Fig. 3: Biogeographic isolation improves model fit for mammals in deeply isolated regions.

Differences in residuals were calculated as the absolute value of residuals in the environment-only model minus the absolute value of residuals in the global model using the residual values of each grid cell, shown here for (a) mammal species richness and (b) mammal mean functional beta diversity turnover. Scales differ for plots based on the units of the response variable. Positive values indicate that including biogeographic isolation improved model fit for grid cells, while negative values indicate that including biogeographic isolation worsened model fit. Maps for mammal phylogenetic alpha diversity and functional richness are very similar to panel a (see Supplementary Fig. 1). Maps are shown with an equirectangular projection.