a Species richness plotted against area of Carajás. Pearson correlation coefficients: r = 0.806094, P = 0.001548 b the number of species shared between site pairs does not change significantly with geographical distance between regions. r = -0.16; P = 0.08 c the number of shared endemic species between site pairs declines with geographical distance between regions. r= -0.45872; P = 1.37e-07.