Microbial population dynamics and evolutionary outcomes under extreme energy limitation
William R. Shoemaker, Stuart E. Jones, Mario E. Muscarella, Megan G. Behringer, Brent K. Lehmkuhl, Jay T. Lennon
Abstract
y. Our findings corroborate reports of long-lived bacteria recovered from ancient environmental samples, while providing insight into mechanisms of persistence. As death rates declined over time, lifespan was extended through the scavenging of dead cells. Although reproduction was suppressed in the absence of exogenous resources, populations continued to evolve. Hundreds of mutations were acquired, contributing to genome-wide signatures of purifying selection as well as molecular signals of adaptation. Consistent ecological and evolutionary dynamics indicate that distantly related bacteria respond to energy limitation in a similar and predictable manner, which likely contributes to the stability and robustness of microbial life.