Molecular Evolution, Models of

Phylogenetic analysis is critical to a wide array of biological investigations, with nearly every subdiscipline of biology having come to depend on the phylogenetic framework to some degree. Modern methods are powerful because they depend on a statistically sophisticated representation of how sequences change over evolutionary time. This entry introduces the fundamental framework for mathematical modeling of that process. A survey of the more widely used models for sequence change is then presented. The entry concludes with a review of how to assess and avoid the negative impact of using too complex, or too simple, a model.