-\description{
- This function estimates ancestral character states, and the associated
- uncertainty, for continuous and discrete characters.
-
- \code{logLik}, \code{deviance}, and \code{AIC} are generic functions
- used to extract the log-likelihood, the deviance (-2*logLik), or the
- Akaike information criterion of a tree. If no such values are
- available, \code{NULL} is returned.
-
- \code{anova} is another generic function that is used to compare
- nested models: the significance of the additional parameter(s) is
- tested with likelihood ratio tests. You must ensure that the models
- are effectively nested (if they are not, the results will be
- meaningless). It is better to list the models from the smallest to the
- largest.
-}