022 Nobel Prize in Physiology or Medicine was officially issued. The award was Swedish scientist Svante Pääbo in recognition of his discovery of the genome of the extinct human race and the human evolution . He will receive a bonus of 10 million Swedish kroner (approximately RMB 6.42 million).When Pääbo received the award message, he was enjoying a cup of coffee in the morning. After the shock subsided, the first thing he thought about was whether he could share the news with his wife Linda.
Svante Pääbo—Revealing the mystery of human evolution through genes
Svante Pääbo was born in Stockholm, Sweden in 1955.
986, Pääbo passed the doctoral thesis defense at Uppsala University , and successively engaged in postdoctoral research at the University of Zurich, Switzerland and the University of California, Berkeley, USA. Later, he became a professor at the University of Munich, Germany in 1990.
999, he founded the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and is still active in the institute today. He also serves as an adjunct professor at the Okinawa Institute of Science and Technology, Japan. He also established a brand new scientific discipline - paleogenomics. His discovery lays the foundation for exploring what makes us unique human beings by revealing the genetic differences that distinguish all living humans from extinct humans.
Scientists have always been committed to the study of ancient humans to explore the origins of human beings and their unique reasons, etc. However, due to the degradation of DNA 2 over tens of thousands of years and the extreme technological challenges brought about by the pollution of microorganisms and contemporary humans, it has long been a question whether 's analysis of ancient DNA in extinct human forms is feasible.
Now, the seemingly impossible task of has been solved by Pääbo. For decades, Pääbo has been developing methods for studying Neanderthal DNA as a postdoctoral student at Alan Wilson, a pioneer in evolutionary biology.
html In the 190s, Pääbo managed to sequence an mitochondrial DNA region from a 40,000-year-old bone, the first time that humans have obtained sequences from extinct relatives.
Figure | DNA is located in two different regions in the cell. Nuclear DNA contains most of the genetic information, while much smaller mitochondrial genome exists in thousands of copies. After death, DNA will degrade over time, and eventually only a small amount will remain. It is also contaminated with DNA from, for example, bacteria and contemporary humans.
After the establishment of the Max Planck Institute in Leipzig, Germany, Pääbo and his team have continuously improved methods for isolating and analyzing DNA from remains of ancient bones. Ultimately, with the support of new technologies and the efforts of several key collaborators with expertise in population genetics and advanced sequence analysis, Pääbo ended up completing the seemingly impossible task and published the first Neanderthal genome sequence in 2010. Comparative analysis shows that Neanderthals and their most recent common ancestor, Homo sapiens, lived about 800,000 years ago.
Pääbo and his colleagues can now investigate the relationship between Neanderthals and modern humans from different parts of the world. Comparative analysis showed that DNA sequences from Neanderthals were more similar to those from contemporary humans from Europe or Asia than those from contemporary humans from Africa. This means that Neanderthals and Homo sapiens hybridized during their thousands of years of coexistence. Among modern humans with European or Asian descent, about 1-4% of the genome comes from Neanderthals. In addition to the above research on
, Pääbo also achieved a more sensational achievement in - an extinct ancient human Denisova was discovered through genomic data retrieved from a 40,000-year-old small finger bone specimen.
This phalanx specimen was found in the Denisova Cave in the south of Siberia and contains very well-preserved DNA.After sequencing it with
, the Pääbo team found that DNA sequences are unique compared to all known sequences in Neanderthals and modern humans.
and comparison with sequences from contemporary humans from different parts of the world shows that gene flow also occurs between Denisova and Homo sapiens. This relationship first appeared in the population of Melanesia and other parts of Southeast Asia, where individuals carry up to 6% of Denisova DNA.
Figure | Pääbo's discovery provides important information on the distribution of the world population when Homo sapiens migrated from Africa to other parts of the world. Neanderthals live in the west of Eurasian , while Denisovan lives in the east. When Homo sapiens spread throughout the continent, hybridization occurs, leaving traces left in our DNA.
Pääbo's discovery gave people a new understanding of our evolutionary history:
When Homo sapiens moved out of Africa, at least two extinct human populations lived in Eurasia. Neanderthals live in the western Eurasian continent, while Denisovans live in the eastern part of the continent. During the expansion and migration of Homo sapiens to Africa and eastward, they not only met and crossed with Neanderthals, but also with Denisovans.
Denisovans are human populations that lived in the last ice age. They belong to a brand new population of humans. By analyzing DNA extracted from fossils of ancient teeth and finger bones, scientists have proved the existence of the Denisovans, a study named one of the top ten scientific breakthroughs in 2012 by Science. Although it is named after Russian fossil samples, this species is actually mainly distributed in China. In November 2020, the State Administration of Cultural Heritage held a working meeting on the important progress of the major project of "Archaeology China". Scientists' research revealed that the Denisovans had lived in the Qinghai-Tibet Plateau for a long time.
Exploration and discovery
The discovery of the Denisovans was in 2008 when scientists discovered a fragment of a phalanx from 40,000 years ago in the Denisovan cave in southern Siberia. This bone contains extremely well-preserved DNA, and the research team led by Svanter Parbo sequenced it. They found that this DNA sequence is unique compared to all known sequences from Neanderthals and today’s humans. Parbo discovered an ancient human that was previously unknown and named it the Denisovan.
Comparative analysis shows that compared with the sequences of contemporary humans from different parts of the world, gene flow also occurred between the Denisovans and Homo sapiens. This relationship first appeared in people in Melanesia and some other parts of Southeast Asia, where people carry 6% of Denisovan DNA.
Caveman and Denisovan migration direction
Scientists have discovered that a mysterious human population lived in this world with our ancestors 30,000 years ago. Scientists call this human population living in the last ice age the "Denisovans". Scientists demonstrate the existence of the Denisovans by analyzing DNA extracted from fossils of teeth and finger bones found in a cave in Siberia. On December 21, 2012, the research was rated as one of the top ten scientific breakthroughs of the year by Science.
DNA test results of "X Girl" show that she was neither an early human nor a caveman, but a previously unknown human population. In the last ice age, they lived with modern people on the earth, when modern people were constantly moving forward in making stone tools, jewelry and artistic creation. This discovery means that there are at least three distinct members of the human genealogy, namely the modern, the Denisovan and the Caveman. It is reported that the skeleton fossils found in the Siberian cave came from a little girl, nicknamed "Girl X". According to the test results released in early 2010, she belongs to a completely new human population. Currently, a comprehensive DNA analysis confirms her position in the increasingly chaotic human genealogy.
Denisovans are the same as Neoser and Homo sapiens, but there are certain differences from the two. Their tooth structure is closer to the common ancestor Heidelberg than the latter two. The mitochondrial genes of the Denisovans are 1 million years apart from the Nippon and Homo sapiens, but the nuclear gene shows that it is a brother group of the Nippons, so its matriline may come from the pioneers. In fact, this race is not unfamiliar to Chinese people. The so-called " Early Homo HOMO " culture, including the Jinniu Mountain culture 280,000 years ago, the Dali culture 200,000 years ago, the Maba culture 130,000 years ago, and the Xujiayao culture 100,000 years ago, were all created by them, but they were not named in time. The Denisovan ruins are known for their numerous stone balls, and they may be the first to use flying stone ropes.
Combined with fossil evidence, we can roughly clarify the evolutionary history of the Denisovans. 300,000 years ago, the Denisovans differentiated from the primitive Nepali, and 280,000 years ago, they arrived in the Jinniu Mountain area of Liaoning. After 80,000 years of survival struggle, they eliminated the local Beijing Homo erectus and became human residents of Northeast Asia region. After that, they migrated repeatedly on the land of China and finally disappeared on the Siberian plains 20,000 to 30,000 years ago.
The demise of the Denisovans may be the same as that of the cousin Neanderthals, and was caused by the decline in competition with Homo sapiens. Starting 50,000 years ago, after the Denisovans returned to North China, the second group of Homo sapiens (New Asians) came to China. With more advanced tools, the Denisovans who had become "indigenous" were defeated step by step. Under pressure from Homo sapiens, the Denisovans were forced to migrate to Siberia and eventually died there.
In May 2019, an ancient human mandibular fossil was discovered in Xiahe County, Gannan Tibetan Autonomous Prefecture, Gansu Province, northeast of the Qinghai-Tibet Plateau. The latest analysis and research confirmed that it was a Denisovan of the Qinghai-Tibet Plateau 160,000 years ago. Today's Tibetan contains a small number of Denisovan gene fragments, so that most of them have the innate ability to adapt to the plateau .
On December 19, 2019, the American magazine Science announced the top ten scientific breakthroughs in 2019 selected by it on the 19th. These include: ancient humans on the Qinghai-Tibet Plateau. Researchers from China, Germany and other countries found that the fossils of human mandibular bone found in a cave on the Qinghai-Tibet Plateau belong to the Denisovan , indicating that as early as 160,000 years ago, this early Homo sapiens had appeared on the Qinghai-Tibet Plateau and adapted to the high-altitude environment there.
In November 2020, the State Administration of Cultural Heritage held an important progress work meeting on the major project of "Archaeology China" and reported on the Baishiya Cave site in Ganga Township, Xiahe County, Gannan Tibetan Autonomous Prefecture, Gansu Province. It is currently the first Paleolithic archaeological site to discover Denisovan fossils and Denisovan DNA in East Asia. It is a major progress in prehistoric archaeology of the Qinghai-Tibet Plateau and a major breakthrough in international Denisovan research. The Chinese research team successfully obtained the first Denisovan mitochondrial gene sequence outside the Denisovan Cave, which ultimately revealed that the Denisovans have successfully adapted to the high-altitude and hypoxia environment and lived on the Qinghai-Tibet Plateau for a long time in the late Pleistocene. It is also a strong evidence to support the widespread distribution of Denisovans in Asia. This research result was recently published online in the journal Science .
Related research
Girl fossil
Cave location
This time the finbone fossil was discovered in Denisova Cave in the Altai Mountains in southern Siberia in 2008, and some decorations and jewelry were also found. The owner of the phalanx is a little girl between 5 and 7 years old. The Denisovans differ from cavemen and modern people in their physical structure, but they also walk upright on two legs. Their teeth are similar to those of the Homo erectus who lived a much older age, such as the Homo erectus who died more than a million years ago.
Genetic information
In modern Melanesian residents, researchers have discovered traces of Denisovan DNA. This shows that the Denisovans had intermarried with the ancestors of Melanesian and may have been widely distributed in Asia.The Melanesia Island Group is located in northern and eastern Australia, which includes New Guinea Island .
The past 100,000 years of history have been seen as simple: humans rose in Africa, and then swept through Eurasian , replacing Neanderthals and other ancient human species encountered. The evidence support of fossils, stone tools, and mitochondrial DNA all show that humans from Africa have not intermarried with other ancient humans. However, in 2011, reanalysis of nuclear DNA of ancient and modern humans showed that most living modern people carried traces of ancient DNA from local ancient humans (a small proportion of the genome). In late December 2010, researchers published a new genome sequence of ancient humans from the Denisova Cave in Siberia (Altai Mountains). Research after
found that genomic DNA of some people living in Southeast Asia inherited 5% of genetic information from the Denisovans, and 4% to 6% of genetic information from the Neanderthals. Two research teams discovered genetic information from Denisovans among Australian Aboriginal people. A study found genetic information of the Denisovans in Filipino small black people, some Southeast Asian islands, and Armenian people. In the fall of 2001, researchers discovered that three relatively independent populations in Africa also carried unusual DNA variants, inherited from ancient African humans 35,000 years ago, far later than the rise of modern humans.
Melanesians retain Denisovan DNA
According to a new study, although Neanderthal DNA can be found in all modern non-African populations, Melanesians also contain obvious genetic components passed down from Denisovans. In the past, many modern populations had crossed with other primitive races, and those primitive races—such as Neanderthals and Denisovans—later extinct. Mapping gene flows from these species and other possible primitive species can help elucidate patterns of human genetics and how this species hybridization that has occurred in the past has affected human evolution.
To learn more about the influence and prominence of Neanderthal and Denisovan genetics in modern humans, Benjamin Vernot and others analyzed the genomes of 1523 people around the world. Their results show that about 1.5% to 4% of the genes in all non-African populations are from Neanderthals, but Melanesians are also people with significant Denisovan ancestry in the population they examined, because 1.9% to 3.4% of the genes in the Melanesian genome are from Denisovans.
researchers then mapped the gene flow of Neanderthal and Denisovan gene sequences; they found that in the history of modern humans, their hybridization with Neanderthal occurred at least three different periods. Conversely, the hybridization of modern humans and Denisovans may have only happened once. Further analysis revealed that certain regions of the modern human genome—including those that function in the developmental cortex and adult striatum—are particularly lacking these ancient genetic lineages. These findings provide new insights into human evolution and gene flow.
Science discipline
Svant Parbo established a brand new scientific discipline - paleogenetics. He extracted, sequenced and sketched Neanderthal genomes from fossils, and analyzed the genetic differences between all modern humans and extinct humans. His discoveries provide the basis for exploring why we are unique humans. In addition, he also sensationally discovered a previously unknown race, the Denisovan.
Reconstructed Face
Jerusalem Hebrew University reconstructed the Denisovan face after methylation study and analysis of the Denisovan DNA. Many of the characteristics of the Denisovans are similar to those of Neanderthals, including a sloping forehead, long face and large pelvis, as well as some unique features in humans, such as a large dental arch.DNA analysis of Denisovans, Neanderthals and humans suggests that Denisovans may have wider skulls than ours or Neanderthals, and they also don’t seem to have chins. [8] Scientific Dispute
Denisova Cave
Scientists have published a controversial discovery claiming to have discovered another "new" human population. This conclusion originated from the discovery on an Indonesian island in 2004, when people discovered a 3-foot (about 0.91 meters) tall ancient fossil, known as the "Hobbit Dwarf". But many researchers refuse to accept the conclusion that the hobbit dwarfs exist, and they believe that the bones found should belong to modern people with developmental disabilities.
Research significance
The newly discovered human population seems to be the "sister group" of cavemen. Its discovery paints a more complex picture of human evolution and leaving Africa.
This study helped us grasp some details. Through further research, we will deepen our understanding of the Denisovans and their interactions with other human populations.
The American Journal of Archaeology selected the top ten archaeological discoveries in the world in 2019. Among them, the Denisovan research on the Qinghai-Tibet Plateau Research Institute of the Chinese Academy of Sciences, led by scholars from Lanzhou University, and the MaxPrussian Institute of Evolutionary Anthropology in Germany, and participated by many domestic and foreign research institutes, was selected as .
recombinant gene
It is reported that this sorting work was carried out using 10 mg DNA samples extracted from fossil finger bones. "The quality of this genome is very high. We sort it many times, and the errors in the results are less than most of the genomes that give modern humans."
Neanderthals and "Denisovans" are both extinct ancient humans who are related to modern humans. This clarity of genome has helped scientists determine the relationship between "Denisovans", Neanderthals and modern humans.
Dr. Sventer Pabo of the MaxPoké Institute in Germany said: "We hope that scientists can use this genome to discover genetic changes that are crucial to the development of modern human culture and technology. These changes prompted modern people to leave Africa about 100,000 years ago and quickly disperse all over the world."
High-quality genome Helps modern genetic research
Normal researchers cannot study the evolution of special parts of the genome through gene sorting, and they use this latest completed high-quality genome version to even distinguish the nuances of the existence of genes inherited by this individual from their mothers and fathers. This complete "Denisovan" gene sequence can be viewed through the Internet by the scientific community. This genome is expected to unveil a new chapter in the history of the "Denisovans" and Neanderthals.
Papo said: "We want everyone to use it freely. We think many scientists will find it very helpful for their research."
is a huge leap in the research of extinct human genes
This genome represents the first high-coverage, complete gene sequence of a branch of our ancestors. The person responsible for compiling the sequence called it a "giant leap in the study of extinct races."
Scientists used earlier gene sequences to find that residents living in New Guinea have 4.8% of the "Denisovan" DNA. According to a paper published in the journal Public Library of Science - Comprehensive, the new technology helped scientists sort every part of the Denisovan genome more than 30 times, which is a more detailed scan.
This time the fossil of the finger bone was discovered in 2008 in the Denisova Cave in the Altai Mountains in southern Siberia, and some decorations and jewelry were also found. The owner of the phalanx is a little girl between 5 and 7 years old. The Denisovans differ from cavemen and modern people in their physical structure, but they also walk upright on two legs. Their teeth are similar to those of the Homo erectus who lived a much older age, such as the Homo erectus who died more than a million years ago.
In the age of Denisovans' survival, our ancestors and cavemen had begun fishing, hunting, wearing jewelry, painting on caves and making carvings with animal bones. In a report published in the journal Nature , the researchers pointed out that DNA test results show that teeth and phalanges belong to a different human population. Scientists only began to have the ability to extract DNA from fossils 10 years ago. Until then, they could only identify bones based on their shape and size.
gene sequencing
A new study describes the complete sequence of the Denisovan genome, thus providing clues to the relationship between these ancient humans—they are closely related to Neanderthals—and modern humans. The fossil evidence of the Denisovans is scarce; the existence of this group was only known in 2010, and the only known fossils are fragments and 2 teeth molars in a certain phalanx excavated in the Denisovan cave in the Altai Mountains of Southern Siberia. Because they only have very small material samples from the phalanx, Svante Paabo and his research team have developed a method to untie DNA strands so that each of its two strands can be used to generate sequencing molecules. This approach allowed the team to obtain an extremely complete genome sequence (30X), similar to the sequences researchers were able to obtain from the modern human genome.
researchers compared the Denisovan genome with the genomes of several modern humans around the world. The Denisovans seem to contribute to the genome of modern humans to some extent, but varying degrees. For example, the Denisovans have more of the same genes as Papua New Guineas than any other existing population studied. Furthermore, the Denisovans have more allele found in Asia and South America than alleles found in European populations, but this may reflect hybrid breeding between modern humans and Neanderthals, the close relative of the Denisovans, rather than gene flow from the Denisovans themselves.
This study reports several other findings. For example, the Denisovans whose genome was sequenced carries alleles associated with dark skin, brown hair and brown eyes of today’s humans. The researchers also produced a list of recent changes in the human genome that occurred after the fork with the Denisovans, namely changes unique to modern humans. The researchers say the Denisovans themselves have extremely low genetic diversity, but this may not be caused by in-combination. Given the wide geographical scope that Denisovans present over time, it is possible that their populations are quite small at the beginning but grow very quickly and have no time to increase gene diversity. The authors of the article said that if further studies show that the population size of Neanderthals has changed in some way over time, this could suggest that a single population scattered from Africa produced Denisovans and Neanderthals.
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