Evolution of the Genetic Apparatus: A Review
This extract was created in the absence of an abstract.
Excerpt
Compelling fossil evidence shows that cells with morphologies similar to those of modern blue-green algae were already abundant 3.5 billion years ago, i.e., within at most a billion years of the formation of the earth. It seems safe to infer that evolution based on a conventional system of nucleic acids and proteins has led from these or similar simple cells to the diversity of living organisms.
I review here the largely speculative literature on the earlier period of evolution—that preceding the fixation of the nucleic acid/protein system in its contemporary form. A period of speculative fever in this field arose in the late 1960s and early 1970s (Woese 1967; Crick 1968; Orgel 1968; Sulston and Orgel 1971a,b). Most of the ideas discussed here, including the hypothesis of a protein-free, catalytic-RNA-dependent organism, were put forward at that time. Often, the same idea occurred independently to several researchers, whereas a single author...
