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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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
Influence of energy intake on reproduction. Understanding reproduction is fundamentally important to ecology and conservation. Despite intensive research, the processes that regulate energy acquisition and allocation for reproduction are still unclear for most animal species. Many of the obstacles to progress in this field of research are logistical, reflecting the complexity and temporal overlap of significant components of energy allocation pathways. Our proposed study avoids many of these l ....Influence of energy intake on reproduction. Understanding reproduction is fundamentally important to ecology and conservation. Despite intensive research, the processes that regulate energy acquisition and allocation for reproduction are still unclear for most animal species. Many of the obstacles to progress in this field of research are logistical, reflecting the complexity and temporal overlap of significant components of energy allocation pathways. Our proposed study avoids many of these logistical difficulties by focusing on animals (snakes) that display clear temporal partitioning between successive segments of the reproductive cascade (i.e., vitellogenesis, ovulation, embryogenesis); and by adopting a simple but novel method (based on stable isotope analysis) to tease apart the relationship between energy acquisition and energy expenditure in different phases of the animal's life-history.Read moreRead less
Does adaptive plasticity play a significant role in the initial colonisation of novel habitats? An increased understanding of the evolutionary and ecological processes responsible for generating Australian biodiversity can facilitate effective management and conservation of this unique resource. Islands are especially significant in this context because they host many kinds of distinctive fauna and flora that have vanished from mainland habitats. It is therefore crucial to understand the biolo ....Does adaptive plasticity play a significant role in the initial colonisation of novel habitats? An increased understanding of the evolutionary and ecological processes responsible for generating Australian biodiversity can facilitate effective management and conservation of this unique resource. Islands are especially significant in this context because they host many kinds of distinctive fauna and flora that have vanished from mainland habitats. It is therefore crucial to understand the biology of these small isolated systems, as a way to preserve those unique systems as well as the distinctive evolutionary processes that occur within them.Read moreRead less
Host plant choice by marine herbivores: ecological, genetic and historical constraints. Understanding the factors that determine plant choice by herbivores is crucial to predicting the ecological effects of herbivores on plants and herbivore adaptation to plants. This proposal aims to establish how evolution of host choice by a marine herbivore is constrained by ecological, genetic and historical factors. It will determine how the spatial arrangement of plants modifies host use, and whether evol ....Host plant choice by marine herbivores: ecological, genetic and historical constraints. Understanding the factors that determine plant choice by herbivores is crucial to predicting the ecological effects of herbivores on plants and herbivore adaptation to plants. This proposal aims to establish how evolution of host choice by a marine herbivore is constrained by ecological, genetic and historical factors. It will determine how the spatial arrangement of plants modifies host use, and whether evolutionary change by herbivores is constrained by genetic relationships among herbivore traits. The generality of important evolutionary hypotheses that predict plant choice by herbivores will be tested by extending such theory to new organisms and environments.Read moreRead less
Cane toads as a model system for demographic analysis and invasive-species control. How do impacts on juvenile stages within a population affect later ages? This project will exploit recently developed methods to control early life-history stages of cane toads to provide a better understanding of population ecology and develop more effective ways to control invasive cane toads.
Facultative sex-determination in a montane lizard. Why is the sex of some reptiles determined by their genetic constitution (sometimes involving heteromorphic sex chromosomes) whereas in other species the animal's sex is determined by the environment (especially, incubation temperature)? Multiple phylogenetic transitions between genetic sex determination (GSD) and environmental sex determination (ESD) suggest that these alternative modes of sex determination possess adaptive significance. Howe ....Facultative sex-determination in a montane lizard. Why is the sex of some reptiles determined by their genetic constitution (sometimes involving heteromorphic sex chromosomes) whereas in other species the animal's sex is determined by the environment (especially, incubation temperature)? Multiple phylogenetic transitions between genetic sex determination (GSD) and environmental sex determination (ESD) suggest that these alternative modes of sex determination possess adaptive significance. However, the selective forces favouring one versus the other remain obscure, despite sustained research in this field by many workers. The recent discovery of BOTH sex-determining systems simultaneously within a single population of alpine lizards provides a unique opportunity to test among competing hypotheses for the evolution of sex-determining systems. I propose an integrated study, in both the field and the laboratory, to clarify the mechanisms and the selective forces involved in the evolution of sex-determination.Read moreRead less
Evolutionary ecology of snakes and lizards. Although reptiles provide excellent "model systems" with which to examine evolutionary and ecological processes, most research in this field has been dominated by studies on other kinds of organisms. I propose a broad-ranging series of studies that will use a diverse array of lizard and snake species to erect and test novel hypotheses on the evolution of phenomena such as mating systems, sexual dimorphism, foraging biology, and reproductive investment ....Evolutionary ecology of snakes and lizards. Although reptiles provide excellent "model systems" with which to examine evolutionary and ecological processes, most research in this field has been dominated by studies on other kinds of organisms. I propose a broad-ranging series of studies that will use a diverse array of lizard and snake species to erect and test novel hypotheses on the evolution of phenomena such as mating systems, sexual dimorphism, foraging biology, and reproductive investment. My experimental studies will clarify the evolutionary role of phenotypic plasticity (that is, direct environmental effects) as well as genetic factors.Read moreRead less
Mate choice near and far: Genetic compatibility, sexual selection, and speciation in Australian grass finches. The pressure on individuals to choose a genetically compatible partner has the capacity to drive the evolution of mating systems and the process of speciation, and is therefore a major engine of biodiversity. Reproductive failure resulting from incompatibility between individuals is more likely when individuals from fragmented and genetically structured populations mate with one another ....Mate choice near and far: Genetic compatibility, sexual selection, and speciation in Australian grass finches. The pressure on individuals to choose a genetically compatible partner has the capacity to drive the evolution of mating systems and the process of speciation, and is therefore a major engine of biodiversity. Reproductive failure resulting from incompatibility between individuals is more likely when individuals from fragmented and genetically structured populations mate with one another. This work will give new insight into biological processes that drive biodiversity and effect the management of threatened populations and endangered species. The proposed research will raise the international profile of Australian science and biodiversity and improve our ability to manage our natural biological resources. Read moreRead less