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Does dormancy increase fitness of bacterial populations in time-varying environments (2008)
| Citations: | 4 - 0 self |
BibTeX
@MISC{Malik08doesdormancy,
author = {Tufail Malik and Hal L. Smith},
title = {Does dormancy increase fitness of bacterial populations in time-varying environments},
year = {2008}
}
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Abstract
A simple family of models of a bacterial population in a time vary-ing environment in which cells can transit between dormant and active states is constructed. It consists of a linear system of ordinary differ-ential equations for active and dormant cells with time-dependent co-efficients reflecting an environment which may be periodic or random, with alternate periods of low and high resource levels. The focus is on computing/estimating the dominant Lyapunov exponent, the fitness, and determining its dependence on various parameters and the two strategies – responsive and stochastic – by which organisms switch between dormant and active states. A responsive switcher responds to good and bad times by making timely and appropriate transitions while a stochastic switcher switches continuously without regard to the environmental state. The fitness of a responsive switcher is exam-ined and compared with fitness of a stochastic switcher, and with the fitness of a dormancy-incapable organism. Analytical methods show that both switching strategists have higher fitness than a dormancy-incapable organism when good times are rare and that responsive switcher has higher fitness than stochastic switcher when good times are either rare or common. Numerical calculations show that stochas-tic switcher can be most fit when good times are neither too rare or too common.
Keyphrases
bacterial population good time time-varying environment dormancy-incapable organism stochastic switcher active state responsive switcher responds environmental state bad time linear system appropriate transition various parameter time vary-ing environment alternate period simple family high resource level time-dependent co-efficients responsive switcher dormant cell organism switch numerical calculation ordinary differ-ential equation dominant lyapunov exponent stochastic switcher switch stochas-tic switcher analytical method
