A video from researchers at Harvard Medical School shows just what happens when a strain of bacteria becomes drug resistant.

The video shows E. coli bacteria colonizing a MEGA-plate petri dish treated with different kinds of bacteria. As the bacteria spread, they encounter the different drugs. Most of the bacterium die, but the few that survive reproduce and come back with a vengeance, this time heartier than ever. This cycle continues until the petri dish is covered with E. coli bacteria that have outlived every antibiotic in the dish.

The visualization of “evolution in action” was filmed over 11 days, according to Wired. The footage was then sped up to show just how fast the bacteria adapted over generations.

The video is especially striking given the concern of the rise of antibiotic resistant diseases. Creator of the MEGA-plate petri dish Roy Kishony told Wired the demonstration of the evolving bacteria further illustrates the need to find new ways to slow down antibiotic resistance development and to find new ways to fight bacterial diseases.