Look Back On The Nucleic Acids Research In The First Half Of The 20th Century And Analyze A Number Of Issues In Visual Cortical Cells Of Old Rhesus Monkeys Author's Name: He Zhang Speciality: History Of Science And Technology

Nucleic acids, which play a awfully important role in metabolism, are the major research object in modern molecular biology. As attention is being paid to in life science, nucleic acids research is also a hot spot in history of science. However, through the generalization and analysis of the related articles, we find that most researches on nucleic acids research history are concentrated in the second half of the 20th century and few in the first half. One of the reasons for this is that the discovery of DNA double helix structure and the beginnings of molecular biology have a great influence on nucleic acids research, which like a"watershed moment". We should see the nucleic acids research before the discovery of DNA double helix structure should be regarded as a whole compare with the research after it. To review and study systematically the nucleic acids research history in the first half of the 20th century are significant to recognize the critical revolution of modern biology in mid-20th century correctly and analyze the reasons of it. In addition, the analysis of this history is benefit to grasp the human cognitive process of nucleic acids and disclosing the inherent law of scientific discovery. By using the method of documentary, we look back on the nucleic acids research history in the first half of the 20th century systematically. Through a host of integration and analysis, this history, in my eyes, can be divided into four parts:1. Early studies on basic chemical composition of nucleic acids2. The determination of the genetic material nature of nucleic acid3. The discovery of DNA double helix structure4. Studies on nucleic acid metabolism in the first half of the 20th century Base on these, a number of key problems have been preliminarily discussed. The chief achievements as follows:1. To summarize the contribution by Levene,the famous nucleic acid chemist, on the nucleic acids research. His tetranucleotide hypothesis has been analyzed in order to give explanations and make impact analysis.2. On the basis of the respective comparison of Avery's transformation, Griffith's transformation, and bacteriophage invasion experiment, we discuss the important meaning of Avery's transformation. Aiming at the fact that the result of Avery's transformation was not given the attention required in those early years, we summarize the subjective and objective reason of it and discusses some controversial issues.3. Avoiding the intense competition in the discovery of DNA double helix structure which is studied frequently, we choose the cooperation between competitors which is rarely concerned as research subject. Base on the analysis and demonstration of the role of cooperation in the competition in the search for DNA double helix structure, we discuss the relationship between competition and cooperation in science discovery.4. Through the tentative analysis of nucleic acid metabolism in the first half of the 20th century, which has touched upon rarely in history of science research, we give its characteristics, significance and the status in the nucleic acids research history. The above researches may provide references for the studies on the nucleic acids research history in the first half of the 20th century. We intend to promote the development of related researches by the discussion of new problems and viewpoints, which are proposed on the basis of the analyzing this history.