The elusive object of desire--interactions of bacteriophages and their hosts.

Bacteria and their viruses (phages) are locked in an evolutionary contest, with each side producing constantly changing mechanisms of attack and defense that are aimed to increase the odds of survival. As a result, phages play central roles in a great variety of genetic processes and increase the rate of evolutionary change of the bacterial host, which could ultimately work to the benefit of the host in a long run.