Classification of cells depending simultaneously of their values of genetic and species diversity for marine (a) and freshwater (c) species. Values of diversity were reported on the global map using a colour gradient depending on the values of the genetic and species diversities for marine species (b) and freshwater species (d) respectively. The colour scale of Fig. 2a–d is defined in the Fig. 2d. The line was represented as the output of a linear model (lm) of the correlation between genetic diversity and species diversity. Person coefficient of correlations calculated in linear regressions (r) are reported on the figure. Drawn with R version 3.2.3.