Phylogeographic divergence in the widespread delicate skink (Lampropholis delicata) corresponds to dry habitat barriers in eastern Australia
1 School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
2 Museum Victoria, Division of Sciences, GPO Box 666, Melbourne, Victoria 3001, Australia
3 Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
4 Division of Evolution, Ecology & Genetics, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia
5 School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
6 Department of Zoology, University of Melbourne, Melbourne, Victoria 3010, Australia
7 School of Biological Sciences, University of Sydney, The Heydon-Laurence Building A08, New South Wales 2006, Australia
BMC Evolutionary Biology 2011, 11:191 doi:10.1186/1471-2148-11-191Published: 4 July 2011
The mesic habitats of eastern Australia harbour a highly diverse fauna. We examined the impact of climatic oscillations and recognised biogeographic barriers on the evolutionary history of the delicate skink (Lampropholis delicata), a species that occurs in moist habitats throughout eastern Australia. The delicate skink is a common and widespread species whose distribution spans 26° of latitude and nine major biogeographic barriers in eastern Australia. Sequence data were obtained from four mitochondrial genes (ND2, ND4, 12SrRNA, 16SrRNA) for 238 individuals from 120 populations across the entire native distribution of the species. The evolutionary history and diversification of the delicate skink was investigated using a range of phylogenetic (Maximum Likelihood, Bayesian) and phylogeographic analyses (genetic diversity, ΦST, AMOVA, Tajima's D, Fu's F statistic).
Nine geographically structured, genetically divergent clades were identified within the delicate skink. The main clades diverged during the late Miocene-Pliocene, coinciding with the decline and fragmentation of rainforest and other wet forest habitats in eastern Australia. Most of the phylogeographic breaks within the delicate skink were concordant with dry habitat or high elevation barriers, including several recognised biogeographic barriers in eastern Australia (Burdekin Gap, St Lawrence Gap, McPherson Range, Hunter Valley, southern New South Wales). Genetically divergent populations were also located in high elevation topographic isolates inland from the main range of L. delicata (Kroombit Tops, Blackdown Tablelands, Coolah Tops). The species colonised South Australia from southern New South Wales via an inland route, possibly along the Murray River system. There is evidence for recent expansion of the species range across eastern Victoria and into Tasmania, via the Bassian Isthmus, during the late Pleistocene.
The delicate skink is a single widespread, but genetically variable, species. This study provides the first detailed phylogeographic investigation of a widespread species whose distribution spans virtually all of the major biogeographic barriers in eastern Australia.