Phylogenetic relationships of the heath dragons (Rankinia adelaidensis and R. parviceps) from the south-western Australian biodiversity hotspot
Jane Melville A D , Luke P. Shoo A B and Paul Doughty CA Department of Sciences, GPO Box 666, Museum Victoria, Melbourne, Vic. 3001, Australia.
B Centre for Tropical Biodiversity and Climate Change, School of Marine and Tropical Biology, James Cook University, Townsville, Qld 4811, Australia.
C Department of Terrestrial Vertebrates, Western Australian Museum, 49 Kew Street, Welshpool, WA 6106, Australia.
D Corresponding author. Email: jmelv@museum.vic.gov.au
Australian Journal of Zoology 56(3) 159-171 https://doi.org/10.1071/ZO07069
Submitted: 12 December 2007 Accepted: 15 September 2008 Published: 27 November 2008
Abstract
Although the south-western Australian region is recognised as a global biodiversity hotspot, there are still significant gaps in our understanding of the biodiversity of this region. We present a phylogenetic study of the heath dragons (Rankinia adelaidensis and R. parviceps) from this region, incorporating a 1612-bp section of mtDNA and two nuclear introns, Gapdh (~244 bp) and Enol (~330 bp). In addition, we present a generic-level analysis of three gene regions (mtDNA, Gapdh, BDNF), which provides clear evidence that Rankinia adelaidensis and R. parviceps are not closely related to Rankinia diemensis from eastern Australia. Instead, the heath dragons are strongly supported as forming a clade with the genus Ctenophorus. In addition, we find that there are significant levels of haplotype divergence between currently recognised subspecies of the heath dragons (R. a. adelaidensis, R. a. chapmani, R. p. parviceps, R. p. butleri). We suggest that the genetic divergences between subspecies result from geographic isolation in allopatry owing to habitat preferences, followed by drift and/or selection. On the basis of these deep divergences and consistent morphological differences between subspecies, we recommend elevating all taxa to full species, and provide a taxonomic revision of the genera Rankinia and Ctenophorus.
Acknowledgements
We thank B. Maryan, R. Sadlier, M. Hutchinson and G. Shea for advice, R. Rose, V. White and B. Ong for assistance in the molecular laboratory and J. Austin, R. Glor and J. Schulte for useful comments on the manuscript. Funding was provided by the Australian Research Council to JM.
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Appendix 1. Previously published sequences used in the analyses with Genbank numbers provided
Mitochondrial DNA
Amphibolurus muricatus, AF128468; A. nobbi, AY132999; A. norrisi, AY133001; A. temporalis, AY133002; Chelosania brunnea, AF128465; Ctenophorus caudicinctus, AF375623; C. clayi, AF375620; C. cristatus, AF375622; C. decresii, AF128470; C. fordi AF375626; C. isolepis, AF375629; C. maculatus, AF375628; C. maculosus, AF375621; C. mckenziei, AF375631; C. nuchalis, AF375633; C. pictus, AF375635; C. rufescens, AF375636; C. salinarum, AF375640; C. scutulatus, AF375632; Diporiphora bilineata, AF128473; D. magna, AY133009; Hypsilurus boydii, AY133013; H. spinipes, AY133018; Lophognathus gilberti, AY133019; L. longirostris, AF128462; Moloch horridus, AF128467; Physignathus lesueurii, AF128463; Pogona barbata, AF128474; P. minor, AY133023; P. vitticeps, AY133026; Rankinia adelaidensis chapmani, AF128471; R. diemensis, AF375619; Tympanocryptis centralis, AY133030; T. cephalus, AY133027; T. intima, AY133029; T. tetraporophora, AY133032.
BDNF
Amphibolurus muricatus, DQ340701; A. nobbi, DQ340702; Ctenophorus caudicinctus, DQ340709; C. fordi, DQ340713; C. pictus, DQ340718; Diporiphora bilineata, DQ340722; Hypsilurus boydii, DQ340727; Moloch horridus, DQ340734; Physignathus lesueurii, DQ340737; Pogona barbata, DQ340738; P. vitticeps, DQ340739; Rankinia adelaidensis, DQ340740; R. diemensis, DQ340741.
Appendix 2. Likelihood model parameters for phylogenetic analyses
Intraspecific phylogenetic analyses
Mitochondrial dataset –– TVM + I + Γ: gamma = 0.8977; proportion of invariable sites = 0.2742; substitution rates A ↔ C 1.2543, A ↔ G 8.3641, A ↔ T 0.9438, C ↔ G 0.4356, C ↔ T 8.3641, G ↔ T 1.0000; and nucleotide frequencies A = 0.3839, C = 0.3102, G = 0.0977, T = 0.2082. Gapdh – HKY + Γ: gamma = 0.3891; T-Ratio = 1.7353; nucleotide frequencies A = 0.2536, C = 0.1707, G = 0.2512 and t = 0.3245. Enol – TIM + I: proportion of invariable sites = 0.2881; substitution rates A ↔ C 1.0000, A ↔ G 2.0232, A ↔ T 0.2981, C ↔ G 0.2981, C ↔ T 1.0232, G ↔ T 1.0000; nucleotide frequencies A = 0.2296, C = 0.2174, G = 0.2251, T = 0.3279.
Generic phylogenetic analyses
Mitochondrial dataset – TVM + I + Γ: gamma = 0.9389; proportion of invariable sites = 0.3396; substitution rates A ↔ C 1.1605, A ↔ G 8.9619, A ↔ T 1.4402, C ↔ G 0.2639, C ↔ T 8.9619, G ↔ T 1.0000; nucleotide frequencies A = 0.3634, C = 0.3229, G = 0.0932, T = 0.2205. Gapdh – HKY + Γ: gamma = 0.2699; T-Ratio = 3.0637; nucleotide frequencies A = 0.2528, C = 0.1779, G = 0.2261 and T = 0.3432. BDNF – HKY + I: proportion of invariable sites = 0.8677; T-Ratio = 2.7617; and nucleotide frequencies A = 0.2920, C = 0.2290, G = 0.2783, T = 0.2500.