Historical Biogeography
Katharine Ann Marske
Ecology and Evolution, Department of Biology, Copenhagen University
Phylogeographic structure and its underlying causes are not necessarily shared among community members, with important implications for using individual organisms as indicators for ecosystem evolution, such as the identification of forest refugia. Over 1000 mitochondrial DNA (COI) sequences and newly developed coalescent phylogeography models were used to construct geo-spatial histories for four co-distributed New Zealand forest beetles. These methods identify historical dispersal patterns via ancestral state reconstruction. Ecological niche models were used to reconstruct the potential geographic distribution of each species during the Last Glacial Maximum (LGM). Combined results yielded a complex picture of temperate forest community evolution. Each species shared some features of its LGM distribution or range expansion pathways with every other, but no general patterns were detected among all four. These results indicate that forest species retreated into and expanded out from the same refugia by a variety of routes, rather than travelling together as an intact forest community, which has important implications for using individual taxa to detect historical ecosystem dynamics.
