[R-sig-phylo] understanding lambda for single trait y versus gls(y~x)

Hi all, My understanding of lambda is that it is a scalar multiplier for the off-diagonal elements of the variance covariance matrix computed from your tree. When lambda = 1, then the trait is evolving according to Brownian motion, when lambda = 0 there is no phylogenetic signal in the data.

Re: [R-sig-phylo] understanding lambda for single trait y versus gls(y~x)

Hi Andrew, The lambda value estimated for your dependent variable and the lambda value you get from the gls analyses differ because the second is the lambda of the residuals of your model. The lambda value of the model (which is estimated when you fit the gls) is a measure of the covariance in