No. 63: May-Jun 1989
Popular writers on biology are fond of saying that the genes and their DNA carry all information necessary for the development of an organism and the transfer of inherited characteristics. With the advent of the multibillion-dollar project to map the human genome (our genetic inventory), we have been seeing this extreme claim more often. The truth is that a map of the human genome will not tell us everything. By way of confirmation, we quote the lead paragraph from a recent article in New Scientist:
"In the early days of molecular biology, during the 1950s and 1960s, scientists as much as journalists fuelled the euphoria that surrounded the cracking of the genetic code. The secret of life was revealed, so many people thought. As our understanding has grown, however, so has our awareness of our ignorance. Research at the forefront of the molecular sciences has shown that we can no longer regard DNA - the stuff of genes - as a direct and complete set of instructions for the synthesis of proteins. The evidence begins to suggest that messages in the DNA are, in themselves, no more precise than the symbols and sounds with which we communicate. As in the languages with which we are familiar, the correct sense of a message written in DNA seems to depend on the rigorous checking and correction of errors, and on the context in which they are read."
The final sentence of the article is really paradigm-shaking:
"Thus genetic and evolutionary changes are no longer confined solely to the genome at the pinnacle of a hierarchy of information and control, but reside also in the interplay between DNA and the other components of cells."
(Tapper, Richard; "Changing Messages in the Genes," New Scientist, p. 53, March 25, 1989.)
Comment. If DNA can be read in more than one way, depending upon the context, our current concept of evolution may be in jeopardy. For example, how does an organism transmit "context" to its offspring; the same thought applies to error-correcting capabilities.