Reading assignment:
We're starting to study phylogenetic trees. Chapter 7 in the Durbin book will probably be the most helpful for this lecture and the next. Mount, chapter 6, is also a good introduction.

There is a nice Trends in Genetics review that is an overview of phylogeny and some of the methods used.

Joseph Felsenstein contributed quite a bit to this field and his writings tend to be informative and fairly amusing; look around on the web for his site to see what he has to say about different methods (as well as the current state of computational biology).