
The Hawaiian silversword alliance (Asteraceae) is one the best examples of a plant adaptive radiation, exhibiting extensive morphological and ecological diversity. Using subspecies of Dubautia laxa as an example, McGlaughlin & Friar show that genetic data demonstrates that members of the species have diverged primarily due to geographic isolation both within and among islands. Despite distinct morphological and ecological traits, subspecies that are distributed allopatrically are determined to have not diverged genetically.