Molecular Biologist Francis Crick delivered his paper “On Protein Synthesis,” published in Symp. Soc. Exp. Biol. 12 (1958): 138-63.
In it Crick proposed two general principles:
1) The Sequence Hypothesis:
“The order of bases in a portion of DNA represents a code for the amino acid sequence of a specific protein. Each ‘word’ in the code would name a specific amino acid. From the two-dimensional genetic text, written in DNA, are forged the whole diversity of uniquely shaped three-dimensional proteins
"In this context, Crick discussed the 'coding problem'—how the ordered sequence of the four bases in DNA might constitute genes that encode and disburse information directing the manufacture of proteins. Crick hypothesized that, with four bases to DNA and twenty amino acids, the simplest code would involve "triplets"—in which sequences of three bases coded for a single amino acid" (Genome News Network, Genetics and Genomics Timeline 1957).
2) The Central Dogma:
“Information is transmitted from DNA and RNA to proteins but information cannot be transmitted from a protein to DNA.” This paper “permanently altered the logic of biology.” (Judson)