The preservation of blood vessels, soft tissues, and endogenous biomolecules in vertebrate fossils has challenged long-standing assumptions that delicate cellular structures cannot survive over geological timescales. Traditionally, proteins and other biological molecules have been regarded as highly labile and therefore expected to degrade rapidly after death through microbial activity, oxidation, hydrolysis, and other taphonomic processes. However, advances in molecular paleontology have demonstrated that trace concentrations of endogenous organic material can persist in exceptionally preserved fossils, providing new opportunities to investigate the molecular and biochemical history of ancient organisms.
Among the biomolecules identified in fossils, porphyrin-containing proteins such as cytochromes, hemoglobin, and myoglobin have attracted particular interest because of their fundamental roles in metabolism throughout the history of life. Their apparent persistence over deep time raises important questions about the geochemical and biological processes that facilitate molecular preservation during fossilisation. One hypothesis developed, over the last two decades, proposes that, in the case of hemoglobin, the breakdown of cells and tissues following death releases heme-bound iron, which can catalyse oxidation reactions and promote iron-mediated free-radical cross-linking of proteins, lipids, and other biomolecules. Simultaneously, heme-derived iron may become associated with iron minerals such as goethite. Together, these processes could generate chemically resistant organic structures that are less susceptible to degradation and therefore more likely to persist over geological timescales. Despite its influence on current models of soft-tissue preservation, this hypothesis has not been rigorously tested through modern experimental studies.
This project will employ experimental taphonomy to investigate the key processes involved in the fossilisation of hemoglobin, including decay, mineralisation, and early diagenetic maturation. Controlled laboratory experiments will simulate decomposition under a range of environmental conditions, including oxic and anoxic settings, as well as biotic and abiotic systems. These experiments will be used to characterise the geochemical transformations undergone by hemoglobin during decay and to determine how these transformations influence the preservation of soft tissues and biomolecules. The results will provide critical insights into the mechanisms responsible for biomolecular preservation and help evaluate the role of hemoglobin-derived iron in promoting the long-term survival of organic materials in the fossil record.<\/p>\n\n\n\n
Aim\u00a0<\/p>\n\n\n\n
This project aims to investigate the geochemical transformations of hemoglobin during decay and the interactions between biological and geochemical processes during the early stages of fossilisation. A multidisciplinary analytical approach will be used to track hemoglobin degradation products, mineral precipitation, and organic matter stabilisation, with particular emphasis on the role of microbial communities in mediating iron cycling and redox conditions during decomposition.<\/p>\n\n\n\n
Objectives <\/p>\n\n\n\n
Significance <\/p>\n\n\n\n
This research is particularly significant because it will directly improve the reliability of biomarker-based reconstructions of past environments and biological systems in the geological record. Biomarkers are widely used to infer past environmental conditions, biological inputs, and metabolic processes preserved in the geological record; however, their interpretation is often complicated by diagenetic alteration and poorly constrained preservation pathways. By systematically investigating the chemical and structural transformations of hemoglobin and its degradation products under controlled experimental conditions, this study will provide a mechanistic framework for understanding biomolecular preservation and distinguishing original biological signals from compounds modified during diagenesis. Such insights will strengthen the interpretation of biomarker records and improve confidence in reconstructions of ancient ecosystems and biogeochemical processes.
In particular, elucidating how iron-rich biomolecules interact with minerals, undergo redox-driven transformations, and become stabilised or degraded will enable more accurate identification of endogenous biomarkers and reduce the risk of misinterpretation. Furthermore, linking these transformations to specific environmental conditions and microbial processes will strengthen the application of biomolecular proxies as reliable indicators of past redox conditions, depositional environments, and biological activity. Ultimately, this research will enhance confidence in organic geochemical tools used across palaeontology and geochemistry, and Earth history studies, enabling more robust reconstructions of ancient ecosystems, environmental change, and biogeochemical cycles.<\/p>\n\n\n\n
Ideal Candidate <\/p>\n\n\n\n
We are seeking a motivated PhD candidate with strong analytical and problem-solving skills. Applicants should have a background in chemistry, biochemistry, geochemistry, or a related discipline. Experience with geochemical, biomolecular, or mineralogical analytical techniques (e.g., SEM, XRD, Raman spectroscopy) is highly desirable. Familiarity with organic geochemistry, or metal\u2013organic interactions, would be advantageous, and experience in microbiology is beneficial. The candidate must demonstrate excellent communication, organisation, and independent research skills. Additionally, the applicants should meet the eligibility criteria for entry into a PhD program at Curtin University.\u00a0<\/p>\n\n\n\n
This project is open to International and Domestic applicants. <\/p>\n\n\n\n
Internship <\/p>\n\n\n\n
Through this project you will also have an overseas internship opportunity with the Japan Agency for Marine-Earth Science and Technology- JAMSTEC.<\/p>\n\n\n\n
Scholarship <\/p>\n\n\n\n
If you are identified as the preferred candidate for this project, you may be considered for an RTP scholarship<\/a>. <\/p>\n\n\n\n Enquires and How to Apply <\/p>\n\n\n\n For enquires about this opportunity contact Professor Kliti Grice at\u00a0K.Grice@curtin.edu.au<\/a><\/p>\n\n\n\n