Fig. 3
Cytonuclear discordance and tests of hybridization reveal reticulate ancestry of all Mweru radiations. Nuclear cartoon topology of the “orthochromines” (a) and serranochromines (c) with green vertical lines showing mitochondrial sister relationships that deviate from the nuclear tree (solid lines) and sharing of mitochondrial haplotypes (dashed lines). Lake Mweru taxa are highlighted with red edges and radiations are shown as triangles, whereas Lake Bangweulu taxa are shown with blue edges. Riverine taxa in the drainage system of Lake Mweru are shown with orange edges. Black vertical lines indicate evidence for hybridization from D statistics (numbered as shown in b and d) and other tests of hybridization. Where data allow, arrow heads indicate the putative direction of gene flow. b and d D statistic results supporting hybridization edges shown in a and c for “orthochromines” and serranochromines, respectively. Error bars indicate three standard deviations from the mean and are depicted in grey if overlapping with 0 (non-significant, |z| < 3). D statistics and z-scores are averaged across multiple tests with different outgroups. Tests for edges 4–6 in b show averages of tests using Pseudocrenilabrus from Lake Mweru, Bangweulu or from the Zambezi/Cunene as P2 as they were all very similar. Likewise, tests where two groups are given for P2 or P3 revealed very similar results for both groups and have thus been averaged. All D statistics used to compute the averages are provided as Supplementary Data 2–4 and 7–8. R scripts and the data underlying the figures are provided at Zenodo with https://doi.org/10.5281/zenodo.3435419.
