Richard Lenski (top) and Jeffrey Barrick view bacteria cultures in Lenski's lab. | Science Buzz

Richard Lenski (top) and Jeffrey Barrick view bacteria cultures in Lenski's lab.

Richard Lenski (top) and Jeffrey Barrick view bacteria cultures in Lenski's lab.

They have watched the bacteria's DNA evolve over 40,000 generations.

Courtesy Michigan State University / photo by G.L. Kohuth.
Michigan State University / photo by G.L. Kohuth retains full Copyright on this image.