Diseases and Human Evolution

Preface

Preface We often ignore the invisible world around us, full of microbes and detritus; we go about our business unaware of our constant interaction with it. Most of the time no harm comes from this. But once in a while throughout our lifetimes, we all confront some invisible microbe or substance that challenges our immune systems to the point of causing disease. How we survive the onslaught depends on several factors—primarily, our genetic programming; the type of germ; and our health status, which includes nutrition, our age, and our own behavior. For most of human history, geography determined what kind of microbes could attack humans. Geography restricted most microbes to specific regions of the world until humans began making the climb toward civilization with the development of agriculture and animal husbandry. Evolving commerce with its long-distance trade routes, crossing various geographic regions throughout the Old World, opened routes for many microbes to spread beyond their original areas. The pace for dispersing germs accelerated through time, particularly with European industrialization and colonization. Today we live in a global community, sharing many microbes that once remained limited to certain regions of the globe. Human evolution can be viewed both as biological and cultural, with cultural evolution causing the most dramatic changes in human history over the past fifteen thousand years. As we have marched toward the modern world, we have affected the microbial world around us and created many of our own human diseases. xi This book focuses on the changes in the patterns of human behavior through cultural evolution and how they have affected the development of human diseases. I have drawn on the work of many researchers in various scientific fields to put together a comprehensive picture of the history and major trends of human diseases. Complex details have been explained in the simplest terms for the benefit of the interested general reader and student. The purpose of this book is to provide basic knowledge to help readers understand how human behavior affects patterns of disease, so that they can better understand the diseases they themselves face. I am grateful to my husband, Art Rohn, for his patience, editorial comments , and encouragement to research and write this book. Also, I thank Charles Williams III for supporting my research at ancient Corinth and for his constant encouragement with this project. xii Preface ...