THE STATISTICAL DETERMINATION OF ANCESTRY USING CRANIAL NONMETRIC TRAITS By JOSEPH T. HEFNER A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2007 © 2007 Joseph T. Hefner 2 To my inamorata, Natalie Marie Uhl, for her love, support, and encouragement—I could not have done it without you 3 ACKNOWLEDGMENTS I would like to acknowledge the support and guidance of my committee members. Michael Warren served as the chair for my Master’s degree and my doctoral work. His relentless efforts to make me a better anthropologist will never be forgotten. Anthony Falsetti, David Daegling, John Krigbaum, and Thomas Hollinger continually gave me sound advice, constructive criticism, and hours of their own research time to assist me in mine—I am forever grateful for their efforts. Finally, Stephen Ousley taught me outside of the classroom in so many ways that I am sure I will never be able to thank him enough. From one contrarian to the another, thank you Steve. This dissertation and my life would not be the same had it not been for our chance encounter at a baseball game. Dennis Dirkmaat of Mercyhurst College deserves special thanks for his tireless support and guidance. As a friend and mentor he has been invaluable—without his creativity and insight, I would not be where I am today. I am also grateful for David Hunt, whose permission and assistance in obtaining skeletal material from the Smithsonian Institution has made this all possible. Lee Meadows Jantz and Richard Jantz also deserve special acknowledgment for their help with the William M. Bass Skeletal Collection and for answering my many questions, even when I was not always sure what I was asking. For their generous giving of time, ideas, and support, I would like to thank John Byrd, Paul Emanovsky, Laurel Freas, Nicholas Herrmann, Stephen Nawrocki, Nicholas Passalaqua, M. Kate Spradley, and Carlos Zambrano. For their participation in the inter-observer error study, I thank Thomas Gore, Anthony Koehl, and several anonymous participants. I would like to thank my family for instilling in me a love of learning, the need for creativity, and the belief in the power of words. My father suggested a stint in college nearly 12 years ago; I hope that I have made him proud with this accomplishment. My mother also 4 deserves recognition. Like her, I saw a goal that would forever change my life and I reached out, took hold, and have never let go. My sister Nicole and my brother David taught me a lot when we were growing up, but more importantly, I learn from them even today. I want to thank you both for your love, your friendship, and your support. Finally, I would like to acknowledge and thank Natalie Uhl, for the hours she and I spent discussing our research, editing each others’ work, and just having fun together. Everyday Natalie reminds me of the things that are important in life. 5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ...............................................................................................................4 LIST OF TABLES...........................................................................................................................8 LIST OF FIGURES .......................................................................................................................10 ABSTRACT...................................................................................................................................12 CHAPTER 1 RACE AND PHYSICAL ANTHROPOLOGY.....................................................................15 Anatomy, Systematics, and the Search for Order...................................................................18 Typology, Polygenism, and the American School .................................................................23 2 THE FORENSIC APPROACH TO ANCESTRY DETERMINATION ...............................34 3 NONMETRIC CRANIAL VARIATION...............................................................................44 Factors Affecting Trait Expression.........................................................................................45 Genes and the Environment.............................................................................................45 Sex, Age, and Trait Correlation.......................................................................................48 General Patterns of Variation .................................................................................................49 4 MATERIALS AND METHODS ...........................................................................................52 Samples...................................................................................................................................52 African Sample................................................................................................................52 European Sample.............................................................................................................52 East Asian Sample...........................................................................................................52 Native American Sample.................................................................................................53 Anatomical Collection.....................................................................................................53 Bass Collection................................................................................................................53 Macromorphoscopic Traits.....................................................................................................54 Statistical Methods..................................................................................................................54 Correlations .....................................................................................................................55 Ordinal Regression ..........................................................................................................55 Correspondence Analysis ................................................................................................57 OSSA...............................................................................................................................58 Naïve Bayesian................................................................................................................60 Linear Discriminant Function Analysis...........................................................................60 k-Nearest Neighbor .........................................................................................................62 Logistic Regression .........................................................................................................62 Canonical Analysis of Principal Coordinates..................................................................63 6 Inter- and Intra-Observer Error .......................................................................................65 5 THE STATISTICAL DETERMINATION OF ANCESTRY................................................68 Statistical Approaches to Ancestry Determination.................................................................68 Ordinal Regression ..........................................................................................................68 Correspondence Analysis ................................................................................................69 Optimized Summed Score Attributes (OSSA) ................................................................70 Naïve Bayesian................................................................................................................71 Discriminant Function Analysis......................................................................................71 k-Nearest Neighbor..........................................................................................................73 Logistic Regression .........................................................................................................74 Canonical Analysis of the Principal Coordinates............................................................75 Inter- and Intra-Observer Error...............................................................................................76 6 CONCLUDING REMARKS..................................................................................................94 A Legacy and A Solution .......................................................................................................94 APPENDIX A MACROMORPHOSCOPIC TRAITS....................................................................................99 Anterior Nasal Spine (ANS)............................................................................................99 Inferior Nasal Morphology (INA)...................................................................................99 Interorbital Breadth (IOB).............................................................................................100 Malar Tubercle (MT).....................................................................................................100 Nasal Aperture Shape (NAS) ........................................................................................101 Nasal Aperture Width (NAW).......................................................................................101 Nasal Bone Contour (NBC)...........................................................................................101