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Independent Transitions between Monsoonal and Arid Biomes Revealed by Systematic Revison of a Complex of Australian Geckos (Diplodactylus; Diplodactylidae).

Oliver PM, Couper PJ, Pepper M - PLoS ONE (2014)

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus

Phylogenetic summaries.(A) Maximum likelihood phylogeny based on the mtDNA gene nd2 estimated using RaxML for all major lineages within the D. conspicillatus complex. Lineage names A-H follow Oliver et al. 2009. Clades are colour-coded to match distributions in Figs. 1 and 3. Nodes with ML support above 95 and Bayesian support (BEAST) above 99 (respectively) are indicated with an asterisk (*). (B) Chronogram and ancestral biome states for the seven species in the revised D. conspicillatus group estimated using BEAST and calibrated with a 3% pairwise mean rate of molecular evolution. Green lineages are from outside the central Australian arid zone (defined by a moisture index of less than 0.4), brown lineages are from inside the Australian arid zone, and the probability (i.e. percentage of reconstructions that feature the observed state) of the inferred ancestral habitat is indicated for major nodes.
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pone.0111895.g002: Phylogenetic summaries.(A) Maximum likelihood phylogeny based on the mtDNA gene nd2 estimated using RaxML for all major lineages within the D. conspicillatus complex. Lineage names A-H follow Oliver et al. 2009. Clades are colour-coded to match distributions in Figs. 1 and 3. Nodes with ML support above 95 and Bayesian support (BEAST) above 99 (respectively) are indicated with an asterisk (*). (B) Chronogram and ancestral biome states for the seven species in the revised D. conspicillatus group estimated using BEAST and calibrated with a 3% pairwise mean rate of molecular evolution. Green lineages are from outside the central Australian arid zone (defined by a moisture index of less than 0.4), brown lineages are from inside the Australian arid zone, and the probability (i.e. percentage of reconstructions that feature the observed state) of the inferred ancestral habitat is indicated for major nodes.

Mentions: Monophyly of D. conspicillatus sensu lato was strongly supported in all analyses (Fig. 2A–B). Within this clade we identified the nine major lineages corresponding to the candidate species identified by Oliver et al. [30], specifically; D. conspicillatus sensu stricto—widespread in the arid zone and extending into the AMT; lineage A—Gulf region, north Queensland; lineage B—western Pilbara and Carnarvon region, Western Australia; lineage C—widespread arid zone; lineage D—western Top End, Northern Territory; lineage E—Kimberley, Western Australia; lineage F—Channel Country, western and central Queensland and far north-west New South Wales; lineage G—around Townsville, Queensland; and lineage H—gulf country, north Queensland (Fig. 1). Monophyly of all major clades is strongly supported, and mean uncorrected genetic divergence between lineages is relatively high (11.3–22.5%) (S1A Table). Lineages B, C, D and E form a clade that is well supported as sister to another clade comprising D. conspicillatus sensu stricto and lineage A. Collectively these clades (D. conspicillatus sensu stricto and A–E) are well supported as sister to the most divergent clade of the complex which contains lineages F–H from eastern Australia.


Independent Transitions between Monsoonal and Arid Biomes Revealed by Systematic Revison of a Complex of Australian Geckos (Diplodactylus; Diplodactylidae).

Oliver PM, Couper PJ, Pepper M - PLoS ONE (2014)

Phylogenetic summaries.(A) Maximum likelihood phylogeny based on the mtDNA gene nd2 estimated using RaxML for all major lineages within the D. conspicillatus complex. Lineage names A-H follow Oliver et al. 2009. Clades are colour-coded to match distributions in Figs. 1 and 3. Nodes with ML support above 95 and Bayesian support (BEAST) above 99 (respectively) are indicated with an asterisk (*). (B) Chronogram and ancestral biome states for the seven species in the revised D. conspicillatus group estimated using BEAST and calibrated with a 3% pairwise mean rate of molecular evolution. Green lineages are from outside the central Australian arid zone (defined by a moisture index of less than 0.4), brown lineages are from inside the Australian arid zone, and the probability (i.e. percentage of reconstructions that feature the observed state) of the inferred ancestral habitat is indicated for major nodes.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4262211&req=5

pone.0111895.g002: Phylogenetic summaries.(A) Maximum likelihood phylogeny based on the mtDNA gene nd2 estimated using RaxML for all major lineages within the D. conspicillatus complex. Lineage names A-H follow Oliver et al. 2009. Clades are colour-coded to match distributions in Figs. 1 and 3. Nodes with ML support above 95 and Bayesian support (BEAST) above 99 (respectively) are indicated with an asterisk (*). (B) Chronogram and ancestral biome states for the seven species in the revised D. conspicillatus group estimated using BEAST and calibrated with a 3% pairwise mean rate of molecular evolution. Green lineages are from outside the central Australian arid zone (defined by a moisture index of less than 0.4), brown lineages are from inside the Australian arid zone, and the probability (i.e. percentage of reconstructions that feature the observed state) of the inferred ancestral habitat is indicated for major nodes.
Mentions: Monophyly of D. conspicillatus sensu lato was strongly supported in all analyses (Fig. 2A–B). Within this clade we identified the nine major lineages corresponding to the candidate species identified by Oliver et al. [30], specifically; D. conspicillatus sensu stricto—widespread in the arid zone and extending into the AMT; lineage A—Gulf region, north Queensland; lineage B—western Pilbara and Carnarvon region, Western Australia; lineage C—widespread arid zone; lineage D—western Top End, Northern Territory; lineage E—Kimberley, Western Australia; lineage F—Channel Country, western and central Queensland and far north-west New South Wales; lineage G—around Townsville, Queensland; and lineage H—gulf country, north Queensland (Fig. 1). Monophyly of all major clades is strongly supported, and mean uncorrected genetic divergence between lineages is relatively high (11.3–22.5%) (S1A Table). Lineages B, C, D and E form a clade that is well supported as sister to another clade comprising D. conspicillatus sensu stricto and lineage A. Collectively these clades (D. conspicillatus sensu stricto and A–E) are well supported as sister to the most divergent clade of the complex which contains lineages F–H from eastern Australia.

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus