One of the items in my backlog of “want to blog about” topics is a recent paper by Francesco Berna and colleagues on evidence for fire dating to one million years ago from the South African cave site of Wonderwerk. The authors make a compelling case for the intentional and controlled use of fire at the site on the basis of microstratigraphic analyses – the examination of individual organic and soil particles prepared in thin section. Other authors have argued for the presence of fire from earlier time periods in the Turkana Basin region of Northern Kenya and from the South African cave site of Swartkrans. These earlier claims for the controlled use of fire are more equivocal than the current paper in the amount of evidence brought to the table and their interpretation. As such, while it is quite possible early humans used fire prior to Wonderwerk, this appears to be the most unambiguous sign of fire usage.
This paper follows up on a paper earlier this year by Dennis Sandgathe and colleagues documenting the lack of clear evidence for sustained use of fire by European Neandertal populations during the late Pleistocene. The authors of this paper draw on excavations at two French cave sites, Roc de Marsal and Pech de l’Aze, that have long and fairly continuous deposition sequences (I commented previously on this article here). It is tempting to think the two papers are in disagreement with one another, but I don’t think that is necessarily the case. Instead I think what the two papers reveal is the nature of technological innovation throughout human evolution – patchy, ephemeral and repetitive.
Fire provides a vast number of evolutionary benefits by transforming elements of nature into usable energy (heat and light) for purposes of cooking, protection, warmth, etc. In theory, mastery of fire is sort of like being able to bring your own personal aircraft carrier group to an evolutionary knife fight. The selective advantages of controlling fire are huge, and yet the initial traces of fire in the archaeological record appear ephemeral and displaced across time and space. Why wouldn’t the cultural knowledge of fire persist? If Pleistocene humans a million years ago are using fire, why shouldn’t Neandertals 100,000 years ago have similar capabilities?
One way of resolving the two papers is to view technological innovation throughout human evolution as an ephemeral process, with repeated development and loss of the same or similar technologies. Despite the evolutionary advantages posed by the control of fire, the demographic constraints on human groups throughout the Pleistocene (small populations with very low inherent potential growth until very recently) coupled with highly variable climatic and environmentally distributed resources (for example, how available were fire fuel resources during glacial periods of late Pleistocene Europe?) could have set up a situation whereby local population extinction or environmental discontinuity led to the frequent loss of advantageous innovations. You can add even more complexity to this view by thinking of human learning systems and cognitive acquisition structures as also being inefficient innovation archivers. A useful analogy for thinking about this relationship between technological innovation and loss is genetic drift and the loss of novel, selectively advantageous alleles, a well-developed theoretical model in population genetics.
1. Berna, F., P. Goldberg, et al. (2012). “Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa.” Proceedings of the National Academy of Sciences. doi:10.1073/pnas.1117620109
2. Sandgathe, D. M., H. L. Dibble, et al. (2011). “On the Role of Fire in Neandertal Adaptations in Western Europe: Evidence from Pech de l’Azé and Roc de Marsal, France.” Paleoanthropology 2011: 216-242. doi:10.4207/PA.2011.ART54