Extended Data Table 1 Assessment of Predictor Impact on Tetrapod Richness Patterns Using General Additive Models

From: The geography of climate and the global patterns of species diversity

  1. These models estimate the influence of climate area, climate isolation (geography of climate component), and principal components one and two (climate itself component), on the observed patterns of tetrapod richness. The analysis was conducted on a gridded climate space, defined with 20 equal interval divisions along the climate axis. Each predictor’s importance is gauged by the reduction in deviance when excluded from a model that initially included all predictors. The collective influence of predictors is evaluated in three dimensions: (i) the joint effect of geography of climate elements (climate area and climate isolation), (ii) the joint effect of climate itself elements (PC1 and PC2), and (iii) the integrated effect of both geographical and climate elements. Thus, the analysis captures the shared influence within each predictor group (i.e., geography of climate or climate itself) and between the two groups. The p-values for each variable are computed using two-sided tests.
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