Location and timing of main phylogeographic breaks across West Africa.(a) Spatial phylogeographic breaks identified for species using broad sampling. Numbers in blue boxes refer to rivers matching the phylogeographic breaks: 1: Bandama; 2: Volta; 3: Niger; 4: Cross;(b) Scatter plot showing the timing of divergence by location of phylogeographic splits depicted above. Divergence date estimates are provided in Suppl. material 1: table S2.