technology. Chen Fahu called it”molecular fossil”. Human bones will disappear over time, but the DNA they carry will stay in the soil and mud in lakes. This is an emerging ancient DNA analysis technology that makes up for the shortcomings of human fossils.

Before the excavation of the site, the research team invited Fu Qiaomei, a researcher from the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, to conduct sediment DNA analysis. The backbone of the research team, Professor Zhang Dongju of Lanzhou University and Fu Qiaomei worked out a sampling plan for ancient DNA analysis of sediment samples to ensure that the samples will not be contaminated by modern humans during the collection and transportation of the samples.

Fu Qiaomei told reporters that the difficulty of work is to distinguish. The sediments are mixed with DNA from various sources, not only human, but also plants and animals. To find the DNA of a person, we must distinguish which individual belongs to. Analysis shows that the ancient DNA of animals in the sediments, including extinct animals such as rhinos and hyenas, is consistent with the remains of animal bones found at the site. At the same time, the ancient human mitochondrial DNA was successfully obtained, and further analysis showed that it was Denisovan DNA. Combined with the results of stratigraphic dating, it is found that the Denisovan DNA mainly appeared in 100,000 years ago and 60,000 years ago, and may be as late as 45,000 years ago, indicating that Denisovans lived for a long time in the late Pleistocene. In the cave.

“You can know who he is by grabbing a handful of soil”. This”magical” technique opens a new window for the study of Paleolithic archaeological sites.”With this kind of technology, it will be much easier to restore the appearance of ancient humans.” Regarding the reporter’s vision, Chen Fahu said that with the current technological development, this is a vision that can be expected.

The latest research results released this time provide reliable stratigraphic, archaeological, chronological and molecular evidence for the activities of the Denisovans at the Baishiya cave site, and provide a further understanding of Denisovan’s The research on the temporal and spatial distribution, genetic characteristics, cultural characteristics, and environmental adaptation of the Wa people provides important scientific basis, and is of great significance for reconstructing the history of ancient human activities on the Qinghai-Tibet Plateau and clarifying the evolutionary history of ancient humans in East Asia. This achievement, led by Lanzhou University, uses the most advanced ancient DNA analysis and optical luminescence dating technology in the world, and invites a number of domestic and foreign research teams to work closely together to complete it. It is the first to extract ancient human DNA from the sediments of Chinese archaeological sites. A success story.

Since 2010, the Lanzhou University environmental archaeology team led by Chen Fahu, director of the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences, has carried out archaeological investigations and research in the Baishiya cave and its Ganga Basin. In 2018, an environmental archaeology team led by Lanzhou University professor Zhang Dongju, mainly graduate students from Lanzhou University, conducted the first archaeological excavation of the Baishiya cave site and invited multiple domestic and foreign research teams to conduct multidisciplinary comprehensive research.