Interpretation of data obtained with recombination-defective meiotic mutants

According to probability laws, additive interaction between factors influencing recombination frequency suggests that the factors affect the same event. This analysis, applied to Carpenter and Sandler's (1974) data, permits separation of different sequential events during establishment of preconditions for exchange. The validity of another mathematical model for meiotic mutant characterization, suggested by those authors, is discussed.