Intra-genomic conflict and the evolution of sexually selected traits. The dynamics of sexual selection may prevent the simultaneous optimization of traits shared by the sexes, or of different traits within each sex. This proposal focuses on the consequences of these conflicts for phenotypic and genomic evolution. First, I will compare selection acting on a sexually dimorphic trait in males and females. Second, I will use artificial selection to create a novel sexually dimorphic trait, and track ....Intra-genomic conflict and the evolution of sexually selected traits. The dynamics of sexual selection may prevent the simultaneous optimization of traits shared by the sexes, or of different traits within each sex. This proposal focuses on the consequences of these conflicts for phenotypic and genomic evolution. First, I will compare selection acting on a sexually dimorphic trait in males and females. Second, I will use artificial selection to create a novel sexually dimorphic trait, and track the evolutionary response. Third, I will investigate the link between two important fitness traits: body size and ageing rate. This work will enhance important on-going research in the laboratory of Robert Brooks (UNSW).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
Evolution of cooperative breeding in birds. The incidence of cooperative breeding in birds varies from 0 to 100% between families of birds, and from <1 to >25% among birds from different regions. However, there has been no theory that successfully predicts these differences. Recent comparative analysis shows the differences result largely from the early evolution of obligate cooperative breeding in some groups, and their subsequent slow rates of speciation. I will use model systems to investiga ....Evolution of cooperative breeding in birds. The incidence of cooperative breeding in birds varies from 0 to 100% between families of birds, and from <1 to >25% among birds from different regions. However, there has been no theory that successfully predicts these differences. Recent comparative analysis shows the differences result largely from the early evolution of obligate cooperative breeding in some groups, and their subsequent slow rates of speciation. I will use model systems to investigate how birds can become committed to cooperative breeding despite the inevitable conflicts, and how one group of birds have been freed from the general rules governing the evolution of sociality.Read moreRead less
Why do females mate with multiple partners? Tests of key hypotheses in the wild. Female animals commonly mate with several males at each reproductive cycle, but we do not know why. Six plausible, testable hypotheses have been proposed to explain how females could benefit directly, or by obtaining advantageous genes for their offspring. The few empirical investigations so far carried out have been in captivity and have not considered all alternative explanations. I propose to experimentally test ....Why do females mate with multiple partners? Tests of key hypotheses in the wild. Female animals commonly mate with several males at each reproductive cycle, but we do not know why. Six plausible, testable hypotheses have been proposed to explain how females could benefit directly, or by obtaining advantageous genes for their offspring. The few empirical investigations so far carried out have been in captivity and have not considered all alternative explanations. I propose to experimentally test the key hypotheses in the wild, using a small mammal uniquely-suited to this purpose because of its unusual, but well-known reproductive strategy. The results will improve our understanding of the role of female behaviour in evolutionary processes.Read moreRead less
Sex, parthenogenesis and adaptation: a novel laboratory 'natural selection' experiment testing the adaptive significance of sexual and asexual reproduction. One of the greatest challenges for evolutionary biology is explaining the widespread occurrence of sexual reproduction. Many theoretical models show some inherent benefits of sex, however these models make assumptions that little or no empirical data exists for. Using a novel phenomenon found in the parasitoid wasp genus Trichogramma, I will ....Sex, parthenogenesis and adaptation: a novel laboratory 'natural selection' experiment testing the adaptive significance of sexual and asexual reproduction. One of the greatest challenges for evolutionary biology is explaining the widespread occurrence of sexual reproduction. Many theoretical models show some inherent benefits of sex, however these models make assumptions that little or no empirical data exists for. Using a novel phenomenon found in the parasitoid wasp genus Trichogramma, I will investigate the adaptive significance of sexual and asexual reproduction in a laboratory natural selection experiment and therefore directly test the theory for the evolution and maintenance of sex. This will be the first such test in a higher organism.Read moreRead less
The Maintenance of Genetic Variation by Antagonistic Sexual Selection. The principle outcomes of my proposed research are fundamental knowledge, training of young scientists and the improvement of Australia's research capacity and profile. My research will have a major impact on two major branches of evolutionary biology that are seldom integrated - sexual selection and quantitative genetics. My research will enable me to establish myself as an independent researcher. Moreover, my collaborations ....The Maintenance of Genetic Variation by Antagonistic Sexual Selection. The principle outcomes of my proposed research are fundamental knowledge, training of young scientists and the improvement of Australia's research capacity and profile. My research will have a major impact on two major branches of evolutionary biology that are seldom integrated - sexual selection and quantitative genetics. My research will enable me to establish myself as an independent researcher. Moreover, my collaborations with one of the leading research laboratories in the UK, will teach me several modern techniques that I can disseminate to Australian students participating on the proposed project.Read moreRead less
Putting sexual selection in a life-history context: What is meant by genetic quality? Theories of sexual signalling have been developed largely without reference to life-history theory and quantitative genetics. We will test recent theory that shows the costs of signals are best measured in units of future survival and reproduction. In a series of field and laboratory experiments on the cricket Teleogryllus commodus, we will test the idea that the "male genetic quality" referred to by good-genes ....Putting sexual selection in a life-history context: What is meant by genetic quality? Theories of sexual signalling have been developed largely without reference to life-history theory and quantitative genetics. We will test recent theory that shows the costs of signals are best measured in units of future survival and reproduction. In a series of field and laboratory experiments on the cricket Teleogryllus commodus, we will test the idea that the "male genetic quality" referred to by good-genes models of sexual selection is quality in the general ability to acquire resources, rather than in how resources are allocated among fitness components.Read moreRead less
The evolution of parental care in leeches: costs and benefits in a clade of hermaphroditic, invertebrate ectotherms. Parental care is a basic element of reproduction in many species. Nearly everything we know about parental care comes from study of vertebrates, especially birds and mammals. Leech is synonymous with exploitation, but many of these annelid worms are devoted parents. Because they differ dramatically from most vertebrates, leeches present an excellent, but as yet unused, opportunity ....The evolution of parental care in leeches: costs and benefits in a clade of hermaphroditic, invertebrate ectotherms. Parental care is a basic element of reproduction in many species. Nearly everything we know about parental care comes from study of vertebrates, especially birds and mammals. Leech is synonymous with exploitation, but many of these annelid worms are devoted parents. Because they differ dramatically from most vertebrates, leeches present an excellent, but as yet unused, opportunity to test our theories and understanding of the evoluton of parental care. We will examine the evolution of degrees of care and sibling competition in leech families, and use molecular markers to better understand the genetic structure of populations of these invertebrates.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