Transitions Between Sexual Systems

Transitions Between Sexual Systems PDF Author: Janet L. Leonard
Publisher: Springer
ISBN: 3319941399
Category : Science
Languages : en
Pages : 370

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Book Description
This book focuses on explaining the distribution of sexual systems (simultaneous hermaphroditism, sequential hermaphroditism, environmental sex determination,dioecy, androdioecy, etc.) among taxa, which remains a major challenge in evolutionary biology. Although significant advances have been made for angiosperms, there is not yet a theory that predicts the sexual system for the majority of animal taxa, and other taxa of plants also remain poorly understood. The problem, particularly for animals, is that sexual systems can be very conservative, with whole phyla and classes being characterized by a single sexual system; for example essentially the whole phylum Platyhelminthes is simultaneously hermaphroditic, whereas the Insecta (Hexapoda) and the Tetrapoda among the vertebrates, are exclusively dioecious. Sex allocation theory on the other hand, suggests that sexual systems should be highly responsive to evolution, changing with population density, life span, patterns of resource availability, etc. The book provides an overview of the topic and then presents a series of chapters, each dealing with a taxon with substantial lability in sexual system in order to identify the factors associated with changes in sexual system in each case. By doing so, the authors reveal factors that have not been considered in formal theory but seem to have a major impact on transitions between sexual systems. This book appeals to a wide readership in fields from zoology and evolutionary biology to botany.

Transitions Between Sexual Systems

Transitions Between Sexual Systems PDF Author: Janet L. Leonard
Publisher: Springer
ISBN: 3319941399
Category : Science
Languages : en
Pages : 370

Get Book Here

Book Description
This book focuses on explaining the distribution of sexual systems (simultaneous hermaphroditism, sequential hermaphroditism, environmental sex determination,dioecy, androdioecy, etc.) among taxa, which remains a major challenge in evolutionary biology. Although significant advances have been made for angiosperms, there is not yet a theory that predicts the sexual system for the majority of animal taxa, and other taxa of plants also remain poorly understood. The problem, particularly for animals, is that sexual systems can be very conservative, with whole phyla and classes being characterized by a single sexual system; for example essentially the whole phylum Platyhelminthes is simultaneously hermaphroditic, whereas the Insecta (Hexapoda) and the Tetrapoda among the vertebrates, are exclusively dioecious. Sex allocation theory on the other hand, suggests that sexual systems should be highly responsive to evolution, changing with population density, life span, patterns of resource availability, etc. The book provides an overview of the topic and then presents a series of chapters, each dealing with a taxon with substantial lability in sexual system in order to identify the factors associated with changes in sexual system in each case. By doing so, the authors reveal factors that have not been considered in formal theory but seem to have a major impact on transitions between sexual systems. This book appeals to a wide readership in fields from zoology and evolutionary biology to botany.

The Evolution of Sex Determination

The Evolution of Sex Determination PDF Author: Leo Beukeboom
Publisher: OUP Oxford
ISBN: 0191631396
Category : Science
Languages : en
Pages : 243

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Book Description
Sexual reproduction is a fundamental aspect of life. It is defined by the occurrence of meiosis and the fusion of two gametes of different sexes or mating types. Sex-determination mechanisms are responsible for the sexual fate and development of sexual characteristics in an organism, be it a unicellular alga, a plant, or an animal. In many cases, sex determination is genetic: males and females have different alleles or different genes that specify their sexual morphology. In animals, this is often accompanied by chromosomal differences. In other cases, sex may be determined by environmental (e.g. temperature) or social variables (e.g. the size of an organism relative to other members of its population). Surprisingly, sex-determination mechanisms are not evolutionarily conserved but are bewilderingly diverse and appear to have had rapid turnover rates during evolution. Evolutionary biologists continue to seek a solution to this conundrum. What drives the surprising dynamics of such a fundamental process that always leads to the same outcome: two sex types, male and female? The answer is complex but the ongoing genomic revolution has already greatly increased our knowledge of sex-determination systems and sex chromosomes in recent years. This novel book presents and synthesizes our current understanding, and clearly shows that sex-determination evolution will remain a dynamic field of future research. The Evolution of Sex Determination is an advanced, research level text suitable for graduate students and researchers in genetics, developmental biology, and evolution.

Major Evolutionary Transitions in Flowering Plant Reproduction

Major Evolutionary Transitions in Flowering Plant Reproduction PDF Author: Spencer C. H. Barrett
Publisher: University of Chicago Press
ISBN: 0226038165
Category : Science
Languages : en
Pages : 216

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Book Description
The first volume to address the study of evolutionary transitions in plants, Major Evolutionary Transitions in Flowering Plant Reproduction brings together compelling work from the three areas of significant innovation in plant biology: evolution and adaptation in flowers and pollination, mating patterns and gender strategies, and asexual reproduction and polyploidy. Spencer C. H. Barrett assembles here a distinguished group of authors who address evolutionary transitions using comparative and phylogenetic approaches, the tools of genomics, population genetics, and theoretical modeling, and through studies in development and field experiments in ecology. With special focus on evolutionary transitions and shifts in reproductive characters—key elements of biological diversification and research in evolutionary biology—Major Evolutionary Transitions in Flowering Plant Reproduction is the most up-to-date treatment of a fast-moving area of evolutionary biology and ecology.

The Evolution of Primary Sexual Characters in Animals

The Evolution of Primary Sexual Characters in Animals PDF Author: Janet Leonard
Publisher: Oxford University Press
ISBN: 0195325559
Category : Medical
Languages : en
Pages : 550

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Book Description
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.

The Major Transitions in Evolution

The Major Transitions in Evolution PDF Author: John Maynard Smith
Publisher: Oxford University Press
ISBN: 019850294X
Category : Nature
Languages : en
Pages : 361

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Book Description
During evolution there have been several major changes in the way genetic information is organized and transmitted from one generation to the next. These transitions include the origin of life itself, the first eukaryotic cells, reproduction by sexual means, the appearance of multicellular plants and animals, the emergence of cooperation and of animal societies. This is the first book to discuss all these major transitions and their implications for our understanding of evolution.Clearly written and illustrated with many original diagrams, this book will be welcomed by students and researchers in the fields of evolutionary biology, ecology, and genetics.

Intersexuality in the Animal Kingdom

Intersexuality in the Animal Kingdom PDF Author: R. Reinboth
Publisher: Springer Science & Business Media
ISBN: 364266069X
Category : Science
Languages : en
Pages : 464

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Book Description
When Richard Goldschmidt' coined the term "intersexuality" in 1915, he intended it to apply to normally dioecious species which exhibit some kind of mixture between male and female characters. However, as knowledge of the bewildering variability present in the sexual orga nization of members of the animal kingdom has increased, the original meaning of the word has changed. Today many authors define inter sexuality as "the presence of both male and female characteristics, or of intermediate sexual characteristics, in a single individual".2 This more extensive and widely accepted concept justifies the title of our book •. Among all the anatomical and physiological features of living organisms the reproductive system has a unique importance for the perpetuation of the species. Conversely, reproductive processes are of little or no account for the viability of the individual. Therefore, within the framework of general biology reproduction has all too often been looked at solely from the point of view of genetics. Lively discussions about genotypic versus phenotypic sex determination long dominated the sci entific literature on sexuality in animals; this one-sided emphasis has tended to obscure many important facets of an organism's ability to reproduce. Recent developments in current biological research have brought the classic problem of sex differentiation into focus again, and the rapid progress being made in comparative endocrinology has added a new di mension to the study of reproductive biology.

Evolutionary Ecology of Social and Sexual Systems

Evolutionary Ecology of Social and Sexual Systems PDF Author: J. Emmett Duffy
Publisher: Oxford University Press
ISBN: 0195179927
Category : Science
Languages : en
Pages : 519

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Book Description
Understanding of animal social and sexual evolution has seen a renaissance in recent years with discoveries of frequent infidelity in apparently monogamous species, the importance of sperm competition, active female mate choice, and eusocial behavior in animals outside the traditional social insect groups. Each of these findings has raised new questions, and suggested new answers, about the evolution of behavioral interactions among animals. This volume synthesizes recent research on the sexual and social biology of the Crustacea, one of the dominant invertebrate groups on earth. Its staggering diversity includes ecologically important inhabitants of nearly every environment from deep-sea trenches, through headwater streams, to desert soils. The wide range of crustacean phenotypes and environments is accompanied by a comparable diversity of behavioral and social systems, including the elaborate courtship and wildly exaggerated morphologies of fiddler crabs, the mysterious queuing behavior of migrating spiny lobsters, and even eusociality in coral-reef shrimps. This diversity makes crustaceans particularly valuable for exploring the comparative evolution of sexual and social systems. Despite exciting recent advances, however, general recognition of the value of Crustacea as models has lagged behind that of the better studied insects and vertebrates. This book synthesizes the state of the field in crustacean behavior and sociobiology and places it in a conceptually based, comparative framework that will be valuable to active researchers and students in animal behavior, ecology, and evolutionary biology. It brings together a group of internationally recognized and rising experts in fields related to crustacean behavioral ecology, ranging from physiology and functional morphology, through mating and social behavior, to ecology and phylogeny. Each chapter makes connections to other, non-crustacean taxa, and the volume closes with a summary section that synthesizes the contributions, discusses anthropogenic impacts, highlights unanswered questions, and provides a vision for profitable future research.

Gender and Sexual Dimorphism in Flowering Plants

Gender and Sexual Dimorphism in Flowering Plants PDF Author: Monica A. Geber
Publisher: Springer Science & Business Media
ISBN: 3662039087
Category : Science
Languages : en
Pages : 319

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Book Description
Written by the leading experts in the field, this book examines the evolutionary advantages of gender dimorphism and sexual dimorphism in flowering plants. Divided into three sections: the first introduces readers to the tremendous variety of breeding systems and their evolution in plants and sets the stage for a consideration of the evolution of dimorphism in reproductive and non-reproductive characters. The second section deals with the evolution of secondary sexual characters, including the theory related to the evolution of sexual dimorphism and its empirical patterns, while the last section deals with the genetics of gender expression and of secondary sexual characters.

Sex Determination in Plants

Sex Determination in Plants PDF Author: CC Ainsworth
Publisher: Garland Science
ISBN: 1135325650
Category : Science
Languages : en
Pages : 201

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Book Description
Indispensable for all plant biologists, this is a fascinating and thorough examination of those factors which affect the sex determination of plant species, describing all of the main classes of plant with unisexual flowers hermaphrodite, monoecious and

Polyploidy and Genome Evolution

Polyploidy and Genome Evolution PDF Author: Pamela Soltis
Publisher: Springer Science & Business Media
ISBN: 3642314414
Category : Science
Languages : en
Pages : 416

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Book Description
Polyploidy – whole-genome duplication (WGD) – is a fundamental driver of biodiversity with significant consequences for genome structure, organization, and evolution. Once considered a speciation process common only in plants, polyploidy is now recognized to have played a major role in the structure, gene content, and evolution of most eukaryotic genomes. In fact, the diversity of eukaryotes seems closely tied to multiple WGDs. Polyploidy generates new genomic interactions – initially resulting in “genomic and transcriptomic shock” – that must be resolved in a new polyploid lineage. This process essentially acts as a “reset” button, resulting in genomic changes that may ultimately promote adaptive speciation. This book brings together for the first time the conceptual and theoretical underpinnings of polyploid genome evolution with syntheses of the patterns and processes of genome evolution in diverse polyploid groups. Because polyploidy is most common and best studied in plants, the book emphasizes plant models, but recent studies of vertebrates and fungi are providing fresh perspectives on factors that allow polyploid speciation and shape polyploid genomes. The emerging paradigm is that polyploidy – through alterations in genome structure and gene regulation – generates genetic and phenotypic novelty that manifests itself at the chromosomal, physiological, and organismal levels, with long-term ecological and evolutionary consequences.