Fig. 4: Combined SNAPP population tree of R. leptorrhynchoides populations based on 2000 SNPs.

Maximum clade credibility tree generated in FigTree v. 1.4.4 (https://github.com/rambaut/figtree/releases) is in black with 95% HPD for height at each node indicated by the grey bar. Branch lengths are measured in expected substitutions per site. Densitree of superimposed gene trees recorded during the MCMC analysis visualises the range of alternative topologies, indicative of past gene flow. Gene trees shown in blue lines indicate most frequent trees, next most frequent are red, third most are green. Numbers represent posterior probabilities of branches. Population codes correspond to those presented in Table 1.