K.J. Gaston – författare

Population and community biology have been based largely on studies of abundant and widespread species. Most species are neither. This study draws together information from different disciplines on rarity. It draws general principles, focusing on the definition and measurement of rarity, its spatial and temporal dynamics, and its causes and interactions with conservation. Rare species are of particular concern to conservation because they tend to have a greater probability of extinction. This book should be of interest to conservation biologists, ecologists, environmental scientists and animal behaviourists.

Most of what we know about the biological world comes from the study of common species, but most species are rare. The bias in our knowledge-base is of particular concern because rare and common species may, and indeed often do, differ in more ways than just their abundance patterns. The editors of this volume had previously reported in the literature a repeated pattern of low dispersal abilities, high levels of self-compatibility, and low reproductive effort among rare species. The purpose of this volume is to further document the existence of rare-common differences and to elucidate the various processes that may contribute to their creation. Rare species and the subject of rarity itself have gained increasing attention in recent years. This book addresses an aspect of their biology, bringing insights from a variety of disciplines to bear on the causes and implications of differences between rare and common species. The book should interest not only those concerned with rare species but also those of more theoretical leanings, as it addresses the fundamental question of how various ecological and evolutionary processes can contribute to the formation of pattern.

This book began life as a review article. That article spawned a symposium which was, in turn, greatly expanded to form the present volume. As the project moved through these developmental stages (hopefully, towards attainment of its full maturity), a number of people have provided invaluable assistance to us, and we would like to take this opportunity to thank them. Gordon Orians must certainly take a high place in that list. He has been both a friend and mentor to W.E.K., and many of the topics explored in this book have emerged from the resultant dialogue. His thought processes, ideas and perhaps even some of his turns of phrase emerge throughout much ofthe book. Gordon also played a pivotal role in inviting in motion, and so he has served as a catalyst the article that set this project to the book as well as one of its reagents. While he has not served as an editor of this book, he is one of its authors in more than just the literal sense.

To say you are writing about rarity is to invite two kinds of response. Either one provokes a discussion of what rarity is, or some comment on the complex­ ity of the subject. The objective of this book is to explore the nature of rarity, its complexity if you like, from one particular perspective on what rarity is. Primarily, it is an opportunity to review, to synthesize, and to question. The book is an attempt to draw together a vast body of literature, to extract from it some general principles, and to raise question marks over areas the founda­ tions of which appear to be either absent or crumbling. A perusal of prefaces suggests that they often dwell as long upon what a book is not about, as upon what it does concern. True to such a tradition, I should state that this is specifically not a book about conservation, although in some quarters anything about rarity is viewed as something about conser­ vation. Nor does it contain more than a passing reference to the undoubtedly important issues of the role of genetics in rarity. Examples have been drawn from a wide variety of taxa. They are, nonethe­ less, somewhat depauperate in cases from marine systems. In part this bias results from the unevenness of my familiarity with the literature, in part it perhaps also reflects differences in the questions asked and approaches to the study of communities and assemblages in terrestrial and marine systems.

This book began life as a review article. That article spawned a symposium which was, in turn, greatly expanded to form the present volume. As the project moved through these developmental stages (hopefully, towards attainment of its full maturity), a number of people have provided invaluable assistance to us, and we would like to take this opportunity to thank them. Gordon Orians must certainly take a high place in that list. He has been both a friend and mentor to W.E.K., and many of the topics explored in this book have emerged from the resultant dialogue. His thought processes, ideas and perhaps even some of his turns of phrase emerge throughout much ofthe book. Gordon also played a pivotal role in inviting in motion, and so he has served as a catalyst the article that set this project to the book as well as one of its reagents. While he has not served as an editor of this book, he is one of its authors in more than just the literal sense.