Are natural clones specialists or generalists? Using a model system to test alternative hypotheses for the advantages of parthenogenesis. Parthenogenetic organisms are all-female and reproduce clonally. Through discovering why these unusual organisms are sometimes successful we can better understand the significance of genetic diversity and sex. The Australian arid zone is a ?hot-spot? for parthenogenesis, with at least five independent examples including a native grasshopper and one of its host ....Are natural clones specialists or generalists? Using a model system to test alternative hypotheses for the advantages of parthenogenesis. Parthenogenetic organisms are all-female and reproduce clonally. Through discovering why these unusual organisms are sometimes successful we can better understand the significance of genetic diversity and sex. The Australian arid zone is a ?hot-spot? for parthenogenesis, with at least five independent examples including a native grasshopper and one of its host plants. I will apply modern molecular tools and ecophysiological techniques to test the hypothesis that parthenogenesis is favoured in this grasshopper because it allows the fixation of locally adapted clones. This research will provide a unique insight into the selective forces operating in the arid zone, Australia's largest ecosystem.Read moreRead less
Ecological and genetic connectivity in seagrasses: the role of sexual reproduction, dispersal and recruitment on meadow restoration. This project's goal is to study the role of dispersal in contemporary demographics and genetics of an Australian seagrass genus Posidonia. The expected outcome of this project is to understand the importance of long-distance dispersal of seeds in determining resilience of seagrasses to both natural and anthropogenic disturbances.
Genetic Rescue of Australia's Arid Zone Plants. Many Australian arid zone plant species have been severely damaged by grazing, loss of pollinators and other impacts and cannot survive without urgent intervention. Some exist as small fragmented populations with too little genetic variation to reproduce or adapt to further environmental change. We propose to combine surveys of genetic (DNA) diversity and the reproductive status of populations in order to identify species that could be saved by a ....Genetic Rescue of Australia's Arid Zone Plants. Many Australian arid zone plant species have been severely damaged by grazing, loss of pollinators and other impacts and cannot survive without urgent intervention. Some exist as small fragmented populations with too little genetic variation to reproduce or adapt to further environmental change. We propose to combine surveys of genetic (DNA) diversity and the reproductive status of populations in order to identify species that could be saved by a process of ‘genetic rescue’. Genetic rescue will involve experimental pollinations to produce highly fit seedlings and later transplanting of these seedlings to augment genetically deficient populations.
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Connectivity and movements of large pelagic species of ecotourism value. The project aims to answer key questions about the biology, ecology and sustainability of the world’s manta ray species to provide the information and tools for management and conservation of these charismatic and valuable species. In particular, the project aims to determine the likely impact of climate variability and fisheries that operate to Australia’s north on manta-based ecotourism in the Indo-Pacific region, as clim ....Connectivity and movements of large pelagic species of ecotourism value. The project aims to answer key questions about the biology, ecology and sustainability of the world’s manta ray species to provide the information and tools for management and conservation of these charismatic and valuable species. In particular, the project aims to determine the likely impact of climate variability and fisheries that operate to Australia’s north on manta-based ecotourism in the Indo-Pacific region, as climate change and active low-value fisheries may both jeopardise a high-value ecotourism industry. The project seeks to explore geographic distributions, local and large-scale movements, population sizes, structure, and inter-connectivity in the region to assess the effect of climate and fisheries on manta ray populations.Read moreRead less
Evolutionary signficance of sexual conflict in orb-web spiders. Multiple mating by females creates intense competition between ejaculates over the fertilisation of her eggs, and has a profound influence on male and female life history and mating strategies. In orb-web spiders, sexual cannibalism creates further conflicts of interest because the male may forfeit future matings. This project examines how life-history and mating strategies interact in these spiders, by identifying the mechanisms t ....Evolutionary signficance of sexual conflict in orb-web spiders. Multiple mating by females creates intense competition between ejaculates over the fertilisation of her eggs, and has a profound influence on male and female life history and mating strategies. In orb-web spiders, sexual cannibalism creates further conflicts of interest because the male may forfeit future matings. This project examines how life-history and mating strategies interact in these spiders, by identifying the mechanisms that determine the outcome of sperm competition; the selection pressures favouring sexual size dimorphism and male size variation; the influence of sexual cannibalism on male mating strategies; and the relationship between female feeding history and her mating behaviour.Read moreRead less
Life history constraints on sexual selection: an investigation using territoriality in butterflies. Contemporary studies into the evolution of male contest behaviour largely ignore the influence of life history. However, contest behaviour should be influenced by life history because the costs of fighting (injury or death) are extracted in a life history currency. Here I aim to measure reproductive value in a territorial butterfly, and to isolate the effects of this parameter, physiological condi ....Life history constraints on sexual selection: an investigation using territoriality in butterflies. Contemporary studies into the evolution of male contest behaviour largely ignore the influence of life history. However, contest behaviour should be influenced by life history because the costs of fighting (injury or death) are extracted in a life history currency. Here I aim to measure reproductive value in a territorial butterfly, and to isolate the effects of this parameter, physiological condition and fighting experience upon male aggression. I propose an innovative experimental approach to unraveling the effects of these covarying life history influences which promises exciting and highly original insights into the evolution of contest behaviour.Read moreRead less
Intersexual arms races - are individuals within marine meta-populations less able to interbreed than assumed? A meta-population structure is thought to describe the inter-connected nature of many populations of marine animals with dispersive larvae. However, new theory predicts some of these populations might be not very inter-connected at all, despite larval migration. In some circumstances, independent, co-evolutionary arms races between sexes might develop within local populations, resulting ....Intersexual arms races - are individuals within marine meta-populations less able to interbreed than assumed? A meta-population structure is thought to describe the inter-connected nature of many populations of marine animals with dispersive larvae. However, new theory predicts some of these populations might be not very inter-connected at all, despite larval migration. In some circumstances, independent, co-evolutionary arms races between sexes might develop within local populations, resulting in individuals becoming increasingly less able to interbreed freely. I will directly test for this, measuring how successfully broadcast spawners can cross-fertilise across populations. This will reveal the genetic structure of these populations and if these animals really do live in a meta-population.Read moreRead less
Boom and bust: the role of fire and rain in driving the dynamics of seeds and rodents in arid Australia. The arid Australian environment oscillates between spectacular boom periods, when biotic productivity and diversity are high, and busts, when biotic resources are depleted. This project first outlines a conceptual model of this dynamic and complex system. It then investigates the roles of rainfall and fire in driving boom-bust events, focusing particularly on food resources (seeds) and their ....Boom and bust: the role of fire and rain in driving the dynamics of seeds and rodents in arid Australia. The arid Australian environment oscillates between spectacular boom periods, when biotic productivity and diversity are high, and busts, when biotic resources are depleted. This project first outlines a conceptual model of this dynamic and complex system. It then investigates the roles of rainfall and fire in driving boom-bust events, focusing particularly on food resources (seeds) and their consumers (desert rodents) in the hyper-variable Simpson Desert. We propose observations and experiments to quantify how these climatic events affect seed production, seed fate, and ultimately the dynamics of desert rodents, and outline their importance for effective management of the desert environment.Read moreRead less
The role of plant chemical defences in the population ecology of mammal herbivores. Plants defend themselves against herbivores by producing toxic compounds in their leaves. Many studies show that such compounds influence diet selection by mammal herbivores, but we understand much less about their effects on populations of such species. This project will investigate how concentrations of leaf toxins in eucalypts affect reproductive success, distribution and abundance of the marsupials that feed ....The role of plant chemical defences in the population ecology of mammal herbivores. Plants defend themselves against herbivores by producing toxic compounds in their leaves. Many studies show that such compounds influence diet selection by mammal herbivores, but we understand much less about their effects on populations of such species. This project will investigate how concentrations of leaf toxins in eucalypts affect reproductive success, distribution and abundance of the marsupials that feed on them. The knowledge gained by this study will be important in modelling populations of these marsupial species and predicting their responses to environmental change.Read moreRead less
Can inbreeding avoidance cause the evolution of sex-biased dispersal? This project aims to combine unique long-term data with a novel Citizen Science approach to seek to provide the first complete test of the hypothesis that inbreeding avoidance can cause one of the best known patterns in mammal and bird societies - sex differences in when and how far juveniles disperse. Dispersal is a critically important ecological and evolutionary process, as it influences the fate of populations, and also de ....Can inbreeding avoidance cause the evolution of sex-biased dispersal? This project aims to combine unique long-term data with a novel Citizen Science approach to seek to provide the first complete test of the hypothesis that inbreeding avoidance can cause one of the best known patterns in mammal and bird societies - sex differences in when and how far juveniles disperse. Dispersal is a critically important ecological and evolutionary process, as it influences the fate of populations, and also determines the individuals with which a disperser will spend the remainder of its life. It therefore shapes the likelihood that kin will interact to cooperate or compete, and determines the pool of individuals with which the disperser can mate.Read moreRead less