September 2015
Vol. III, No. 9
Fire: a Burning Issue in Human Evolution
By: Ron Shimelmitz
Fire is reflected in almost every aspect of our mundane existence; its use and control constitutes an essential part of material life. From cooking our meals to the various materials we use, the products of pyrotechnology, fire is also an intimate component in human social life. Phrases such as “hearth and home” and “fireside chat” resonate deeply with us.
Yet we are also alone in the animal world in manipulating and controlling fire. Somewhere in our deep past the ability to use fire altered the course of human evolution in crucial ways. Nevertheless, while the oldest documented instance of fire use by hominins (modern humans and our extinct immediate ancestors) dates to at least a million years ago. The most important impacts on human anatomy and behavior occurred only when the use of fire became a permanent feature of hominin life. When this transformation occurred remains a controversial issue. But we are closer than ever to understanding this critical change.
In the 1930’s a cluster of four cave sites were excavated by British archaeologist Dorothy Garrod, at the opening of Nahal Me’arot at the western edge of Mount Carmel, Israel. The largest of these caves was named ‘Tabun Cave’ (‘Cave of the Oven’). Ironically, eighty years later, through the renewed research of Tabun Cave, groundbreaking evidence regarding the emergence of the systematic use of fire by ancient hominins was identified in this cave.
A study I published recently in the Journal of Human Evolution (along with co-authors Steven L. Kuhn, Arthur, J. Jelinek, Amy E. Clark, Avraham Ronen, and Mina Weinstein Evron) sheds new light on this burning issue. Our team of researchers, from the Zinman Institute of Archaeology at the University of Haifa and the School of Anthropology at the University of Arizona, has collaborated on analysis of material from excavations at Tabun Cave, Israel. We have shown that the adoption of fire as a regular and habitual part of human life occurred quite abruptly approximately 350,000 years ago. Since then fire use has remained a constant feature embedded in our behavior.
Tabun Cave is one of the most important Paleolithic sites in the East Mediterranean. It is part of the “Sites of Human Evolution at Mount Carmel: The Nahal Me’arot / Wadi el-Mughara Caves” and is listed as a World Heritage site by UNESCO. The cave was first excavated by Dorothy Garrod in the 1930s. In the late 1960s, Professor Arthur Jelinek from the University of Arizona renewed fieldwork at Tabun Cave in what was considered to be one the most scientific and multidisciplinary archaeological project of its time. Excavations at the cave continued until 2003, directed by Professor Avraham Ronen from the Zinnan Institute of Archeology.
By analyzing data from the two latter excavation campaigns our team was able to reconstruct a sequence of 100 superimposed layers, containing evidence for repeated use of the cave by human ancestors throughout the last 500,000 years. Such a long multi-layered sequence is a very rare phenomenon, matched by very few other sites globally. This long sequence is one of the strengths of the new study, since it allows the investigators to draw conclusions about repeated human behavior in one place, rather than isolated cases. In the case of Tabun Cave, the team tracked the use of fire by examining the frequency of burnt flint artifacts.
The flints, ubiquitous and abundant discarded byproducts of tool making, are a particularly good indicator of the frequency of fire use. They were burned accidentally as fires were built within the cave. Unlike many other traces of combustion, such as charcoal and ash, flints do not easily succumb over time to chemical alteration or dissolution. The frequency of burned flints provides a “signal” of fire use that is little affected by changing geological or chemical conditions.
Interestedly, within the lower eight meters of sediments at Tabun cave, documenting its earliest occupations, burnt material was very rare, often absent. Then, beginning rather abruptly in layers dating to approximately 350,000 years ago, evidence for burning becomes more common. More significantly, there is substantial evidence of substantial use of fire in every layer studied dating to after this interval.
Tabun is not an isolated example. If the habitual use of fire represented a beneficial “technological mutation” in the behavior of human ancestors then it should be widely expressed at other sites dating to the same time period. Indeed, evidence from other contemporaneous sites in the region shows a similar jump in the regularity of fire use roughly at the same time. This demonstrates that the transformation was not limited to a single location.
Understanding when the “technological mutation” of habitual fire occurred is not just a matter of curiosity. It will change the way we understand critical developments throughout our evolution. Diverse researchers argue that our big brains and small stomachs, our ability to colonize diverse global environments, and even aspects of family life and sociality were dependent on the domestication of fire. Thus, understanding whether constant and regular use of fire occurred a million years ago, several hundred thousands years ago, or even more recently, has an important bearing of how we understand the milestones of human evolution.
We emphasize in our research that the evidence from Tabun and other nearby caves does not tell us about the first use of fire by our human ancestors. Instead, it shows when fire became a regular and habitual component in the “camp life” of these early hominins. While the mere use of fire may well have contributed to early evolutionary developments in the human line, the integration of fire as a ubiquitous part of life also had decisive effects on populations that roamed the land over the past 350,000 years.
Ron Shimelmitz is a post-doctoral research fellow at the Zinman Institute of Archaeology, University of Haifa.
