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.

本研究提出一种全新的系统发育比较方法（phylogenetic comparative method）——协方差系统发育分析（PANCOVA），该方法借助种间数据与系统发育树，可估算重大事件对表型进化速率以及性状间关联的双重影响。例如，该方法可用于建模关键创新、新栖息地定殖或环境变化所带来的效应。本方法以最大似然法（maximum likelihood）进行优化，并基于学界通用的系统发育广义最小二乘（phylogenetic generalized least squares）框架构建，该框架灵活性强，可轻松拓展以纳入其他因素与参数。作为示例，本研究探究了鸟类亲本投资与相对端脑体积之间的关联，并将PANCOVA的分析结果与其他系统发育比较方法的结果进行了对比。