Reading the hidden clock in a grain of sand

Zenobia Jacobs, University of Wollongong. Credit:
Zenobia Jacobs, University of Wollongong. Credit:

Dr Zenobia Jacobs wants to know where we came from, and how we got here. When did our distant ancestors leave Africa and spread across the world? Why? And when was Australia first settled?

Zenobia has developed a way of accurately dating when individual grains of sand were buried with human artefacts. And that technique (optically stimulated luminescence or OSL) is transforming our understanding of human evolution.

Working in South Africa she found a community that had been living relatively sophisticated lives—harvesting shellfish and using ochre pigments for decoration—more than 160,000 years ago, about 120,000 years earlier than previously thought. And recently she and her colleagues identified the earliest evidence of engineering—some 72,000 years ago.

Now her work has brought her to the University of Wollongong to work with Prof. Bert Roberts, one of the team who discovered the Flores ‘hobbit’.

She plans to track the movement of the Aboriginal people into and throughout Australia.

“It’s of incredible relevance to the whole ‘Out of Africa’ theory. When did our ancestors leave Africa? Why? Which routes did they chose and how quickly did they disperse?”

In 2009 Zenobia received one of three L’Oréal Australia For Women in Science Fellowships.

Further information: Zenobia Jacobs,,