At dawn, Han Jian once again put on his fossil collection tools and came to his familiar "battlefield" - the "Kuanchuanpu Biota" in the southern Shaanxi region. As a member of the early life research team of Northwest University, mainly academician Shu Degan, researcher Han Jian has been looking at this place for ten years.
The picture shows the backbone members of the early life research group of Northwest University (the third from the left is Academician Shu Degan).
Each time they go out into the field, the team will collect hundreds of informative fossils back to the laboratory located in the Northwestern University research building to analyze and study them one by one. With the help of acid etching, microscopic electron microscopy, micro-CT and other technical means, they were able to carry out an "ancient dialogue" with life more than 500 million years ago. A decade of silent dialogue led them to discover the oldest distant ancestor of mankind: the crested cruciferous sac. This miniature animal, which is only 1 mm in adult size, is the oldest primitive post-mouth animal ever found and is thought to represent the earliest miniature human distant ancestor of the Ezoogene. This discovery pushes the recognition of the early ancestors of human beings from 520 million years ago to 535 million years ago, which is very close to the beginning of the Ephemeral Universe (540 million years ago), and its volume has also been pushed from "centimeter- to "millimeter-level". On February 9, 2017, Nature magazine published a research article in the form of a cover highlight paper, and commented that the study "found empirical evidence for the 'major unsolved case' of the study of the ancient origin of mankind", which shocked the international academic and press circles. The New York Times, the BBC, the Guardian, the Times and other media have published long-form reports.
This paper is the 13th research paper published in the international top academic journals "Nature" and "Science" in the 20 years by the early life research team of Northwest University led by Academician Shu Degan.
Focus on the frontier and concentrate on cracking the world's "unsolved cases"
In the process of exploring biological evolution, the puzzle that puzzled Darwin was that the theory of evolution lacked the support of evidence from "transitional taxa of evolution". The spring light insects of the "basic animal sub-niche" discovered by Shu Degan's team, the cactus Dianworm of the "proto-mouth animal sub-niche", the archaea phylum, paleocysts, Yunnan insects, Chinese eels, Yangtze River sea squirts, Kunming fish, and wrinkled cysts in the "hindzoological sub-niche" are all reliable representatives of transitional taxa of animal high-order meta-evolution. These important scientific findings enabled the team to reveal the origin and evolutionary relationships of the three key phyla of animal sublimites, empirically demonstrated the continuity of animal evolution between the Precambrian and Cambrian periods, and then constructed a complete early animal tree framework for the first time. This is the first time that after Darwin proposed the "tree evolution" conjecture that life on earth is the ancestor of all things, for the first time, scholars have outlined the basic outline of the "big tree" of the evolution of the three major branches of the basic animal, proto-mouth animal and post-mouth animal when the origin of the animal phyla erupted. "In the face of the sequential evidence of the evolution of animal trees at the source time, Darwin must have smiled if he had a spirit in the sky." Shudgan said.
In addition to empirical research, the early life team of Northwestern University also boldly made theoretical innovations and proposed a new hypothesis of "three-act Cambrian explosion". The hypothesis is that from 560 million years to 520 million years, lasting about 40 million years, the three sub-boundaries of basic animals, proto-mouthed animals and post-mouthed animals have successively changed from quantitative to qualitative changes, and phyla outbreaks occurred sequentially, resulting in the first formation of a complete animal tree framework on the earth during the Chengjiang fauna period, and the Cambrian explosion basically ended. The new hypothesis reveals the evolution of the animal kingdom over a period of 40 million years, from the bitenoderm to the trioderm, to the inversion of the mouth and anus, and the continuous upgrading of the metabolic system, reflecting the stage and continuity of the Cambrian explosion process, revealing the essential connotation of the Cambrian explosion event that puzzled Darwin. This hypothesis and its series of fossil empirical results "Earth Animal Tree Formation" won the second prize of the 2016 National Natural Science Award.
Through decades of tireless efforts, they have accomplished seemingly "impossible tasks." Local universities can not only do basic scientific research, but also make world-class results.
The picture shows Academician Shu Degan at work.
Preaching and receiving, the scientific spirit is passed on from generation to generation
In 1995, under the organization and coordination of Shu Degan, the "Institute of Early Life of Northwestern University" was established. So far, the young and middle-aged backbone of the research team, such as Hua Hong, Zhang Xingliang, Han Jian, Zhang Zhifei, and Liu Jianni, have all been independently trained by Northwest University. The team currently employs 6 key researchers, ranging in age from 70 to 38, all with doctoral degrees and experience in studying abroad and international cooperation research, and chairing national basic research projects.
Zhai Mingguo, an academician of the Chinese Academy of Sciences, once evaluated the team with "faith and persistence": "Having faith is having scientific concepts and problem-oriented." They take the evolution of life as the core and the biological evolutionary chain (biological tree) as the key to discovering problems and solving problems; if they persist, they are immersed in research and do not see different ideas. ”
To do research in the provincial colleges and universities located in the northwest, it is not only necessary to sit on the cold bench, but also to withstand poverty and withstand pressure. Academician Shu Degan once laughed that 18 years ago, the photos of "Kunming fish", "Haikou fish" and "Yunnan insects" submitted to Nature were washed out by them in the "self-built dark room" of the men's toilet of the Department of Geology; Zhang Xingliang, who is 1.83 meters tall, traveled with him when he was studying for a master's degree, and whenever he ordered food, he would consider trying to save as much as possible, saying "Teacher Shu, let's order a roasted tofu bar"... Even under such conditions, in the face of invitations from foreign scientific research institutes, Shu Degan and his team were still unmoved: "The best research should be done by Chinese, and new academic ideas should be proposed by Chinese", which is their answer. When talking about naming the research objects, Shu Degan said, "The reason why we named the ancient creatures we found with the words 'Huaxia eel', 'Kunming fish', 'Haikou fish', 'Yangtze River sea squirt' and so on is to commemorate the place where they were found and record China's important contributions in the history of science." China needs more people to cultivate this monument and add more honor to our great country that has created countless excellent civilizations. ”
In 2017, when interviewed by Xinhua News Agency and other central media, Shu Degan's first sentence of introducing the results said: "The main contributor to the discovery of 'coronal wrinkled sacs' is Han Jian, Han Jian is the first author of the paper, and the field work and laboratory work are basically completed by Han Jian." Reporter Xu Zuhua immediately sighed, "The team leader has such a mind and pattern, which is really enviable." "We must bring up and push young people up as soon as possible, and guide cultural genes to be passed on from generation to generation." "Academic inheritance is higher than personal gains and losses, and team leaders should create the greatest development space for young people, so that young people have independent research directions and are full of confidence in the future." Shudgan said so, and even more so. It is under the guidance of Shu Degan's teaching from entry to talent, from learning to being a person, the sharing and communication within the team is very smooth, the overall resource advantages of the team are fully utilized, and the "academic tree" can thrive and flourish.
Honest and diligent, self-improvement and silent progress
Some people attribute the scientific echelon and fruitful results of the paleontological research team to the "Shudegan phenomenon", and Shudegan hastily resigned: "This is not a phenomenon, we are the team of Northwest University, in fact, adhering to the school motto of 'honesty and diligence'."
Northwest University's 115-year history of running schools, the four-character school motto of "honesty and diligence" and the spirit of "hard work and self-improvement" have been refined, and under the inspiration of this spirit, a group of professors and experts are willing to dedicate silently. From the series of achievements of Shu Degan's team, to the "Hou's Theory" founded by Hou Boyu, to Professor Zhang Bosheng's "Theory of Crustal Wavy Mosaic Structure", Professor Wang Shutang's "Wang's Theorem"... Xi Daren has created one miracle after another in a difficult environment.
In addition to passing on the spirit of Xida, institutional guarantees also play a vital role in the development of academic teams. Northwestern University has always encouraged teachers and teams engaged in basic research to focus on generating major original achievements, devote themselves to research, and accumulate for a long time. In terms of talent recruitment, scientific research project management, curriculum setting, resource use and other aspects, they have given more autonomy, which has stimulated their scientific research motivation. In 2016, the school clarified the idea of "rewarding high-end, mobilizing backbones, and supporting young people", and produced policies, mechanisms, and measures, and achieved remarkable results.
After winning the first prize of the National Natural Science Award, Shu Degan was invited by domestic universities with high salaries and generous positions. He said, "I don't want to be a quiet place in Xida, where we can conduct research more without distraction." ”