Theoretical Studies on Sex Ratio Evolution. (MPB-22), Volume 22


Book Description

This book deals with a key area of population genetics: the ratio of the sexes in a population, or the allocation of resources to male versus female reproductive function. Samuel Karlin and Sabin Lessard establish the formal theoretical aspects of the evolution of sex ratio within the constraints of genetic mechanisms of sex determination. Their results generalize and unify existing work on the topic, strengthening previous conceptions in some cases and, in other instances, offering new directions of research. There are two main approaches to understanding the causes and effects of sex ratio. One approach focuses on the optimization and adaptive functions of sex allocation, while the other emphasizes the consequences of genetic sex determination mechanisms. In discussing the utility of these two approaches, Professors Karlin and Lessard examine the principal sex-determining mechanisms and facts involved in sex ratio representations, the various genetic and environmental factors that contribute to adaptive sex expression, and the evolution of sex determining systems and controls. From a population genetic perspective, the authors derive evolutionary properties in support of the high incidence of 1:1 sex ratio in natural populations and investigate the conditions that can explain the occurrence of biased sex ratio.




Theoretical Studies on Sex Ratio Evolution


Book Description

This book deals with a key area of population genetics: the ratio of the sexes in a population, or the allocation of resources to male versus female reproductive function. Samuel Karlin and Sabin Lessard establish the formal theoretical aspects of the evolution of sex ratio within the constraints of genetic mechanisms of sex determination. Their results generalize and unify existing work on the topic, strengthening previous conceptions in some cases and, in other instances, offering new directions of research. There are two main approaches to understanding the causes and effects of sex ratio. One approach focuses on the optimization and adaptive functions of sex allocation, while the other emphasizes the consequences of genetic sex determination mechanisms. In discussing the utility of these two approaches, Professors Karlin and Lessard examine the principal sex-determining mechanisms and facts involved in sex ratio representations, the various genetic and environmental factors that contribute to adaptive sex expression, and the evolution of sex determining systems and controls. From a population genetic perspective, the authors derive evolutionary properties in support of the high incidence of 1:1 sex ratio in natural populations and investigate the conditions that can explain the occurrence of biased sex ratio.




Sex Ratios


Book Description

Sex ratios, the proportions of males and females in any given species, are important in evolutionary and behavioural ecology. This volume explores the context to and methods for many aspects of research on sex ratios, and will be an indispensable reference for all those working in this area.




The Theory of Sex Allocation. (MPB-18), Volume 18


Book Description

This book is the first comprehensive treatment of sex allocation from the standpoint of modern evolutionary theory. It shows how the determination of sex ratio, resource allocation to sperm versus egg within simultaneous hermaphroditism, and the evolution of sex reversal can he explained as examples of a single process. The genetical theory, developed mostly with graphical arguments, also specifies when hermaphroditism and dioecy are themselves evolutionary stable. The work balances theory with field and laboratory research, providing critical tests of the theory by empirical studies of sex ratio in parasitoid wasps and mites, sex reversal in shrimp and coral reef fish, and allocation of resources to pollen versus seeds in higher plants. In addition, the author oilers an encyclopedic review of the field and laboratory work of other scientists, reviews many as yet untested hypotheses in sex allocation, and points toward numerous plant and animal systems that hold promise for future tests.







Social Evolution in Ants


Book Description

Biologists have long been intrigued and confounded by the complex issues in the evolution and ecology of the social behaviour of insects. The self-sacrifice of sterile workers in ant colonies has been particularly difficult for evolutionary biologists to explain. This text presents an overview of the current state of scientific knowledge about social evolution in ants and shows how studies on ants have contributed to an understanding of many fundamental topics in behavioural ecology and evolutionary biology.




Sex Allocation


Book Description

Recent decades have witnessed an explosion of theoretical and empirical studies of sex allocation, transforming how we understand the allocation of resources to male and female reproduction in vertebrates, invertebrates, protozoa, and plants. In this landmark book, Stuart West synthesizes the vast literature on sex allocation, providing the conceptual framework the field has been lacking and demonstrating how sex-allocation studies can shed light on broader questions in evolutionary and behavioral biology. West clarifies fundamental misconceptions in the application of theory to empirical data. He examines the field's successes and failures, and describes the research areas where much important work is yet to be done. West reveals how a shared underlying theoretical framework unites findings of sex-ratio variation across a huge range of life forms, from malarial parasites and hermaphroditic worms to sex-changing fish and mammals. He shows how research on sex allocation has been central to many critical questions and controversies in evolutionary and behavioral biology, and he argues that sex-allocation research serves as a key testing ground for different theoretical approaches and can help resolve debates about social evolution, parent-offspring conflict, genomic conflict, and levels of selection. Certain to become the defining book on the subject for the next generation of researchers, Sex Allocation explains why the study of sex allocation provides an ideal model system for advancing our understanding of the constraints on adaptation among all living things in the natural world.




Social Evolution in Ants


Book Description

Biologists since Darwin have been intrigued and confounded by the complex issues involved in the evolution and ecology of the social behavior of insects. The self-sacrifice of sterile workers in ant colonies has been particularly difficult for evolutionary biologists to explain. In this important new book, Andrew Bourke and Nigel Franks not only present a detailed overview of the current state of scientific knowledge about social evolution in ants, but also show how studies on ants have contributed to an understanding of many fundamental topics in behavioral ecology and evolutionary biology. One of the substantial contributions of Social Evolution in Ants is its clear explanation of kin selection theory and sex ratio theory and their applications to social evolution in insects. Working to dispel lingering skepticism about the validity of kin selection and, more broadly, of "selfish gene" theory, Bourke and Franks show how these ideas underpin the evolution of both cooperation and conflict within ant societies. In addition, using simple algebra, they provide detailed explanations of key mathematical models. Finally, the authors discuss two relatively little-known topics in ant social biology: life history strategy and mating systems. This comprehensive, up-to-date, and well-referenced work will appeal to all researchers in social insect biology and to scholars and students in the fields of entomology, behavioral ecology, and evolution.




Evolutionary Community Ecology


Book Description

Cover -- Title -- Copyright -- Dedication -- Contents -- Acknowledgments -- 1. Ecological Opportunities, Communities, and Evolution -- 2. The Community of Ecological Opportunities -- 3. Evolving in the Community -- 4. New Species for the Community -- 5. Differentiating in the Community -- 6. Moving among Communities -- 7. Which Ways Forward? -- Literature Cited -- Index




Evolution in Age-Structured Populations


Book Description

The populations of many species of animals and plants are age-structured, i.e. the individuals present at any one time were born over a range of different times, and their fertility and survival depend on age. The properties of such populations are important for interpreting experiments and observations on the genetics of populations for animal and plant breeding, and for understanding the evolution of features of life-histories such as senescence and time of reproduction. In this new edition Brian Charlesworth provides a comprehensive review of the basic mathematical theory of the demography and genetics of age-structured populations. The mathematical level of the book is such that it will be accessible to anyone with a knowledge of basic calculus and linear algebra.