Ancestral state reconstruction is a method for inferring ancestral character states at the internal nodes of a phylogenetic tree. The method uses the character values at the tips along with the branch lengths and tree topology. Along with a particular model of evolution, this information can be used to reconstruct character states in the history of the clade of interest.

This method assumes that the model is correct, that both the tree and tip data are known without error, and that the assumed model of character evolution is correct.

This app uses a Brownian motion model for continuous characters and an equal-rates Mk model for discrete characters.