Fig. 3

Scatter plots illustrating the decay of linkage disequilibrium within each of the four genetic lineages, as estimated using r², over physical distance. The r² values between each pair of sites is shown in blue, smoothed using the smoothScatter function in R. The red line illustrates the nonlinear regression of r² over physical distance, as determined using the method described in [32]. R was found to reach half of its original value in a physical distance of 1.42Mb, 150kb, 130kb and 33kb within lineages A, B, C and D, respectively