In order to achieve our stated goals, we will focus on three species pairs that exhibit wet/dry transitions and have different phylogenetics depths within the Hawaiian silversword alliance (HSA). Detailed field based ecophysiological measurements will be taken for one population of each our six focal species. Quantitative trait loci mapping will be conducted on an outcross mapping population of Dubautia  menzeisii and D. reticulata. Regions identified in the QTL and a priori gene screening will be examined in two populations of each of our focal species to test for evidence of functional involvement in species differentiation. Finally, a suite of functional traits will be examined across the HSA.