Drift and Selection in Greek Figure- Painted Pottery
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Cultural Evolution in the Age of Athens: Drift and Selection in Greek Figure- Painted Pottery &&&&&& Peter M. Schauer UCL 2008 Volume 1 of 2 1 I, Peter M. Schauer, confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated in the thesis. 2 Abstract Variation in Greek figure-painted pottery has previously been unsystematically described as the result of social, political and art historical influences. In this study we propose that variation arises from the process of copying itself. The neutral model states that if there are no other forces at work, at time t the frequency of a variant in a population of variants will be in proportion to its frequency at time t-1, modified by the probability that new variants might be invented and old ones might fail to be copied each time there is a copying event, a process known as drift. We test the degree to which variation in figure- painted pottery can be explained by this model using evolutionary approaches to archaeology and culture change (Neiman 1995, Bentley et. al. 2004, Bentley et. al. 2007). We develop and expand these approaches through computer simulation. Using data from the Beazley archive, we created a new database containing a sample of 38,707 Attic figure-painted vases dating from 650 to 300 BC. Within this sample we explore the diversity, distribution and turnover rate of motifs over time, between shapes and across different decorative techniques. We also explore correlations between shape and motif, and examin the variant frequencies underlying the emergence of the red- figured technique. We show that much of the variation in motifs on figure-painted pottery can be explained as being the result of random copying. Where the neutral model is not sufficient as an explanation of observed variation, we show whether selection is due to bias towards novelty or conformity. These results show that an evolutionary approach to cultural change provides us with a powerful tool for assessing previous research and allows us to identify areas in which further research is required. 3 Table of contents List of tables – page 5 List of figures – 8 Chapter 1. Introduction: An evolutionary approach to change in Attic figure-painted pottery 1.1 Introduction - 14 1.2 Research overview - 20 1.3 Producers and consumers - 22 1.4 Changes in figure-painted pottery - 24 1.5 Sources and applications - 27 1.6 Quantitative? - 30 Chapter 2. Testing neutrality 2.1 Diversity and distributions - 35 2.2 Frequency - 38 2.3 The new model - 40 2.4 Making comparisons - 44 2.5 Turnover rate - 47 Chapter 3. Data gathering 3.1 Background - 49 3.2 Capture - 50 3.3 Errors and Cleaning - 53 3.4 Variables - 56 3.5 Data preparation complete - 68 Chapter 4. Results 4.1 Cups - 70 4.2 Skyphos - 79 4.3 Oinochoe - 85 4.4 Krater - 90 4.5 Lekythoi - 96 4.6 Amphorae - 102 4.7 Hydria - 107 4.8 Pyxis - 112 4.9 Plates - 116 4.10 Ritual - 120 4.11 All shapes - 124 4.12 Summary and discussion - 130 Chapter 5. Motifs: Proportions, shapes and turnover 5.1 Motif proportions - 144 5.2 Motif specialisation - 154 5.3 Variation - 163 5.4 Turnover rate - 170 Chapter 6. Techniques: From black to red 6.1 Techniques - 174 6.2 Technique and shape - 177 6.3 Techniques and motifs - 181 Chapter 7. Discussion: Trendy Nikes and the rise of red-figure 7.1 Introduction - 182 7.2 Results overview - 185 7.3 Iconography - 188 7.4 From black to red - 201 Chapter 8. Postscript: After the Beazley archive 8.1 Whose muse? - 213 8.2 Open access - 215 8.3 Implications for the Beazley archive - 218 Bibliography - 223 Figures – 253 (Volume 2) 4 List of tables Tables Chapter 3. 3.1 Shape categories. - 66 Tables Chapter 4.1 Cups 4.1.1 Sample size. - 70 4.1.2 Sample size over time. - 71 4.1.3 New and total motifs in the cups sample. - 72 4.1.4 Mutation and drift by technique and time period. - 73 4.1.5 Estimates of theta. - 75 4.1.6 Comparison of |tf-te| for model and data. - 76 4.1.7 R-squared values. - 77 4.1.8 R-squared values, model and data comparison. - 78 4.1.9 Summary of results. - 79 Tables Chapter 4.2 Skyphos 4.2.1 Sample size. - 79 4.2.2 Sample size over time. - 80 4.2.3 New and total motifs. - 80 4.2.4 Mutation and drift by technique and time period. - 81 4.2.5 Estimates of theta. - 82 4.2.6 Comparison of |tf-te| for model and data. - 83 4.2.7 R-squared values. - 84 4.2.8 R-squared values, model and data comparison. - 84 4.2.9 Summary of results. - 85 Tables Chapter 4.3 Oinochoe 4.3.1 Sample size. - 85 4.3.2 Sample size over time. - 86 4.3.3 New and total motifs. - 87 4.3.4 Mutation and drift by technique and time period. - 87 4.3.5 Estimates of theta. - 88 4.3.6 Comparison of |tf-te| for model and data. - 88 4.3.7 R-squared values. - 89 4.3.8 R-squared values, model and data comparison. - 89 4.3.9 Summary of results. - 90 Tables Chapter 4.4 Krater 4.4.1 Sample size. - 91 4.4.2 Sample size over time. - 91 4.4.3 New and total motifs. - 92 4.4.4 Mutation and drift by technique and time period. - 92 4.4.5 Estimates of theta. - 93 4.4.6 Comparison of |tf-te| for model and data. - 94 4.4.7 R-squared values. - 94 4.4.8 R-squared values, model and data comparison. - 95 4.4.9 Summary of results. - 96 Tables Chapter 4.5 Lekythoi 4.5.1 Sample size. - 96 4.5.2 Sample size over time. - 97 4.5.3 New and total motifs. - 98 4.5.4 Mutation and drift by technique and time period. - 98 4.5.5 Estimates of theta. - 99 4.5.6 Comparison of |tf-te| for model and data. - 100 4.5.7 R-squared values. - 100 4.5.8 R-squared values, model and data comparison. - 101 5 4.5.9 Summary of results. - 101 Tables Chapter 4.6 Amphorae 4.6.1 Sample size. - 102 4.6.2 Sample size over time. - 102 4.6.3 New and total motifs. - 103 4.6.4 Mutation and drift by technique and time period. - 103 4.6.5 Estimates of theta. - 105 4.6.6 Comparison of |tf-te| for model and data. - 105 4.6.7 R-squared values. - 106 4.6.8 R-squared values, model and data comparison. - 106 4.6.9 Summary of results. - 107 Tables Chapter 4.7 Hydria 4.7.1 Sample size. - 107 4.7.2 Sample size over time. - 108 4.7.3 New and total motifs. - 108 4.7.4 Mutation and drift by technique and time period. - 109 4.7.5 Estimates of theta. - 110 4.7.6 Comparison of |tf-te| for model and data. - 110 4.7.7 R-squared values. - 111 4.7.8 R-squared values, model and data comparison. - 111 4.7.9 Summary of results. - 112 Tables Chapter 4.8 Pyxis 4.8.1 Sample size. - 113 4.8.2 Sample size over time. - 113 4.8.3 New and total motifs. - 113 4.8.4 Mutation and drift by technique and time period. - 114 4.8.5 Estimates of theta. - 115 4.8.6 Comparison of |tf-te| for model and data. - 115 4.8.7 R-squared values. - 115 4.8.8 R-squared values, model and data comparison. - 116 4.8.9 Summary of results. - 116 Tables Chapter 4.9 Plates 4.9.1 Sample size. - 117 4.9.2 Sample size over time. - 117 4.9.3 New and total motifs. - 117 4.9.4 Mutation and drift by technique and time period. - 118 4.9.5 Estimates of theta. - 119 4.9.6 Comparison of |tf-te| for model and data. - 119 4.9.7 R-squared values. - 119 4.9.8 R-squared values, model and data comparison. - 120 4.9.9 Summary of results. - 120 Tables Chapter 4.10 Ritual 4.10.1 Sample size. - 121 4.10.2 Sample size over time. - 121 4.10.3 New and total motifs in the cups sample. - 122 4.10.4 Mutation and drift by technique and time period. - 122 4.10.5 Estimates of theta. - 123 4.10.6 Comparison of |tf-te| for model and data. - 123 4.10.7 R-squared values. - 123 4.10.8 R-squared values, model and data comparison. - 124 4.10.9 Summary of results. - 124 Tables Chapter 4.11 All shapes 4.11.1 Sample size. - 124 4.11.2 Sample size over time. - 125 4.11.3 New and total motifs. - 125 6 4.11.4 Mutation and drift by technique and time period. - 126 4.11.5 Estimates of theta. - 127 4.11.6 Comparison of |tf-te| for model and data. - 127 4.11.7 R-squared values. - 128 4.11.8 R-squared values, model and data comparison. - 129 4.11.9 Summary of results. - 130 Tables Chapter 4.12 Summary and discussion 4.12.1 Theta results at the 5% level. - 130 4.12.2 R-squared results at the 5% level.