Figure 5: Plot of species richness as a function of total surface area of the drainage for river basins from tropical South America, Central America and tropical Africa. Black circles represent the basins that were in contact with a rain forest refuge zone during the LGM; white circles represent basins completely isolated from rain forest refuges. Lines correspond to simple linear regressions for each group. Variables are expressed in logarithmic values (Ln): redrawn from Tedesco et al. [46].