Invitation Only
Speaker: Victor Sourjik, Ph.D. (Max Planck Institute For Terrestrial Microbiology)
Title: How physics guides evolution: Lessons from bacterial motility
Bacterial motility is one of the quantitatively best-understood behaviors in biology, and we use it as a model to investigate how the interplay between physics and physiology has shaped the evolution of biological systems. One central question here is how much of their limited cellular resources bacteria allocate into “expensive” motile behavior. Our results suggest that the key features of the resource investment strategy of E. coli can be quantitatively explained by the physical limitations on bacterial propulsion and the fitness trade-off between motility and growth. We further investigated whether experimental evolution under laboratory conditions can compensate for the lack of essential chemotaxis genes of E. coli. While the absence of highly evolutionary conserved core pathway components could not be circumvented by such short-term evolutionary adaptation, we were able to re-evolve chemotactic-like behavior in strains lacking the individual adaptation enzymes or phosphatase. This finding demonstrates surprisingly rapid evolution of alternative strategies of bacterial behavior that are physically possible but not normally biologically utilized.