Phylogeny, radiation, and transoceanic dispersal of New Zealand alpine buttercups: Molecular evidence under split decomposition

The "Alpine Ranunculi of New Zealand" are a monophyletic group of species distributed between the News Zealand alps. Australian alps. and the subantarctic Campbell and Auckland Islands. For this group we determined and analyzed sequences for the nuclear ITS and chloroplast J(SA) regions. This latter region was identified from all amplified fragment length polymorphism (AFLP) gel as being potentially phylogenetically informative. We have used quartet puzzling to represent the overall phylogenetic structure of these sequence data and split decomposition to investigate more closely sequences from two lineages within the alpine radiation. We describe molecular the phylogenetic information among evidence that shows that diversification of alpine, Ranunculi has accompanied the onset of Pliocence mountain building in New Zealand, and that during range expansion of species, regional speciation into novel alpha habitats has occurred with parallel evolution of morphologies between more distantly related species. Our analyses also show that, during diversification and range expansion. the New Zealand alps acted as a center for long-distance dispersal to Australia and the New Zealand subantarctic islands.