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 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
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
Hybridization, polyploidy and the evolution of parthenogenesis in the Australian desert. This project considers the ecology and evolution of Australian animals that reproduce by parthenogenesis, i.e. without sex. These animals have long fascinated evolutionary biologists for the clues they provide about the role of sex in evolution. The Australian desert is a hot-spot for parthenogenesis, providing a unique opportunity to study the ecological and evolutionary forces favouring the loss of sex. Ou ....Hybridization, polyploidy and the evolution of parthenogenesis in the Australian desert. This project considers the ecology and evolution of Australian animals that reproduce by parthenogenesis, i.e. without sex. These animals have long fascinated evolutionary biologists for the clues they provide about the role of sex in evolution. The Australian desert is a hot-spot for parthenogenesis, providing a unique opportunity to study the ecological and evolutionary forces favouring the loss of sex. Our research will exploit Australian cases of parthenogenesis to understand how genetic changes associated with the transition to parthenogenesis affect ecological success. This will significantly extend our understanding of both the role of sex in evolution, and of the evolutionary history of the Australian arid zone.Read moreRead less
Identifying genes causing thermal evolution of ectotherm body size. Cold-blooded animals increase in body size as they are found in populations at greater distances from the equator. These patterns are due to populations adapting to temperature. The aim of this project is to identify the genes involved in this adaptation process. We will do this by taking advantage of a well-studied body size cline in the vinegar fly on the east coast of Australia, and by building on an international collaborati ....Identifying genes causing thermal evolution of ectotherm body size. Cold-blooded animals increase in body size as they are found in populations at greater distances from the equator. These patterns are due to populations adapting to temperature. The aim of this project is to identify the genes involved in this adaptation process. We will do this by taking advantage of a well-studied body size cline in the vinegar fly on the east coast of Australia, and by building on an international collaboration between a leading UK and two Australian research groups. In doing so we will provide an explanation at the molecular level for one of the great unresolved phenomena in biology: why do cold-blooded animals get bigger in the cold? The research also leads to the potential to manipulate body size in animals.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
Testing the DNA decay hypothesis of ecological specialization. Australia's biodiversity has been increasingly threatened by climate change and fragmentation from habitat loss. To conserve biodiversity we need to identify species most at risk of extinction. One way species avoid extinction is to evolve and adapt to changing conditions, however, it now appears that many species have a limited adaptive potential. Here we develop and test a new idea that helps to predict species most threatened b ....Testing the DNA decay hypothesis of ecological specialization. Australia's biodiversity has been increasingly threatened by climate change and fragmentation from habitat loss. To conserve biodiversity we need to identify species most at risk of extinction. One way species avoid extinction is to evolve and adapt to changing conditions, however, it now appears that many species have a limited adaptive potential. Here we develop and test a new idea that helps to predict species most threatened by climate change and other types of stresses. We also identify the sets of genes that are involved in adapting to dry/cold conditions and toxins. This information provides a rapid way of identifying species most at risk and least likely to adapt, and a new perspective on Australia's biodiversity.Read moreRead less
A high-through-put method for unlocking the mitochondrial genomes of significant pathogens. The national/community benefits of this research are: (1) to develop a long-term, high quality scientific and technological program contributing to national objectives, including the maintenance of a strong capability in basic research, the development of new scientific concepts and the enhancement of international collaborative links; (2) to strengthen the links between basic and applied research; (3) to ....A high-through-put method for unlocking the mitochondrial genomes of significant pathogens. The national/community benefits of this research are: (1) to develop a long-term, high quality scientific and technological program contributing to national objectives, including the maintenance of a strong capability in basic research, the development of new scientific concepts and the enhancement of international collaborative links; (2) to strengthen the links between basic and applied research; (3) to develop excellence in research by promoting collaborative research, resulting in a more efficient use of resources in a national and international context; (4) to enhance the skills-base in biology and biotechnology; and (5) to substantially increase global visibility through quality research, leading to an increased investment in Australian science.Read moreRead less
Mobility of log-dependent invertebrates in fragmented forest. Clearing of Australian native forests continues apace. This leads to declines in total forest area and creates isolated remnants with depleted woody debris. Critical forest processes driven by invertebrates occur in this debris. Despite its major economic and conservation significance, there is little information on the impacts of habitat loss and alteration on organisms in decomposing logs. We will utilize recent advances in popu ....Mobility of log-dependent invertebrates in fragmented forest. Clearing of Australian native forests continues apace. This leads to declines in total forest area and creates isolated remnants with depleted woody debris. Critical forest processes driven by invertebrates occur in this debris. Despite its major economic and conservation significance, there is little information on the impacts of habitat loss and alteration on organisms in decomposing logs. We will utilize recent advances in population genetics to compare impacts on a suite of log-dependent invertebrates in an islands-of-bush-in-a-sea-of-pines model. This will facilitate improvements in conservation and sustainable management outcomes in forests.Read moreRead less
Breaking selective constraints: is Hsp90 a capacitor of evolutionary change? Gene action and expression can be modulated by genetic mechanisms. If a general mechanism controlling gene expression exists that can be easily manipulated it has the potential to allow animal and plant breeders to quickly produce and select for new characters of agricultural importance without relying on transgenics and long-term breeding programs. It would also assist in the development of tools for identifying and de ....Breaking selective constraints: is Hsp90 a capacitor of evolutionary change? Gene action and expression can be modulated by genetic mechanisms. If a general mechanism controlling gene expression exists that can be easily manipulated it has the potential to allow animal and plant breeders to quickly produce and select for new characters of agricultural importance without relying on transgenics and long-term breeding programs. It would also assist in the development of tools for identifying and detecting genes that increase susceptibility to human diseases, such as cancer, that are only expressed under certain conditions environmental. I intend to determine whether the protein Hsp90 represents a general mechanism controlling gene expression. Read moreRead less