The lag phase is the initial phase of bacterial growth curve where new bacterial cells are still adapting to their new environment and preparing themselves for the digestion of new medium (nutrient supply). They are metabolizing but not yet growing at this phase.
After the lag phase follows the log phase where bacteria starts to grow in logarithmic manner, releasing energy and waste as they start utilizing provided nutrients.
Character displacement – trait evolution stemming from selection to lessen resource competition or reproductive interactions between species – has long been viewed as an important mechanism for enabling closely related species to coexist.