Sgro Honours Projects

Does the nutritional environment of parents affect offspring stress resistance and the potential for climatic adaptation?

Background:  Studies attempting to understand organismal responses to climate change have focussed on climatic stressors. However food limitation is one of the most common environmental challenges faced by organisms. How energy intake is balanced to optimise fitness under changing climates, and how this affects the capacity of organisms to respond to climate change, is unknown. Parental effects, where the environment experienced by parents affects the fitness of the offspring generation, are widespread, and increasingly predicted to affect adaptation to climate change. Despite this, no studies have yet examined how the nutritional environments of parents will influence offspring fitness under combinations of both nutritional and thermal stress.

Project Aims:  This project will determine the extent to which the nutritional environment of parents affects offspring fitness under combinations of thermal and nutritional stress likely to be experienced under climate change.

Techniques: Drosophila husbandry, experimental design, data analysis, possibly molecular work.

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Feeding ecology of Drosophila and its impacts on climatic adaptation

Background:  On-going global change is resulting in changes in both the thermal and nutritional environments experienced by organisms, Yet, we know very little about how the combined effects of thermal and nutritional stress will affect the ability of animals to respond to changing climatic conditions.

Project Aims: This project will track how the nutritional and thermal environments of Drosophila change throughout the summer and spring months in the field in south-eastern Australia. Field-caught individuals will also be assessed for their ability to withstand both nutritional and thermal stress, and this data linked back to the nutritional and thermal environments experienced in nature. This project will shed light on how changes in nutrition and thermal stress influence the sensitivity of animals to climatic change.

Techniques:  Field sampling of Drosophila feeding and breeding sites; animal husbandry, experimental design and data analysis. There are no pre-requisites for this project, although a real interest in evolutionary ecology/evolutionary biology would be an advantage.

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The potential for transgenerational effects to increase or reduce climate change risk

Background: Understanding which organisms will be most vulnerable to climate change remains a crucial challenge in conservation biology. Models predicting which species will be most at risk of future warming typically compare estimates of CTmax, a trait which measures the ability of adults to survive high temperature stress, to temperatures currently experienced in nature to estimate warming tolerance. However, this measure ignores the fact that many species are no longer fertile at temperatures much lower than the temperatures adults can withstand, and thus, may be underestimating climate change risk. Transgenerational or carry-over effects, such as maternal and/ or epigenetic effects, can increase or decrease fitness and heat tolerance due to beneficial phenotypic plasticity or the accumulation of cellular damage across generations respectively. Nonetheless, studies that examine reproductive fitness across temperature, typically measure fitness on organisms exposed to different temperatures for one generation only. The extent to which transgenerational or carry over effects (maternal and/ or epigenetic effects) might lead to over or underestimating climate change risk remains to be explicitly examined.

Project Aims: This project aims to investigate the extent to which transgenerational effects may alter estimates of climate change risk in tropical and temperate species of Drosophila.

Techniques:  Drosophila husbandry, experimental design, data analysis.

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