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 d istributed between the News Zealand alps. Australian alps. and the subantar ctic Campbell and Auckland Islands. For this group we determined and analyz ed sequences for the nuclear ITS and chloroplast J(SA) regions. This latter region was identified from all amplified fragment length polymorphism (AFL P) gel as being potentially phylogenetically informative. We have used quar tet puzzling to represent the overall phylogenetic structure of these seque nce data and split decomposition to investigate more closely sequences from two lineages within the alpine radiation. We describe molecular the phylog enetic 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 i nto novel alpha habitats has occurred with parallel evolution of morphologi es between more distantly related species. Our analyses also show that, dur ing diversification and range expansion. the New Zealand alps acted as a ce nter for long-distance dispersal to Australia and the New Zealand subantarc tic islands.