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Author: Janet L. Leonard Publisher: Springer ISBN: 3319941399 Category : Science Languages : en Pages : 363
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.
Author: Janet L. Leonard Publisher: Springer ISBN: 3319941399 Category : Science Languages : en Pages : 363
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.
Author: Leo Beukeboom Publisher: OUP Oxford ISBN: 0191631396 Category : Science Languages : en Pages : 240
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.
Author: Janet Leonard Publisher: Oxford University Press ISBN: 0195325559 Category : Language Arts & Disciplines Languages : en Pages : 550
Book Description
This edited volume explores primary sexual characters in a wide variety of animal taxa. It provides an overview of sexual diversity, the selective pressures that have shaped it, and an introduction to the data and theoretical issues in sexual selection that are changing our view of sexual processes.
Author: John Maynard Smith Publisher: Oxford University Press ISBN: 019850294X Category : Nature Languages : en Pages : 361
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.
Author: Spencer C. H. Barrett Publisher: University of Chicago Press ISBN: 0226038165 Category : Science Languages : en Pages : 216
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.
Author: Rachel Pepper Publisher: Cleis Press ISBN: 157344801X Category : Family & Relationships Languages : en Pages : 240
Book Description
Transitions of the Heart is the first collection to ever invite mothers of transgender and gender variant children of all ages to tell their own stories about their child’s gender transition. Often “transitioning” socially and emotionally alongside their child but rarely given a voice in the experience, mothers hold the key to familial and societal understanding of gender difference. Sharing stories of love, struggle, and acceptance, this collection of mother's voices, representing a diversity of backgrounds and sexual orientations, affirms the experience of those who have raised and are currently raising transgender and gender variant children between the ages of 5-50. Edited by Rachel Pepper, a gender specialist and co-author of the acclaimed book The Transgender Child, Transitions of the Heart will prove an invaluable resource for parents coming to terms with a child’s gender variance or transition.
Author: R. Reinboth Publisher: Springer Science & Business Media ISBN: 364266069X Category : Science Languages : en Pages : 464
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.
Author: Nicole Valenzuela Publisher: Smithsonian Institution Scholarly Press ISBN: Category : Science Languages : en Pages : 204
Book Description
Edited by the world's foremost authorities on the subject, with essays by leading scholars in the field, this work shows how the sex of reptiles and many fish is determined not by the chromosomes they inherit but by the temperature at which incubation takes place.
Author: Tetsuo Kuwamura Publisher: Springer Nature ISBN: 981196095X Category : Science Languages : en Pages : 256
Book Description
This book provides a comprehensive review of hermaphroditism in fishes. It focuses on the behavioral ecology of functional hermaphroditism in fishes and discusses its evolution. Approximately 99% of all vertebrate species consist of separate-sex individuals (gonochorists), i.e., pure males and pure females. The other 1% of vertebrate species are hermaphroditic, and almost all of them are fishes. Among hermaphroditic fishes, four major types of hermaphroditism are known: simultaneous (or synchronous) hermaphroditism, protandry (male-to-female sex change), protogyny (female-to-male sex change), and bidirectional sex change (or reversed sex change in protogynous species). The book examines the occurrence of hermaphroditism in relation to phylogeny and mating systems. It also reviews the hypotheses for the evolution of hermaphroditism, and the size-advantage model, which is the main theory for the evolution of sex change, tested in relation to the mating system. The appendix in the last chapter provides an annotated list of hermaphroditic fish species (ca. 500 spp.).
Author: Janet L. Leonard
Author: Janet L. Leonard
Author: William Richard Rice
Author: Leo Beukeboom
Author: Janet Leonard
Author: John Maynard Smith
Author: Spencer C. H. Barrett
Author: Rachel Pepper
Author: R. Reinboth
Author: Nicole Valenzuela
Author: Tetsuo Kuwamura