Virus-genetic theory testing by data processing machines. II. Fit of classical genetic T4 data.

Abstract This is the second of three papers presenting the results of theory testing operations performed by IBM 7090 and 7094 machines. In this paper the results of theory testing operations simulating in the IBM 7094 machine a series of classical genetic experiments are compared with experimental data available for Escherichia coli phage T4 and T2. The machine runs (or experiments) were performed in much the same way as the genetic experiments they were supposed to simulate. As input or parent phages we used output or progeny phages obtained in earlier machine runs and punched on IBM cards by the machine. Both wild type phages and phages with several markers (usually 12 markers) were used as input phages. Also phage heterozygotes for one or several markers were often used as input phages. By these procedures we were able to repeat or simulate by the machine a long series of crossing experiments and other types of classical genetic experiments in the IBM 7094 machine and compare them with T2 and T4 data as a test for the theoretical model used. Among the phenomena duplicated by the machine in these tests we may quote: localized negative interference and its effect on the genetic map; clone size of low frequency recombinants; the effect of premature lysis on recombination frequency and other properties of progeny phages; properties of partial heterozygotes and their progeny; etc. The results presented are found to be in good agreement with the genetic experiments described in the literature on phage T4 and T2. Only a portion of the T4 experiments simulated in this paper and none of the experiments simulated in the subsequent paper (radiation-genetic and partial phage experiments) were used for parameter fitting.