Phylogenetic correlations.

Pagel's λ calculated for the four variables listed in the first column for both an equal branch length and proportional phylogenetic hypothesis (see Methods and Text S1). Pagel's λ is the degree of phylogenetic dependence of the data, calculated as the maximum likelihood estimate of the multiplier of the off-diagonal elements of the variance-covariance matrix implied by the phylogeny, following Freckleton et al. [44]. LnL λ is the log-likelihood of the maximum likelihood value of Pagel's λ. LnL1 is the log-likelihood value for the model with Pagel's λ set to 1. LnL0 is the log-likelihood value for the model with Pagel's λ set to 0 (equivalent to a standard general linear model). All maximum likelihood values of λ are significantly different from both 0 and 1, as calculated using a likelihood ratio test (α = 0.05).