NEANDERTAL DENTAL MORPHOLOGY: IMPLICATIONS FOR MODERN HUMAN ORIGINS by Shara Elaine Bailey A Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy ARIZONA STATE UNIVERSITY December 2002 NEANDERTAL DENTAL MORPHOLOGY: IMPLICATIONS FOR MODERN HUMAN ORIGINS by Shara Elaine Bailey has been approved September 2002 APPROVED: , Chair Supervisory Committee ACCEPTED: ____________________________________ Department Chair ____________________________________ Dean, Graduate College ABSTRACT Research on Neandertal dentitions has been limited primarily to simple dental metrics, dental proportions and a few dental traits that seem to distinguish these from anatomically modern Homo sapiens (e.g., derived incisor morphology and taurodont molars). Consequently, Neandertal postcanine dental morphology has been generally assumed to be much like our own. This research examines this assumption through a systematic and comparative study of Neandertal postcanine dental morphology. Results are interpreted in light of two competing models for modern human origins: Multiregional Evolution (MRE) and Recent African Origin (RAO). Postcanine dental data were collected using the well-standardized methodology of the Arizona State University dental anthropology system. Additional dental traits were added by the author. Samples include individuals representing Homo erectus, archaic Homo sapiens, Neandertals, early anatomically modern Homo sapiens, Upper Paleolithic Europeans and seven recent human geographic populations. Univariate and multivariate statistical analyses, together with cladistic analysis, were used to make quantified assessments of Neandertal affinities. The results are inconsistent with predictions of the Multiregional Evolution hypothesis as it concerns Europe: phenetic analyses indicate that contemporary and Upper Paleolithic Europeans are among the groups least similar to Neandertals, and that there is no evidence of gradual evolution toward the modern human dental condition in Europe. In addition, Neandertals were found to exhibit a number of dental traits whose frequencies and combination of occurrence should be considered uniquely derived in iii their lineage. The results of the cladistic analysis are inconsistent with the phylogenetic hypothesis that Neandertals and amHs share a recent common ancestor that is unique to them. Instead, the data are consistent with a hypothesis that archaic Homo sapiens and Neandertals share a more recent common ancestor with each other then either does with anatomically modern Homo sapiens. Finally, the complete lack of derived Neandertal dental traits in Upper Paleolithic Europeans is difficult to reconcile with hypotheses of intensive gene flow between Neandertals and Upper Paleolithic Europeans. The fact that Upper Paleolithic Europeans and early amHs are phenetically similar, together with the fact that Upper Paleolithic Europeans are less similar to recent Europeans than to some other recent groups, likely indicates that the modern European dental pattern was acquired relatively recently. Finally, the overall phenetic similarity and evidence for dental synapomorphies between Neandertals and European archaic Homo sapiens conform to the hypothesis that European archaic Homo sapiens is best interpreted as an early representative of the Neandertal lineage. iv For my father and mother, C. David Bailey and Frieda B. Bailey v ACKNOWLEDGEMENTS First and foremost I thank my advisor and committee chair, Professor William H. Kimbel, who has been as much a friend as a mentor. I thank my committee members, Professors Erik Trinkaus, Geoffrey L. Clark, Mary W. Marzke and G. Richard Scott, for their assistance and support. I also thank Christy G. Turner, II who initially inspired me to undertake this project. I am grateful to all the people who provided access to the fossils examined for this dissertation: I. Tattersall, K. Mowbray and G. Sawyer at the American Museum of Natural History, New York; P. Ungar at the University of Arkansas, Fayetteville; C. Stringer and R. Kruzinski at the Natural History Museum, London; Y. Rak of the Sackler School of Medicine, Tel Aviv; G. Manzi at the University of Rome; G. Giacabini of the University of Turin; F. Mallegni of the University of Pisa; G. Koufos, of the Aristotle University of Thessaloniki; H. de Lumley at the Institute of Human Paleontology, Paris, Y. Coppens of the College of France, Paris; P. Tassy at the National Museum of Natural History, Paris; J. Leopold of the Museum of National Antiquities, St. Germain-en-Laye; M. Tavaso and F. Marchal at the Laboratory of Historical Geology, Marseille; J-J. Cleyet-Merle and A. Morala at the National Museum of Prehistory, Les Eyzies; V. Merlin-Anglade at the Museum of Périgord; E. Ladier at the Museum of Natural History, Montauban; R. Ziegler at the National Museum of Natural History, Stuttgart; S. Dusek at the Museum of Prehistory, Weimar; H-E. Joachim at the State Museum of the Rhine, Bonn; W. Menghin at the Museum of Prehistory, Berlin; N. Farsan of the University of Heidelberg; M. Teschler-Nicola, at the Natural History Museum, vi Vienna; R. Orban and P. Semal of Royal Institute of Natural Sciences of Belgium, Brussells; J. Radovčić at the Croatian Natural History Museum, Zagreb; M. Paunovič of the Institute for Quaternary Geology and Paleontology, Zagreb; J. Svboda, of the Institute of Archaeology Dolní Věstonice; and M. Dockalova at the Moravian Museum, Brno. At Arizona State University (ASU) first thanks go to the Anthropology Department staff for their support throughout my graduate career. I thank all my friends over the years at ASU who provided much needed distractions, stimulating conversations and emotional support. But I especially thank Catherine Willermet, Nancy Mahoney and Joshua Lipschultz, who who have stuck by me with patience and understanding through some difficult periods of my life. I thank my non-ASU friends Neil Weintraub, Michael Kriz and John Walter for their support and especially Samantha Kavky who inspired me to continue my education in the first place. Finally, I thank my parents Dave and Frieda Bailey for their emotional and financial support, and for always believing I was capable of great things. I also thank my brother, David Bailey, for his advice and philosophical insights, and my sister Tina Eckhart for her emotional support and for reminding me to keep my eye on the road and not on the mountain that lay ahead. This project was supported by the National Science Foundation (BCS-0002481) the Leakey Foundation, the International P.E.O. Sisterhood, Sigma Xi and the Department of Anthropology Research and Development committee. vii TABLE OF CONTENTS Page LIST OF TABLES...........................................................................................................xiii LIST OF FIGURES ......................................................................................................... xvi INTRODUCTION .............................................................................................................. 1 Overview..........................................................................................................................1 The debate over modern human origins ..........................................................................2 The Neandertal problem ..................................................................................................5 Objectives ......................................................................................................................10 Hypotheses to be addressed ...........................................................................................10 Significance ...................................................................................................................12 DENTAL ANTHROPOLOGY AND THE ORIGIN OF MODERN HUMANS ............ 13 Introduction....................................................................................................................13 Neandertal dental morphology (Taurodont molars and beyond)...................................15 Dental morphology and theories of modern human origins ..........................................18 MATERIALS.................................................................................................................... 25 Anatomically modern Homo sapiens (amHs) sample ...................................................25 Neandertal sample..........................................................................................................26 Archaic Homo sapiens sample.......................................................................................26 Homo erectus sample.....................................................................................................27 METHODS ....................................................................................................................... 36 Terminology...................................................................................................................36 viii Page Data collection ...............................................................................................................43 Non-metric data .............................................................................................................44 The Arizona State University dental anthropology system .......................................44 A supplemental scoring system .................................................................................45