Human Brain Evolution

The evolution of the human brain and cognitive ability is one of the central themes of physical/biological anthropology. This book discusses the emergence of human cognition at a conceptual level, describing it as a process of long adaptive stasis interrupted by short periods of cognitive advance. These advances were not linear and directed, but were acquired indirectly as part of changing human behaviors, in other words through the process of exaptation (acquisition of a function for which it was not originally selected). Based on studies of the modem human brain, certain prerequisites were needed for the development of the early brain and associated cognitive advances. This book documents the energy and nutrient constraints of the modern brain, highlighting the significant role of long-chain polyunsaturated fatty acids (LC-PUFA) in brain development and maintenance. Crawford provides further emphasis for the role of essential fatty acids, in particular DHA, in brain development, by discussing the evolution of the eye and neural systems. This is an ideal book for Graduate students, post docs, research scientists in Physical/Biological Anthropology, Human Biology, Archaeology, Nutrition, Cognitive Science, Neurosciences.  It is also an excellent selection for a grad student discussion seminar.

Foreword: Evolution, Encephalization, Environment vii Phillip V. Tobias Introduction xiii Kathlyn M. Stewart and Stephen C. Cunnane Contributors xix Chapter 1 Macroevolutionary Patterns, Exaptation, and Emergence in the Evolution of the Human Brain and Cognition 1 Ian Tattersall Introduction 1 Natural Selection 1 Macroevolution 2 Patterns in Human Evolution 3 Symbolic Cognition 5 Exaptation and Emergence 8 Large Brains and Aquatic Resources 9 References 10 Chapter 2 Long-Chain Polyunsaturated Fatty Acids in Human Brain Evolution 13 Michael A. Crawford Introduction – Lipids and Evolution 13 The Evolution of Complex Life Forms 14 The Language of Lipids 15 DHA 17 Evolution of Homo sapiens 20 DHA and Neural Pathways? 22 A Comment on AA 24 The Third Phase of Earth’s Life History – AA and Reproduction in Mammals 25 Darwin and the Conditions of Existence 26 Implications 27 Conclusion 28 Acknowledgments 28 Notes 28 References 28 Chapter 3 Human Brain Evolution: A Question of Solving Key Nutritional and Metabolic Constraints On Mammalian Brain Development 33 Stephen C. Cunnane Introduction 33 Brain Evolution in Hominins 35 Need for a New Paradigm 38 Brain Development 40 Energy Requirements of the Brain 41 Nutrients and Brain Function 44 Brain-Selective Nutrients 46 Critical Importance of Baby Fat in Humans 52 Gene – Nutrient Interactions 57 Conclusions 59 Acknowledgments 61 References 61 Chapter 4 Metabolic and Molecular Aspects of the Critical Role of Docosahexaenoic Acid in Human Brain Function 65 J. Thomas Brenna Docosahexaenoic Acid (DHA) Molecular Structure 65 DHA and Neural Function 66 Metabolic and Biophysical Considerations 68 Functional Importance of DHA in Retinal and Neural Membranes 70 Dietary Need for Preformed DHA 71 DHA Intake During Pregnancy and Lactation: Effects on Higher CNS Functions of the Mother and Infant 73 Summary 74 References 74 Chapter 5 Lessons From Shorebased Hunter-Gatherer Diets Iin East Africa 77 Frits A.J. Muskiet and Remko S. Kuipers Introduction 77 Our Genetic Background 78 Adaptation to the Conditions of Existence 79 Western Diets and the Human Genome 81 Brain-Selective Nutrients in Health and Disease 83 Dietary Fatty Acids at the Land–Water Interface 84 Tanzanian Breast Milk Fatty Acids Versus Western Recommendations 89 Estimated Fatty Acid Intakes from Shore-Based Paleolithic Diets 93 Conclusions 96 Notes 97 References 97 Appendix 103 Chapter 6 Thyroid Hormone, Iodine and Human Brain Evolution 105 Sebastiano Venturi and Michel E. Bégin Introduction 105 Thyroid Hormone Metabolism and Function 105 Fetal Development 108 Antioxidant Activity of Iodine 108 Dietary Sources of Iodine 110 Iodine Defi ciency Disorders 111 Human Brain Evolution 113 Thyroid Hormone, Iodine, and Human Brain Evolution 117 Conclusion 118 References 119 Chapter 7 Food For Thought: The Role of Coastlines and Aquatic Resources in Human Evolution 125 Jon M. Erlandson Introduction 125 Food for Thought 126 Human Nutrition and Physiology 127 Archaeological Evidence for the Antiquity of Fishing 128 Conclusions 132 Acknowledgments 133 Notes 133 References 133 Chapter 8 The Case for Exploitation of Wetlands Environments and Foods By Pre-Sapiens Hominins 137 Kathlyn M. Stewart Introduction 137 Hominid Exploitation of Wetlands Environments and Resources 139 Early Hominins: Colonization of New Environments 144 Plio-Pleistocene Climate Instability and Use of Wetlands Resources 147 Intensification of Wetlands Vegetation Exploitation 149 The Shift to High-Quality Foods 151 Preconditions for Encephalization 155 Precessional Forcing, Drying Lakes/Rivers, and Die-Offs of Aquatic Faunas 157 Mammal Meat: A Later Hominin Adaptation? 158 Postscript: H. heidelbergensis and H. sapiens 160 Summary 161 Acknowledgments 162 References 162 Chapter 9 Brain Size in Carnivoran Mammals That Forage at the Land–Water Ecotone, with Implications for Robust Australopithecine Paleobiology 173 Alan B. Shabel Introduction 173 Methods 177 Results 177 Discussion 183 Acknowledgments 186 References 186 Chapter 10 Coastal Diet, Encephalization, and Innovative Behaviors in the Late Middle Stone Age of Southern Africa 189 John Parkington Introduction 189 Changes 190 Climate Change 196 A New Narrative 198 References 200 Chapter 11 Human Brain Evolution: A New Wetlands Scenario 203 Stephen C. Cunnane and Kathlyn M. Stewart Human Brain Evolution 203 Neurochemical and Nutritional Evidence 203 The Fossil Evidence 204 Plausibility, Prediction, and Parsimony 205 Salient Points 206 Conclusion 207 Reference 207 Index 209