title: Independent Transitions between Monsoonal and Arid Biomes Revealed by Systematic Revison of a Complex of Australian Geckos (Diplodactylus; Diplodactylidae).
abstract: How the widespread expansion and intensification of aridity through the Neogene has shaped the Austral biota is a major question in Antipodean biogeography. Lineages distributed across wide aridity gradients provide opportunities to examine the timing, frequency, and direction of transitions between arid and mesic regions. Here, we use molecular genetics and morphological data to investigate the systematics and biogeography of a nominal Australian gecko species (Diplodactylus conspicillatus sensu lato) with a wide distribution spanning most of the Australian Arid Zone (AAZ) and Monsoonal Tropics (AMT). Our data support a minimum of seven genetically distinct and morphologically diagnosable taxa; we thus redefine the type species, ressurrect three names from synonymy, and describe three new species. Our inferred phylogeny suggests the history and diversification of lineages in the AAZ and AMT are intimately linked, with evidence of multiple independent interchanges since the late Miocene. However, despite this shared history, related lineages in these two regions also show evidence of broadly contrasting intra-regional responses to aridification; vicarance and speciation in older and increasingly attenuated mesic regions, versus a more dynamic history including independent colonisations and recent range expansions in the younger AAZ.
authors.affiliation: Department of Zoology, University of Melbourne, Melbourne, Victoria, Australia; Department of Sciences, Museum Victoria, Melbourne, Victoria, Australia; Division of Evolution, Ecology & Genetics, Research School of Biology, The Australian National University, Canberra, Australian Captital Territory, Australia.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Oliver
authors.affiliation: Queensland Museum, Brisbane, Queensland, Australia.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Couper
authors.affiliation: Division of Evolution, Ecology & Genetics, Research School of Biology, The Australian National University, Canberra, Australian Captital Territory, Australia.
authors.forename: Mitzy
authors.initials: M
authors.lastname: Pepper
mesh_terms: D000818:Animals; D001315:Australia; D005075:Biological Evolution; D004272:DNA, Mitochondrial; D017753:Ecosystem; D008116:Lizards / Q000033:anatomy & histology / Q000235:genetics; D008297:Male; D010802:Phylogeny
chemical_list: D004272:DNA, Mitochondrial