No. 40: Jul-Aug 1985
Most current textbooks pronounce that the genetic code is not only universal to life but that it must. Alterations in the code, the reasoning goes, would garble genetic messages. Such dogma, however, is based on another dogma, which states that all life on earth derives from a single ancestral line in which the genetic code is fixed and has always been fixed -- a "frozen" accident hit upon "by chance" on the primitive earth. Recently, though, small deviations from the code have turned up in ciliated protozoons and mycoplasmas, much to everyone's surprise.
(Scott, Andrew; "Genetic Code Is Not So Universal," New Scientist, p. 2l, April 11, 1985.)
Comment. No major deviations from the standard genetic code have been found; but then no one has really looked, because everyone knew the code was universal. It would be quite a shock if terrestrial life were found to have several genetic foundations and as many schemes of evolution.