title: Phylogeography of the antilopine wallaroo (Macropus antilopinus) across tropical northern Australia.
abstract: The distribution of antilopine wallaroo,Macropus antilopinus, is marked by a break in the species' range between Queensland and the Northern Territory, coinciding with the Carpentarian barrier. Previous work onM. antilopinusrevealed limited genetic differentiation between the Northern Territory and QueenslandM. antilopinuspopulations across this barrier. The study also identified a number of divergent lineages in the Northern Territory, but was unable to elucidate any geographic structure. Here, we re-examine these results to (1) determine phylogeographic patterns across the range ofM. antilopinusand (2) infer the biogeographic barriers associated with these patterns. The tropical savannahs of northern Australia: from the Cape York Peninsula in the east, to the Kimberley in the west. We examined phylogeographic patterns inM. antilopinususing a larger number of samples and three mtDNA genes: NADH dehydrogenase subunit 2, cytochrome b, and the control region. Two datasets were generated and analyzed: (1) a subset of samples with all three mtDNA regions concatenated together and (2) all samples for just control region sequences that included samples from the previous study. Analysis included generating phylogenetic trees based on Bayesian analysis and intraspecific median-joining networks. The contemporary spatial structure ofM. antilopinusmtDNA lineages revealed five shallow clades and a sixth, divergent lineage. The genetic differences that we found between Queensland and Northern TerritoryM. antilopinussamples confirmed the split in the geographic distribution of the species. We also found weak genetic differentiation between Northern Territory samples and those from the Kimberley region of Western Australia, possibly due to the Kimberley Plateau-Arnhem Land barrier. Within the Northern Territory, two clades appear to be parapatric in the west, while another two clades are broadly sympatric across the Northern Territory. MtDNA diversity ofM. antilopinusrevealed an unexpectedly complex evolutionary history involving multiple sympatric and parapatric mtDNA clades across northern Australia. These phylogeographic patterns highlight the importance of investigating genetic variation across distributions of species and integrating this information into biodiversity conservation.
authors.affiliation: Australian Centre for Ancient DNAUniversity of AdelaideNorth TerraceAdelaideSouth Australia5005Australia; Environment Institute and School of Biological SciencesUniversity of AdelaideNorth TerraceAdelaideSouth Australia5005Australia.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Wadley
authors.affiliation: Environment Institute and School of Biological Sciences University of Adelaide North Terrace Adelaide South Australia 5005 Australia.
authors.forename: Damien A
authors.initials: DA
authors.lastname: Fordham
authors.affiliation: Australian Centre for Ancient DNAUniversity of AdelaideNorth TerraceAdelaideSouth Australia5005Australia; Environment Institute and School of Biological SciencesUniversity of AdelaideNorth TerraceAdelaideSouth Australia5005Australia.
authors.forename: Vicki A
authors.initials: VA
authors.lastname: Thomson
authors.affiliation: Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Burwood Victoria 3125 Australia.
authors.forename: Euan G
authors.initials: EG
authors.lastname: Ritchie
authors.affiliation: Australian Centre for Ancient DNAUniversity of AdelaideNorth TerraceAdelaideSouth Australia5005Australia; Environment Institute and School of Biological SciencesUniversity of AdelaideNorth TerraceAdelaideSouth Australia5005Australia; Sciences DepartmentMuseum VictoriaCarlton GardensMelbourneVictoria3001Australia.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Austin
keywords: Biogeographic barriers; Carpentarian; divergence; genetics; macropod; marsupial; tropical savannah