Southern Cross Uni geochemist’s ARC funding to unlock secrets of earliest human evolution

Associate Professor Renaud Joannes-Boyau

Southern Cross University Associate Professor Renaud Joannes-Boyau will track back in time using pre-historic teeth to observe how our earliest human ancestors co-existed alongside two other ‘pre-human species’.

One of the tools to do this, newly set-up at the University’s Lismore campus, is a specialised laser sampling technique that vaporises microscopic portions on the surface of the tooth.

Associate Professor Renaud Joannes-Boyau’s ground-breaking research is one of four Southern Cross University-led projects successful in the latest announcements of Australian Research Council (ARC) funding – with more than $1.94 million awarded to the University, described as a ‘stunning result for Southern Cross and for all the researchers involved’ by Deputy Vice Chancellor (Research) Professor Mary Spongberg.

His Discovery Project ‘Decoding the geochemical record of early human fossils’ (DP220100195) was awarded $368,118 and aims to use cutting-edge geochemical imaging of fossil teeth from South Africa, to reconstruct the behaviour of our earliest human ancestors.

“These teeth date as far back as two million years, and can be used as a roadmap to the behaviour of early hominin species, such as diet, breastfeeding habits, migration and seasonal behaviour, and ageing,” said Professor Joannes-Boyau from Southern Cross University’s Faculty of Science and Engineering.

“Five years ago, I started working with an international team excavating the site. In 2019 we finally published the age of the site and hominin fossils in Science. We had found three different and contemporary species in the same site, a rare find. This year I’ll travel to South Africa to bring back fossil teeth from about 10 to 15 distinct individuals, including from the oldest Homo species found in South Africa.”

Professor Joannes-Boyau said the project will leverage Southern Cross University’s new $2 million, cutting-edge tandem trace element and isotopes equipment established at the University’s Lismore campus in 2020 and 2021, funded by an ARC Linkage Infrastructure, Equipment and Facilities (LIEF) grant secured in 2020 (LE200100022).

The state-of-the-art equipment uses a specialised laser sampling technique to vaporise microscopic portions on the surface of the tooth. The gas containing the sample is then analysed for chemical signatures with a mass spectrometer – enabling researchers to develop geochemical imaging at a microscopic scale relating to diet and health of prehistoric individuals.

He explained how teeth grow similarly to trees, developing sequentially.

“Teeth form by adding layer after layer of dental tissues every day and are particularly valuable for reconstructing the biological events occurring during the early period of an individual’s life. They preserve precise temporal changes and chemical records of key elements incorporated in the food we eat,” he said.

“The aim of this project is to reconstruct the infanthood records of our earliest human ancestors, to shine a light on adaptive strategies that allowed our genus to outcompete other hominin species during a time of climate variability. We don’t know much about the behaviour of these species, such as whether they were co-habiting or whether they were competing for the same resources, so this project could completely transform our understanding of early human evolution in South Africa.

“I’ll be working alongside my colleague Associate Professor Gary Schwartz from our partner institution Arizona State University, and other colleagues associated with the excavation in South Africa, and will be looking to secure a post-doctoral researcher and PhD student to assist with the anatomy and geochemistry components.”

In a rare feat, Associate Professor Joannes-Boyau has also achieved success on a Griffith University-led Discovery Project in the same ARC funding round. The project ‘Early art culture and occupation along the northern route to Australia’ (DP220100462), led by Griffith University’s Professor Maxime Aubert – an Adjunct Professor at Southern Cross University – will also leverage the use of the trace element and isotopes facility equipment at Southern Cross University’s Lismore campus.

This project aims to uncover archaeological evidence for early humans in Indonesia’s northern island chain, from Borneo to West Papua, which houses the world’s earliest known figurative cave art, thought to be more than 45,000 years old. This region is the most likely maritime route used by modern humans during the initial movement of people to Australia around 65,000 years ago.

“Using geochemistry, we will be dating samples of the rock art and the fauna and human remains from the beautiful remote areas of Borneo in Indonesia back here in the lab at Lismore campus,” Associate Professor Joannes-Boyau said.

“We expect to gain new insights not only into the world’s first artists, but also the ancient past of Indonesia, as well as the art and cultural lifeways of the ancestors of the First Australians.

“I’m very pleased to be working on both of these ARC-funded projects. Our new tandem trace element and isotopes equipment at Southern Cross was crucial in securing both grants and this shows the national and global importance of the cutting-edge work we are doing here in this lab, alongside our high-impact research publications. This is great for Southern Cross University and our international research reputation.”

Overview of Southern Cross University’s other successful ARC grants in this round:

  • Strengthening relationships for young people in residential care, Associate Professor Lynne McPherson, Round 1 Linkage grant, awarded $429,569 (LP210100177)

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