Watson and Crick’s scientific relationship unified the various disciplinary approaches discussed above: Watson, a student of Luria and the phage group, recognized the need to utilize crystallography to elucidate the structure of DNA; Crick, a physicist enticed by Schroedinger’s to turn to biology, became trained in, and contributed to the theory of, x-ray crystallography.
At Cambridge University, Watson and Crick found that they shared an interest in genes and the structure of DNA (see the entry on scientific revolutions).
Watson and Crick’s second paper of 1953, which discussed the genetical implications of their recently discovered (Watson and Crick 1953a) double-helical structure of DNA, used both “code” and “information”: .
In more detail, the transfer of information from nucleic acid to nucleic acid, or from nucleic acid to protein may be possible, but transfer from protein to protein, or from protein to nucleic acid is impossible.
The field of molecular biology studies macromolecules and the macromolecular mechanisms found in living things, such as the molecular nature of the gene and its mechanisms of gene replication, mutation, and expression.
Given the fundamental importance of these macromolecular mechanisms throughout the history of molecular biology, a philosophical focus on the concept of a mechanism generates the clearest picture of molecular biology’s history, concepts, and case studies utilized by philosophers of science.
And the import of experimental methods from physics to biology raised the question of the relation between those disciplines.
Molecular biology’s classical period began in 1953, with James Watson and Francis Crick’s discovery of the double helical structure of DNA (Watson and Crick 1953a,b).
Alfred Hershey and Martha Chase (1952) used phage viruses to confirm that the genetic material transmitted from generation to generation was DNA and not proteins (see Hershey-Chase Experiment in Other Internet Resources).
Muller (1927) used x-rays to intervene on and alter gene function, thus revealing the application of methods from physics to a biological domain (see Elof Carlson on Muller’s Research in Other Internet Resources).