Populations may live across geographic ranges with gradients in environmental variables. These differences can lead to local adaptations through selection of favorable traits in populations. As climate change causes global temperatures to rise, these environments can change, potentially creating a new selection pressure. The goal of my project is to look at Yellow Warblers in the Galapagos (Setophaga petechia aureola) across elevational gradients to try to predict future ranges of these birds and the potential of their persistence with changing environments. I will use RADseq to determine single nucleotide polymorphisms (SNPs) from yellow warbler samples collected from several islands and at different elevations. After sequencing, genome wide association studies will be used to find any associations between these SNPs and elevation, as well as temperature and precipitation. Genomic vulnerability shows how the gene-environment association changes for given projected environmental variables, and how well-suited current populations are for future climate regimes. Finally, using museum specimens, a comparative analysis between past and present populations can be performed to possible shifts in allele frequency and gene-environment association.