This year is 20 yearsNS Anniversary of human genome sequencing. In honor of this event, a research team led by Professor FU Qiaomei of the Institute of Vertebrate Paleontology (IVPP) of the Chinese Academy of Sciences reviewed ancient DNA (aDNA), the latest advances in the field of DNA. Obtained from the wreckage of past creatures.
Research on ancient DNA began with short DNA fragments and then advanced with widespread application of high-throughput sequencing (HTS) technology. In 2010, the publication of three draft ancient genomes (ie, Neanderthals, Denisovans, and a 4000-year-old (kyr) modern man from Greenland) marked a new era in aDNA research.
The genomes of the extinct archaic humans (Neanderthals and Denisovans) have been reconstructed. Importantly, Denisovans were initially identified using only aDNA data. These two archaic strains have been shown to have separated from modern humans about 550,000 years ago (ka). Then they were about 400ka apart from each other.
These aDNA analyzes show that ancient and modern humans did not remain isolated from each other after a separation of about 550 ka. Multiple waves of gene transfer have been discovered between archaic humans (ie Neanderthals and Denisovans) and modern humans. In addition, the two ancient language lines were mixed, as shown by an ancient language individual (Denisova 11), about 50 years old, who had a Neanderthal mother and a Denisovan father.
For the early modern human population, genetic data support African origin. However, it remains difficult to determine a single model to characterize the origin of African ancestry. In any case, in Africa, between 250 and 200 ka, the five major branches that contributed to the ancestors of early modern humans began to divide into each other in a short period of time.
In Eurasia, genomic data is obtained from an early stage Modern people It can be traced back to 45ka as early as possible. These data reveal the pedigree of some early modern humans.Some of them do not show detectable genetic continuity with later populations, while others, including those representing ancient Northern Siberia, ancient Europeans and ancient Asians, are genetically associated with the present. May be Human population..Will increase over time Population structureThroughout the Eurasian Continent, more population interactions and higher migrations have occurred.
“During the Last Glacial Maximum (LGM), population changes are seen in Europe, East Asia and Siberia during the harsh periods of 27-19 ka. The warm and stable climate after the LGM causes the population to grow. We moved and interacted, “said Professor FU.
The study of ancient DNA has effectively broadened our understanding of human history. But we just went underwater. We need to work harder. This should include genomes older than 30 kyr and further sampling from regions such as Africa, Asia and Oceania. It further expands the scope of aDNA research by leveraging other ancient molecular information such as proteomics, isotopes, microbiological and epigenetic data. In addition, investigate adaptive variants.
In addition to gaining a better understanding of human history, aDNA research has deepened our understanding of human biology. Exploring how humans have adapted to extreme environments such as LGM and infectious pathogens in the past will help us face new challenges such as future climate change and additional pandemics.
Yichen Liu et al, Insight into human history from the first decade of ancient human genomics, Chemistry (2021). DOI: 10.1126 / science.abi8202
Chinese Academy of Sciences
Quote: Https: //phys.org/news/2021-09-decoding-human-history-ancient-dna.html with ancient DNA (2021, September 24) obtained from September 24, 2021 Decoding history
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