PREFACE The human species may be the most widespread species in the world today. Humans have been moving tremendous distances ever since Homo erectus moved out of Africa. To highlight this fact, this uniqueness of humans, we have prepared a new box feature for this edition which we call Migrants and Immigrants.” Almost half the chapters now contain a box about some aspect of the movement of people, ranging from prehistory to recent times. Examples are research on when hominids first migrated out of Africa, possible routes humans may have taken in their migration to the Americas, the spread of foods in recent times, arranging marriages in the diaspora, and the problem of refugees. We have decided to reintroduce a separate chapter on theoretical approaches in cultural anthropology, which reviewers suggested. The separate chapter on Explanation and Evidence” now has new material on ethics in fieldwork and an expanded discussion of cross-cultural research. Ethical issues are also given more attention in various other chapters. In updating the book, we try to go beyond descriptions, as always. We are interested not only in what humans are and were like; we are also interested in why they got to be that way, in all their variety. When there are alternative explanations, we try to communicate the necessity to evaluate them logically as well as on the basis of the available evidence. Throughout the book, we try to communicate that no idea, including ideas put forward in textbooks, should be accepted even tentatively without supporting tests that could have gone the other way.Ember, Carol R. is the author of 'Anthropology ', published 2006 under ISBN 9780132277532 and ISBN 0132277530.