Although molecular phylogenetic analysis can be extremely complex, this reference provides an introduction to the subject that is straightforward to read. The reference begins with consideration of trees, which are structures used to model actual evolutionary relationships between genes or entire lifeforms. It then provides an introduction to molecular and population genetics. Coding as well as noncoding DNA (tandem repeats, transposable elements, retroviruses, spacer DNA) is considered. The reference then considers how genetic change can be measured, followed by how we can deduce molecular phylogenies. The validity of the molecular clock is then considered, along with a discussion of the neutralist-selectionist debate. The reference finally considers how different phylogenies can be combined to determine actual phylogeny, reconciled trees, and rates of diversification.