Optimality properties of a proposed precursor to the genetic code.
We calculate the optimality score of a doublet precursor to the canonical genetic code with respect to mitigating the effects of point mutations and compare our results to corresponding ones for the canonical genetic code. We find that the proposed precursor is much less optimal than that of the canonical code. Our results render unlikely the notion that the doublet precursor was an intermediate state in the evolution of the canonical genetic code. These findings support the notion that code optimality reflects evolutionary dynamics, and that if such a doublet code originally had a biochemical significance, it arose before the emergence of translation.
Butler
Thomas
T
Department of Physics and Institute for Genomic Biology, University of Illinois at Urbana Champaign, 1110 West Green Street, Urbana, Illinois 61801, USA.
Goldenfeld
Nigel
N
D019143:Evolution, Molecular; D005815:Genetic Code; D008957:Models, Genetic; D009154:Mutation