Thought Experiment 1

Luria & Delbruck Thought Experiment #1 : Induction

Most bacterial cells are naturally sensitive to bacteriophage (black cells). In the last generation, ten cells are observed to be resistant (blue). If this resistance were due to induction caused by exposure to bacteriophage in the fourth generation, and all cells have an identical chance of becoming resistant, then each culture will be expected to have a roughly equal number of resistant cells. If the average number of resistant cells per culture is small, the observed fluctuation among cultures will follow the Poisson Distribution, in which the variance equals the mean.