Through the Wormhole, Season 6 (2015)

Morgan Freeman:
  Richard doesn't have billions of years to watch evolution in action, but he does have the span of one lifetime, which he has dedicated to performing the longest evolutionary experiment in the history of science.  Twenty-seven years ago, Richard plucked twelve genetically-identical E. coli bacteria from a container and allowed them to start their own populations in twelve separate worlds.  Ever since, day after day, he's watched each of the twelve populations multiply and compete amongst themselves for a limited amount of food.