PvM posted Entry 2161 on April 17, 2006 05:07 PM.
Trackback URL: http://www.pandasthumb.org/cgi-bin/mt/mt-tb.fcgi/2156
Recent research on the origins and evolution of the genetic code have shown how “The standard genetic code enhances adaptive evolution of proteins” in a paper by Wen Zhu, Stephen Freeland, Journal of Theoretical Biology 239 (2006) 63–70
Not only is the genetic code ‘optimal’ in the sense that the effects of point mutations or mistranslations on the phenotype are minimized, a property which seems to argue for stasis, but the genetic code also speeds up the rate of adaptive evolution, a property which seems to argue for rapid change.
Again we see how the concept of robustness and evolvability are intricately linked in the genetic code.
The standard genetic code, by which most organisms translate genetic material into protein metabolism, is non-randomly organized. The Error Minimization hypothesis interprets this non-randomness as an adaptation, proposing that natural selection produced a pattern of codon assignments that buffers genomes against the impact of mutations. Indeed, on the average any given point mutation has a lesser effect on the chemical properties of the utilized amino acid than expected by chance. Might it also, however, be the case that the non-random nature of the code effects the rate of adaptive evolution? To investigate this, here we develop population genetic simulations to test the rate of adaptive gene evolution under different genetic codes. We identify two independent properties of a genetic code that profoundly inﬂuence the speed of adaptive evolution. Noting that the standard genetic code exhibits both, we offer a new insight into the effects of the ‘‘error minimizing’’ code: such a code enhances the efﬁcacy of adaptive sequence evolution.
Please remind me again how ID explains these observations? Poof…?
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