Reacción a "Hominids used fire more than 700,000 years earlier than previously estimated, according to a study involving Spanish researchers"

Is the study based on sound data and methods?

“The study presents an innovative complementary methodological approach and provides interesting evidence of opportunistic fire use. Methodologically, it helps to complement the identification of burnt faunal remains that has been carried out using FTIR [Fourier transform infrared spectroscopy]. This is a complementary technique which, moreover, is non-destructive, making it very interesting.

Evidence of fire older than that previously found at Wonderwerk provides a starting point for identifying this early stage of fire in an opportunistic manner, a stage characterised by being archaeologically very subtle.

Until now, some of the oldest published evidence of fire had in common the fact that it came from open-air sites, in environments where recurrent natural fires would occur naturally. This made it difficult to identify the anthropogenic origin of the fire. In other words, elements produced by combustion could be identified, but they could not be clearly linked to an event of fire use by hominins. In studies of the pyroarchaeological record (the record of fire at archaeological sites), controversy and debate over what this actually signifies are ever-present, and I do not believe these results are an exception.

Wanderwerk Cave and these results are somewhat different, as they concern the interior of a cave within an archaeological sequence that is stratigraphically consistent with the evidence documented 80 metres further in. However, we will have to wait and see if there are further results that can also identify this use of fire from a more direct approach, using ash and thermally altered sediments as was done for stratum 10 and published in PNAS in 2021 by Berna”.

How does this fit in with previous work? What new insights does it provide?

“Wonderwerk Cave and its Stratum 10 was already one of the sites with the oldest evidence of anthropogenic fire in Africa, dating back a million years, with the clearest documented evidence in the form of ash and thermally altered sediments. It was clear evidence in terms of both archaeological context and evidence of fire. The fact that it is a cave provides much greater certainty than the evidence identified at open-air sites.”

Are there any significant limitations to bear in mind?

“Opportunistic fire use implies a very sporadic occurrence over time and is short-lived. In the archaeological record, it is always a major challenge to identify evidence of this behaviour. This type of evidence, especially when it is indirect, always generates controversy within the research community. But I believe the publication of this evidence is important, because it prompts the research community to work on this hypothesis of fire use in chronologies much older than previously thought. This is the part I find most interesting; the hypothesis that hominins from 1.8 million years ago used fire will lead researchers of these time periods to focus on this specific issue regarding the use of fire, generating lines of research and methodological improvements that may (or may not) establish new paradigms on the use of fire in human evolution.

For those of us dedicated to the study of fire, this mobilisation of research, resources and methodologies is what pleases us most, as it brings the spotlight back onto fire—a highly significant technology that has often been relegated to the background in favour of stone tool industries or human remains. Tool-making has been shown not to be exclusive to our species. Could it be the use of fire that makes us human?”

What is the practical relevance of this study in Spain?

“Everything seems to indicate that the evolution of fire use took place across various different spaces and times. Understanding the dynamics of fire use and its evolution in Africa is important for seeing how this mechanism—which is technological but has significant social implications—might have developed through different dynamics in other parts of the world.

In Western Europe, there are also various debates surrounding the use and production of fire, and methodological improvements could be of great use to us in our archaeological contexts.

The Iberian Peninsula is a context where intensive work is being carried out on issues linked to the use of fire throughout prehistory, and this is evident because there are a large number of sites with well-identified and characterised evidence.”