geiger (version 1.2-13)

ic.sigma: Estimate Evolutionary VCV Matrix

Description

Uses independent contrasts to estimate the evolutionary variance-covariance matrix for n quantitative characters.

Usage

ic.sigma(phy, data, data.names=NULL)

Arguments

phy

Phylogenetic tree in 'phylo' format

data

Data matrix

data.names

Tip names for data vector that match tree species; ignored if data includes names

Value

• Returns the estimated evolutionary variance-covariance matrix of the variables under a multivariate Brownian motion model. If you have n characters in your analysis, this will be an nxn matrix. Diagonal elements represent rate estimates for individual characters, while off-diagonal elements represent the estimated covariance between two characters.

Details

Data for this function should be a matrix of continuously-valued variables.

References

Revell, L. J., L. J. Harmon, R. B. Langerhans, and J. J. Kolbe. 2007. A phylogenetic approach to determining the importance of constraint on phenotypic evolution in the neotropical lizard, Anolis cristatellus. Evolutionary Ecology Research 9: 261-282.

Examples

data(geospiza)
attach(geospiza)

ic.sigma(geospiza.tree, geospiza.data)