DETERMINING THE ANTIQUITY OF DOG ORIGINS: CANINE DOMESTICATION AS A MODEL FOR THE CONSILIENCE BETWEEN MOLECULAR GENETICS AND ARCHAEOLOGY A Dissertation by MICHELLE JEANETTE RAISOR Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY August 2004 Major Subject: Anthropology DETERMINING THE ANTIQUITY OF DOG ORIGINS: CANINE DOMESTICATION AS A MODEL FOR THE CONSILIENCE BETWEEN MOLECULAR GENETICS AND ARCHAEOLOGY A Dissertation by MICHELLE JEANETTE RAISOR Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved as to style and content by: _________________________ ______________________ D. Bruce Dickson D. Gentry Steele (Chair of Committee) (Member) __________________________ ______________________ Harry J. Shafer Lisa M. Howe (Member) (Member) ___________________________ David L. Carlson (Head of Department) August 2004 Major Subject: Anthropology iii ABSTRACT Determining the Antiquity of Dog Origins: Canine Domestication as a Model for the Consilience between Molecular Genetics and Archaeology. (August 2004) Michelle Jeanette Raisor, B.S, Texas A&M University; M.A., Texas A&M University Chair of Advisory Committee: Dr. D. Bruce Dickson Archaeologists have favored a date of 14,000-15,000 years before present (BP) for canine domestication. However, recent studies of mutations in the mitochondrial DNA sequence by molecular geneticists have implied that dogs were domesticated over 100,000 years ago, which has challenged traditional theory. Geneticists have further hypothesized that dogs originated from wolf ancestors based upon the number of substitutions observed in dog and wolf haplotypes. Although both disciplines provide substantial evidence for their theories, the origin of dog domestication remains controversial. Several areas continue to be debatable. First, both geneticists and archaeologists incorrectly use the term domestication to describe events that clearly can not be proven to under human control. Second, the evolutionary development of canines is viewed by molecular biologists as well as archaeologist to be indicators of domestication without any further exploration of other probable causes. Third, the studies in canine genetics are so complex that most archaeologists have difficulty in providing evidence that would be contradictory to molecular theory. Fourth, both fields iv of study continually ignore innate behavioral characteristics of wolves that would make domestication highly improbable. Fifth, geneticists rely heavily on data gathered from sequencing of mitochondrial DNA, which has been assumed to maternally inherited. However recent human studies have shown that this assumption has now been proven to be incorrect. And finally, not only are morphological traits of fossilized dogs and wolves so similar that making a taxonomic identification improbable, but also the amount of archaeological remains available are too sparse and fragmented for accurate affiliation. An alternate theory of canine domestication will be proposed utilizing data gathered from the archaeological record and molecular research. I hypothesize that dogs diverged naturally from wolves 100,000 years ago as a result of the natural course of evolution, not human intervention, and had already evolved into a dog prior to being domesticated by humans 14,000-15,000 years ago. Evidence will be presented to clearly show that this hypothesis is a more accurate scenario of canine domestication. v ACKNOWLEDGEMENTS This dissertation would not have been possible without the assistance of several people. I am especially indebted to Dr. D. Bruce Dickson, my committee chairman, who gave unselfishly of his time. His continued encouragement and interest made this project possible. His willingness to share his expertise added considerably to my knowledge of archaeology and kept me focused. I would also like to thank Dr. D. Gentry Steele for his continuing support, interest and for his many kindnesses extended to me while I was a graduate student. As both a professional anthropologist and friend, he became my mentor, for which I will always be especially grateful. I want to extend my thanks to my friend Dr. James N. Rugila, DVM. He not only spent an enormous amount of time taking care of my ailing dogs, but also his expertise in molecular genetics and physiology was more help than he will ever know. He was very patient with my endless questions. Finally, I wish to thank my parents Harry and JoAnn Raisor for their encouragement and for raising me to persist despite any obstacle. vi TABLE OF CONTENTS Page ABSTRACT.............................................................................................................. iii ACKNOWLEDGEMENTS...................................................................................... v TABLE OF CONTENTS.......................................................................................... vi LIST OF FIGURES................................................................................................... ix LIST OF TABLES.................................................................................................... xi CHAPTER I INTRODUCTION...................................................................................... 1 II BASICS OF MOLECULAR GENETICS................................................... 9 What is DNA?................................................................................... 9 What is a gene?................................................................................. 13 What is a mitochondrial DNA?......................................................... 14 Mitochondrial inheritance................................................................. 16 What is a microsatellite?................................................................... 17 Nuclear and mitochondrial size......................................................... 17 What is PCR?.................................................................................... 19 Development of the canine genetic map........................................... 20 Organization of the canine genetic map............................................ 27 Microsatellites as genetic markers.................................................... 29 Evolutionary relationships of canids................................................. 31 Molecular evolution of canids........................................................... 36 Timing of genetic divergence............................................................ 41 Phylogenetic tree of the dog and wolf............................................... 43 Ethiopian wolf................................................................................... 62 Coyote............................................................................................... 64 Red wolf............................................................................................ 67 Jackals............................................................................................... 75 Variability of wild-type dog breeds.................................................. 77 Genetic variability of primitive dog breeds....................................... 79 Australian dingo................................................................... 79 New Guinea Singing dog..................................................... 84 Carolina dogs....................................................................... 86 vii CHAPTER Page III BEHAVIOR OF WOLVES....................................................................... 88 Reproductive development................................................................ 89 Neonatal development....................................................................... 89 Behavioral development.................................................................... 91 Facial expressions............................................................................. 101 Instinctual vs. cognitive processing.................................................. 104 IV THE ARCHAEOLOGICAL RECORD..................................................... 112 The complicated process of domestication....................................... 113 Morphometric differences in the skeletal remains of dog and wolf................................................................................. 128 The fossil record of Canis familiaris................................................. 144 North America....................................................................... 145 Meso America and South America....................................... 157 Greenland.............................................................................. 158 Great Britain.......................................................................... 160 Germany................................................................................ 163 France.................................................................................... 166 Ireland.................................................................................... 168 Sweden and Denmark............................................................ 169 Hungary................................................................................. 169 Iraq........................................................................................ 171 Russia.................................................................................... 172 Armenia................................................................................. 174 Israel...................................................................................... 175 Africa..................................................................................... 178 Egypt..................................................................................... 178 Kazakhstan............................................................................ 179 Thailand................................................................................. 181 Australia................................................................................ 183 Japan...................................................................................... 183 Siberia.................................................................................... 185 China..................................................................................... 187 V DISCUSSION............................................................................................. 191 Problems with mtDNA inheritance....................................... 191 Potential limitations of DNA sequencing.............................. 201 Some new alternative methods.............................................. 207 viii CHAPTER Page Limitations of current molecular studies............................... 212 Contributions of animal behavior studies to the understanding of dog domestication..................................... 223 Limitations of the archaeological record............................... 233 VI CONCLUSION........................................................................................... 238 Domestication of the Dog: An Alternative Hypothesis.................... 238 LITERATURE CITED............................................................................................. 257 APPENDIX: THE AUTHOR'S ENGLISH SETTERS............................................ 276 VITA ........................................................................................................................ 278 ix LIST OF FIGURES FIGURE Page 1 Over 400 varieties exist today, ranging in size, shape and color.................. 10 2 Modern breeds of dogs exhibit many differences in head shapes................. 11 3 Mastiff-like breeds were depicted on Egyptian tombs, similar to the mastiff above....................................................................................... 12 4 Canine mitochondrion, complete genome..................................................... 15 5 Labrador retrievers have been used to study the genetic inheritance of narcolepsy. .................................................................................................... 25 6 Four phylogenetic divisions proposed by Wayne and Ostrander (1999) based upon DNA analysis............................................................................. 38 7 Composite family tree of canids. ................................................................. 39 8 Neighboring-joining tree of wolf and dog haplotypes based on 261 bp of control region sequence. .............................................................. 46 9 Haplotypes found in East Asia, Europe, and Southwest Asia are indicated in separate networks with orange, blue, and green........................ 50 10 Siberian Husky.............................................................................................. 52 11 Hairless breeds of dogs from top left to bottom, Chinese crested, Xoloitzcuintli (Mexican hairless), and Peruvian Inca Orchid....................... 53 12 Coyote (Canis latrans).................................................................................. 64 13 Red wolf (Canis rufus).................................................................................. 68 14 Australian dingo, Canis lupus dingo............................................................. 80 15 Examples of primitive dogs........................................................................... 83 16 Wolf pups are born blind and deaf with limited motor ability...................... 90 x FIGURE Page 17 Socialized wolves will become more bold and assertive as they become more confident with their experimenters, sometimes leading to a full blown attack. ...................................................................... 100 18 Various behavioral tests have shown that wolves are unable to skillfully interpret human social cues, facial expressions and lack the ability to have face/eye contact with humans.......................................... 111 19 After multiple generations, tame foxes began exhibiting changes in coat texture and color such as piebald spotting. ........................................... 124 20 Elements comprising the canid skull and mandible of a modern wolf, Canis lupis. ............................................................................ 130 21 The skulls of a 43 kg wolf (left) and a 43 kg dog (right).............................. 133 22 Skull and mandible of a domestic dog, Canis familiaris. ........................... 135 23 Comparison of skulls of present-day wolf, late Paleolithic wolf, and late Paleolithic short-faced wolf.......................................................................... 138 24 A mitochondrial mutation may have led to selective replication of paternally derived DNA (green) in muscle. ................................................ 194 25 Egyptian artists often depicted dogs resembling the present day Pharaoh hound. ......................................................................... 237