highly significantP < 0.0001
Regressions of environmental suitability index versus latitude were highly significant (Fig. 4 ) but with low predictive power (Fig. 4 ) by a low R -value (“black” form: R 2 = 0.0004, P < 0.0001, intercept = 0.54; “red” form: R 2 = 0.002, P < 0.0001, intercept = 0.66).