Unlocking the secrets of earliest human evolution

Primary Researcher: Associate Professor Renaud Joannes-Boyau 

Institution: Southern Cross University  

An ARC-supported project is using geochemical analysis on fossilised teeth of early humans from South Africa to highlight the adaptive strategies that allowed our human ancestors to outcompete other species in a time of climate variability.  

Lead investigator of this ARC Discovery Project, Associate Professor Renaud Joannes-Boyau from Southern Cross University’s Faculty of Science and Engineering, said that these teeth date as far back as 2 million years, and can be used as a roadmap to the behaviour of early human species, such as diet, breastfeeding habits, migration and seasonal behaviour, and ageing.  

‘Teeth’s continuous layering process from birth to early adulthood makes them invaluable for reconstructing early life events and preserving precise records of temporal changes and elemental composition from food, water, and environment,’ Associate Professor Joannes-Boyau said.  

Little is known about the behaviour of these species, such as whether they were co-habiting or whether they were competing for the same resources. The results from observing the distribution of trace-elements and isotopes archived in fossil teeth will provide key insights into our origins, our unique adaptation, and our unmatched evolutionary success.  

Associate Professor Joannes-Boyau said, ‘This project has the potential to completely transform our understanding of early human evolution in South Africa. By unravelling how our genus, outshined and outlasted other hominin species that coexisted in the region for hundreds of thousands to millions of years prior to our arrival.’  

Associate Professor Joannes-Boyau flew to South Africa in early 2022 to personally escort the invaluable human remains to the unique Southern Cross University Geoarchaeology and Archaeometry Research Group facility. The samples, usually kept behind the 500kg reinforced door of the Phillip V Tobias Fossil Hominid vault at the University of Witwatersrand, were on loan for this unique project.  

Associate Professor Joannes-Boyau is working alongside Associate Professor Gary Schwartz from partner organisation Arizona State University, and other colleagues associated with the excavation in South Africa.  

Image: Supplied by Associate Professor Joannes-Boyau