Research progress and development trend of life science in the 21st century

In the second half of the 20th century, the great progress made in various fields of life science, especially the breakthrough achievements in molecular biology, has revolutionized the position of life science in natural science. Many scientists believe that in the future of natural science, life science will become the leading discipline, and even predict that the 21st century is the century of biology, although there are different views on these assertions, but there is no doubt that in the 21st century, life science will continue to flourish, and life science plays a huge role in promoting natural science. No less than 19th and first half of 20th century physics. If in the past the life sciences have benefited from the introduction of concepts, methods and techniques from physics, chemistry and mathematics, then in the future the life sciences will have a unique way of positive feedback and return to the rest of the natural sciences. When the 21st century comes, some far-sighted scientists, thinkers and politicians will increasingly serious human social problems, such as population, the earth's environment, food, resources and health and other major problems to be solved, all place their hopes on the progress of life science and biotechnology.

1. Life sciences will become the leading discipline of natural sciences in the 21st century

The discovery of the DNA double helix structure model in the 1950s, the establishment of the "central law" of genetic information transmission and the establishment of DNA recombination technology have fundamentally changed the face of life science. The combination of molecular biology and genetics will take 10115 years to determine the full sequence of the 3 billion base pairs (genetic code) of the human genome, which contains about 100,000 genes in human cells. The "working draft" of the human genome has so far been sequenced with 99.99% accuracy and completion, and will continue to discover and elucidate a large number of new important genes, such as genes that control memory and behavior, genes that control cell aging and programmed death, new oncogenes and tumor suppressor genes, and genes associated with a large number of diseases. These results will be used in the service of human health.

After the 1970s, with the development of molecular biology and the emergence of bioengineering represented by genetic engineering, biotechnology made it possible to purposefully improve the traits and qualities of organisms through the precise cutting and purposeful recombination of DNA strands. The achievements of bioengineering so far have shown attractive prospects in production, and although there are still many controversial issues, it is very likely to become a new industry in the 21st century.

Developmental biology will rapidly rise, it will answer countless scientists for more than 100 years have been assiduously unsolved major issues, how a fertilized egg through cell division and differentiation to develop into an incredibly complex structure and function of the individual, elucidates the spatial and temporal orderly process control mechanism in ontogeny, Thus creating conditions for human beings to thoroughly control the growth and development of animals and plants.

The discovery that RNA molecules have both genetic information and enzyme functions provides a new opportunity to solve the problem of "how life originated" that has been advancing for decades. In the 21st century, people will also try to synthesize life in the laboratory. It has been possible to use biotechnology to amplify the DNA of ancient organisms or freeze-dried corpses preserved in special environments, reveal their genetic code, establish gene banks of extinct organisms, and study the evolution and classification of organisms.

The rise of neuroscience heralds another peak in the life sciences. The brain is an extremely complex high-level structural system containing 1011 cells. At the beginning of the 21st century, there will be major breakthroughs in the study of brain function at all levels from molecular to behavioral level, which will clarify learning. Memories. Thinking. There will also be significant advances in behavioral and emotional mechanisms. Theoretical advances in brain function will lead to the development of a new generation of intelligent computers, which may be the best example of the future return of the life sciences to the natural and technological sciences.

Ecology may be the science that most directly serves the human living environment and plays an important role in the sustainable and coordinated development of national economy. The theory and practice of ecology provide decision-making basis for the construction of the Three Gorges Reservoir in China. Protecting biological diversity is one of the most urgent tasks in life science. According to reliable data, about 100 kinds of organisms are extinct on the earth every day, and many of them have died out before being recognized by human beings, which is undoubtedly a disaster for human beings. The research results of ecology and biodiversity conservation and utilization will guide human beings to actively protect their living environment in accordance with the laws of nature, otherwise the material and spiritual civilization of human beings will be disastrously affected.

In response to the rapid development of life sciences, governments of developed countries and some international organizations have successively put forward life-science research programs with huge investment, such as the International Geosphere and Biosphere Program, the Human Genome Mapping and Sequencing Program, the Human Frontier Science Program, the Decade of the Brain, and the Research on Biodiversity Utilization and Conservation. The Human Genome Mapping and Sequencing Project alone has a budget of $3 billion.

Due to the development of life science, the demand for talents has soared in recent years, in addition to more and more physicists, chemists and technical scientists have been attracted to the field of biological research, in the United States, for example, in recent years, the statistics of 480,000 doctoral degree recipients engaged in life science accounted for 51%. The flow of outstanding young scientists to the forefront of life science is the driving force and source of the prosperity of life science in the 21st century.

2. Major sub-disciplines and development trends of life sciences in the early 21st century

In the 1980s, visionary biologists listed molecular biology (including molecular genetics), cell biology, neurobiology and ecology as the four basic disciplines of current biological science, which undoubtedly correctly reflected the general trend of modern life science. Genetics (mainly molecular genetics) is not only currently a leading discipline in the biological sciences, but will retain its central role in the life sciences for years to come. Some scientists have long predicted that the combination of molecular biology, cell biology and genetics will inevitably promote the vigorous development of developmental biology, thus proposing that developmental biology will become the "new master" of life science in the 21st century, and this prediction has gradually become a reality.

The mainstream position of molecular biology (including molecular genetics) in the life sciences, and the huge role it plays in promoting the development of the entire life sciences is indisputable. Cell is the basic structure and function unit of life activities, cell biology as a basic subject of biological science must be paid attention to. Many bioscientists believe that the rise of neuroscience or brain science will represent the next high point in the development of the life sciences, which will then contribute to the rise of cognitive and behavioral sciences. Ecology may be the discipline that most directly serves human living environment and plays an important role in the sustainable and coordinated development of national economy.

A. Molecular biology

Molecular biology is a discipline that studies the nature and laws of life phenomena at the molecular level. Nucleic acids and proteins (some people think that sugar) are the most basic substances of life, so the study of the structure and function of nucleic acids and proteins is still the main content of molecular biology research in the future. Protein is the main bearer of life activities, and almost all life activities rely on proteins (including enzymes) to carry out. In addition to clarifying the structure of peptide chains formed by amino acids with a certain sequence, the study of protein molecular structure and function will pay special attention to the specific three-dimensional spatial structure of peptide chains in the future, because the biological function of proteins is closely related to its spatial configuration, and nucleic acid is the carrier and transmitter of genetic information. The transfer process of genetic information from DNA to RNA a protein, known as the "central law" of genetic information transfer, is the core of molecular biology (molecular genetics) research. Its basic problems have been relatively clear, the current research focus is:

(1) After about 10115 years, the complete sequence of 3 billion base pairs of the human genome (genetic code) can be measured, which is a milestone work;

(2) The regulation of eukaryotic gene expression at all levels is still a task for a long time to come. The concepts, methods and techniques of molecular biology and the penetration of various disciplines are forming many new disciplines, such as molecular genetics, cellular molecular biology, neuromolecular biology, molecular taxonomy, molecular pharmacology and molecular pathology. Therefore, the leading role of molecular biology in the life sciences will continue.

B. Genetics

Genetics is more independent than molecular biology. But modern genetics and molecular biology are inseparable, intersecting disciplines that are hard to separate. Some famous geneticists refer to genetics in general as genetics, because modern genetics is mainly the study of the transmission and expression of genetic information in organisms. The information carried by genes is determined by the structure of genes, and the expression of information is realized by the function of genes, so genetics studies the structure and function of genes. From the perspective of genetics, the mechanism of all life phenomena is ultimately related to the structure and function of genes. Therefore, genetics will remain the core discipline and driving force of life sciences for a long time to come.

It is estimated that there are about 100,000 genes in human cells, and less than 5% have been clarified so far, so the discovery and elucidation of new genes related to important life activities and diseases will be an important task in the next few decades.

C. Cell biology

Wilson, a famous biologist, put forward a famous saying as early as the 1920s that "all the key problems in biology must be found in the cell", which still has deep connotations. Weissmann and Morgan have tried to establish a unified theory of heredity, development and evolution on the basis of cell research, although there was no specific way to find a solution, but the importance of knowledge about cells in the biological sciences is obvious. Cell is the basic unit of the structure and function of all life activities, cell biology is the science that studies the basic law of cell life activities, cell structure. Cell metabolism, cell heredity, cell proliferation and differentiation, cell information transmission and cell communication are the main research contents of cell biology. Although the content of cell biology research in the future is comprehensive, it may be summarized as two basic points: first, how genes and gene products control important life activities of cells, such as growth, proliferation, differentiation and aging, etc., which involves a new problem, how signals are transmitted inside and outside cells; The second is how the gene products-protein molecules and other biological molecules build and assemble into the structure of the cell and carry out the ordered life activities of the cell.

In the next 20 years and more, important progress and breakthroughs are expected on the following issues:

① The structure and function of chromosome, the main executor of the storage, replication and expression of genetic information, may be clarified at different structural levels.

② The study of cytoskeleton (including nuclear skeleton and chromosome skeleton) will get all-round progress.

The combination of cell biology with molecular biology and genetics will make important breakthroughs in the study of cell differentiation mechanism and lay the foundation for the rapid development of developmental biology.

The mechanism of cell senescence and programmed cell death will be clarified at a deeper level.

With cell molecular biology as the backbone discipline combined with other disciplines, the ideal of artificial assembly of living bodies may be gradually realized.

D. Developmental biology

How to develop from a fertilized egg into a structurally and functionally complex individual through cell division and differentiation is a major subject in life science and developmental biology that has not been solved so far. In recent decades, breakthrough achievements and knowledge accumulation in molecular biology, genetics and cell biology have created conditions for solving this major topic, which is the reason for the rapid development of developmental biology in the future.

The fundamental problem to be solved in developmental biology today is how the genes of cells selectively express specific proteins according to certain spatial and temporal relationships, thus controlling cell differentiation and ontogeny. Elucidating that genes control the development of embryos at multiple levels is not only a problem involving individual genes, but a series of regulatory genes in time and space, so as to control the development process. Although this is a very difficult subject, in recent years, it has begun to emerge and made breakthroughs. It is estimated that developmental biology will go further along this road in the future, and it is expected to achieve fruitful results.

E. Neuroscience (or brain science)

Neuroscience is the study of the structure and function of human and animal nervous system (mainly brain), at the molecular level, neural network level, overall level and even behavioral level to clarify the activity of the nervous system, especially the brain. The structure and function of the brain is a highly complex system containing 10, 11 cells. It is the basis of feeling, movement, learning, memory, emotion, behavior and thinking. How the brain cells guide human and animal behavior is one of the most promising and fascinating areas of future biology; The rise of neuroscience heralds another peak in the life sciences. Neuroscience or brain science is bound to contribute to the rise of cognitive and behavioral science in the next century. It is not unreasonable, therefore, for governments to invest heavily in this issue, including the US President's signature "naming January 1, 1990 as the Decade of the Brain".

Breakthroughs in neuroscience that could be heralded in the coming decades could include:

Elucidate the basis of learning, memory, and cognition at the molecular to behavioral levels;

(2) A series of genes and gene products related to memory and behavior will soon be discovered and clarified;

(3) The differentiation of nerve cells and the development of the nervous system have made great progress;

(4) The theoretical progress and breakthrough of brain function (such as pattern recognition, associative memory, and the explanation of thinking logic mechanism) will promote the development of a new generation of intelligent computers and intelligent robots;

The causes of a range of neurological diseases and psychosis are expected to be explained in neurobiological research.

F. Principal morphology (including conservation of species diversity)

Ecology is the study of the relationship between organisms and their surroundings, including abiotic and living environments. As ecological theory and application is related to the world environmental protection. The rational development and protection of resources and even the continued survival of human beings on the earth are closely related, especially in the case of the deteriorating earth environment, the importance of ecology has become very prominent. The main task of future ecology is to coordinate the relationship between human activities and the environment. Therefore, the concept and research content of the classical discipline of ecology must be constantly changed to meet the requirements of the protection of human living environment and the sustainable development of social economy.

Future ecological research may focus on the following aspects:

The relationship between the diversity, stability and evolution of ecological communities and human activities;

(2) Impacts of global climate change on ecosystem structure and function;

(3) The protection and sustainable use of biodiversity is also more urgent to protect the living environment of human beings, especially to save endangered species;

Urban ecology and economic ecology will develop rapidly;

Ecological engineering and ecological technology will play a role in the construction of the national economy.