ORCID Profile
0000-0002-4416-5224
Current Organisation
Natural History Museum
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Publisher: Mary Ann Liebert Inc
Date: 08-2012
Publisher: Oxford University Press (OUP)
Date: 08-2023
Abstract: The Australian continent’s size and isolation make it an ideal place for studying the accumulation and evolution of bio ersity. Long separated from the ancient supercontinent Gondwana, most of Australia’s plants and animals are unique and endemic, including the continent’s frogs. Australian frogs comprise a remarkable ecological and morphological ersity categorized into a small number of distantly related radiations. We present a phylogenomic hypothesis based on an exon-capture dataset that spans the main clades of Australian myobatrachoid, pelodryadid hyloid, and microhylid frogs. Our time-calibrated phylogenomic-scale phylogeny identifies great disparity in the relative ages of these groups which vary from Gondwanan relics to recent immigrants from Asia and include arguably the continent’s oldest living vertebrate radiation. This age stratification provides insight into the colonization of, and ersification on, the Australian continent through deep time, during periods of dramatic climatic and community changes. Contemporary Australian frog ersity highlights the adaptive capacity of anurans, particularly in response to heat and aridity, and explains why they are one of the continent’s most visible faunas.
Publisher: Wiley
Date: 02-2023
DOI: 10.1111/ZSC.12575
Abstract: Using molecular genetic data, recognised ersity within the gecko genus Cyrtodactylus has more than doubled, with many lineages that were once thought to be wide‐ranging being delimited into multiple independent species. On the Southeast Asian island of Borneo, there has been a recent renewed focus on reptile taxonomy, as genetic data have demonstrated a high amount of unrecognised bio ersity. We herein advance this taxonomic trend by delimiting three distinct species within the Cyrtodactylus consobrinus species complex: C. consobrinus, C. kapitensis sp. n., and C. hutan sp. n. To do so, we use a combination of ddRADseq and single‐locus data, and morphological data. Using genomic data, we test species and population boundaries within the consobrinus species complex and show minimal population structure but high species‐level ersity. Despite not finding uniquely diagnostic morphological characters to delimit the new species, we suggest a combination of characters that can be used to identify each lineage. Lastly, we use our data to comment on the status of C. malayanus , with indications that this lineage is also better considered a species complex. These data highlight the prevalence of unrecognised lineages on Borneo, many of which face threats due to increasing deforestation and other anthropogenic pressures.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Western Australian Museum
Date: 2023
Publisher: Elsevier BV
Date: 06-2020
Publisher: Center for Open Science
Date: 11-04-2019
Abstract: Synthesising trait observations and knowledge across the Tree of Life remains a grand challenge for bio ersity science. Despite the well-recognised importance of traits for addressing ecological and evolutionary questions, trait-based approaches still struggle with several basic data requirements to deliver openly accessible, reproducible, and transparent science. Here, we introduce the Open Traits Network (OTN) – a decentralised alliance of international researchers and institutions focused on collaborative integration and standardisation of the exponentially increasing availability of trait data across all organisms. The OTN embraces the use of Open Science principles in trait research, particularly open data, open source, and open methodology protocols and workflows, to accelerate the synthesis of trait data across the Tree of Life. Increased efforts at all levels – from in idual scientists, research networks, scientific societies, funding agencies, to publishers – are necessary to fully exploit the opportunities offered by Open Science in trait research. Democratising access to data, tools and resources will facilitate rapid advances in the biological sciences and our ability to address pressing environmental and societal demands.
Publisher: Wiley
Date: 11-03-2017
DOI: 10.1111/EVO.13207
Abstract: Trends in global and local climate history have been linked to observed macroevolutionary patterns across a variety of organisms. These climatic pressures may unilaterally or asymmetrically influence the evolutionary trajectory of clades. To test and compare signatures of changing global (Eocene-Oligocene boundary cooling) and continental (Miocene aridification) environments on a continental fauna, we investigated the macroevolutionary dynamics of one of Australia's most erse endemic radiations, pygopodoid geckos. We generated a time-calibrated phylogeny (>90% taxon coverage) to test whether (i) asymmetrical pygopodoid tree shape may be the result of mass turnover deep in the group's history, and (ii) how Miocene aridification shaped trends in biome assemblages. We find evidence of mass turnover in pygopodoids following the isolation of the Australian continental plate ∼30 million years ago, and in contrast, gradual aridification is linked to elevated speciation rates in the young arid zone. Surprisingly, our results suggest that invasion of arid habitats was not an evolutionary end point. Instead, arid Australia has acted as a source for ersity, with repeated outward dispersals having facilitated ersification of this group. This pattern contrasts trends in richness and distribution of other Australian vertebrates, illustrating the profound effects historical biome changes have on macroevolutionary patterns.
Publisher: Springer Science and Business Media LLC
Date: 17-02-2020
Publisher: CSIRO Publishing
Date: 25-05-2023
DOI: 10.1071/ZO23007
Abstract: Skinks (Family Scincidae) are the most erse family of lizards (~1745 described species worldwide), and the Australasian region (Australia, New Caledonia, New Zealand) is a recognised global hotspot ( species) for skinks. Here we focus on determining the phylogenetic relationships and biogeography within the tribe Eugongylini, one of three lineages in the region. We used mtDNA (ND2) and nuclear (RAG-1, c-mos) DNA sequences and phylogenetic analyses to reveal the presence of three well-supported lineages of Australian Eugongylini. We found a sister relationship between the monotypic genera Eroticoscincus and Harrisoniascincus, and that the monotypic Anepischetosia has close affinities with Carinascincus coventryi and Pseudemoia. C. coventryi represents a separate lineage from the main Carinascincus radiation. Emoia was not found to be monophyletic, with Emoia s.s. part of an Australian lineage, and the remainder of the genus representing an older ergence within the tribe. The widespread and speciose Cryptoblepharus represented a well-supported lineage within an Australian lineage. Our analyses confirm previous suggestions that four Sphenomorphus species (louisiadensis, minutus, bignelli, and aignanus) are misplaced, and are part of the Eugongylini. Our phylogenetic analyses support the hypothesis that the origin of the tribe lies in Asia, with dispersal events to Africa, Australasia, and Oceania.
Publisher: Magnolia Press
Date: 30-06-2015
DOI: 10.11646/ZOOTAXA.3980.3.4
Abstract: We describe a new gecko of the genus Blaesodactylus from a karstic outcrop in deciduous dry forest of Ankarana National Park, northern Madagascar. Blaesodactylus microtuberculatus sp. nov., the fifth recognized species of Blaesodactylus, is distinguished from all other congeners, B. ambonihazo, B. antongilensis, B. boivini and B. sakalava by a combination of small, homogeneous gular granules, unspotted venter and lack of tubercles on distal part of original tail. Mitochondrial (ND2 and ND4) and nuclear (RAG-1) DNA identify a consistent ergence between B. microtuberculatus and its allotopic sister species B. boivini. We highlight habitat partitioning in these allotopic congeners where Blaesodactylus microtuberculatus inhabits karstic outcrops in Tsingy massif, and B. boivini dwells on tree trunks in deciduous dry forest.
Publisher: Wiley
Date: 02-07-2018
DOI: 10.1111/JBI.13385
Publisher: The Royal Society
Date: 17-10-2018
Abstract: On deep time scales, changing climatic trends can have a predictable influence on macroevolution. From evidence of mass extinctions, we know that rapid climatic oscillations can indirectly open niche space and precipitate adaptive radiation, changing the course of ecological ersification. These dramatic shifts in the global climate, however, are rare events relative to extended periods of protracted climate change and biome turnover. It remains unclear whether during gradually changing periods, shifting habitats may instead promote non-adaptive speciation by facilitating allopatry and phenotypic conservatism. Using fossil-calibrated, species-level phylogenies for five Australian radiations comprising more than 800 species, we investigated temporal trends in biogeography and body size evolution. Here, we demonstrate that gradual Miocene cooling and aridification correlates with the restricted phenotypic ersification of multiple ecologically erse vertebrate groups. This probably occurred as species ranges became fractured and isolated during continental biome restructuring, encouraging a shift towards conservatism in body size evolution. Our results provide further evidence that abiotic changes, not only biotic interactions, may act as selective forces influencing phenotypic macroevolution.
Publisher: Magnolia Press
Date: 07-07-2016
DOI: 10.11646/ZOOTAXA.4136.3.7
Abstract: Based on near-topotypic specimens of Dixonius vietnamensis from Khanh Hoa Province in southern Vietnam genetic analyses showed that the recently described D. taoi is sister to D. vietnamensis and several separate forms exist which previously have been misidentified as D. vietnamensis and D. siamensis. The Dixonius population from Vinh Cuu Nature Reserve, Dong Nai Province, Vietnam, represents an undescribed species. Dixonius minhlei sp. nov. can be distinguished from its congeners based on the following diagnostic characters: small size (up to 47.5 mm SVL) 7-9 supralabials 14-15 rows of keeled tubercles on dorsum 20-23 ventral scale rows 7 or 8 precloacal pores in males a canthal stripe running from rostrum through the eye and terminating at back of head lateral second pair of postmentals maximum one quarter the size of first pair dorsum olive gray with more or less discernible brownish olive blotches. This is the sixth species of Dixonius known to occur in Vietnam.
Publisher: Wiley
Date: 30-01-2020
DOI: 10.1111/EVO.13909
Abstract: Biome shifts are thought to be relatively rare, but some clades shift among starkly different environments with relative ease. What causes these shifts, and how do they shape phenotypic evolution? Roycroft et al. found that biome shifts in the Pseudomys Division of murid rodents were repeatedly accompanied by body size evolution in accordance with Bergmann's rule, suggesting adaptive evolution in response to changing climate conditions.
Publisher: The Royal Society
Date: 12-2022
Abstract: Lineages may ersify when they encounter available ecological niches. Adaptive ergence by ecological opportunity often appears to follow the invasion of a new environment with open ecological space. This evolutionary process is hypothesized to explain the explosive ersification of numerous Australian vertebrate groups following the collision of the Eurasian and Australian plates 25 Mya. One of these groups is the pythons, which demonstrate their greatest phenotypic and ecological ersity in Australo-Papua (Australia and New Guinea). Here, using an updated and near complete time-calibrated phylogenomic hypothesis of the group, we show that following invasion of this region, pythons experienced a sudden burst of speciation rates coupled with multiple instances of accelerated phenotypic evolution in head and body shape and body size. These results are consistent with adaptive radiation theory with an initial rapid niche-filling phase and later slow-down approaching niche saturation. We discuss these findings in the context of other Australo-Papuan adaptive radiations and the importance of incorporating adaptive ersification systems that are not extraordinarily species-rich but ecomorphologically erse to understand how bio ersity is generated.
Publisher: Springer Science and Business Media LLC
Date: 17-07-2017
DOI: 10.1038/S41598-017-05261-9
Abstract: Over the past decade, DNA barcoding has become a staple of low-cost molecular systematic investigations. The availability of universal primers and subsidized sequencing projects (PolarBOL, SharkBOL, SpongeBOL) have driven this popularity, often without appropriate investigation into the utility of barcoding data for the taxonomic group of interest. Here, our primary aim is to determine the phylogenetic value of DNA barcoding (mitochondrial locus COI ) within the gecko genus Cyrtodactylus . With new species described since last systematic investigation, Cyrtodactylus represents one of the most erse extant squamate genera, and their contemporary distribution spans the Indian subcontinent, eastward through Indochina, and into AustraloPapua. The complex biogeographic history of this group, and morphology-only designation of many species have complicated our phylogenetic understanding of Cyrtodactylus . To highlight the need for continued inclusive molecular assessment, we use Vietnamese Cyrtodactylus as a case study showing the geopolitically paraphyletic nature of their history. We compare COI to the legacy marker ND2 , and discuss the value of COI as an interspecific marker, as well as its shortcomings at deeper evolutionary scales. We draw attention back to the Cold Code as a subsidized method for incorporating molecular methods into species descriptions in the effort to maintain accurate phylogenies.
Publisher: Cold Spring Harbor Laboratory
Date: 18-09-2019
DOI: 10.1101/772558
Abstract: Studying organismal ecology and evolution on deep timescales provides us opportunities to identify the processes driving patterns in ersity and forms. Macroecological and macroevolutionary studies of trait evolution however, often fail to account for sources of artifactual variation in the data—be it phylogenetic, temporal, or other. In some instances, this may not affect our evolutionary understanding, and accounting for sources of uncertainty may only subdue confidence in our inferences. In more dramatic cases, narrow views of trait uncertainty may result in conclusions that are misleading. Because macroevolutionary analyses are built atop a number of preconceived hypotheses regarding the relationships between taxa, origination and ergence times, intraspecific variation, and environmental variables, it is important to incorporate and present this uncertainty. Here I use a dataset for Australian kangaroos to demonstrate the importance of incorporating uncertainty when testing patterns of ersification. After accounting for fossil age uncertainty, I provide evidence that a proposed Pliocene origin of Macropus kangaroos is at odds with combined evidence molecular and morphological dating methods. Depending on the estimated crown age of kangaroos, the evolution of hypsodonty is as likely caused by the continental expansion of C 4 grasses as it is by increasing windborne dust levels or paleotemperature fluctuations. These results suggest that previous interpretations of the radiation of modern kangaroos are not as bulletproof as we believe, and that multiple factors have likely influenced their remarkable ersification across the Australian continent. More broadly, this demonstrates the importance of incorporating uncertainty in comparative ecological and evolutionary studies, and the value in testing the assumptions inherent in our data and the methods we employ.
Publisher: Magnolia Press
Date: 13-05-2020
DOI: 10.11646/ZOOTAXA.4778.1.1
Abstract: Despite decades of phylogenetic studies, the generic and species-level relationships of some Australian elapid snakes remain problematic. The morphologically conservative genus Parasuta comprises small nocturnal snakes with a particularly obfuscated taxonomic history. Here we provide a molecular phylogenetic analysis of all currently recognised species including members of the sister genus Suta and provide new morphological data that lead to a taxonomic revision of generic and species boundaries. We failed to find support for monophyly of Parasuta or Suta, instead supporting previous evidence that these two genera should be combined. Our species-level investigations revise the boundaries between P. gouldii (Gray) and P. spectabilis (Krefft) resulting in recognition that both P. spectabilis bushi (Storr) and P. spectabilis nullarbor (Storr) are conspecific with P. gouldii. We also find the Pilbara population of P. monachus (Storr) to be specifically distinct. As a consequence of this information, we synonymise Parasuta with its senior synonym Suta, redescribe S. gouldii, S. monachus and S. spectabilis to clarify morphological and geographical boundaries and describe S. gaikhorstorum sp. nov., which differs from all other described Suta species, including the geographically proximate and similar-looking S. monachus, by a combination of molecular genetic markers, morphometric attributes, details of colouration and scalation. The recognition of S. gaikhorstorum sp. nov. adds to the growing list of the many endemic reptiles from this exceptionally erse biotic region. We also designate a lectotype for S. spectabilis from the original syntype series, highlight a distinctive population from the Great Victoria Desert in Western Australia and comment on further unresolved issues regarding the relationships between S. dwyeri (Worrell) and S. nigriceps (Gȕnther).
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.YMPEV.2015.10.005
Abstract: Of the more than 1500 species of geckos found across six continents, few remain as unfamiliar as the pygopodids - Family Pygopodidae (Gray, 1845). These gekkotans are limited to Australia (44 species) and New Guinea (2 species), but have erged extensively into the most ecologically erse limbless radiation save Serpentes. Current phylogenetic understanding of the family has relied almost exclusively on two works, which have produced and synthesized an immense amount of morphological, geographical, and molecular data. However, current interspecific relationships within the largest genus Delma Gray 1831 are based chiefly upon data from two mitochondrial loci (16s, ND2). Here, we reevaluate the interspecific relationships within the genus Delma using two mitochondrial and four nuclear loci (RAG1, MXRA5, MOS, DYNLL1), and identify points of strong conflict between nuclear and mitochondrial genomic data. We address mito-nuclear discordance, and remedy this conflict by recognizing several points of mitochondrial introgression as the result of ancient hybridization events. Owing to the legacy value and intraspecific informativeness, we suggest the continued use of ND2 as a phylogenetic marker. Results identify strong support for species groups, but relationships among these clades, and the placement of several enigmatic taxa remain uncertain. We suggest a more careful review of Delma australis and the 'northwest Australia' clade. Accurately assessing and addressing species richness and relationships within this endemic Australian Gekkotan genus is relevant for understanding patterns of squamate speciation across the region.
Publisher: Magnolia Press
Date: 10-11-2015
DOI: 10.11646/ZOOTAXA.4040.1.4
Abstract: We describe a new species of Dixonius on the basis of five specimens from Phu Quy Island, Binh Thuan Province, in southern Vietnam. The new species can be distinguished from congeners based on molecular and morphological differences. Diagnostic features are: small size (SVL up to 44 mm) 7 or 8 supralabials 11 or 12 rows of keeled tubercles on dorsum 21-23 ventral scale rows 5 or 6 precloacal pores in males a canthal stripe running from rostrum through the eye and terminating behind the head second pair of postmentals about one third to one half size of first pair ground color of dorsum brown, with one or two rows of light yellow or orange spots in one or two rows along flanks, and irregular bands or a reticulated network of dark marks on dorsum. This is the fifth species of Dixonius known to occur in Vietnam.
Publisher: Magnolia Press
Date: 10-04-2015
DOI: 10.11646/ZOOTAXA.3946.3.1
Abstract: The Australian pygopodid lizard genus Delma is characterised by morphologically conservative but genetically ergent lineages and species. An initial assessment of molecular and morphological variation in Delma australis Kluge, 1974 throughout its main distribution in Western and South Australia reveals at least two undescribed species that are presently included under this epithet. Here we describe the most distinctive and easily diagnosed taxon of these, D. hebesa sp. nov., from the proteaceous scrub and mallee heath on the south coast sandplains of southwestern Western Australia. We also foreshadow the need for an expanded genetic framework to assist in unequivocally diagnosing additional candidate species in D. australis, which is redescribed herein and shown to be monophyletic for those specimens s led, albeit displaying geographic variation in a range of molecular and morphological characters. Delma hebesa sp. nov. differs from all other described Delma species, including regional populations of D. australis, by a combination of molecular genetic markers, colouration and scalation. Based on phylogenetic affinities and shared morphologies, a D. australis species-group is proposed to accommodate D. australis, D. torquata and the new species described herein. The addition of another new vertebrate species from southwestern Western Australia, recognised globally as a bio ersity 'hotspot', underlines our lack of understanding of genetic ersity and evolutionary histories in this bio erse region.
Publisher: Oxford University Press (OUP)
Date: 29-01-2021
Abstract: Hybridization between species occurs more frequently in vertebrates than traditionally thought, but distinguishing ancient hybridization from other phenomena that generate similar evolutionary patterns remains challenging. Here, we used a comprehensive workflow to discover evidence of ancient hybridization between the Komodo dragon (Varanus komodoensis) from Indonesia and a common ancestor of an Australian group of monitor lizards known colloquially as sand monitors. Our data comprise $& $300 nuclear loci, mitochondrial genomes, phenotypic data, fossil and contemporary records, and past resent climatic data. We show that the four sand monitor species share more nuclear alleles with $V$. komodoensis than expected given a bifurcating phylogeny, likely as a result of hybridization between the latter species and a common ancestor of sand monitors. Sand monitors display phenotypes that are intermediate between their closest relatives and $V$. komodoensis. Biogeographic analyses suggest that $V$. komodoensis and ancestral sand monitors co-occurred in northern Australia. In agreement with the fossil record, this provides further evidence that the Komodo dragon once inhabited the Australian continent. Our study shows how different sources of evidence can be used to thoroughly characterize evolutionary histories that deviate from a treelike pattern, that hybridization can have long-lasting effects on phenotypes, and that detecting hybridization can improve our understanding of evolutionary and biogeographic patterns.[Biogeography introgression Komodo dragon phylogenetic networks phylogenomics reticulation Varanus.]
Publisher: Public Library of Science (PLoS)
Date: 06-2021
DOI: 10.1371/JOURNAL.PBIO.3001210
Abstract: Global bio ersity loss is a profound consequence of human activity. Disturbingly, bio ersity loss is greater than realized because of the unknown number of undocumented species. Conservation fundamentally relies on taxonomic recognition of species, but only a fraction of bio ersity is described. Here, we provide a new quantitative approach for prioritizing rigorous taxonomic research for conservation. We implement this approach in a highly erse vertebrate group—Australian lizards and snakes. Of 870 species assessed, we identified 282 (32.4%) with taxonomic uncertainty, of which 17.6% likely comprise undescribed species of conservation concern. We identify 24 species in need of immediate taxonomic attention to facilitate conservation. Using a broadly applicable return-on-investment framework, we demonstrate the importance of prioritizing the fundamental work of identifying species before they are lost.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Cold Spring Harbor Laboratory
Date: 30-03-2019
DOI: 10.1101/593699
Abstract: Polyploidy has played an important role in evolution across the tree of life but it is still unclear how polyploid lineages may persist after their initial formation. While both common and well-studied in plants, polyploidy is rare in animals and generally less well-understood. The Australian burrowing frog genus Neobatrachus is comprised of six diploid and three polyploid species and offers a powerful animal polyploid model system. We generated exome-capture sequence data from 87 in iduals representing all nine species of Neobatrachus to investigate species-level relationships, the origin and inheritance mode of polyploid species, and the population genomic effects of polyploidy on genus-wide demography. We resolve the phylogenetic relationships among Neobatrachus species and provide further support that the three polyploid species have independent autotetraploid origins. We document higher genetic ersity in tetraploids, resulting from widespread gene flow specifically between the tetraploids, asymmetric inter-ploidy gene flow directed from sympatric diploids to tetraploids, and current isolation of diploid species from each other. We also constructed models of ecologically suitable areas for each species to investigate the impact of climate variation on frogs with differing ploidy levels. These models suggest substantial change in suitable areas compared to past climate, which in turn corresponds to population genomic estimates of demographic histories. We propose that Neobatrachus diploids may be suffering the early genomic impacts of climate-induced habitat loss, while tetraploids appear to be avoiding this fate, possibly due to widespread gene flow into tetraploid lineages specifically. Finally, we demonstrate that Neobatrachus is an attractive model to study the effects of ploidy on the evolution of adaptation in animals.
Publisher: Brill
Date: 06-11-2020
DOI: 10.1163/22244662-20191078
Abstract: Subspecies designations for herpetofauna in Western Australia were largely coined in the 20th century where rigorous evolutionary concepts to species were not consistently applied. Rather, subspecies tended to designate geographic populations of similar-looking taxa to nominate forms, usually differing in size, pattern or colour and, at best, a few scalation differences. Here we re-evaluate two pygopodoid taxa from Western Australia using a combination of published and original genetic data coupled with a reassessment of morphology. We review these differences in light of an integrative taxonomic approach that looks to find multiple independent lines of evidence to establish the evolutionary independence of populations. For the pygopod species Pletholax gracilis , we found consistent diagnostic characters (e.g. body size, visibility of ear opening, scalation) and a deep genetic ergence between the two subspecies. We therefore raise each subspecies to full species: P. gracilis and P. edelensis . The two subspecies of the carphodactylid gecko Nephrurus wheeleri were also assessed, and we found strong genetic and morphological evidence (e.g. body size, scalation, pattern) to raise these to full species: N. wheeleri and N. cinctus . By revisiting Storr’s morphological insights and newly acquired genetic evidence, in addition to a thorough re-examination of morphological traits, our study provides a robust foundation to raise Storr’s morphological subspecies into full species based upon multiple lines of evidence. Such an approach applied to other subspecies in the Australian herpetofauna also may result in revised taxonomies.
Publisher: Wiley
Date: 09-12-2021
DOI: 10.1111/EVO.14403
Abstract: How biotic and abiotic factors act together to shape biological ersity is a major question in evolutionary biology. The recent availability of large datasets and development of new methodological approaches provide new tools to evaluate the predicted effects of ecological interactions and geography on lineage ersification and phenotypic evolution. Here, we use a near complete phylogenomic-scale phylogeny and a comprehensive morphological dataset comprising more than a thousand specimens to assess the role of biotic and abiotic processes in the ersification of monitor lizards (Varanidae). This charismatic group of lizards shows striking variation in species richness among its clades and multiple instances of endemic radiation in Indo-Australasia (i.e., the Indo-Australian Archipelago and Australia), one of Earth's most biogeographically complex regions. We found heterogeneity in ersification dynamics across the family. Idiosyncratic biotic and geographic conditions appear to have driven ersification and morphological evolution in three endemic Indo-Australasian radiations. Furthermore, incumbency effects partially explain patterns in the biotic exchange between Australia and New Guinea. Our results offer insight into the dynamic history of Indo-Australasia, the evolutionary significance of competition, and the long-term consequences of incumbency effects.
Publisher: Wiley
Date: 19-12-2018
DOI: 10.1111/EVO.13657
Abstract: Testing hypotheses on drivers of clade evolution and trait ersification provides insight into many aspects of evolutionary biology. Often, studies investigate only intrinsic biological properties of organisms as the causes of ersity, however, extrinsic properties of a clade's environment, particularly geological history, may also offer compelling explanations. The Andes are a young mountain chain known to have shaped many aspects of climate and ersity of South America. The Liolaemidae are a radiation of South American reptiles with over 300 species found across most biomes and with similar numbers of egg-laying and live-bearing species. Using the most complete dated phylogeny of the family, we tested the role of Andean uplift in biogeography, ersification patterns, and parity mode of the Liolaemidae. We find that the Andes promoted lineage ersification and acted as a species pump into surrounding biomes. We also find strong support for the role of Andean uplift in boosting the species ersity of these lizards via allopatric fragmentation. Finally, we find repeated shifts in parity mode associated with changing thermal niches, with live-bearing favored in cold climates and egg-laying favored in warm climates. Importantly, we find evidence for possible reversals to oviparity, an evolutionary transition believed to be extremely rare.
Publisher: Pensoft Publishers
Date: 06-04-2023
Abstract: Several specimens of Pachydactylus angolensis , a poorly known Angolan endemic gecko, have recently been collected in southern Angola, considerably increasing its known distribution range. Previous observations led to the hypothesis that two different morphological forms exist in the country—a coastal form and an inland form. Based on the morphological examination of historical and recently collected specimens, as well as on newly generated molecular data, we conducted a taxonomic revision of this putative species complex. The results support the separation of these two forms as two different species. The coastal form belongs to the nominotypic population, while the inland form is here described as a new species, Pachydactylus maiatoi sp. nov. . A brief comment on the biogeographical implications of this discovery is also provided.
Publisher: Public Library of Science (PLoS)
Date: 11-05-2020
Publisher: Cold Spring Harbor Laboratory
Date: 03-05-2023
DOI: 10.1101/2023.05.03.539251
Abstract: The Australian continent’s size and isolation make it an ideal place for studying the accumulation and evolution of bio ersity. Long separated from the ancient supercontinent Gondwana, most of Australia’s plants and animals are unique and endemic, including the continent’s frogs. Australian frogs comprise a remarkable ecological and morphological ersity categorized into a small number of distantly related radiations. We present a phylogenomic hypothesis based on an exon-capture dataset that spans the main clades of Australian myobatrachoid, pelodryadid hyloid, and microhylid frogs. Our time-calibrated phylogenomic-scale phylogeny identifies great disparity in the relative ages of these groups which vary from Gondwanan relics to recent immigrants from Asia and include arguably the continent’s oldest living vertebrate radiation. This age stratification provides insight into the colonization of, and ersification on, the Australian continent through deep time, during periods of dramatic climatic and community changes. Contemporary Australian frog ersity highlights the adaptive capacity of anurans, particularly in response to heat and aridity, and explains why they are one of the continent’s most visible faunas.
Publisher: Hindawi Limited
Date: 20-04-2021
DOI: 10.1111/JZS.12470
Publisher: Springer Science and Business Media LLC
Date: 09-03-2020
Publisher: Cold Spring Harbor Laboratory
Date: 03-02-2021
DOI: 10.1101/2020.02.02.931188
Abstract: Organismal interactions drive the accumulation of ersity by influencing species ranges, morphology, and behavior. Interactions vary from agonistic to cooperative and should result in predictable patterns in trait and range evolution. However, despite a conceptual understanding of these processes, they have been difficult to model, particularly on macroevolutionary timescales and across broad geographic spaces. Here we investigate the influence of biotic interactions on trait evolution and community assembly in monitor lizards ( Varanus ). Monitors are an iconic radiation with a cosmopolitan distribution and the greatest size disparity of any living terrestrial vertebrate genus. Between the colossal Komodo dragon Varanus komodoensis and the smallest Australian dwarf goannas, Varanus length and mass vary by multiple orders of magnitude. To test the hypothesis that size variation in this genus was driven by character displacement, we extended existing phylogenetic comparative methods which consider lineage interactions to account for dynamic biogeographic history and apply these methods to Australian monitors and marsupial predators. We use a phylogenomic approach to estimate the relationships among living and extinct varaniform lizards, incorporating both exon-capture molecular and morphological datasets. Our results suggest that communities of Australian Varanus show high functional ersity as a result of continent-wide interspecific competition among monitors but not with faunivorous marsupials. We demonstrate that patterns of trait evolution resulting from character displacement on continental scales are recoverable from comparative data and highlight that these macroevolutionary patterns may develop in parallel across widely distributed sympatric groups.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Ian Brennan.