Fig. 4

Sampling statistics. (a) Correlation between number of sampled individuals per deme and number of alleles found for shared and region-specific alleles. The correlation lines are non-significant (grey area represents the 95% confidence interval). (b) and (c) Rarefaction curves for the probability of discovery of new alleles with successive sampling. Only sampling of shared alleles comes to a saturation in our data. Note that shared alleles have a higher frequency, i.e. the total numbers are larger than for region-specific alleles, although the number of different alleles is smaller