Study sheds new light on human fire history

Ground fire at Norris Geyser basin

Ground fire at Norris Geyser basin in Yellowstone National Park

Human populations in North America might have used fire as a tool thousands of years earlier than previously thought, according to new research.

The study from the University of Portsmouth has cast new light on the fire history of the California Channel Islands, a chain of eight islands located in the Pacific Ocean off the coast of Southern California.

The study found a significant period of charcoal deposition, which occurred between 12,500 to 14,000 years ago, possibly coinciding with the arrival of the first humans on the island.

Dr Mark Hardiman, senior lecturer in Geography and lead author of the study, said: “This study allows us to paint a much better picture of what these early occupied landscapes would have looked like.

Dr Mark Hardiman

Dr Mark Hardiman

“The sedimentary record that exists in the canyon is truly spectacular and records ‘snapshots’ of the landscape changes which were occurring on the islands at the end of the last ice age.

“The rich concentrations of charcoal fragments found in the often complex sedimentary sections are evidence of past burning. Until now, there was very little understanding about when this burning had occurred and how it fitted in with human arrival on the island.”

Dr Hardiman worked with colleagues from Royal Holloway, University of London, the University of California, Northern Arizona University and Oxford University on the paper, which is published today in the Philosophical Transactions of the Royal Society B.

The researchers studied the Arlington Canyon on Santa Rosa Island, which is famous for the discovery of the ‘Arlington Springs Man’ – some of the earliest human remains found in the Americas.

Dr Hardiman said: “It is well observed that native people used fire as a tool in more recent times but its use by these much earlier vanguard populations – who arrived in North America towards the end of the last ice age – remains somewhat elusive.

Charcoal rich sediments deposited at the end of the last ice age

Charcoal rich sediments deposited at the end of the last ice age

“We cannot say for sure if this shift relates to the arrival of people or rapid climate changes which are known to occur during this period – there is no ‘smoking gun’ so to speak – but this does raise new questions which can now be investigated in more detail.”

Dr Hardiman wants to conduct further research into whether a direct correlation between this large increase in evidence for fire and human arrival on the islands can be proved.

Co-author Professor Andrew Scott from Royal Holloway, University of London, added: “If we can verify a direct link, we can then try and find out who these early people were and calculate when exactly they arrived on the islands. We might find a fascinating gateway to the past, which goes back even further than the current human story for the islands.”

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