The Winding Road to Discovering the Link between Genetic Material and DNA

Abstract

This is an account of the three-centuries long journey to the discovery of the link between DNA and the transformation principle of heredity beginning with the discovery of the cell in 1665 and leading up to the 1953 discovery of the genetic code and the structure of DNA.  This account also illustrates the way science works and how scientists do science as well as the fact that scientists are also subject to the same human foibles and short-comings as people in any field of endeavor.  Their use of the scientific method helps them find the path back from false starts and erroneous conclusions but does not assure a smooth progression toward the truth.  What emerges from this example is the scientists’ search for explanations based on empirical evidence, with the goal of trying to disapprove, rather than prove, a given theory and explanation.  As scientific knowledge increases, answers to scientific questions may become outdated, or they may generate a new set of questions that require new ways of thinking and conducting experiments.  Science educators have already recognized the value of historical materials and events in fostering an accurate understanding of science and in achieving desirable, positive and realistic attitudes toward science and in developing scientifically aware citizens. This is simple because the history of science can provide a vital background for students, detailing how science and scientists work and how scientific knowledge is created, validated, and influenced. However, desirable attitudes and behaviors toward science are not likely to be achieved unless history of science is learned and appreciated by all young citizens. Thus, there is a need for educators to involve, investigate, and explore the application of historical science and to show how this can contribute to accurately and explicitly show what science is, how it works, how scientists operate as a social group and how human societies direct and react to scientific endeavors both locally and globally (McComas, 2015, Cherif, 1988, Klopfer, 1969). And it is here where the history of science, the nature of science and how scientists do science is of enduring interest to us as well as to many educators in the scientific community. For those who might use this essay as classroom reading material, we provide a set of questions as an appendix that teachers and faculty may use to reinforce understanding of the essay.

Key Words: DNA, Genetic Code, Scientific inquiry, scientific discovery, Scientific method, Empirical evidence, Theory and explanation, How science works, Humanity and civic engagement