Publication Date:
2011-03-29
Description:
How is diversity maintained? Environmental heterogeneity is considered to be important, yet diversity in seemingly homogeneous environments is nonetheless observed. This, it is assumed, must either be owing to weak selection, mutational input or a fitness advantage to genotypes when rare. Here we demonstrate the possibility of a new general mechanism of stable diversity maintenance, one that stems from metabolic and physiological trade-offs. The model requires that such trade-offs translate into a fitness landscape in which the most fit has unfit near-mutational neighbours, and a lower fitness peak also exists that is more mutationally robust. The 'survival of the fittest' applies at low mutation rates, giving way to 'survival of the flattest' at high mutation rates. However, as a consequence of quasispecies-level negative frequency-dependent selection and differences in mutational robustness we observe a transition zone in which both fittest and flattest coexist. Although diversity maintenance is possible for simple organisms in simple environments, the more trade-offs there are, the wider the maintenance zone becomes. The principle may be applied to lineages within a species or species within a community, potentially explaining why competitive exclusion need not be observed in homogeneous environments. This principle predicts the enigmatic richness of metabolic strategies in clonal bacteria and questions the safety of lethal mutagenesis as an antimicrobial treatment.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Beardmore, Robert E -- Gudelj, Ivana -- Lipson, David A -- Hurst, Laurence D -- G0802611/Medical Research Council/United Kingdom -- England -- Nature. 2011 Apr 21;472(7343):342-6. doi: 10.1038/nature09905. Epub 2011 Mar 27.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Mathematics, Imperial College London, Huxley Building, 180 Queen's Gate, London SW7 2A7, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21441905" target="_blank"〉PubMed〈/a〉
Keywords:
Adaptation, Biological/genetics
;
*Biodiversity
;
*Biological Evolution
;
*Genetic Fitness/genetics
;
Genotype
;
Metabolism/*genetics
;
*Models, Biological
;
Models, Genetic
;
Mutagenesis/genetics
;
Saccharomyces cerevisiae
;
*Selection, Genetic/genetics
;
Stochastic Processes
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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