Evolution of digital organisms at high mutation rates leads to survival of the flattest

@article{Wilke2001EvolutionOD,
  title={Evolution of digital organisms at high mutation rates leads to survival of the flattest},
  author={Claus O. Wilke and Jia Lan Wang and Charles Ofria and Richard E. Lenski and Christoph Adami},
  journal={Nature},
  year={2001},
  volume={412},
  pages={331-333}
}
Darwinian evolution favours genotypes with high replication rates, a process called ‘survival of the fittest’. However, knowing the replication rate of each individual genotype may not suffice to predict the eventual survivor, even in an asexual population. According to quasi-species theory, selection favours the cloud of genotypes, interconnected by mutation, whose average replication rate is highest. Here we confirm this prediction using digital organisms that self-replicate, mutate and… 
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References

SHOWING 1-10 OF 34 REFERENCES
Evolvability of an RNA virus is determined by its mutational neighbourhood
TLDR
It is shown that evolvability in the RNA bacteriophage φ6 is also determined by the accessibility of advantageous genotypes within the mutational neighbourhood (the set of mutants one or a few mutational steps away), despite the fact that this phage has the characteristic high mutation rate of RNA viruses.
The approach to mutation–selection balance in an infinite asexual population, and the evolution of mutation rates
  • T. Johnson
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1999
TLDR
A method is described for calculating the dynamics of the distribution of fitness in an infinite asexual population which is subject to unconditionally deleterious mutations with independent effects, and the frequency of a mutator subpopulation may be more than an order of magnitude greater than recent theoretical work has suggested.
Genome complexity, robustness and genetic interactions in digital organisms
TLDR
The findings support the view that interactions are a general feature of genetic systems and the complex organisms are more robust than the simple ones with respect to the average effects of single mutations.
Role of mutator alleles in adaptive evolution
TLDR
Whether high mutation rates might play an important role in adaptive evolution is considered, as models of large, asexual, clonal populations adapting to a new environment show that strong mutator genes can accelerate adaptation, even if the mutator gene remains at a very low frequency.
Stationary mutant distributions and evolutionary optimization.
Adaptive evolution on neutral networks
  • C. Wilke
  • Biology
    Bulletin of mathematical biology
  • 2001
TLDR
It is demonstrated that despite the absence of higher fitness genotypes, adaptation takes place as regions with more advantageous distributions of neutral genotypes are discovered, as well as the transitions between epochs.
Evolution of high mutation rates in experimental populations of E. coli
TLDR
The rise of spontaneously originated mutators in populations of E. coli undergoing long-term adaptation to a new environment corroborate computer simulations of mutator evolution in adapting clonal populations, and may help to explain observations that associate high mutation rates with emerging pathogens and with certain cancers.
Mutation-selection balance and the evolutionary advantage of sex and recombination.
TLDR
It is shown that equilibrium mean fitness is least for asexual populations, and synergistic epistasis on the scale of log fitness, such that log fitness declines more steeply as n increases, means fitness behaves in the opposite way.
PERSPECTIVE: SPONTANEOUS DELETERIOUS MUTATION
TLDR
A broad array of data are reviewed that collectively support the hypothesis that deleterious mutations arise in flies at rate of about one per individual per generation, with the average mutation decreasing fitness by about only 2% in the heterozygous state.
Neutral evolution of mutational robustness.
TLDR
The results quantify the extent to which populations evolve mutational robustness-the insensitivity of the phenotype to mutations-and thus reduce genetic load.
...
...