Virtually all aspects of human behavior show enormous variation both within and between cultural groups, including material culture, social organization and language. Thousands of distinct cultural groups exist: about 6,000 languages are spoken today, and it is thought that a far greater number of languages existed in the past but became extinct. Using a Darwinian approach, this book seeks to explain this rich cultural variation. There are a number of theoretical reasons to believe that cultural diversification might be tree-like, that is phylogenetic: material and non-material culture is clearly inherited by descendants, there is descent with modification, and languages appear to be hierarchically related. There are also a number of theoretical reasons to believe that cultural evolution is not tree-like: cultural inheritance is not Mendelian and can indeed be vertical, horizontal or oblique, evidence of borrowing abounds, cultures are not necessarily biological populations and can be transient and complex. Here, for the first time, this title tackles these questions of cultural evolution empirically and quantitatively, using a range of case studies from Africa, the Pacific, Europe, Asia and America. A range of powerful theoretical tools developed in evolutionary biology is used to test detailed hypotheses about historical patterns and adaptive functions in cultural evolution. Evidence is amassed from archaeological, linguist and cultural datasets, from both recent and historical or pre-historical time periods. A unifying theme is that the phylogenetic approach is a useful and powerful framework, both for describing the evolutionary history of these traits, and also for testing adaptive hypotheses about their evolution and co-evolution. Contributors include archaeologists, anthropologists, evolutionary biologists and linguists, and this book will be of great interest to all those involved in these areas.

" This book] brings together high-quality papers from many different fields: endocrinology, evolutionary biology, demography, economics, psychology, sociology, anthropology... It can be seen as a practical tool for researchers in the field, and it provides a large amount of data across a wide range of populations and helps to find a common ground between theories emerging from different fields. It is the kind of book that will never end up in the last dusty row of your shelves because you will continually refer to it, picking up here and there empirical and theoretical data for the next decades." BioOne. Research Evolved

From a comparative perspective, human life histories are unique and raising offspring is unusually costly: humans have relatively short birth intervals compared to other apes, childhood is long, mothers care simultaneously for many dependent children (other apes raise one offspring at a time), infant mortality is high in natural fertility/mortality populations, and human females have a long post-reproductive lifespan. These features conspire to make child raising very burdensome. Mothers frequently defray these costs with paternal help (not usual in other ape species), although this contribution is not always enough. Grandmothers, elder siblings, paid allocarers, or society as a whole, help to defray the costs of childcare, both in our evolutionary past and now. Studying offspring care in a various human societies, and other mammalian species, a wide range of specialists such as anthropologists, psychologists, animal behaviorists, evolutionary ecologists, economists and sociologists, have contributed to this volume, offering new insights into and a better understanding of one of the key areas of human society.

Gillian Bentley is a biological anthropologist and reproductive ecologist and a Royal Society Research Fellow at University College London. Her prior work focused on explaining why different human populations occupying a range of environments have varying levels of reproductive hormones. She now directs projects that interface with reproduction and reproductive health, working with the migrant Bangladeshi community in London. Recent publications include "Infertility in the Modern World: Present and Future Prospects, " edited with C.G.N. Mascie-Taylor (Cambridge University Press, 2000).

Ruth Mace is Professor of Evolutionary Anthropology at University College London. She works on the evolutionary ecology of social and subsistence systems. Particular interests include parental investment, mainly in African populations but also in the UK, and also macro-evolutionary studies on the evolution of cultural diversity. Recent publications include "The Evolution of Cultural Diversity: A Phylogenetic Approach, " edited with C. Holden and S. Shennan (UCL Press, 2005).

From a comparative perspective, human life histories are unique and raising offspring is unusually costly: humans have relatively short birth intervals compared to other apes, childhood is long, mothers care simultaneously for many dependent children (other apes raise one offspring at a time), infant mortality is high in natural fertility/mortality populations, and human females have a long post-reproductive lifespan. These features conspire to make child raising very burdensome. Mothers frequently defray these costs with paternal help (not usual in other ape species), although this contribution is not always enough. Grandmothers, elder siblings, paid allocarers, or society as a whole, help to defray the costs of childcare, both in our evolutionary past and now. Studying offspring care in a various human societies, and other mammalian species, a wide range of specialists such as anthropologists, psychologists, animal behaviorists, evolutionary ecologists, economists and sociologists, have contributed to this volume, offering new insights into and a better understanding of one of the key areas of human society.