The expression of sexual dimorphism in human skeletal remains from ancient Egypt: regional and temporal differences and the impact on modern and population- specific metric sex estimation methods A thesis submitted to the University of Manchester for the degree of PhD in the Faculty of Life Sciences 2014 Emily Jane Marlow Table of Contents List of Tables ………………………………………………………………………... 8 List of Figures ……………………………………………………………………... 15 List of Equations ………………………………………………………………….. 17 Abbreviations ……………………………………………………………………… 18 Abstract …………………………………………………………………………….. 20 Declaration …………………………………………………………………………. 21 Copyright Statement ……………………………………………………………... 21 Acknowledgements ………………………………………………………………. 22 Preface ……………………………………………………………………………… 23 Map of Ancient Egypt .…………………………...………………………………. 24 Chronology of Ancient Egypt …………………………………………………... 25 1 INTRODUCTION ........................................................................................28 1.1 General introduction and project overview .................................................................. 28 1.1.1 Research questions ............................................................................................. 29 1.1.2 Thesis outline ...................................................................................................... 30 1.2 Human remains in Egyptology .................................................................................... 31 1.2.1 Biological information .......................................................................................... 31 1.2.1.1 The ancient Egyptian population ..................................................................... 31 1.2.1.2 Palaeopathology .............................................................................................. 39 1.2.1.3 Diet .................................................................................................................. 45 1.2.2 Cultural information ............................................................................................. 46 1.3 Developmental biology ................................................................................................ 49 1.3.1 Sex determination and differentiation .................................................................. 49 1.3.1.1 Sex differences in early development ............................................................. 50 1.3.2 Skeletal biology ................................................................................................... 52 1.3.2.1 Skeletal development and growth ................................................................... 52 1.3.2.2 Temporal changes in human growth ............................................................... 61 2 1.4 Evolutionary and environmental biology ..................................................................... 67 1.4.1 Sexual selection and genetic influences ............................................................. 67 1.4.2 Environmental influences .................................................................................... 73 1.4.2.1 Diet and nutritional stresses ............................................................................ 74 1.4.2.2 Climate and altitude ......................................................................................... 79 1.4.2.3 Ecological influences ....................................................................................... 87 1.4.2.4 Division of labour ............................................................................................. 88 1.4.3 Ontogeny ............................................................................................................. 94 1.5 Fundamentals of palaeodemography: the estimation of sex ...................................... 97 1.5.1 Morphological sex estimation .............................................................................. 97 1.5.1.1 Reliability, scoring systems and weighting of traits ......................................... 99 1.5.1.2 Geometric morphometrics and ‘virtual’ osteology ......................................... 108 1.5.1.3 Population differences in morphology ........................................................... 114 1.5.2 Metric sex estimation ......................................................................................... 116 1.5.2.1 Computer program-based methods .............................................................. 123 1.5.2.2 Population differences in body size and proportions .................................... 125 1.5.2.3 The role of reference collections ................................................................... 127 1.5.3 Molecular sex estimation ................................................................................... 129 1.6 Aims, objectives, and hypotheses ............................................................................. 131 1.6.1 Hypotheses ....................................................................................................... 132 2 MATERIALS AND METHODS .................................................................134 2.1 Materials .................................................................................................................... 134 2.1.1 Identification and selection of skeletal collections ............................................. 134 2.1.2 Selection of skeletons ....................................................................................... 138 2.1.2.1 Data collection ............................................................................................... 140 2.1.3 Cemetery sites and excavations ....................................................................... 141 2.1.3.1 Keneh (Qena) ................................................................................................ 141 2.1.3.2 Sheikh Farag ................................................................................................. 143 3 2.1.3.3 Giza ............................................................................................................... 147 2.1.3.4 Thebes ........................................................................................................... 154 2.2 Sex estimation ........................................................................................................... 159 2.2.1 Morphological sex estimation ............................................................................ 159 2.2.1.1 Issues and considerations ............................................................................. 160 2.2.1.2 The Phenice characteristics .......................................................................... 163 2.2.1.3 Morphological assessment of the bony pelvis............................................... 165 2.2.1.4 Morphological assessment of the skull ......................................................... 167 2.2.1.5 Weighting and ranking of morphological methods and traits ........................ 169 2.2.2 Metric sex estimation ......................................................................................... 177 2.2.2.1 Selection of metric methods and skeletal dimensions .................................. 177 2.2.2.2 Measuring procedures and application of discriminant functions ................. 188 2.3 Intra-observer and inter-observer error ..................................................................... 204 2.3.1 Test of intra-observer error ................................................................................ 205 2.3.2 Test of inter-observer error ................................................................................ 207 2.3.3 Other calculations and equations ...................................................................... 208 2.4 Age at death estimation ............................................................................................ 210 2.5 Statistical analyses .................................................................................................... 211 2.5.1 Missing data ...................................................................................................... 213 2.5.2 Independent and paired samples t-tests ........................................................... 216 2.5.3 Analysis of Variance (ANOVA) .......................................................................... 216 2.5.4 Projection pursuit and PCA ............................................................................... 219 2.5.5 Discriminant function analysis and logistic regression ...................................... 222 2.5.5.1 Overview of discriminant function analysis ................................................... 222 2.5.5.2 Overview of logistic regression ..................................................................... 225 2.5.5.3 Discriminant function analysis versus logistic regression ............................. 227 2.6 Test sample and methods ......................................................................................... 231 2.6.1 Test sample ....................................................................................................... 232 4 2.6.2 Test methods ..................................................................................................... 234 3 RESULTS .................................................................................................236 3.1 Descriptive demographics of sample ........................................................................ 236 3.1.1 Sample size