Population Dynamics in the Late Glacial Refugium of Southwest France C.M. Collins PhD November 2012 University of Sheffield Acknowledgements I would first of all like to thank my supervisor Andrew Chamberlain for ad- vising me throughout my PhD. In addition many people aided me through- out the three years of my PhD. I am grateful to Pierre-Yves Demars for giving me access to his archaeological database. I am also grateful to Matt Grove for allowing me to utilize his method for working with radiocarbon dates and assisting me in doing so. As well as providing help with Matlab and LATEX, James Hook also joined me in many interesting conversations. I would also like to thank the following people for general useful discus- sions and advice: Jean-Pierre Bocquet-Appel, Paul Mellars, Michael White, Caitlin Buck, Rob Dinnis, Jenni French, Tom O'Mahoney, Tom Booth and Isabelle Heyerdahl-King. Tom Hannan was kind enough to read a draft of my thesis and provide detailed feedback. I am also grateful to Bob John- ston for taking me on as a PhD student after the departure of Andrew from Sheffield in my final weeks of study. The University of Sheffield provided me with a scholarship that supported this endeavour. Thanks also go to my parents and friends for supporting me over the past years. Abstract In this thesis I explore population processes in the Upper Palaeolithic of Southwest France. Traditionally, prehistorians have regarded the region as a `refugium' during the Last Glacial Maximum, into which populations contracted during periods of climatic deterioration in Europe. This refuge zone status has been used to explain the proliferation of artworks and diverse archaeological traces found in the region. Innovation and demography have been theoretically linked for some time. High population densities are thought to lead to high innovation rates. Two possible mechanisms link these two variables. In the first scenario, high pop- ulation densities cause intra-species competition, which leads to a pressure to innovate. The second scenario is a simple `numbers game'; high popu- lation density increases the probability of innovation occurring and being transmitted from person to person. In this thesis I explore population processes in the Upper Palaeolithic of Southwest France using the proxies of radiocarbon dates and intra-site lithic densities. I demonstrate that there are several peaks in population in the re- gion, including ones coinciding with the onset and end of the LGM. Based on this data, I argue that the region served as a refugium during the LGM and also at several other points during the Upper Palaeolithic. I demonstrate that there is a negative relationship between climate and population in the region. This contrasts with the situation for modern hunter-gatherers. The cold conditions of the Pleistocene create a `unique situation', where usual rules linking population and environment are interrupted as populations contract into refugia. I also test the relationship between demography and innovation, using lithic assemblage diversity data as a proxy for innovation. I demonstrate that population and innovation are positively correlated. This relationship is unchanged in modern hunter-gatherers. I argue that the mechanism linking demography and innovation has changed from prehistory to the present day. Environment, demography and innovation all interact in a complex manner during the Upper Palaeolithic and I shed some light on wider patterns of human behaviour through exploring these processes in this fascinating period. 4 Contents 1 Aims and Objectives 1 1.1 Aims and Objectives . 1 2 Theoretical Background 1 2.1 Demography and Innovation . 1 2.2 Cultural Evolution and Transmission . 7 2.3 Cultural Transmission and Population Densities . 10 2.4 Population, innovation and human evolution . 11 2.5 Hunter-gatherer demography . 12 2.6 Previous Studies into Archaeological Demography . 20 2.6.1 Ethnography . 20 2.6.2 Dates as Data . 22 2.6.3 Genetic Evidence . 24 2.6.4 Dietary shifts: The Broad Spectrum Revolution . 27 2.6.5 `Bottom-up' approaches: carrying capacity . 28 2.7 Previous studies into Innovation in Prehistory . 29 i ii CONTENTS 3 Archaeological Background 31 3.1 Geography and Environmental Background . 31 3.1.1 Climate . 33 3.2 Southwest France as a Refugium . 40 3.3 Lithic Technology of Southwest France . 43 3.3.1 The Aurignacian . 44 3.3.2 The Gravettian . 49 3.3.3 The Solutrean . 52 3.3.4 The Badegoulian . 55 3.3.5 The Magdalenian . 56 3.3.6 The Azilian . 58 3.4 Summary of Technocomplexes . 61 3.5 Settlement . 61 3.5.1 Settlement in France . 61 3.5.2 Regional Settlement . 63 3.6 Site Area . 68 3.7 Human Remains . 69 3.8 Changes in Resource Use across the Upper Palaeolithic . 70 3.9 Research Bias: A quick note . 72 3.10 Summary of Background Chapters . 73 4 Materials and Methods 75 4.1 Radiocarbon Methods . 75 CONTENTS iii 4.1.1 Calibration . 78 4.1.2 Radiocarbon Dates as Proxies for Human Activity . 83 4.1.3 Taphonomic Correction . 84 4.1.4 Calibration . 86 4.1.5 Model construction in Oxcal . 97 4.2 Kernel Density Estimation . 98 4.3 Intra-site Lithic Density Method . 100 4.4 Diversity of lithic artefacts . 104 4.5 Summary of Methods . 108 5 Results 109 5.1 Radiocarbon Results . 109 5.1.1 Impact of Bayesian Dating . 117 5.1.2 Testing the Summed Probability Method . 119 5.2 Kernel Density Estimation Results . 127 5.3 Intra-site Lithic Density Results . 133 5.4 Diversity results . 142 5.4.1 Distribution of tools . 142 5.4.2 Diversity measures by technocomplex . 149 5.4.3 Diversity over time in the Upper Palaeolithic . 153 5.5 Climate as a Variable . 155 5.5.1 Temperature and Diversity . 155 6 Discussion and Conclusions 163 iv CONTENTS 6.1 Methodological Findings . 166 6.2 Key demographic results . 171 6.3 Key Innovation Results . 176 6.4 Implications for human behaviour . 178 6.5 Further interesting results . 184 6.6 Summary . 187 6.7 Future Directions . 187 7 Appendix A 189 7.1 Chapter Two data tables . 189 8 Appendix B 204 8.1 Chapter Four Appendices . 204 8.2 Useful Code . 220 8.2.1 Oxcal code . 220 8.2.2 Diversity methods Matlab code . 222 8.2.3 KDE Matlab code . 227 9 Appendix C 232 9.1 Chapter Five Appendices . 232 9.2 The Sonneville-Bordes tool typology and tool distributions by techno- complex: Tables . 232 9.3 Results: Lithic Densities . 255 9.4 Results: Lithic Assemblage Diversity . 265 9.4.1 Mann Whitney U-tests on densities of tools . 278 CONTENTS v 9.5 Mann Whitney U-tests on Diversity Measures . 302 10 Appendix D 322 10.1 A Gazeteer of Sites used in this Thesis . 322 10.1.1 Abri Pataud . 322 10.1.2 Combe Sauni`ere . 329 10.1.3 Cuzoul de Vers . 332 10.1.4 La Doue . 332 10.1.5 Le Facteur . 332 10.1.6 Faur´elieII . 332 10.1.7 La Ferrassie . 336 10.1.8 Flageolet I . 336 10.1.9 Flageolet II . 336 10.1.10 Gandil . 336 10.1.11 Gare de Couze . 337 10.1.12 Grotte XVI . 337 10.1.13 Jamblancs . 337 10.1.14 Chez Jugie . 337 10.1.15 Laugerie Haute Est . 337 10.1.16 Laugerie Haute Ouest . 353 10.1.17 La Madeleine . 353 10.1.18 Montgaudier . 357 10.1.19 Le Morin . 360 vi CONTENTS 10.1.20 Moulin du Roc . 361 10.1.21 P´egouri´e . 362 10.1.22 Peyrugues . 362 10.1.23 Le Piage . 362 10.1.24 Le Placard . 372 10.1.25 Pont d'Ambon . 372 10.1.26 Le Qu´eroy . ..