This function returns a so-called phylogenetic variance covariance matrix (e.g., see vcv.phylo), but (optionally) including ancestral nodes and under different evolutionary models.
vcvPhylo(tree, anc.nodes=TRUE, ...)object of class "phylo".
logical value indicating whether or not to include ancestral nodes.
optional arguments including internal (synonym of anc.nodes) and model (can be "BM", "OU", or "lambda".
A matrix.
Revell, L. J. (2012) phytools: An R package for phylogenetic comparative biology (and other things). Methods Ecol. Evol., 3, 217-223.