Ongoing gene flow among Australian alpine Poa

Recently radiated groups pose a taxonomic challenge even with extensive molecular data, as they may be genetically differentiated only at small and/or patchy regions of the genome. Griffin and Hoffmann investigate species’ structure among the Poa that dominate the Australian alpine zone, which have radiated in the last 0.5–1.2 million years. Using a Bayesian approach to co-estimate nuclear and chloroplast gene trees with an overall dated tree, they find that most species are not genetically distinct, despite distinguishable phenotypes, which suggests recent adaptive divergence with ongoing inter-taxon gene flow.