Role of serpentine soil in divergent selection and population differentiation in Mt. Tamalpais populations of native flower Erythranthe guttata

Serpentine soils found on Mt. Tam provide a harsh, high metal environments that are inhabitable to most plants unless highly specialized. Native species Erythranthe guttata is unique in that it is able to survive on both serpentine and non-serpentine soils. With these drastically different selection pressures, we expect these populations to genetically diverge, but close proximity with high gene flow between populations may prevent this. My research tests if ecologically distinct populations of E. guttata on serpentine and non-serpentine soils are genetically distinct, deduced by molecular data found by genotyping via RADSeq methods. This molecular data will be used to better understand the roles of isolation-by-distance and isolation-by-adapttion in differentiation of populations of E. guttata in Marin County, and further our understanding of evolutionary relationships between E. guttata ecotypes.