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 on M. antilopinus revealed limited genetic differentiation between the Northern Territory and Queensland M. antilopinus populations 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 of M. antilopinus and (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 in M. antilopinus using 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 of M. antilopinus mtDNA lineages revealed five shallow clades and a sixth, divergent lineage. The genetic differences that we found between Queensland and Northern Territory M. antilopinus samples 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 of M. antilopinus revealed 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.

Multi-Species Phylogeography of Arid-Zone Sminthopsinae (Marsupialia: Dasyuridae) Reveals Evidence of Refugia and Population Expansion in Response to Quaternary Change

“…Small dasyurids continue to persist in Australian arid habitats despite wide-scale extinctions and declines in other arid-adapted mammals [ 25 ], and our data add to a growing number of studies finding low levels of genetic structure in widely occurring arid species (reviewed in [ 81 ]). This is in contrast to species-specific responses to Pleistocene environmental change that are driven by differences in species ecological requirements [ 5 , 16 ] and demonstrates the adaptive success of small dasyurids to harsh and changing environmental conditions, which allow them to persist in these environments.…”

“…In arid Australia, intraspecific population structure results from repeated population contraction and expansion events that occurred throughout the Pleistocene from multiple localized refugia. These cyclical processes in the arid zone tend to produce species-specific responses due to varying habitat and ecological requirements within different lineages, compared to widespread southern and northern contraction among Northern hemisphere species during glaciation cycles [ 16 ].…”

MtDNA-Based Phylogeography of the Red Alga Agarophyton vermiculophyllum (Gigartinales, Rhodophyta) in the Native Northwest Pacific

“…Genealogic relationships of mtDNA cox1 haplotypes were inferred using the median-joining algorithm implemented in Network v.5.0.1.1 (Bandelt et al, 1999). Intraspecific relationships of cox1 haplotypes were also assessed by minimum spanning network (MSN) in Arlequin.…”

Gastrointestinal helminth parasites of the common wallaroo or euro, Osphranter robustus (Gould) (Marsupialia: Macropodidae) from Australia

“…A number of parasite species are restricted to O. r. woodwardi , although they may also occur in the sympatric host O. antilopinus , while another series of parasites is restricted to northern Australia, including northern Queensland, thereby being found in O. r. robustus , O. r. erubescens and O. r. woodwardi , again, with some also occurring in O. antilopinus . The Carpentaria Gap, a zone of floral and faunal disjunction south of the Gulf of Carpentaria has been invoked to explain the disjunct distribution of plant and animal species between northern Queensland and the Northern Territory, including genetically distinct populations of O. antilopinus (Wadley et al ., 2016), and while this may facilitate an explanation of the parasite species restricted to O. r. woodwardi , it provides no explanation for the species found across northern Australia including Queensland other than a distribution restricted to the monsoonal tropical region of northern Australia. Additional caution is needed in assessing such current distributions of nematode parasites, as C. eileithyia is found commonly in O. r. woodwardi in the Northern Territory (Beveridge, 1998), but was found in a single individual of O. r. robustus in northern Queensland, suggesting that more intensive sampling may be needed before definitive conclusions can be drawn about nematode distributions.…”