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
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
LIZARD SOCIAL BEHAVIOUR AND THE INFLUENCE OF PARASITES. We ask why stable social group living in animals, with well documented benefits, is relatively rare. One cost is the enhanced opportunity for parasite and disease transmission among group members. We will explore, for a lizard, the impact of group living on parasite infections, and the costs of infection. We expect to produce observational and experimental results with an unusual level of detail, and with a fresh taxonomic perspective to in ....LIZARD SOCIAL BEHAVIOUR AND THE INFLUENCE OF PARASITES. We ask why stable social group living in animals, with well documented benefits, is relatively rare. One cost is the enhanced opportunity for parasite and disease transmission among group members. We will explore, for a lizard, the impact of group living on parasite infections, and the costs of infection. We expect to produce observational and experimental results with an unusual level of detail, and with a fresh taxonomic perspective to influence debate in this central area of behavioural ecology. We will also produce new information on behavioural ecology of Australian fauna, important for conservation management and ecotourism.Read moreRead less
Testing metabolic theories in ecology. There are striking similarities in the way plants and animals take up and use energy (metabolism), despite enormous variation in size and life-style. This project will make the first experimental comparison of the predictions of the two major theories for these broad patterns. The results will significantly progress this controversial and exciting field.
Pathways to semelparity versus early maturity in animals and plants. The project aims to resolve an important but unresolved question in life history evolution and ecology- which mechanisms and constraints lead to semelparity (breeding once, which is rare), and which lead to fast life history (breeding early, which is common) in animals and plants. Theory predicts that both may be adaptations to schedules of adult death. Understanding why males and females have either semelparous or fast life hi ....Pathways to semelparity versus early maturity in animals and plants. The project aims to resolve an important but unresolved question in life history evolution and ecology- which mechanisms and constraints lead to semelparity (breeding once, which is rare), and which lead to fast life history (breeding early, which is common) in animals and plants. Theory predicts that both may be adaptations to schedules of adult death. Understanding why males and females have either semelparous or fast life history strategies is crucial to predicting survival of harvested and threatened species under pressure from climate change, drought, predators, and diseases that kill adults. Expected project outcomes include improved ability to address agents of decline of threatened animals and plants including semelparous species.Read moreRead less