Figure 4.

Estimates of the number of “four-types,” i.e., the number of pairs of sites where all four combinations of two mutants are present, against the minimum number of recombination events required to produce them, plotted by pulp for each patient (symbols as in Fig. 2 legend). The number of recombination events that need to be invoked to explain the data is much lower than the number of four-types (as shown by the large number of points above the dotted line, which has an intercept 0 and slope 1).