Figure 4

Extrapolation of strain-specific insertions. The number of specific insertions is plotted as a function of the number n of strains. For each n, markers are the 6!/[(n - 1)!·(6 - n)!] values obtained for the different strain combinations. The continuous curve represents the least-squares fit of the function F _s (n) = κ _s exp [-n/τ _s ] + Ω where κ _s = 578.35 ± 198.07, -1/τ _s = -1.36 ± 0.18 and Ω = 5.1 ± 1.1. The best fit was obtained with a correlation of 0.998.