EXPERIMENTS ON SPONTANEOUS AND CHEMICALLY INDUCED MUTATIONS OF BACTERIA GROWING IN THE CHEMOSTAT
This extract was created in the absence of an abstract.
Excerpt
In an earlier paper we reported observations on the spontaneous mutations of bacteria occurring in a continuous flow device we call the Chemostat (Novick and Szilard, 1950a). In this device we maintain a bacterial population in the growth phase over an indefinite period of time by maintaining the concentration of one of the growth factors—called the controlling growth factor—at a low fixed value.
A number of different mutations will occur in a population so maintained in the Chemostat, but in the experiments reported here we are concerned only with the mutation from sensitivity to the bacterial virus T5 to resistance to this virus. In the absence of selection for or against the mutant, and if reverse mutations can be neglected, the mutant population in the Chemostat will increase linearly with time, over periods of time short enough to disregard “evolutionary” changes (Novick and Szilard, 1950a).
By plotting the number of
