Figure 5. Variation partitioning and model comparison of isolating mechanisms driving nuclear genetic differentiation (FST) in Atta cephalotes. Variation partitioning analysis based on RDA results of the full model (IBE + IBB + IBD) into environmental (IBE: temperature and precipitation), barrier (IBB: Andes mountains), and spatial (IBD: geographic distance) components. Each circle represents the variation explained for each mechanism, and their overlap is the fraction of shared variation. Model selection and significance are indicated by the AIC and P-values. The IBE model remained significant after controlling for IBD (Conditioned model: F: 1.66, P: 0.04, AIC: 0.09), while IBB was not significant when accounting for IBD (Conditioned model: F: 1.49,P: 0.11, AIC: 0.56).