Scientists at Harvard Medical School performed an experiment to demonstrate how quickly bacteria can evolve and adapt. The team used a two-foot by four-foot “mega-plate” petri dish coated with strips of agar containing increasing concentrations of medicine to create the visualization. The bacteria were able to evolve to combat the antibiotics at each stage in just a matter of days.
To observe how the bacterium Escherichia coli adapts to increasingly higher doses of antibiotics, researchers divided the dish into sections and saturated them with various doses of medication. The outermost rims of the dish were free of any drug. The next section contained a small amount of antibiotic—just above the minimum needed to kill the bacteria—and each subsequent section represented a 10-fold increase in dose, with the center of the dish containing 1,000 times as much antibiotic as the area with the lowest dose.
via The Atlantic