Data from: Phylogenetic ANCOVA: estimating changes in evolutionary rates as well as relationships between traits

We present a new phylogenetic comparative method—phylogenetic analysis of
covariance (PANCOVA)—that uses interspecific data and a phylogeny to
estimate the effects of major events on both the rate of phenotypic
evolution and the association between traits. It could be used, for
example, to model the impact of a key innovation, colonization of a new
habitat, or environmental change. The approach is optimized with maximum
likelihood and is formulated under the familiar phylogenetic generalized
least squares framework, which is flexible and easily extended to
incorporate other factors and parameters. As an example, we explore the
relationship between parental investment and relative telencephalon size
in birds and contrast the results of PANCOVA with those from other
phylogenetic comparative methods.