Biological Anthropology: Concepts and Connections

PREFACE xvi

ABOUT THE AUTHOR xxi

Introduction

FAQs For Biological Anthropology   3

How Old Is the Planet and What Organisms Have Lived on It Over That Time? 3

If Life on Our Planet Has Changed So Much Over Time, What About the Planet Itself? 6

Have Humans Changed? 6

Where Did Modern Science Come From? 7

Where Is Uzbekistan? 8

Chapter 1 Introduction to Evolutionary Fact and Theory  13

Anthropology Is the Study of Human and Nonhuman Primates 15

Anthropology Is a Scientific Discipline 16

Critical Thinking Is the Systematic Assessment of Information 16

The Scientific Method Is a Way of Testing Ideas About the World Around Us 18

Connections: That’s a Fact, Jack . . . Or Is It? 19

Scientific Investigation Is a Collaborative Process 21

Evolutionary Theory Is the Cornerstone of Anthropology 22

Evolution Is Both Fact and Theory 22

Connections: Making a Monkey Out of You? 22

Early Explanations of Life Were Both Philosophical and Religious 23

The Scientific Revolution Opened the Door to Systematic Study of the World 25

Evolutionary Thought Emerged From Scientific Collaboration 26

Charles Darwin Proposed Natural Selection as the Mechanism of Evolution 31

Connections: Can You Understand Evolution and Be Religious? 39

What We Know/Questions That Remain 40

Summary 40

Critical Thinking 41

Resources 42

References 43

Chapter 2 Basics of Human Biology 45

The Place of Human Beings in Nature 47

Where Do Humans Fit In? 47

Connections: Why Do Monkeys Look Like Little People and Our Dogs Understand Us? 47

How Are Relationships Among Organisms Determined? 48

Human Morphology: The Body’s Form and Structure 49

Tissues Cover Us and Bind Us Together 49

The Skeleton: Our Basic Form 50

The Musculature Interacts With the Skeleton 55

Connections: My Bones Ache... 55

All Mammals Share Common Skeletal Structures 55

Human Physiology: The Systems of the Body 57

The Circulatory and Respiratory Systems Transport Nutrients and More 57

The Nervous System and Brain Control the Actions of the Body and Assess the

Organism’s Surroundings 58

The Endocrine System Regulates and Communicates Hormonal Information

Throughout the Body 60

The Digestive System Processes Nutrients 61

The Reproductive System Enables Us to Produce Offspring 62

Connections: Whoa, Where Did That Come From? The Fascinating

Development of Human Genitals 64

All of These Systems (and More) Are Interconnected 64

What We Know/Questions That Remain 65

Summary 66

Critical Thinking 66

Resources 67

Chapter 3 Introduction to Genetics and Genomics 69

Heredity Is the Passing of Genetic Information From Generation to Generation 70

Connections: “Gene”—What Is in a Word? 71

DNA Is the Molecule of Heredity 72

DNA Is Found in Cells 72

DNA Has a Specific Structure 73

DNA Has Three Main Functions 74

Connections: Why It Is Important to Understand What DNA Does 82

Mendel’s Basic Model of Inheritance 82

Traits Are Passed From Generation to Generation 82

Mendel’s Work Continues to Inform Current Knowledge 84

The Relationship Between Genes and Traits Is Complex 85

Four Ways Genes Produce Traits 86

Are There Specific Genes for Certain Diseases? 87

Most DNA Doesn’t Appear to Do Anything! 87

Does DNA Cause Certain Behaviors? 88

Connections: My Genes Made Me Do It! 88

Population Genetics Helps Us Understand Evolution 89

What We Know/Questions That Remain 90

Summary 91

Critical Thinking 91

Resources 92

References 93

Chapter 4 Modern Evolutionary Theory 95

Evolutionary Change Occurs In Populations In Four Ways 96

Mutations Are Changes in the DNA 98

Gene Flow Is the Movement of Alleles Within and Between Populations 99

Genetic Drift Is a Change in Allele Frequency Across Generations Due to Random Factors 100

Current Concepts of Natural Selection Involve an Understanding of Genetics 101

Connections: Survival of the Fittest? Not Really 104

Speciation Is the Process by Which New Species Arise 108

Species Can Be Defined in Many Ways 108

Connections: Species, Schmeecies . . . I Know One When I See It and So Do They 109

Subspecies Are Divisions Within a Species 110

Phyletic Gradualism and Punctuated Equilibrium: Different Paces of Change 111

Similarities Can Result From Either Parallel or Convergent Evolution 112

Biodiversity in Evolution: Why We Should Care About Biological Variation 113

Connections: Why Conserve Stuff Anyway? 114

What We Know/Questions That Remain 115

Summary 115

Critical Thinking 116

Resources 117

References 117

Chapter 5 Primate Behavioral Ecology 119

Comparative Primatology Provides Insights Into Modern Human Behavior 120

The Living Primates Are Widespread and Diverse 120

Comparing the Primates Helps Us Understand Behavior 127

Connections: Monkey See, Monkey Do, and Humans Too? 129

To Study Behavior, We Have to Measure It 129

Specific Methodologies Are Used to Measure Primate Behavior 129

A Behavior Can Be Viewed From Five Perspectives 130

Behavior and Genetics Are Interconnected 131

Behavioral Ecology Provides the Basis for Evolutionary Investigations of Behavior 132

Socioecological Pressures Affect Organisms in Five Areas 132

Success of a Behavioral Adaptation Is Measured in Terms of Energy Costs

and Benefits 133

Reality Is More Complex Than Suggested by Cost-Benefit Analyses 135

Connections: Are All Men Jerks? 136

General Behavior Patterns in the Living Primates 137

Mother-Infant Bonds Are the Core of Primate Societies 137

There Are a Few Primary Grouping Patterns in Primates 138

Affiliation and Grooming Are Important in Primate Societies 138

Hierarchies and Dominance Help Structure Primate Societies 139

Dispersal and Life History Patterns Are Important to Social Behavior 140

Cooperation and Conflict Are Integral to Primate Societies 141

Social Organization in Two Nonhuman Primate Societies: Macaques and Chimpanzees 141

Macaques: A Widespread Primate Genus 141

Chimpanzees: Our Closest Relatives 146

Humans Are Also Primates, and Human Behavior Has an Evolutionary History 151

Social Organization and Behavior in Humans 152

Comparisons With Macaques 152

Comparisons With Chimpanzees 153

What Is Uniquely Human? 154

Connections: Why We Never Shut Up 154

What We Know/Questions That Remain 155

Conserving the Nonhuman Primates Is a Critical Challenge 156

Summary 156

Critical Thinking 157

Resources 158

References 158

Chapter 6 Early Primate Evolution 161

Fossils Provide Direct Evidence of an Organism’s Existence 162

Humans Are Members of the Order of Mammals Called Primates 165

A Very Brief History of the Mammals 165

Connections: Homiothermy is Cool! 167

Primates Are Mammals With Specific Characteristics 167

The Fossil Primates 168

The Earliest Possible Primates Are Found in the Paleocene 168

Why Did Primates Evolve Out of Early Mammalian Groups? 170

True Primates Appear in the Eocene 171

Anthropoids (Simiiformes) Radiate in the Oligocene 173

Connections: Why Care About 30-Million-Year-Old Dead Primates? 174

Hominoid Primates Radiate During the Miocene 176

Connections: Ok, So Is Gigantopithecus Bigfoot? 181

Nonhominoid Anthropoid Primates Radiate During the Pliocene and Pleistocene 182

Evolutionary Relationships Among These Fossil Primates Area Matter of Debate 182

What We Know/Questions That Remain 184

Summary 184

Critical Thinking 185

Resources 185

References 186

Chapter 7 Early Hominin Evolution 189

Connections: Why Walking on Two Legs Makes Birth Painful for Mom 191

Classification of Hominids/Hominins Is a Subject of Debate 191

Early Hominins Evolved Primarily in East Africa 195

Early Possible Hominins 196

Hominins of the Middle and Late Pliocene Were Bipedal and Sexually Dimorphic 200

Connections: Big Guys With Small Teeth Rock! 203

Were There Early Hominins in Southern Africa? 205

Evolutionary Relationships Are Unclear 205

Fossils Give Us Clues About Early Hominin Behavior 206

Habitat: Where They Lived 207

Diet: What Did They Eat, and How Did They Get It? 207

Tools: Did They Use Bone, Wood, or Stone Tools? 207

Social Life: How Did They Live Together? 208

The Bipedalism That Wasn’t 208

Connections: Hyenas, Wolves, and Saber-Toothed Cats, Oh My! 209

The Evolution of Bipedality Has Several Possible Explanations 209

What We Know/Questions That Remain 211

Summary 212

Critical Thinking 213

Resources 213

References 214

Chapter 8 Plio-Pleistocene Hominins and the Genus Homo 217

Changes at the Late Pliocene-Pleistocene Boundary 219

The Robust Hominins Had Unique Cranial and Dental Anatomy 220

The Genus Paranthropus: Hominins With Massive Chewing Adaptations 220

Robust Hominin Behavior 225

The Gracile Hominins Shared Characteristics With Both Earlier and Later Groups 226

Genus Australopithecus: Three Plio-Pleistocene Forms 226

Are These Australopithecines Ancestral to Humans? 230

Early Homo: A New Genus Emerges 231

Connections: Where Is the Missing Link? 232

Gracile Hominin Behavior and the Advent of Biocultural Evolution 235

The Genus Homo Diversifies: The First Humans 237

A Classification Debate: One Genus but How Many Species? 238

Physical Characteristics of H. erectus 240

Geographic Distribution of H. erectus 241

Connections: Is that You Frodo? Ardi? 243

When Did Hominins Expand Beyond Africa? 245

Why Did Hominins Expand Beyond Africa? 246

1. erectus Material Culture and the Expansion of the Biocultural Evolution 246

Connections: What’s the Deal With Fire? 250

What We Know/Questions That Remain 251

Summary 252

Critical Thinking 253

Resources 253

References 254

Chapter 9 The Rise of Modern Humans 257

Archaic Homo Sapiens and the Changing Speed of Innovation 259

The Oldest Archaic Human Fossils Are Found in Africa 259

Archaic Human Fossils Are Found Across Eurasia 261

Archaic Humans Are Found in China but Not in Southeast Asia 262

Is Homo heidelbergensis a True Species? 264

The Neanderthals Were Not as Different as First Thought, but They Were Different 264

Connections: I’m No Neanderthal! 266

Material Culture of the Archaic Humans 267

Increased Complexity in Tool Use and Hunting 267

Dietary and Behavior Changes Associated With New Tool Kits 268

Social Patterns: High Levels of Communal Cooperation 269

Postmortem Modification of Bodies 270

Why Did the Neanderthals Disappear? 270

The Appearance of “Anatomically Modern” Homo sapiens 272

Anatomically Modern Humans Are Defined Morphologically, Not Behaviorally 272

The Earliest Anatomically Modern Fossils Are Found in Africa 273

The Eurasian Record Demonstrates the Spread of Modern Humans 274

Blades and Associated Industries Revolutionized the Human Tool Kit 277

Changing Technologies and Behavioral Patterns Affected Diet 279

Modern Humans Used Art and Symbols 279

Connections: Art for Art’s Sake? 281

Burial of the Dead Was Ubiquitous and Postmortem Modification Common 282

Connections: Why We Love Our Dogs (At Least Some of Us Do) 282

Current Human Patterns Began to Emerge 20,000 Years Ago 283

The Origin of Modern Humans Is a Matter of Debate 283

The Case for a Recent African Origin 284

The Case for Multiregional Evolution 287

The Case for Multiple Dispersals 288

As Usual, Reality Is Not This Clear 289

What We Know/Questions That Remain 290

These Models Influence the Way We Think About Human Differences 291

Summary 291

Critical Thinking 292

Resources 293

References 293

Chapter 10 Human Biological Diversity in Context 297

A Basic Summary of Human Evolution: The Origin of Behavioral and Biological Diversity 299

Humans Have Long Exhibited Biological Diversity 300

A Visible but Misunderstood Variation: Skin “Color” 301

Connections: Everyone Tans! But Skin Color is Still Culturally Defined 302

Another Visible Difference: Body Shape and Size 305

A Cornerstone of Variation Research: Skull Morphology 307

Connections: Skulls Are Us? 307

Sex Differences Are Seen in the Skeletal and Soft Tissue of Humans 309

The Impact of Disease Environments: Variation in the Human Immune System 311

Blood Groups Vary Within and Across Populations 312

Most Genetic Variation Is Found Within Populations 314

Human Biological Diversity Is Best Explained Using a Biocultural Approach 315

Natural Selection and Human Cultural Behavior 316

Examples of Selection and Adaptation in Human Variation 317

Race Is A Very Poor Way to Describe Variation In Homo Sapiens Sapiens 321

What Is the Evidence Regarding Biological Races in Humans? 322

Connections: Is High Blood Pressure a Black Thing? 324

There Is a Scientific Study of Human Biological Variation 325

Why Does the Notion of Biological Race Persist? 326

A Very Brief History of Racism 326

Modern Notions Are Also Due to a Lack of Context 328

What We Know/Questions That Remain 331

Summary 332

Critical Thinking 332

Resources 333

References 334

Chapter 11 The Present and Future of Human Evolution 337

How Do We Study Human Behavioral Evolution? 338

Sociobiology 338

Human Behavioral Ecology (HBE) 339

Evolutionary Psychology (EP) 339

Dual-Inheritance Theory (DIT) 340

Biocultural Approaches to Studying Modern Humans 341

A Modern Approach to Studying the Evolution (Past and Future) of Human Behavior 341

Humans Are Still Evolving 343

Diseases and Modern Humans 343

Connections: Can Evolutionary Perspectives Be Applied to Modern Medicine? 346

Cultural Patterns Influence Morphology 348

Culture, Evolution, and the Future: Where Are We Headed? 352

Human Densities and Global Population Are Dramatically Different Today 352

Genetic Manipulation Can Influence Our Evolution 356

Connections: Where Is That Banana From? 357

Some of Our Behavior Reflects Adaptations 357

Understanding Biological Anthropology and Understanding Ourselves 358

What We Know/Questions That Remain 359

Summary 359