Internationally-renowned archaeologist Professor Zenobia Jacobs, who pioneered the technique of dating history through a grain of sand, reflects on her childhood in South Africa and her serendipitous road to research
P rofessor Zenobia Jacobs is the first to admit that her life has been a series of fortunate events.
From her idyllic early childhood in the Kruger National Park in South Africa, all the way through to her work now in the University of Wollongong’s Faculty of Science, Medicine and Health, it seemed she was at the right place, at the right time.
Over the past two decades, Professor Jacobs has helped pioneer technical developments in the dating of single grains of sand buried at geological and archaeological sites. She has sought to expand our understanding of the evolutionary history of Homo sapiens and their interactions with other hominin groups around the world, and the environments in which they lived.
She is now an ARC Future Fellow and professor in the Centre for Archaeological Science and the School of Earth, Atmospheric and Life Sciences, as well as a chief investigator in the ARC Centre of Excellence for Australian Biodiversity and Heritage.
You would be forgiven for thinking that Professor Jacobs, who works at the forefront of scientific discoveries, has always had her eye on a microscope or nose in scientific journals, but it wasn’t until she was in her 20s that she made her first forays into the world of physics and laser beams.
“I grew up in the middle of nowhere, in Kruger National Park [in South Africa]. It was a very conservative and isolated childhood, but really the best you could ever hope for,” she says.
“It’s a place where animals are your friends, a beautiful place to grow up. In Year 11, I decided to go on a Rotary Youth Exchange and came to Australia. I did Year 12 in Perth when I was 17 and it was the place where the world opened up for me. It showed me opportunities beyond South Africa and taught me some important life lessons. One particular life lesson was that there are no problems, only challenges.”
Surprisingly, Professor Jacobs says science was not a subject she did much of at school; she actually dropped the subject at the end of Year 9.
“I was always much more about the humanities side of things in school. Our school was under-resourced and although I had amazing teachers, they lost me somewhere along the line in science and math,” she says.
After finishing school, Professor Jacobs enrolled at university to study political science and it was here that she says the amazing confluence of events started that led to her being recognised as one of the world leaders in archaeological dating.
“I was standing in line at university to register and needed another subject and archaeology stood out – it started with an A and appeared on the first page of the little booklet I was consulting. I thought it looked interesting although I didn’t know what it was all about.
“I grew up in South Africa during the Apartheid era so I was never really exposed to the concept of human evolution, but once I was at university, I started thinking differently and fell in love with archaeology.”
Although she persevered with her political science degree, she also became increasingly curious about humans, who we were and where we came from, and included archaeology and geography in her study load.
I grew up in South Africa during the Apartheid era so I was never really exposed to the concept of human evolutionProfessor Zenobia Jacobs
When it came time to do an Honours year Professor Jacobs says she began thinking about what would best equip her to get a job. And when she discovered archaeology also included working with numbers and recognising patterns, her decision was made.
“I knew if I continued with geography I could get a job in geographical information systems. It was a safe course to follow but my passion was in archaeology,” she says.
“I actually loved maths throughout school, but I was terrible at it even though I was good at pattern recognition. I thought I could do something in archaeology that would also satisfy my love of numbers.”
At that time in South Africa, one of the key archaeological questions was the age of the African Middle Stone Age (MSA).
“There were major discoveries, such as engraved ochres and ostrich eggshells, shell beads strung together as a necklace and composite tools that led to breakthroughs in our understanding of modern human behaviour,” Professor Jacobs says.
These discoveries started to indicate that Homo sapiens developed more complex behaviours, the use of symbols, and probably language, much earlier than previously thought.
“The question was ‘how much earlier and when?’” she says. “We knew that these artefacts were older than the 50,000-year-old limit of radiocarbon dating and at the time there was no reliable way to determine the age of the African Middle Stone Age.”
Professor Jacobs decided that for her Honours year she would research alternative dating methods that could possibly provide a solution to this problem.
She contacted Professor John Vogel, an authority in radiocarbon dating at the Council for Science and Industrial Research, in Pretoria, and asked if she could work with him during her university break to get a better understanding of what radiocarbon dating and some other techniques, including luminescence and uranium-series dating, also used in his laboratory may involve.
She arrived in Pretoria, a city in South Africa. Coincidentally, it was at the same time as another world-renowned researcher who was at the forefront of developing luminescence dating and was interested in nurturing a South African student in the development and application of luminescence dating with an interest in the MSA of South Africa.
“Professor Ann Wintle is the mother of luminescence dating and had made major breakthroughs in the physics of dating. I was terrified of her,” Professor Jacobs recalls.
Professor Jacobs need not have worried. It was Professor Wintle, a British geophysicist, who approached her and offered Professor Jacobs the opportunity to complete a PhD at the University of Wales, Aberystwyth.
“She came to me and said she had been observing me in the lab and liked my work ethic and asked if I would like to do a PhD under her supervision,” Professor Jacobs says. “I’d never thought of doing a PhD – no-one in my family had ever done one.”
Before she could start her PhD, Professor Jacobs had to find a way to fund her studies at the University of Wales, where Professor Wintle was in residence.
“I had to get there on a scholarship and I accumulated the best selection of rejection letters,” she says. “But I managed to eventually secure funds to pay my living expenses and university fees.”
Although she didn’t have a science background, and hadn’t studied physics or chemistry at school or university, Professor Jacobs says her career really started taking shape in Wales.
“I really wanted to know about the archaeology of South Africa and although Professor Wintle and I came from different backgrounds, we learned from each other. She took me through the steps of the science behind luminescence dating. I was meticulous and hard-working and never gave up and realised I had innate ability to do science,” she says.
“I think for someone like me it was easier to learn the physics because I knew what I wanted to do. Learning the science behind something you want to use makes the process of learning it a little bit easier. You can do anything if you want to do it and shouldn’t be restricted by what you have learned at school.”
At the time of her PhD, luminescence dating was going through a revolution. (Luminescence dating uses the amount of light emitted from certain rocks and soil to determine the age of the material or the time of a specific event). Lasers had come into play and the University of Wollongong’s Professor Richard Roberts was “tinkering” with the idea of dating individual grains of sands.
“Professor Roberts wrote some of the first papers on using individual grains of sand in luminescence dating. He didn’t have the best equipment. He was essentially using a kitchen lamp to stimulate the grains, whereas we would use much more powerful laser beams, but the concept was there,” Professor Jacobs says.
Her other PhD supervisor, Professor Geoff Duller, was closely involved in the development of the measurements system and created the software that would be used in single grain luminescence dating. Again, serendipity played a part in the next phase of Professor Jacobs’ career.
“I was the lucky student to use the prototype equipment and software and apply it something I was passionate about,” she says. “A lot of my career has not been by design but a series of fortunate circumstances.”
In 2005, Professor Jacobs contacted Professor Roberts and asked him if she could relocate to Wollongong and continue her research.
“I told him I had some money to support some of my salary and could bring some equipment over with me. He called me back in 24 hours and I was on my way to University of Wollongong. UOW gave me a break at a critical juncture in my nascent career.”
By 2009, Professor Jacobs had secured more funding through another scientific grant and soon after was awarded her first ARC fellowship. Since then she has won a number of research awards including an Australian l’Oreal For Women in Science fellowship, the Sir Nicholas Shackleton Medal from the International Union for Quaternary Research, Scopus Young Researcher Award, and has been listed as a Thomsen Reuters (now Clarivate Analytics) Highly Cited Researcher in five consecutive years from 2014.
She is now one of the world leaders in luminescence dating and, in collaboration with Professor Roberts and Associate Professor Li Bo and a vibrant group of students and postdocs, is unlocking the secrets of the timing our evolution and migration around the world.
“From a little girl growing up in Kruger National Park who didn’t know what archaeology was to what I am doing now, I often wonder how it all came about,” Professor Jacobs says.
“Kruger National Park and my home town of Phalaborwa hosts amazing archaeological remains. I remember learning about it at school and seeing remnants of copper melting ovens, hut structures and pots in the rocky outcrops that dotted the landscape. I was fascinated by it, but ignorant of its meaning.
“I wonder whether subconsciously these remnants of the people who left it behind to see and learn from, made an everlasting impression on me and unknowingly set me on a path of discovery into the human past.”