Serotonin is a hormone that significantly influences aggressive and impulsive behaviors and many psychiatric drugs work by targeting components of the serotonin pathway. Moreover, several genetic variants that affect serotonin regulation have been linked to a variety of behavioral conditions, such as alcoholism and antisocialism. Because of the association between serotonin and behavior, the study of its evolution may grant insight into how evolution acts on a molecular level to shape behavior. This project examines the evolutionary history of the serotonin system in rhesus macaques (Macaca mulatta). In this study, genes related to serotonin functioning are sequenced in a sample of rhesus macaques, as well as in ten other macaque species and a vervet monkey (Chlorocebus aethiops). Tests designed to detect and distinguish multiple evolutionary forces are applied to the sequence data. In this manner, the types of evolutionary forces most likely to have shaped the serotonin system can be inferred. The results of this study will deepen understanding of the biological basis of behavioral evolution. It incorporates knowledge from a wide range of fields and brings it together to study the evolution of behavior in a novel way. In addition, the methods used in this study will provide detailed description of the genetic variation found within macaque species and will build on knowledge provided by the recent publication of the rhesus macaque genome. In terms of broader impacts, this is a doctoral dissertation project that will complete the training of a female Hispanic graduate student. This research also has biomedical implications, as macaques are a common model used in studies of psychiatric conditions and their treatment. Finally, there is some evidence of parallel evolution in the serotonin system of both rhesus macaques and humans. Future comparative studies between humans and macaques may highlight important factors that influence behavioral evolution.
