Symmetry breaking and adaptation: evidence from a 'toy model' of a virus.
We argue that an induced breaking of the genetic synonym symmetry due to the action of genetic operators such as mutation can enhance the adaptability of a species to changes in the environment. In the case of a virus, the claim is that the codon bias in the neutralization epitope improves the virus' ability to generate mutants that evade the induced immune response. We support our claim with a simple 'toy model' of a viral epitope evolving in competition with the immune system. The effective selective advantage of a higher mutability leads to a dominance of codons that favor non-synonymous mutations. As further evidence we present a simple model for a genetic regulatory network that leads to adaptive evolution in a population of giraffes by means of an induced symmetry breaking rather than through any direct selective advantage.
Vargas
J M
JM
Facultad de Ingeniería, UNAM, DF, Mexico.
Stephens
C R
CR
Waelbroeck
H
H
Zertuche
F
F
D000222:Adaptation, Physiological; D000596:Amino Acids / Q000235:genetics; D000818:Animals; D002875:Chromosomes / Q000235:genetics*; D003062:Codon / Q000235:genetics; D003198:Computer Simulation; D019143:Evolution, Molecular; D017709:Fractals; D015870:Gene Expression; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007107:Immune System / Q000502:physiology; D008957:Models, Genetic; D008962:Models, Theoretical; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D014780:Viruses / Q000235:genetics* / Q000276:immunology
D000596:Amino Acids; D003062:Codon