Figure 2

Suspected hybrids from Iceland are genetically intermediate compared to continental eels. In analogy to an urn model and in reference to the group of 16 suspected hybrid Icelandic eels, groups of 16 genotypes each were drawn 1000 times from either continental eel population with the mean ancestry proportion calculated for each draw. The permutation test illustrates bimodality, as expected under a two-species model with American eels (orange), and European eels (blue). The mean ancestry proportion of the suspected hybrid eel group is exactly intermediate (red pointer; Q _suspects  = 0.40; P < 0.001), whereas the mean for Icelandic eels with European haplotypes is not significantly different from the European eel population (black pointer; Q _mean  = 0.65; P > 0.05).