Name: Arjun Ramamurti High School: Lexington High School Mentor: Dr. Susan Offner

1. Name: Arjun Ramamurti • High School: Lexington High School • Mentor: Dr. Susan Offner • Project Title: Exploring the Guenon Mystery: An Evolutionary Analysis Using Phylogenetic Trees • The evolution of the guenon monkey (genus Cercopithecus) has been a mystery for two reasons: a mutation allows guenons to pass down additional chromosomal fragments, as a result of which their genome ranges from 48 to 72 chromosomes; and behavioral irregularities deter breeding among guenons that have no physical barrier to doing so. It has long been believed that these complications would distort the accuracy of a simple phylogenetic analysis. Therefore, the premise of this study was that understanding guenon evolution required both phylogenetic and morphological analyses, as proposed in Ruvolo (1988). Few studies of guenon evolution have followed this principle, including those at the last guenon symposium (Glenn & Cords, 2002). Furthermore, this study used DNA sequences rather than protein electrophoresis for the phylogenetic analysis—something Ruvolo (1988) was unable to do for lack of DNA sequencing information. In this study, a phylogenetic tree was developed for sixteen guenon species using two independent DNA sequences. Morphological and behavioral data in eleven categories, compiled for the study, largely corroborated the tree results. An analysis of chromosome number (2n) was used as a secondary check of tree data. Finally, a potential path of migration for the guenon out of Central Africa over the last one million years was posited. By combining both phylogenetic analysis using DNA sequences and morphological data, this study offers a possible solution to the guenon mystery.