Counting the cost of living in modern and fossil animals

The energetic cost of living defines how animals interact with their environment. The rate at which animals capture and expend energy dictates where and how they can live, and their relative sensitivity to ecological and environmental change. Energetic traits face strong selection, and morphological features are often assumed to imply changes in bioenergetic traits. Energy is typically measured by assessing heat production or the oxygen consumption rates. Both of these approaches are extremely difficult to apply in field conditions or on fossil samples. Consequently, despite the fundamental importance of energy expenditure in ecology, evolution and conservation physiology, we have very little comparative quantitative information on the realised energetic costs of living for wild animals in either modern or fossil settings. Recently, chemical proxies for realised metabolic rate have been proposed, based on carbon isotope compositions (Chung et al 2019), trace metals (Limberg et al 2018) and concentrations of respiratory macromolecules preserved in ancient biominerals (Weimann et al 2022). This project will refine, improve and intercompare proxies for field metabolic rate. You will apply metabolic proxies to provide the first empirical data for how metabolic level varies among modern and fossil organisms, linking physiology and evolutionary ecology.