Patterns of Genetic Variation in Tiquilia

Science Center, Bent Corridor

The purpose of this project was to study the genetic variation in species of the genus Tiquilia. There are twenty-seven species of Tiquilia, some of which display gypsum endemism, or the confinement of a plant to the substrate gypsum, which occurs naturally in island-like formations. We hope to learn how gypsum “islands” affect the genetic differences that occur based on geography (phylogeography) of Tiquilia and how it compares to non-gypsum endemic plants. We hypothesize that there will be greater variation in gypsum endemic plants because of the segregated nature of the gypsum ‘islands.’ We compared genetic differences by sequencing DNA from several species of Tiquilia. We tested species that grow solely on gypsum (Tiquilia hispidissima), species that grow both on and off gypsum (Tiquilia greggii) and species that grow predominately off gypsum (Tiquilia canescens). The sequenced DNA was used to build phylogenies that showed us the variation by species.