THE EVOLUTION OF STRESS-INDUCED HYPERMUTATION IN ASEXUAL POPULATIONS
Article first published online: 28 FEB 2012
© 2012 The Author(s).
Volume 66, Issue 7, pages 2315–2328, July 2012
How to Cite
Ram, Y. and Hadany, L. (2012), THE EVOLUTION OF STRESS-INDUCED HYPERMUTATION IN ASEXUAL POPULATIONS. Evolution, 66: 2315–2328. doi: 10.1111/j.1558-5646.2012.01576.x
- Issue published online: 3 JUL 2012
- Article first published online: 28 FEB 2012
- Accepted manuscript online: 1 FEB 2012 02:56PM EST
- Received August 17, 2011, Accepted January 3, 2012
- Mathematical models/simulations;
- population genetics;
- phenotypic plasticity;
- genetic variation;
Numerous empirical studies show that stress of various kinds induces a state of hypermutation in bacteria via multiple mechanisms, but theoretical treatment of this intriguing phenomenon is lacking. We used deterministic and stochastic models to study the evolution of stress-induced hypermutation in infinite and finite-size populations of bacteria undergoing selection, mutation, and random genetic drift in constant environments and in changing ones. Our results suggest that if beneficial mutations occur, even rarely, then stress-induced hypermutation is advantageous for bacteria at both the individual and the population levels and that it is likely to evolve in populations of bacteria in a wide range of conditions because it is favored by selection. These results imply that mutations are not, as the current view holds, uniformly distributed in populations, but rather that mutations are more common in stressed individuals and populations. Because mutation is the raw material of evolution, these results have a profound impact on broad aspects of evolution and biology.