D. Briggs & S.M. Walters
Pp. xxi + 512. Cambridge University Press, Cambridge.
?22·95 (paperback), ISBN 0-521-45918-4.
The first edition of this book (Briggs & Walters 1969) was published by Weidenfeld & Nicolson in a paperback version which fell to pieces almost immediately it was used. This made such a useful review of recent developments in the study of plant evolution almost useless to students. The second edition, taken over by Cambridge University Press (Briggs & Walters 1974), was largely rewritten. It both extended and developed the scope of the book and, at the same time, did not fall to pieces. It also introduced some intriguing insights into the historical development of the subject – aspects rarely covered in undergraduate classes today and often not understood by new researchers. By the time the second edition was being prepared, some 11 years later, the authors had recognized that the ‘deme’ terminology which they had widely employed in the first edition had not really gained widespread acceptance, and the use of the terms was largely abandoned.
The second edition became almost a classic work and so it is with satisfaction that we now have a third edition of a highly recommendable book. The first five chapters remain practically unaltered and still provide the historical approach, which gave so much insight into the development of the subject in the second edition. Importantly for the book, the development and use of molecular techniques has begun to make significant contributions to the study of plant variation and evolution, and intrigues us with the prospects for its future contribution. In an ironic twist the authors could not have anticipated how far the very first line of their original introduction in 1969 (‘we live in an age of molecular biology’) was going to be fulfilled in the third edition of their book. Then, those of us that studied the traditional branches of biology were perceived as old fashioned scientists being pushed aside by ‘modern’ molecular biologists and this was what Briggs and Walters were concerned about. To some extent this is still true even now, and it is extraordinary how little botany actually finds its way into the undergraduate biologist's (or even plant scientist’s) curriculum. Rather than finding that the study of variation was being overtaken by molecular biology, it has turned out that the new discipline is bringing substantial benefits to our understanding of evolution and population structure and so it is being fully incorporated into the studies of plant biosystematics and genecology. It is these new dimensions to the subject which are fully explored in the third edition.
The molecular basis of variation is newly described in chapter 6 (including electrophoresis and the development of DNA studies) in order that the molecular approaches to plant variation and evolution presented in the later chapters can be fully appreciated by the reader. The chapters on hybridization, genecology and speciation all contain valuable insights into the present contribution of, and the potential future role for, molecular techniques in their study.
Some practical help is given to students of plant variation to undertake project work and know which sampling methods to use and how to analyse statistically the data obtained. The chapter on evolution now contains a discussion of cladistics that all taxonomists should read, and adds some original comments on the much talked about (but often improperly understood) transgenic plants. The final chapter explores the obvious link that exists between an understanding of plant variation and conservation, and this edition now discusses threats to biodiversity (called ‘bildiversity’ in the index!) and includes the new IUCN categories, genetics of small populations and methods for protection and recovery (and a thoughtful two pages on the arguments for conservation). A glossary and an extensive bibliography are provided.
The authors draw their examples from wild and cultivated plants (look up Triticum and you will find all the recent studies on the origin of bread wheats and the present uncertainties about their ancestry) and with no schism between pure and applied aspects of plant biology.
The book is principally designed for readers to improve their understanding of plant variation and evolution. The topic is splendidly described and thoroughly discussed throughout. The new edition accurately reflects current developments in the subject and the opportunity has been taken by the authors to further improve its usefulness to undergraduates, teachers and researchers. There is no other comparable text available. As a textbook on variation in plants, this book is a classic.