DoctorLuisa Fitzpatrick

Project Total: $8,485; Climate change poses an obvious threat to global biodiversity and even more to the species whose physiological function depend upon environmental temperature (e.g., ectotherms). Warming and heatwaves can have significant impacts on physiology of the organisms. Physiological function has been found to mediate the response of an organisms to environment and thus, variation in life history traits, characterised by growth, reproduction, senescence, and survival, among species. The primary goal of evolutionary ecology is to understand the diversity of life-history patterns. Life histories are determined by combined genetic and environmental factors, and underpinned by cellular processes, such as telomere dynamics. Telomeres are the repetitive DNA sequences that protect chromosomal ends and provide genetic stability during cellular replication. Within each cell division, telomeres shorten. Telomere shortening has been found to be associated with decline in biological function, including lifespan of individuals and thus, could lead to population decline. Telomere dynamics within individuals are significantly impacted by thermal stress such as frequent heat wave which can reduce telomeres and thus cellular function, ultimately affecting individual survival. My PhD focuses on the the Tasmanian spotted snow skink (Carinascincus ocellatus), a vulnerable reptile species displaying variation in telomere dynamics and life history traits across a broad climatic range. This research project builds upon more than two decades of ongoing study, aiming to deepen our understanding of the intricate relationship between environmental variation, life history traits, and telomere dynamics. Leveraging an established age-structured population, the study will investigate the impact of maternal age and environmental factors on offspring telomere length and associated life-history traits. Through simulated heatwave experiments, the research will explore the causal relationships between telomere length and life-history traits, shedding light on the underlying mechanisms while molecular approaches will be employed to uncover the genetic component of telomere dynamics (heritability). By integrating these diverse lines of inquiry, the project seeks to elucidate the intricate links between telomere dynamics, population dynamics, and environmental change, offering valuable insights into the broader ecological and evolutionary implications. All ethical requirements and veterinary competencies will be met. Funded by: Holsworth Wildlife Research Endowment - Grant ($16,985); University of Tasmania.

Project Total: $24,500; Biological ageing of organisms (senescence) is associated with a decline in function and an increase in mortality. Senescence has been widely observed in natural populations of mammals and birds; however, more research is needed to understand the causes of reproductive senescence across species. The most effective way to understand reproductive senescence (and contribute to our understanding of such processes in humans) is by combining long-term studies of wild populations with detailed experimental approaches. Our laboratory group has been studying wild populations of spotted snow skink in Tasmania for over 20 years and performing thermal manipulations in the laboratory that accelerate growth (and thus ageing processes). Reproductive senescence and other age-related declines are underpinned by processes that occur at the cellular level, through declines in telomere length. Telomeres are protective sequences of nucleotides on DNA, which prevent errors in recombination. Telomeres shorten every time a cell divides and when they no longer protect chromosomes, cellular senescence occurs. My project will combine long-term population data with state-of-the-art molecular approaches to examine links between telomere decline, age and reproductive output. This research will shed light on senescence in ectotherms, and increase our knowledge of the links between lifestyle, ageing and telomere biology. Funded by: Department of Education, Skills and Employment - Fellowship-Endeavour Research ($24,500); University of Tasmania.

Project Total: $16,250; Understanding how animals live across a wide climatic range is vital in the current period of climate uncertainty. The life history of reptiles is particularly important as their thermal environment directly influences them and little is known of the process of ageing in this group. Ageing, or senescence of wild animals is a key subject in the study of evolutionary biology today. Central to this is our growing knowledge of telomeres; caps on the end of chromosomes which slow age-related cell decline. There has been relatively little investigation into ageing in reptile taxa. Studying patterns of senescence in a reptile will make an important contribution to life history theories of ageing in the field of biogerontology. Building on an unparalleled dataset, this project uses the model system of the spotted snow skink (Niveoscincus ocellatus) to explore biological theories of aging across different environments and examine the relationships between telomeres, life history and environment. Linking variation within populations and divergence between populations is particularly important in predicting and managing climate change effects as the ability of populations and species to respond to climate change will depend on how individuals adapt to novel environmental conditions. Funded by: Holsworth Wildlife Research Endowment - Grant ($16,250); University of Tasmania.