Paperback, acid-free paper, pp. xii + 535, 55 tables, 105 figures Taxonomic and subject indexes. Also available clothbound (ISBN 0-412-02381-4, ยฃ49.00) Birth, growth, reproduction and death, these components of the life history of an organism are the fundamentals of biological existence. The exquisite details of molecular biology, biochemistry, physiology, development and behaviour are simply the mechanisms by which life histories are achieved. But why, when we survey the range of living organisms, do we see such a diversity of life histories? How does this diversity relate to the environments in which the life histories are played out? How will life history patterns chdnge as the environmental conditions change? From the pioneering studies of R.A. Fisher, Lamont Cole and G.C. Williams, life history theory has developed as biologists have sought to answer these questions. The theory assumes that natural selection operates on life history traits, tending to maximize some measure of fitness. But this process takes place against a background of trade-offs and constraints which restrict what combinations of traits are biologically possible. Professor Roff has been an important contributor to the development of this theory, and particularly its application to insects and fishes. With life history theory coming of age, Roff reviews its present state of development in this book of 535 pages.
The first four chapters set the scene for the main themes of the book. Chapter 1 defines the problems that are the subject of life history theory. Chapter 2 provides a dense review of quantitative genetics, noting that for life history traits to evolve under natural selection, there must be genetic variation for those traits in the evolving populations. Chapter 3 introduces the concept of global measures of fitness, a concept central to life history theory. In Chapter 4, the mathematical techniques used in the development of life history theory are reviewed. The emphasis is on the use of calculus (linked to an appendix giving a brief review of differentiation), but dynamic programming and the use of matrices are also briefly described. Chapters 5 and 6 discuss the two central components of life history theory: age and size schedules of births and deaths as summarized in life tables (Chapter 5), and the concept of the cost of reproduction (Chapter 6). This latter chapter makes the important point that the question is now not whether there are costs, but under what circumstances and in what ways a cost is exhibited. Chapter 7 reviews models that seek to predict the age and size at maturity and includes a good discussion of Roff's own model for teleost fishes. Reproductive effort in relation to semelparous and iteroparous life histories is the subject of Chapter 8. Chapters 9 and 10 describe the application of life history theory to the questions of how many offspring should be produced per breeding attempt (clutch size) and how large each propagule should be. In 'Last Thoughts', Roff reviews the main theses argued in the text and poses five questions relevant to the future development of life history theory. There are useful systematic and subject indexes.
The book is evidently written for postgraduates and research workers. It is impressive in the detail in which the various models are analysed, discussed and related to eLnpirical data (always a strength of Roff's work). There is a long, valuable bibliography. The organization of chapters weakens the book because the first four form a dense obstacle