1 The biological diversity ofherding populations : an introduction

This volume evolved from a 1997 symposium held at the American Asso­ ciation for the Advancement of Science (AAAS) Meetings in Seattle, Washington. This symposium drew together the leading scholars of nomadic pastoralists from anthropology, demography, genetics and medicine. They focused upon the ecology and population biology of contemporary herding groups from Africa, Asia, Europe, and the Middle East. While previous publications have summarized sociocultural vari­ ation in pastoralist groups (see Barfield, 1993), no previous volume has attempted to merge the ecological, demographic, health, and biological facets of the herding existence. Nomadic pastoralists are of great fascination to the more sedentary westerners, who tend to romanticize the nomads for their free spirit, apparently unencumbered by geographical and political boundaries. Nomads are envied for their perceived freedom, being able to break camp and move on to the next pasture. Bruce Chatwin (a writer and adventurer) in an essay entitled "It's a Nomad Nomad World" (Chatwin, 1996) extended this romantic fascination to hypothesize that humans are naturally migratory and that sedentism is the cause of many of the ills of contemporary society. In this introduction, we begin by addressing several key questions about pastoralists: What is nomadic pastoralism, and why does it exist? Why are nomads constantly on the move? What common il'atures do the nomadic societies share? We will then provide an overview of the chapters in this volume, highlighting several central themes addressed throughout the volume.