Sea-level changes and palaeo-ranges: reconstruction of ancient shorelines and river drainages and the phylogeography of the Australian land crayfish Engaeus sericatus Clark (Decapoda: Parastacidae )

Historical sea levels have been influential in shaping the phylogeography of freshwater-limited taxa via palaeodrainage and palaeoshoreline connections. In this study, we demonstrate an approach to phylogeographic analysis incorporating historical sea-level information in a nested clade phylogeographic analysis (NCPA) framework, using burrowing freshwater crayfish as the model organism. Our study area focuses on the Bass Strait region of southeastern Australia, which is marine region encompassing a shallow seabed that has emerged as a land bridge during glacial cycles connecting mainland Australia and Tasmania. Bathymetric data were analysed using Geographical Information Systems (GIS) to delineate a palaeodrainage model when the palaeocoastline was 150 m below present-day sea level. Such sea levels occurred at least twice in the past 500 000 years, perhaps more often or of larger magnitude within the last 10 million years, linking Victoria and Tasmania. Inter-locality distance measures confined to the palaeodrainage network were incorporated into an NCPA of crayfish (Engaeus sericatus Clark 1936) mitochondrial 16S rDNA haplotypes. The results were then compared to NCPAs using present-day river drainages and traditional great-circle distance measures. NCPA inferences were cross-examined using frequentist and Bayesian procedures in the context of geomorphological and historical sea-level data. We found distribution of present-day genetic variation in E. sericatus to be partly explained not only by connectivity through palaeodrainages but also via present-day drainages or overland (great circle) routes. We recommend that future studies consider all three of these distance measures, especially for studies of coastally distributed species.

Where and when does a ring start and end? Testing the ring-species hypothesis in a species complex of Australian parrots

Speciation, despite ongoing gene flow can be studied directly in nature in ring species that comprise two reproductively isolated populations connected by a chain or ring of intergrading populations. We applied three tiers of spatio-temporal analysis (phylogeny/historical biogeography, phylogeography and landscape/population genetics) to the data from mitochondrial and nuclear genomes of eastern Australian parrots of the Crimson Rosella Platycercus elegans complex to understand the history and present genetic structure of the ring they have long been considered to form. A ring speciation hypothesis does not explain the patterns we have observed in our data (e.g. multiple genetic discontinuities, discordance in genotypic and phenotypic assignments where terminal differentiates meet). However, we cannot reject that a continuous circular distribution has been involved in the group's history or indeed that one was formed through secondary contact at the 'ring's' east and west; however, we reject a simple ring-species hypothesis as traditionally applied, with secondary contact only at its east. We discuss alternative models involving historical allopatry of populations. We suggest that population expansion shown by population genetics parameters in one of these isolates was accompanied by geographical range expansion, secondary contact and hybridization on the eastern and western sides of the ring. Pleistocene landscape and sea-level and habitat changes then established the birds' current distributions and range disjunctions. Populations now show idiosyncratic patterns of selection and drift. We suggest that selection and drift now drive evolution in different populations within what has been considered the ring.

The role of the ord arid intrusion in the historical and contemporary genetic division of long-tailed finch subspecies in northern Australia

The effect of separation by biogeographic features followed by secondary contact can blur taxonomic boundaries and produce complex genetic signatures. We analyzed population structure and gene flow across the range of the long-tailed finch (Poephila acuticauda) in northern Australia (1) to test the hypothesis that Ord Arid Intrusion acted as the causative barrier that led to divergence of P. acuticauda subspecies, (2) to determine whether genetic data support the presence of a gradual cline across the range or a sudden shift, both of which have been suggested based on morphological data, and (3) to estimate levels of contemporary gene flow within this species complex. We collected samples from 302 individuals from 10 localities. Analyses of 12 microsatellite loci and sequence data from 333 base pairs of the mitochondrial control region were used to estimate population structure and gene flow, using analysis of molecular variance (AMOVA), haplotype network analysis, frequency statistics, and clustering methods. Mitochondrial sequence data indicated the presence of three genetic groups (regions) across the range of P. acuticauda. Genetic diversity was highest in the east and lowest in the west. The Ord Arid Intrusion appears to have functioned as a biogeographic barrier in the past, according to mtDNA evidence presented here and evidence from previous studies. The absence of isolation by distance between adjacent regions and the lack of population genetic structure of mtDNA within regions indicates that genetic changes across the range of P. acuticauda subspecies are characterized by discrete breaks between regions. While microsatellite data indicate a complete absence of genetic structure across this species’ range, it appears unlikely that this results from high levels of gene flow. Mitochondrial data do not support the presence of contemporary gene flow across the range of this species.

Comparative phylogeography of alpine invertebrates indicates deep lineage diversification and historical refugia in the Australian Alps

Aim: Comparative phylogeographic analyses of alpine biota from the Northern Hemisphere have linked patterns of genetic diversification to glacial expansion and contraction events in the Pliocene and Pleistocene. Furthermore, the extent of diversification across species groups appears to be associated with vagility. In this study we test whether these patterns apply to a geologically stable system from eastern Australia with comparatively shallow elevational gradients and minimal influence from historical glacial activity. Location: The Australian Alps, Victoria, eastern Australia. Methods: We considered phylogeographic patterns across five alpine invertebrate species based on mitochondrial and nuclear DNA sequence data. Bayesian inference methods were used to estimate species phylogenies and divergence times among lineages. GIS tools were used to map interpopulation genetic divergence and intrapopulation genetic diversity estimates and to visualize spatial patterns across species, providing insights into patterns of endemism and demographic history. Results: Phylogeographic patterns and the timing of lineage diversification were consistent across taxonomic groups. Mountain summits harbour highly differentiated haplogroups, including summits connected by high-elevational plateaus, pointing to diversifications being maintained since the early to mid-Pleistocene. These findings are consistent with previous studies of alpine mammals and reptiles, demonstrating a high degree of endemism in this region, regardless of species vagility. Main conclusions: The fine spatial scales at which deep genetic differentiation among alpine communities was observed in this study are unprecedented. This suggests that glacial periods have had less of an impact on species distributions and genetic diversity than they have in alpine systems in the Northern Hemisphere. Historical gene flow among sky-island populations has been limited despite connecting snowlines during glacial periods, suggesting that factors other than snow cover have influenced patterns of gene flow in this region. These findings emphasize the unique phylogeographic history affecting Victorian alpine biodiversity, and the importance of conserving biodiversity from multiple mountain summits in this region of high endemism.

Adaptation and change in the Australian life insurance industry : an historical perspective

In the wake of the deregulation of the financial sector in Australia in the 1980s and 1990s the life insurance industry has undergone a period of rapid change and reorganisation. Part of this adjustment has been the move towards the integration of financial service provision and the rise of bancassurance. This paper investigates the strategies adopted by Australian life insurers as they moved into the increasingly competitive environment triggered by the lifting of government restrictions on banking practices. It compares the approach of life insurers with that adopted in an earlier period of expansion and change. During the 1950s and 1960s an influx of foreign owned insurance companies into the Australian market precipitated the diversification of domestic life insurers into other insurance markets. The catalyst for change in both cases was the change in information costs brought about by the change in the competitive environment. The experience of the Australian life insurance market would suggest that there is a link between changing information costs and changing organisational structures. However this link is circumscribed by the institutional environment.

Molecular phylogeny of the Cheilodactylidae and Latridae (Perciformes: Cirrhitoidea) with notes on taxonomy and biogeography

Phylogenetic relationships among cheilodactylid and latrid fishes were estimated from cytochrome oxidase I and cytochrome b mitochondrial DNA sequences. Two South African cheilodactylids, Cheilodactylus fasciatus and Cheilodactylus pixi, were divergent from the remaining members of their genus and family, and the monophyly of these groups was rejected based on parametric bootstrap analysis. As C. fasciatus is the nominal species for the genus and family, widespread taxonomic reassignment is implicated for the remaining 12 and 17 members of these groups, respectively. As these 17 cheilodactylids are not genetically or morphologically distinct from the latrids, it is proposed that the Latridae should be expanded to encompass them. The inferred relationships among those Cheilodactylus requiring generic reassignment were largely unresolved, and hence few recommendations can be made regarding their placement. Divergence time estimates indicate that chance oceanic dispersal subsequent to Gondwanan fragmentation best explains the Southern Hemisphere radiation of cheilodactylids.

Phylogeography of the widespread Australian freshwater prawn, Macrobrachium australiense (Decapoda, Palaemonidae)

Aim: To investigate the phylogeographic structure of the widespread freshwater prawn, Macrobrachium australiense, within and between major Australian drainage basins using mitochondrial sequence data. This will enable the investigation of historical connections between major drainages and examination of hypotheses of biogeographic associations among Australian freshwater basins.

Location: Inland, eastern and northern Australia.

Methods: Sequencing 16S rRNA and ATPase 6 protein coding mitochondrial DNA genes from M. australiense from 19 locations from inland, eastern and northern Australia.

Results: Within drainage basins, haplotype trees are monophyletic, with the exception of the Finke River from the Lake Eyre Basin. Macrobrachium australiense from the two main inland drainages, the Murray–Darling and Lake Eyre Basin are divergent from each other and do not form a monophyletic group, instead the Murray–Darling Basin haplotypes clade with eastern coastal haplotypes. Haplotypes from neighbouring eastern coastal drainages were found to be quite divergent from each other.

Main conclusions: The phylogeographic relationships among M. australiense suggest that the two major inland drainages, the Murray–Darling Basin and the Lake Eyre Basin, are not biogeographically closely associated to each other. Instead the Murray–Darling Basin is more closely allied with the eastern coastal drainages across the Great Dividing Range. Despite their proximity the neighbouring southeast Queensland coastal Mary and Brisbane Rivers are also biogeographically divergent from each other. The results also indicate that the Finke River appears to have been isolated from the remainder of the Lake Eyre Basin catchment for a significant period of time.

Phylogenetic relationships of the globally distributed freshwater prawn genus Macrobrachium (Crustacea: Decapoda: Palaemonidae): biogeography, taxonomy, and the convergent evolution of abbreviated larval development

There has hitherto been little research into evolutionary and taxonomic relationships amongst species of the freshwater prawn genus Macrobrachium Bate across its global distribution. Previous work by the authors demonstrated that the endemic Australian species did not evolve from a single ancestral lineage. To examine whether other regional Macrobrachium faunas also reflect this pattern of multiple origins, the phylogeny of 30 Macrobrachium species from Asia, Central/South America and Australia was inferred from mitochondrial 16S rRNA sequences. Phylogenetic relationships demonstrate that, despite some evidence for regional diversification, Australia, Asia and South America clearly contain Macrobrachium species that do not share a common ancestry, suggesting that large-scale dispersal has been a major feature of the evolutionary history of the genus. The evolution of abbreviated larval development (ALD), associated with the transition from an estuarine into a purely freshwater lifecycle, was also mapped onto the phylogeny and was shown to be a relatively homoplasious trait and not taxonomically informative. Other taxonomic issues, as well as the evolutionary origins of Macrobrachium, are also discussed.

A historical review of the nurse practitioner role in Australia

Internationally, the nurse practitioner role has been shown to be cost-effective, safe, and instrumental in improving patient outcomes. The nurse practitioner role in Australia is in its infancy. Major stakeholders such as the nurses' boards and state departments of health throughout Australia were contacted to identify major policies and discussion papers. Database searches were conducted in CINAHL and EBSCOhost. Disparity between states exists in all facets of the nurse practitioner role, especially in definition of the role, scope of practice, educational qualifications, and specialized functions. Access to Medicare funding is unobtainable, resulting in inequity of access to health services for disadvantaged communities. The State Nurse Practitioner Taskforce Reports highlight the disparity between the role of nurse practitioner in each State of Australia and has led to fragmentation of the role at a national level. There is a need for consistency, which could be achieved if it were coordinated by a national nursing body with a voice in national health policy development and implementation