  We presents the closed form formulae for the likelihood Hessian matrix of a
family of multivariate continuous-trait Gaussian Markov trait evolution model
along a given phylogeny, in which the trait vector's mean is an affine function
of that of its ancestor and the variance is not dependent of the trait.
Accompanied with this work is an R package called 'glinvci', publicly available
on The Comprehensive R Archive Network (CRAN), that can compute Hessian-based
approximate confidence regions for these models while at the same time allowing
users to have missing data, lost traits, and multiple evolutionary regimes.
