A Spanish cave guards the earliest fire of Stone Age Europe

Heat-shattered sherd from sediment with combustion. Image: Michael Walker

Heat-shattered sherd from sediment with combustion. Image: Michael Walker

Firm evidence of fire 800,000 years ago, published in Antiquity June 2016 (1), comes from the southeastern Spanish Palaeolithic site with a late Early Pleistocene fauna which is the Cueva Negra del Estrecho del Río Quípar (“Black Cave of the R. Quípar Gorge”).

Systematic excavation of this large rock-shelter began in 1990 and ongoing excavations are conducted under the auspices of MUPANTQUAT, the Murcian Association for the Study of Palaeoanthropology and the Quaternary and its annual Field School, www.mupantquat.com.

Discovery of deep sediment with combustion. Image: Michael Walker

Discovery of deep sediment with combustion. Image: Michael Walker

Indications of ancient fire were uncovered first in 2011 in a closed sedimentary deposit sealed below a depth of 4.5 metres of overlying archaeological layers (2).

All the layers are shown by magnetostratigraphy as being earlier than the boundary at 780,000 years ago  between the Matuyama and Brunhes magnetochrons (3), and contain remains of both large and small mammals that existed in Spain between one million and 700,000 years ago (4). Pollen analysis and bird remains including water-fowl (5, 6, 7), together with sedimentary analysis (8), indicate mild moist conditions with an erstwhile swampy lake beside the cave, suggesting the interglacial time 860,000-810,000 years ago of marine isotope stage 21. Guided by a precautionary principle concerning assessment of very fragmentary mammalian fossils, publications before 2009 had assigned the sedimentary accumulation to the Middle Pleistocene. Later excavations have increased numbers of fossils and their detailed palaeontological examination shows that the faunal composition is typical of the end of the Early Pleistocene in Spain and the dawn of the Middle Pleistocene.

Charred and calcined bone fragments from sediment with combustion. Image: Michael Walker

Charred and calcined bone fragments from sediment with combustion. Image: Michael Walker

Convincing evidence of combustion at Cueva Negra has been established thanks to generous international collaboration with MUPANTQUAT by scientists in Spain, Germany, USA, Italy and Canada, who have employed contrasting analytical methods that converge in their conclusions (1):

  • Thermoluminescence, TL: chert (flint) had been heated at >400°C.
  • Low and high-power microscopy confirm thermally-altered chert (flint).
  • Fourier Transform infrared spectroscopy, FTIR: bone had been heated at >400-450ºC though below <700-800ºC.
  • Electron spin resonance palaeothermometry, ESR: bone had been heated at >400-450ºC.
  • Scanning scanning electron microscopy, SEM, and energy-dispersive spectroscopy, EDAX: show discolouration of bone owes to thermal alteration (not to staining by iron or manganese oxides).
  • Taphonomical analysis of 2,300 micromammalian bones: statistical analysis of calcined and markedly thermally-discoloured bones vis-à-vis relatively less altered bones found significant proportional differences between layers with and without other signs of combustion.
  • Sedimentological macroscopical and micromorphological comparison of different layers
    Chemical and mineral comparison of different sedimentary layers by thermogravimetrical analysis with mass spectrometry,  granulometry by laser diffraction, X-ray fluorescence, XRF, and X-ray diffraction, XRD, studies; hydroxyapatite (2.5%) in the altered sediment is compatible with degradation of bone.

Whilst the most we can say at present is that we have incontrovertible evidence of a place where there was combustion, a bonfire if you like, and we do not know yet the extent of its area, it is nevertheless a most significant discovery because of  both its great antiquity and the intriguing Palaeolithic finds from the cave which range from an “Acheulian” hand-axe fashioned on an oval limestone cobble to small artifacts on chert (flint), brought from both nearby and distant raw-material sources (10), including flakes removed by repetitive recurrent flaking of small cores (2, 4, 9), comprising an assemblage showing instances of Modes A, B, C, D, E, F, and G, in terms of Shea’s novel approach to stone tools (11, 12).

Excavating sediment with combustion in 2015. Image: Michael Walker

Excavating sediment with combustion in 2015. Image: Michael Walker

That variety implies cognitive versatility, manual dexterity, and technical skilfulness, among which behaviour involving fire is hardly out of place, and which also seem to have characterized other early sites with strong evidence of combustion, such as Wonderwerk Cave in South Africa around one million years ago and Gesher Benoth Ya’akov in Israel around 780,000 years ago, at both of which, coincidentally, hand-axes have been excavated – though this need not imply diffusion to western Europe where fashioning the earliest hand-axes may have arisen independently (13).

It would be imprudent to conjecture that such coincidences reflect the handiwork or behaviour of a single species of ancient Homo, whether H. erectus, H. antecessor, or H. heidelbergensis (putative archaic teeth reported from Cueva Negra are subject to ongoing critical scrutiny). The important matter for Palaeoanthropology to consider is the widespread capacity among late Early Pleistocene humans for behaving in ways that may have helped them to survive in disparate Old World environments.

The part played by fire in early human evolution is an, er, hot potato. At some Early Pleistocene sites traces of combustion could owe to bush fires or even glowing volcanic ash, especially at open sites in dry landscapes. At Cueva Negra, however, it is unlikely that flying sparks from a bush fire outside ignited brushwood inside, causing a roaring blaze and a temperature of >400ºC. Moreover, Cueva Negra and Genoth Benoth Ya’akov were beside rivers. Plausibly, smouldering brands left by bush fires were carried into Wonderwerk Cave and Cueva Negra so that fire could be tended where rain or wind could not put it out. No fire-pit or hearth stones have been found at Cueva Negra, hence it is unlikely that the heat of a tended fire could be controlled.

The denizens of Cueva Negra may have been less afraid of fire outside than animals they saw fleeing from it. That may have induced them to meddle with fire in order to drive animals towards natural death-traps, such as swamps, where they could be dismembered. A tended fire in a cave could serve several different purposes at the same time, such as deterring the approach of fierce animals, providing warmth, or roasting food.

Were foodstuffs roasted or cooked at Cueva Negra? It is impossible to say. Cogent physiological arguments (14) imply that cooking could have played a part in human evolution from at least 1.5 Ma, and, plausibly, influenced the expansion of brain volume (15), thanks to the enhanced digestion and absorption of nutrients which cooking afforded to pregnant women, lactating mothers, growing infants, children, and adolescents. Nevertheless, hearths seem to be absent from Palaeolithic sites before half-a-million years ago. We still cannot say when or where early humans first began to control the heat of a fire and engage in regular cookery.

(Information provided by Michael J. Walker, Emeritus Professor, Department of Zoology & Physical Anthropology, Murcia, University, and Chair of MUPANTQUAT: mjwalke@gmail.com)

Footnotes
1.    Antiquity 90 no. 351, 571-89 (2016)
2.    Quaternary International 294, 135-59 (2013)
3.    Nature 461, 82-5 (2009)
4.    Human Evolution 31, 1-67 (2016)
5.    Global Ecology and Biogeography 12, 119-29 (2003)
6.    In Settlement Dynamics in the Middle Palaeolithic and Middle Stone Age Vol. 2, N.J.Conard (Ed), Tübingen Studies in Prehistory (2004), 461-511.
7.    Internet Archaeology issue 5, Autumn/Winter (1998) http://intarch.ac.uk/journal/issue5/walker_index.html
8.    Quaternary Science Reviews 89, 195-9 (2013)
9.    Eurasian Prehistory 4, 3-43 (2006)
10.    Quartär 60, 7-28 (2013)
11.    J. Archaeological Method and Theory 20, 151-86 (2013).
12.    Stone Tools in Human Evolution by J.J. Shea (in press, Cambridge UP).
13.    Le Paradoxe Acheulén by E. Nicoud (2013, CTHS, Paris).
14.    Catching Fire. How Cooking Made us Human by R. Wrangham (2009, Basic Books, NY; Profile Books, London).
15.    Proceedings of the National Academy of Sciences USA 109, 18571-6 (2012).
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References (complete)
1.    Antiquity 90 no. 351, 571-89 (2016)    [“Combustion at the late Early Pleistocene Palaeolithic site of Cueva Negra del Estrecho del Río Quípar (Murcia, Spain)” by M.J.Walker, D.Anesin, D.E.Angelucci,  A.Avilés-Fernández, F.Berna, A.T.Buitrago-López, Y.Fernández-Jalvo, M.Haber-Uriarte, A.López-Jiménez, M.López-Martínez, I.Martín-Lerma, J.Ortega-Rodrigáñez, S.E.Rhodes, D. Richter, T.Rodríguez-Estrella, J-L.Schwenninger, A.R.Skinner]

2.    Quaternary International 294, 135-59 (2013)    [“Cueva Negra del Estrecho del Río Quípar (Murcia, Spain): A late Early Pleistocene hominin site with an “Acheulo-Levalloiso-Mousteroid” Palaeolithic assemblage” by M.J.Walker, M.V.López Martínez, J.S.Carrión-García, T.Rodríguez-Estrella, M.San-Nicolás-del-Toro, J-L.Schwenninger, A.López-Jiménez, J.Ortega-Rodrigáñez, M.Haber-Uriarte, J-L.Polo-Camacho, J.García-Torres, M.Campillo-Boj, A.Avilés-Fernández, W.Zack]

3.    Nature 461, 82-5 (2009)    [“The oldest hand-axes in Europe” by G.R.Scott, L.Gibert]

4.    Human Evolution 31, 1-67 (2016)   [“A view from a cave: Cueva Negra del Estrecho del Río Quípar (Caravaca de la Cruz, Murcia, southeastern Spain). Reflections on fire, technological diversity, environmental exploitation, and palaeoanthropological approaches” by M.J.Walker, D.Anesin, D.E.Angelucci, A.Avilés-Fernández, F.Berna, A.T.Buitrago-López, J.S.Carrión, A.Eastham, Y.Fernández-Jalvo, S.Fernández-Jiménez, J.García-Torres, M.Haber-Uriarte, A.López-Jiménez, M.V.López-Martínez, I.Martín-Lerma, J.Ortega-Rodrigáñez, J.L.Polo-Camacho, S.E.Rhodes, D.Richter, T.Rodríguez-Estrella, G.Romero-Sánchez, M.San-Nicolás-del-Toro, J-L.Schwenninger, A.R.Skinner, J.van-der-Made, W.Zack]

5.    Global Ecology and Biogeography 12, 119-29 (2003)   [“Glacial refugia of temperate, Mediterranean and Ibero-North African flora in south-eastern Spain: new evidence from cave pollen at two Neanderthal man sites” by J.S.Carrión, E.I.Yll, M.J.Walker, A.J.Legaz, C.Chaín, A.López]

6.    In Settlement Dynamics in the Middle Palaeolithic and Middle Stone Age Volume 2, N.J.Conard (Ed), Tübingen Studies in Prehistory (2004), 461-511.    [“Neanderthals and their landscapes: Middle Palaeolithic land use in the Segura drainage basin and adjacent areas of southeastern Spain” by M.J.Walker, J.Gibert Clols, A.Eastham, T.Rodríguez Estrella, J.S.Carrión García, E.I.Yll, A.J.Legaz López, A.López Jiménez, M.López Martínez, G.Romero Sánchez]

7.    Internet Archaeology issue 5, Autumn/Winter (1998) http://intarch.ac.uk/journal/issue5/walker_index.html    [“Two SE Spanish middle palaeolithic remains: Sima de las Palomas del Cabezo Gordo and Cueva Negra del Estrecho del Río Quípar (Murcia province)” by M.J. Walker, J. Gibert, F. Sánchez, A.V. Lombardi, I. Serrano, A. Eastham, F. Ribot, A. Arribas, A. Cuenca, J-A. Sánchez-Cabeza, J. García-Orellana, L. Gibert, S. Albaladejo, J.A. Andreu]

8.    Quaternary Science Reviews 89, 195-9 (2013)   [“Rethinking stratigraphy and site formation of the Pleistocene deposit at Cueva Negra del Estrecho del Río Quípar (Caravaca de la Cruz, Spain)” by D.Angelucci, D.Anesin, M.López-Martínez, M.Haber-Uriarte, T.Rodríguez-Estrella, M.J.Walker]

9.    Eurasian Prehistory 4, 3-43 (2006)    [“Cueva Negra del Estrecho del Río Quípar (Murcia, Southeast Spain): An Acheulian and Levalloiso-Mousteroid assemblage of Palaeolithic artifacts excavated in a Middle Pleistocene faunal context with hominin skeletal remains” by M.J.Walker, T.Rodríguez Estrella, J.S.Carrión García, M.A.Mancheño Jiménez, J-L.Schwenninger, M.López Martínez, A.López Jiménez, M.San Nicolás del Toro, M.D.Hills, T.Walkling]

10.    Quartär 60, 7-28 (2013)   [“Stone procurement and transport at the late Early Pleistocene site of Cueva Negra del Estrecho del Río Quípar (Murcia, SE Spain)” by W.Zack, A.Andronikov, T.Rodríguez-Estrella, M.López-Martínez, M.Haber-Uriarte, V.Holliday, D.Lauretta, M.J.Walker]

11.    J. Archaeological Method and Theory 20, 151-86 (2013).   [“Lithic Modes A–I: A new framework for describing global-scale variation in stone tool technology illustrated with evidence from the East Mediterranean Levant by J.J.Shea]

12.    Stone Tools in Human Evolution by J.J. Shea (in press, Cambridge UP).

13.    Le Paradoxe Acheulén by E. Nicoud (2013, CTHS, Paris).

14.    Catching Fire. How Cooking Made us Human by R. Wrangham (2009, Basic Books, NY; Profile Books, London).

15.    Proceedings of the National Academy of Sciences USA 109, 18571-6 (2012).   [Metabolic constraint imposes trade-off between body size and number of brain neurons in human evolution by K. Fonseca-Azevedo, S. Herculano-Houzel]