Toward Defining the Course of Evolution: Minimum Change for a Specific Tree Topology

Toward defining the course of evolution: minimum change for a specific tree topology. Syst. Zool., 20:406–416.—A method is presented that is asserted to provide all hypothetical ancestral character states that are consistent with describing the descent of the present-day character states in a minimum number of changes of state using a predetermined phylogenetic relationship among the taxa represented. The character states used as examples are the four messenger RNA nucleotides encoding the amino acid sequences of proteins, but the method is general.