An interesting treatise exploring how it could have been possible for random events in primordial evolutionary history to give rise to something as incredibly complex as protein synthesis via translation of a genetic code.
"Indeed, the translation system might appear to be the epitome of irreducible complexity because, although some elaborations of this machinery could be readily explainable by incremental evolution, the emergence of the basic principle of translation is not. Indeed, we are unaware of translation being possible without the involvement of ribosomes, the complete sets of tRNA and aminoacyl-tRNA synthetases (aaRS), and (at least, for translation to occur at a reasonable rate and accuracy) several translation factors. In other words, staggering complexity is inherent even in the minimally functional translation system. Thus, as outlined above, it appears that the evolutionary origin of translation is to be sought along the exaptation route, i.e., by retrodiction of the ancestral functions of various components of the translation system that would allow them to evolve functionalities enabling their recruitment for translation.
Even this, however, does not do the full justice to the difficulty of the problem. The origin of translation appears to be truly unique among all innovations in the history of life in that it involves the invention of a basic and highly non-trivial molecular-biological principle, the encoding of amino acid sequences in the sequences of nucleic acid bases via the triplet code[15,16]. This principle, although simple and elegant once implemented, is not immediately dictated by any known physics or chemistry (unlike, say, the Watson-Crick complementarity) and seems to be the utmost innovation of biological evolution."
No comments:
Post a Comment