Five characteristics of any current species suffice to determine their history.
by
Mike Steel
University of Canterbury
Coauthors: Charles Semple (University of Canterbury)

In this talk I will first describe the close relationship between the combinatorial concept of ``compatibility'' of multi-state characters and the biological notion of ``homoplasy''.

We will then review a recent graph-theoretic characterization for when a compatible collection of multi-state characters supports a unique tree. A pleasing consequence of this result is that any fully resolved phylogenetic tree can be uniquely defined by just a handful of multi-state characters. This contrasts with the situation for binary characters, or more generally characters having a bounded number of states, where the number of characters required to define a tree grows linearly with the number of species. We will see how this may have some consequences for the analysis of certain types of genomic data such as gene orders.

http://web.math.canterbury.ac.nz/~mathmas

Date received: October 29, 2001