Exact phase diagram of a quasispecies model with a mutation rate modifier.
We consider an infinite asexual population with a mutator allele which can elevate mutation rates. With probability f, a transition from nonmutator to mutator state occurs but the reverse transition is forbidden. We find that at f=0, the population is in the state with minimum mutation rate, and at f=fc, a phase transition occurs between a mixed phase with both nonmutators and mutators and a pure mutator phase. We calculate the critical probability fc and the total mutator fraction Q in the mixed phase exactly. Our predictions for Q are in agreement with those seen in microbial populations in static environments.
Nagar
Apoorva
A
School of Physics, Korea Institute for Advanced Study, Seoul 130-722, South Korea. apoorva@kias.re.kr
Jain
Kavita
K
D000483:Alleles; D006238:Haploidy; D008957:Models, Genetic; D009154:Mutation; D012100:Reproduction, Asexual / Q000235:genetics*