Selections from from The Testimony of the Synthesases, by Timothy R. Stout.
(These selections by Marko Malyj are of the article published in Creation Matters, a publication of Creation Research Society, Volume 16, Number 2, March/April 2011, to appear at http://www.creationresearch.org/creation_matters/pdf/2010/CM15%2006%20low%20res.pdf)
|Fig. 7 A DRT (Direct RNA Template) |
model for the origin of coded translation.
They proposed (see his Fig. 7) that an RNA string could serve as a Direct RNA Template for assembling an amino acid string, thus functioning as a crude ribosome. Further, they proposed that, in time, this direct process evolved into the fully functioning ribosome with its indirect coding (i.e., usage of tRNAs, synthetases etc.).
There is a fundamental weakness in the approach proposed by Yarus et al. They assume that one can start with a simple code and gradually, step-by-step, modify it into a new one. However, codes do not change from one mapping to another in such a smooth manner. Once a code has been established, the products of that particular mapping will be all over the place, appearing at many locations and used for many unrelated purposes.
Therefore, even if an accidental mapping change (mutation) produced an incidental, isolated advantage, on the whole its adoption would result in a large number of system-wide errors. The lethal impact of the sheer number of such errors would tend to overwhelm any incidental advantage the modification might otherwise produce. Natural selection would thus select away from modification of an established code.
This exquisitely designed system points not to a gradual, step-wise appearance from purely random events, but to creation by a living God!
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Yarus, M., J.J. Widmann, and R. Knight. 2009. RNA-amino acid binding: a stereochemical era for the genetic code. J. Mol. Evol, 69:406–429. http://www.springerlink.com/content/b418465308240147/fulltext.pdf