Stephen Bovio (EEB student, Rosenthal Lab) will be defending his dissertation proposal this Thursday, April 11 and everyone is invited to attend the public portion of the proposal defense (info below).  His public presentation will be at 2 pm in WFES 411.

His talk title is Evolutionary consequences of natural and sexual selection on hybridizing swordtails

Summary: Hybridization is a common phenomenon that serves as an important evolutionary mechanism by which diversity can arise. When two genetically divergent species hybridize, the resulting admixture generates novel genotypic and phenotypic combinations that selection can act upon. In the Rosenthal lab, we study two freshwater species of fish, Xiphophorus birchmanni and X. malinche, that form natural replicated hybrid zones in the Sierra Madre Oriental in Hdg, MX. The birchmanni-malinche system offers a unique opportunity to study long-standing evolutionary questions regarding the consequences of ecological and sexual selection on hybrid populations due to their unique natural history and ecological circumstances. Xiphophorus malinche are found at high elevations while X. birchmanni are found at lower elevations – at intermediate elevations, hybrids form. The core of my dissertation will focus on the collection and analysis of data generated from our long-term research project aimed at monitoring hybrid evolution for ten generations. Replicated mesocosms at high, intermediate, and low elevations initially seeded with F1 hybrids will enable me to characterize changes in phenotypes and genotypes for early generation hybrids. Specifically, I will investigate how thermal selection and pre- and postmating sexual selection act on early generation hybrid populations.