Darwin identified the existence of separate male and female gametes as one of the central mysteries of evolutionary biology. 150 years later, the question of why male gametes exist remains an intriguing puzzle. In this, the first book solely devoted to the evolution of anisogamy, top theorists in the field explore why gamete dimorphism characterizes nearly all plants and animals. Did separate male and female gametes evolve as a result of competition, or does anisogamy instead represent selection for cooperation? If disruptive selection drove the evolution of anisogamy, with male gametes focused on search and fusion, and female gametes provisioning the new zygote, why do some algal species continue to produce gametes of a single size? Does sperm limitation, or escape from infection, better explain the need for extremely small, highly mobile sperm? Written by leaders in the field, this volume offers an authoritative and cutting-edge overview of evolutionary theory.
This book explores the relationship between various types of reproduction and the evolutionary process. Starting with the concept of meiosis, George C. Williams states the conditions under which an organism with both sexual and asexual reproductive capacities will employ each mode. He argues that in low-fecundity higher organisms, sexual reproduction is generally maladaptive, and persists because there is no ready means of developing an asexual alternative. The book then considers the evolutionary development of diverse forms of sexuality, such as anisogamy, hermaphroditism. and the evolution of differences between males and females in reproductive strategy. The final two chapters examine the effect of genetic recombination on the evolutionary process itself.
Sperm Biology represents the first analysis of the evolutionary significance of sperm phenotypes and derived sperm traits and the possible selection pressures responsible for sperm-egg coevolution. An understanding of sperm evolution is fast developing and promises to shed light on many topics from basic reproductive biology to the evolutionary process itself as well as the sperm proteome, the sperm genome and the quantitative genetics of sperm. The Editors have identified 15 topics of current interest and biological significance to cover all aspects of this bizarre, fascinating and important subject. It comprises the most comprehensive and up-to-date review of the evolution of sperm and pointers for future research, written by experts in both sperm biology and evolutionary biology. The combination of evolution and sperm is a potent mix, and this is the definitive account. - The first review survey of this emerging field - Written by experts from a broad array of disciplines from the physiological and biomedical to the ecological and evolutionary - Sheds light on the intricacies of reproduction and the coevolution of sperm, egg and reproductive behavior
These proceedings of the 2018 XIII International Symposium on Spermatology focus on comparative biology, and encourages discussion and the exchange of ideas. The aim of this Symposium was to provide a unique opportunity and bring together scientists from a wide spectrum of research fields – human, domestic animals and other mammals, vertebrates, insects, and plants. The underlying focus is on the function of the spermatozoon – a common feature for sexual reproduction, but extremely varied. By exploring the variability, a better understanding of male reproductive functions can develop. These proceedings address the mechanisms of physiology and pathophysiology, rather than diagnosis and treatment. The symposium featured keynote lectures by invited speakers, followed by presentations on specific aspects of the general topic of the session. Experimental studies are given priority over clinical studies of patient populations. The proceedings comprise both keynote speakers' texts and selected free communications. Posters were considered for publication in the proceedings, and the volume includes exhibited materials on the work of prominent spermatologists, highlighting their important past achievements in the field.
Sexual Biology and Reproduction in Crustaceans covers crustacean reproduction as it deals with the structural morphology of the gamete-producing primary sex organs, such as the testis and ovary, the formation and maturation of gametes, their fusion during fertilization, and embryonic development that lead to the release of larvae. Constituting a diverse assemblage of animals, crustaceans are best known by their common representatives, such as shrimps, lobsters, and crabs, but also include many more less familiar, but biologically important forms. This work covers the variety of ways in which both male and female gametes are produced by evolving different sexual systems in crustaceans, the range of reproductive systems, and the accordingly, and highly diverse, mechanistic modes of sex determination. In addition, the book features such topics as genetic and environmental determinants in sex determination pattern, variability of mechanisms of fertilization among different species, the origin of different mating systems, the associated mating and brooding behaviors, and the adaptive ability to different environmental conditions with discussion on the evolutionary ecology of social and sexual systems in certain species, which have shown eusocial tendencies, similar to social insects. Marine species occupying diversified ecological niches in tropical and temperate zones reproduce under definitive environmental conditions. Therefore, reproductive ecology of different crustaceans inhabiting different ecological niches also constitutes another important aspect of the work, along with yolk utilization and embryogenesis leading to release of different larval forms, which reflect on their aquatic adaptability. - Forms a valuable source of recent references on the current research in crustacean reproductive physiology - Covers various mating and breeding systems, providing illustrative examples for sexual selection, parental care of developing eggs and embryos, and the evolution of other reproductive behaviors - Features contributions written in the form of review articles, enabling readers to not only gain information in the respective subject, but also help them stimulate ideas in their chosen field of research - Includes a glossary created by the author to define technical terms - Demonstrates the ability of crustacean species to serve as useful model systems for other organisms, to investigate issues related to sexual conflict, mate choice, and sperm competition - Discusses techniques in endocrine research to help researchers in aquaculture develop protocols in the control of reproduction
This book contains the proceedings of the International Symposium on the Mechanisms of Sexual Reproduction in Animals and Plants, where many plant and animal reproductive biologists gathered to discuss their recent progress in investigating the shared mechanisms and factors involved in sexual reproduction. This now is the first book that reviews recent progress in almost all fields of plant and animal fertilization. It was recently reported that the self-sterile mechanism of a hermaphroditic marine invertebrate (ascidian) is very similar to the self-incompatibility system in flowering plants. It was also found that a male factor expressed in the sperm cells of flowering plants is involved in gamete fusion not only of plants but also of animals and parasites. These discoveries have led to the consideration that the core mechanisms or factors involved in sexual reproduction may be shared by animals, plants and unicellular organisms. This valuable book is highly useful for reproductive biologists as well as for biological scientists outside this field in understanding the current progress of reproductive biology.
This encyclopedia, representing one of the most multi-disciplinary areas of research, is a comprehensive examination of the key areas in animal cognition and behavior. It will serve as a complementary resource to the handbooks and journals that have emerged in the last decade on this topic, and will be a useful resource for student and researcher alike. With comprehensive coverage of this field, key concepts will be explored. These include social cognition, prey and predator detection, habitat selection, mating and parenting, development, genetics, physiology, memory, learning and perception. Attention is also given to animal-human co-evolution and interaction, and animal welfare. All entries are under the purview of acknowledged experts in the field.
Primary sexual traits, those structures and processes directly involved in reproduction, are some of the most diverse, specialized, and bizarre in the animal kingdom. Moreover, reproductive traits are often species-specific, suggesting that they evolved very rapidly. This diversity, long the province of taxonomists, has recently attracted broader interest from evolutionary biologists, especially those interested in sexual selection and the evolution of reproductive strategies. Primary sexual characters were long assumed to be the product of natural selection, exclusively. A recent alternative suggests that sexual selection explains much of the diversity of "primary" sexual characters. A third approach to the evolution of reproductive interactions after copulation or insemination has been to consider the process one of sexual conflict. That is, the reproductive processes of a species may reflect, as does the mating system, evolution acting on males and on females, but in different directions. In this volume, authors explore a wide variety of primary sexual characters and selective pressures that have shaped them, from natural selection for offspring survival to species-isolating mechanisms, sperm competition, cryptic female choice and sexual arms races. Exploring diverse reproductive adaptations from a theoretical and practical perspective, The Evolution of Primary Sexual Characters will provide an unparalleled overview of sexual diversity in many taxa and an introduction to the issues in sexual selection that are changing our view of sexual processes.
Among the most important innovations in the history of life is the transition from single-celled organisms to more complex, multicellular organisms. Multicellularity has evolved repeatedly across the tree of life, resulting in the evolution of new kinds of organisms that collectively constitute a significant portion of Earth’s biodiversity and have transformed the biosphere. This volume examines the origins and subsequent evolution of multicellularity, reviewing the types of multicellular groups that exist, their evolutionary relationships, the processes that led to their evolution, and the conceptual frameworks in which their evolution is understood. This important volume is intended to serve as a jumping-off point, stimulating further research by summarizing the topics that students and researchers of the evolution of multicellularity should be familiar with, and highlighting future research directions for the field.
