In 2018, archaeologist and Oxford professor Tom Higham received a Distinguished Alumni Award from the University of Waikato in recognition of his outstanding achievements in archaeology. We caught up with Tom, who is a world leader in radiocarbon dating and archaeological science, and hear why he attributes much of what he does now to his time at Waikato.
Not many people can say they were making historically significant discoveries during their early university studies – but Tom Higham can.
The archaeologist, now a professor at Oxford University in the UK, honed his speciality in radiocarbon dating as a PhD student with the University of Waikato’s Radiocarbon Dating Laboratory. From there, Tom went on to make some key discoveries in archaeology, including the movement of Neanderthals in Europe and discovering the DNA of a new species of modern human in an ancient cave in Russia – but more on that later.
What is radiocarbon dating, anyway?
Tom describes radiocarbon dating as the best method we have for dating the human past; covering the period from today back more than 50,000 years.
“We use radiocarbon as a tracer to work out how the earth system works. For example, the nuclear era saw many thermonuclear bombs tested in the atmosphere. What most people don’t realise is that a small amount of radiocarbon is produced in this process. This so-called ‘hot’ radiocarbon, artificially created, entered the Earth’s life ways and has allowed us to track it to see where carbon disperses in the oceans and land, how it mixes, and through this helped us to understand a great deal more about life on earth, climate change, and how the world works.”
An early start in archaeology and key discoveries at Waikato
Tom was exposed to archaeology early in life, helping his archaeologist father at sites as a teenager, including excavating the early Neolithic site of Khok Phanom Di in Thailand.
It was Tom’s father, who happened to notice a situations vacant in the local paper, who put Tom on to postgraduate study at Waikato. The University was looking for a doctoral student in the radiocarbon lab, with a half-time chemistry technician job attached.
“I had around six months left to finish my MA dissertation at Otago University. The timing was good, so I applied and got it.”
At Waikato, Tom worked to understand the chronology of Polynesian settlement in New Zealand, which included dating one of our oldest archaeological sites and earliest known human settlements – Wairau Bar in Marlborough. He used high precision radiocarbon dating to date moa eggshell carbonate, working out the first people arrived in the late 13th Century AD. This project became his first scientific publication, in Antiquity Journal.
Tom says he loved his time at Waikato – the climate, the ease of getting around, and the people.
“I loved the can-do attitude of the people I worked with and the other researchers in the School of Science. I enjoyed being surrounded by bright people doing interesting work. Many of the collaborations I formed then I still value today,” he says.
“I worked very closely with Professor Alan Hogg who was my PhD supervisor, alongside Emeritus Professor Ken Mackay. I learned the basics of radiocarbon dating from Alan and his technician Helen McKinnon - Alan does a brilliant job running the Waikato Radiocarbon Lab, which is a world-class facility and a leader in the calibration of the radiocarbon timescale.”
Fieldwork around the world
A familiar image of an archaeologist is that of a khaki-clad scientist digging around in the dirt of ancient ruins. Tom’s career would tell you that’s pretty accurate.
He’s helicoptered into remote New Zealand forests in search of trees to help explain past climate changes, taught high school and university students at different land sites, and worked with local tangata whenua on archaeological site assessments and excavations.
Since moving to Oxford in 2001, his research in Europe has attracted international attention. His work on Neanderthals and their disappearance is a highlight for him, and in 2014 he summarised a decade of work on this in science journal Nature, explaining that Neanderthals and modern humans overlapped for about 5000 years before Neanderthals disappeared – and is an area he is still exploring with his team of researchers at Oxford.
More recently, Tom has been working at the Denisova Cave in Siberia, the first place a new species of humans was found – Denisovans. The project, funded by the European Research Council, has had far-reaching consequences, increasing our understanding of how modern humans spread out from Africa into Eurasia where they replaced Neanderthals. “We know this group dates from about 200,000 years ago at Denisova, and now we are working to figure out more about their ancient distribution. We know that Denisovans and modern humans interbred and some living people contain a proportion of their DNA from them – these are people living in Melanesia, East Asia, and smaller amounts in Native Americans, South Asians, and Finns.”
Receiving a Distinguished Alumni Award
Tom says it was a real career highlight to receive his Distinguished Alumni Award in 2018. “It was tremendous to be honoured by my alma mater and I was extremely happy and excited by the honour. I had a brilliant trip back to Hamilton to receive the award, give a talk and meet old friends and new. It was an unforgettable experience.”