Figure 4.

Correlations in nucleotide diversity among replicate populations. Pearson's correlation coefficient calculated for the nucleotide diversity of genomic windows between each pair-wise comparison of replicate populations within founders, shuffled, core, and edge populations (n = 666, 105, 231, 231 pair-wise comparisons respectively). Standard Tukey boxplots are shown to visualize the distribution of correlation coefficients. Edge populations had lower correlation in nucleotide diversity among replicates compared to founders, core, and shuffled populations (randomization test for the effect of experimental group: p = 0.002), suggesting that gene surfing results in increased variability among edge populations. (Online version in colour.)