Dr Herries’ specialty is human evolution and the migrations of early modern humans and their ancestors (hominins). Homo sapiens arriving in Australia is one of the end-points of that early migration arc. Dr Herries is also known for his work on early human species in South African cave sites – potentially the ancestors of all of us.
He’s skilled at understanding the age of a site and its artefacts, and putting them on a temporal scale. He then assesses larger questions of migration to work out how something evolved from one stage to another.
‘What excites me is understanding how early humans lived – understanding the hidden story of how we managed to survive as a species, while all other human species have perished,' he says. ‘Rather than simply cataloguing how many archaeological artefacts we discover.'
Dr Herries reckons you need to know a little about a lot when running an archaeological site: genetics, zoology, botany – and your particular specialty. He brings to the field a profound understanding of geology.
‘If you’re going to pull something out of the ground,’ he explains, ‘then you have to know everything about where it came from. If you don't know that, then leave it in.’
From rocks and hammers to electric cages
Dr Herries is collaborating on several research projects with commercial archaeological surveyors, Aboriginal Victoria and traditional land owners.
Along the way, he’s spent time nurturing relationships with traditional owners.
Aboriginal groups usually want to know a lot more. They want to know what their ancestors were doing. What were those stone blades used for?
'While commercial companies often only have a chance to catalogue artefacts because of time constraints, Aboriginal groups usually want to know a lot more. They want to know what their ancestors were doing. What were those stone blades used for? We look at contexts and narratives, which are incredibly hard to decipher.'
One project is in northern Victoria, where a series of fire pits were discovered along a riverbank. Typically for Australian archaeology, the site was discovered when a sand quarry wanted to expand its diggings. After an initial archaeological survey, Dr Herries was called in when they discovered potentially significant remains.
The site was just what he had been looking for, perfect for helping him understand the pyro-technology of early Australia, and solving long-standing riddles about the changing environment.
‘Was it humans using fire that caused the extinction of megafauna? Climate change? Understanding fire technology will help us understand how early Australians impacted and changed the environment.’
Dr Herries is also looking at how people heated stones, altering the chemistry to make stone tools.
‘With chemical analysis of fireplace soils and the clay balls used for heat retention, we’re trying to discover what was cooked there.’
The modern high-tech lab is such a strong contrast to the dusty fields and caves of Dr Herries’ site work, where excavation is done with simple brushes, spatulas, barrows and sieves. Australian archaeology laboratories are among the world’s most advanced, and the best techniques for dating human remains are Australian.
As a kid, Dr Herries, anticipated his future self: he looked for fossils by breaking up rocks with a hammer.
'Now, I work within a giant electrified cage in my lab so the Earth’s magnetic field is not present to remagnetise samples when we reheat them. That’s not exactly what I imagined when I studied to be an archaeologist.'
Reconstructing the void
Every archaeologist wants to find a snapshot of that one person on a landscape 30,000 or 3 million years ago, and work out what they were doing in that moment. Boxgrove, a famous English site, has a preserved knee-print in mud and shards of flint from a tool made 500,000 years ago. If you recompile all the stone shards, there's a void in a block of rock that perfectly represents the tool that was made and carried away.
It's so rare to find those snapshots in time of what a person was doing, rather than what generations of people did over very long periods of time.
'It's so rare to find those snapshots in time of what a person was doing, rather than what generations of people did over very long periods of time,' Dr Herries says.
In this way, Australian archaeology is very different to Greek and Roman digs, which unearth giant structures and townscapes with many centuries or generations of continuous habitation.
'In Australia, we're studying sites for evidence of much more ephemeral human impact.'
Australia's archaeological record displays so much more of the transitory nature of people moving through an environment and leaving very personal imprints. There’s also the earliest evidence of cremation, of people buried symbolically. There is no other record of these funerary practices from the period anywhere else in the world.
Dr Herries tries to visualise landscapes from thousands and millions of years ago. He looks at factors like erosion, sea levels, climate change and the concurrent evolution of a myriad of other species of animals and plants. He uses techniques like ground-penetrating radar, 3D imaging and soil analysis – powerful tools for reconstructing lost worlds.
In South Africa, he also has a field school that has been running for four years. It includes La Trobe students alongside students from other Australian and International universities. Participants do a three-week stint. They're taught how to excavate these unique sites and conserve the fossil bone. They're taken to see all the original hominin fossil skulls in vaults – an introduction to human evolution.
‘Recently,’ Dr Herries says, ‘we found 10 new hominin specimens including a couple of partial skulls, which are very rare. Some were found by our undergraduate students.'
And so with this globe-spanning work, Dr Herries is taking La Trobe research into the future by exploring the very distant past. In the process, he’s deepening our insight into how we all arrived at this point in time.