Fig. 2.

Breakdown of mutualisms coincides with shifts to high altitudes. (A) Estimated coefficient values from a Bayesian hierarchical model testing the effect of altitude on mutualistic strategy, showing means and 95% confidence intervals (CI). The models control for phylogenetic autocorrelation, and a detailed description of regression components is presented in SI Appendix, SI Materials and Methods. Values reflect standardized data and can be interpreted as relative effect sizes. (Inset) Fitted values of phylogenetic signal (Pagel’s λ, mean, and 95% CI). (B) Frequencies of mutualism breakdown in the lowlands versus at high altitudes inferred in a correlated Bayesian analysis (SI Appendix, SI Materials and Methods). (Inset) Stochastic mapping reconstructions of mutualism and altitude. All transition states are shown in SI Appendix, Fig. S8.