Evolution and Biodiversity of Wild Polyploids
Author: Elvira Hörandl
Publisher: Frontiers Media SA
Published: 2021-09-28
Total Pages: 181
ISBN-13: 2889713733
DOWNLOAD EBOOK →Author: Elvira Hörandl
Publisher: Frontiers Media SA
Published: 2021-09-28
Total Pages: 181
ISBN-13: 2889713733
DOWNLOAD EBOOK →Author: Walter H. Lewis
Publisher: Springer Science & Business Media
Published: 2012-12-06
Total Pages: 576
ISBN-13: 1461330696
DOWNLOAD EBOOK →Polyploidy as a dramatic mutational event in the process of evolution has wide implications in nature and for the generation of new and improved crops. The three day Conference on POLYPLOIDY: BIOLOGICAL RELEVANCE focused on three aspects of this natural phenomenon: the first emphasized the characteristics of polyploidy, the second described the occurrence of polyploidy among plants and animals, and the third considered past and future areas of both fundamental and pragmatic research that involve polyploidy. New information relative to origin, cytogenetics, ecology, physiology, biochemistry, and populational studies stress the need to reexamine current views on the origins of polyploidy and its significance among both plants and animals. There are major differences in the occurrence of polyploidy between. plant groups and it is proving a much more common event among bisexual vertebrates than heretofore considered possible. Crop development and improvement must utilize approaches based fundamentally on more natural systems; in fact future research should focus more on polyploidy as a natural phenomenon that needs study at all levels of endeavor from field-oriented populational aspects to sophisticated molecular analyses and genome manipulations. This volume provides a summary of current knowledge of polyploidy pertinent to botanists, zoologists, and agriculturists who are interested in the evolution o~natural systems and who are concerned with the contribution that crop improvement can make to human well-being. Walter H. Lewis St. Louis, Missouri October, 1979 v ACKNOWLEDGMENTS The Host Committee thanks all speakers and moderators for their generous contribution to the Conference and to this volume.
Author: Pamela S. Soltis
Publisher: Springer Science & Business Media
Published: 2012-10-03
Total Pages: 417
ISBN-13: 3642314422
DOWNLOAD EBOOK →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.
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DOWNLOAD EBOOK →Hybrid zones between cytotypes with different ploidy levels are particularly interesting for studying the ecology and the evolution of reproductive interactions between closely related taxa. Diploid-polyploid hybrid zones differ fundamentally from those between diploids in that they reflect certain conditions that are characteristic of the early stage of polyploid establishment, and allow tests of hypotheses relating to the dynamics and evolution of polyploid complexes. Recent theoretical and empirical studies have provided important data on the evolution of isolating mechanisms in diploid-polyploid contact zones, but have also shown that introgression might counteract the evolution of isolating mechanisms.
Author: Anestacia S. Robinson
Publisher:
Published: 2020
Total Pages: 23
ISBN-13:
DOWNLOAD EBOOK →Whole genome duplication, or polyploidy, is a common process in plants by which failures in meiosis or fertilization result in offspring with twice the number of chromosomes. This doubles the number of copies of every gene, an effect thought to generate new ‘raw material’ upon which natural selection can act. Few studies exist examining the consequences of polyploidy for plant physiological traits. Doubling the number of gene copies may have unknown effects on leaf structure and function. In this study, I compare diploid, tetraploid, and hexaploid species within the genus Helianthus (wild sunflowers). Forty different accessions of wild sunflowers were grown under standardized greenhouse conditions and phenotyped for both leaf functional traits and leaf hyperspectral reflectance. Interestingly, I find that whole genome duplication can have effects on leaf functional traits relevant to both size and ecophysiology, and thus that polyploidy may lead to functional trait differentiation between polyploids and their diploid progenitors.
Author: Edward O. Wilson
Publisher: Harvard University Press
Published: 1992
Total Pages: 458
ISBN-13: 9780674212985
DOWNLOAD EBOOK →View a collection of videos on Professor Wilson entitled "On the Relation of Science and the Humanities" "In the Amazon Basin the greatest violence sometimes begins as a flicker of light beyond the horizon. There in the perfect bowl of the night sky, untouched by light from any human source, a thunderstorm sends its premonitory signal and begins a slow journey to the observer, who thinks: the world is about to change." Watching from the edge of the Brazilian rain forest, witness to the sort of violence nature visits upon its creatures, Edward O. Wilson reflects on the crucible of evolution, and so begins his remarkable account of how the living world became diverse and how humans are destroying that diversity. Wilson, internationally regarded as the dean of biodiversity studies, conducts us on a tour through time, traces the processes that create new species in bursts of adaptive radiation, and points out the cataclysmic events that have disrupted evolution and diminished global diversity over the past 600 million years. The five enormous natural blows to the planet (such as meteorite strikes and climatic changes) required 10 to 100 million years of evolutionary repair. The sixth great spasm of extinction on earth--caused this time entirely by humans--may be the one that breaks the crucible of life. Wilson identifies this crisis in countless ecosystems around the globe: coral reefs, grasslands, rain forests, and other natural habitats. Drawing on a variety of examples such as the decline of bird populations in the United States, the extinction of many species of freshwater fish in Africa and Asia, and the rapid disappearance of flora and fauna as the rain forests are cut down, he poignantly describes the death throes of the living world's diversity--projected to decline as much as 20 percent by the year 2020. All evidence marshaled here resonates through Wilson's tightly reasoned call for a spirit of stewardship over the world's biological wealth. He makes a plea for specific actions that will enhance rather than diminish not just diversity but the quality of life on earth. Cutting through the tangle of environmental issues that often obscure the real concern, Wilson maintains that the era of confrontation between forces for the preservation of nature and those for economic development is over; he convincingly drives home the point that both aims can, and must, be integrated. Unparalleled in its range and depth, Wilson's masterwork is essential reading for those who care about preserving the world biological variety and ensuring our planet's health.
Author: Susumu Ohno
Publisher: Springer Science & Business Media
Published: 2013-12-11
Total Pages: 171
ISBN-13: 364286659X
DOWNLOAD EBOOK →It is said that "necessity is the mother of invention". To be sure, wheels and pulleys were invented out of necessity by the tenacious minds of upright citi zens. Looking at the history of mankind, however, one has to add that "Ieisure is the mother of cultural improvement". Man's creative genius flourished only when his mind, freed from the worry of daily toils, was permitted to entertain apparently useless thoughts. In the same manner, one might say with regard to evolution that "natural selection mere(y tnodifted, while redundanry created". Natural selection has been extremely effective in policing alleHe mutations which arise in already existing gene loci. Because of natural selection, organisms have been able to adapt to changing environments, and by adaptive radiation many new species were created from a common ancestral form. Y et, being an effective policeman, natural selection is extremely conservative by nature. Had evolution been entirely dependent upon natural selection, from a bacterium only numerous forms of bacteria would have emerged. The creation of metazoans, vertebrates and finally mammals from unicellular organisms would have been quite impos sible, for such big leaps in evolution required the creation of new gene loci with previously nonexistent functions. Only the cistron which became redun dant was able to escape from the relentless pressure of natural selection, and by escaping, it accumulated formerly forbidden mutations to emerge as a new gene locus.
Author: Ramón Carmona
Publisher: Springer Science & Business Media
Published: 2008-11-09
Total Pages: 465
ISBN-13: 1402084374
DOWNLOAD EBOOK →Sturgeons are considered “living fossils”, sharing many morphological and biological features with ancestral fish. Furthermore, sturgeons are of the utmost interest from an economic perspective, not only for the caviar but for the flesh. However, the wild populations of the majority of the species are at serious risk of extinction all over the world. So, it is urgent to develop strategies for both farming culture and conservation and recovery in natural habitats. This book provides a comprehensive view of the biology and sustainable development of sturgeons putting emphasis on the Southern Europe autochthonous species such as Acipenser nacarii and Acipenser sturio that share geographical distribution. Other relevant species (such as Huso huso, A. oxyrhinchus, A. ruthenus, A. stellatus) and areas (Germany, Russia, North America) are also considered. The contents are organised in three sections: Taxonomy and Biogeography (including the morphological and genetic analyses that clarify the taxonomy and phylogeny of sturgeons, focused on those from Southern Europe), Biology and Aquaculture (where several aspects of the developmental biology, feeding, and reproduction are considered in relation to the improvement of sturgeon farming), and Recovery and Conservation (that collates and analyses different recovery research actions, the ecology of the rivers for restoration as well as the problems related to the trade of caviar).
Author: Shabir Hussain Wani
Publisher: Scientific Research Publishing, Inc. USA
Published: 2015-05-31
Total Pages: 395
ISBN-13: 1618960695
DOWNLOAD EBOOK →Plant breeding during its evolution has been utilizing biodiversity for producing better crops. Nowadays everyone is concerned about saving the biodiversity. Intensive agricultural practices, climate change and Industrialization are having a straight impact on biodiversity. Use of single new improved varieties of crops for large areas is a big threat for crop biodiversity. Modern breeding approaches are also suggesting going back towards the land races and farmer’s varieties for gene hunting for resistance to various biotic and abiotic stresses. This book includes the description about biodiversity and crop improvement. It also addresses the utilization of plant genetic resources and crop wild relatives for crop improvement through application of traditional plant breeding techniques as well as molecular and genomic approaches. Through this multi authored book an effort has been made to assimilate the most topical results about biodiversity and crop improvement with contemporary plant breeding approaches. Eleven chapters written by leading scientists involved in crop Improvement research worldwide provide sufficient coverage of the major factors impacting utilization of biodiversity for crop improvement.
Author: Richard Primack
Publisher: Open Book Publishers
Published: 2019-09-10
Total Pages: 712
ISBN-13: 1783747536
DOWNLOAD EBOOK →Conservation Biology in Sub-Saharan Africa comprehensively explores the challenges and potential solutions to key conservation issues in Sub-Saharan Africa. Easy to read, this lucid and accessible textbook includes fifteen chapters that cover a full range of conservation topics, including threats to biodiversity, environmental laws, and protected areas management, as well as related topics such as sustainability, poverty, and human-wildlife conflict. This rich resource also includes a background discussion of what conservation biology is, a wide range of theoretical approaches to the subject, and concrete examples of conservation practice in specific African contexts. Strategies are outlined to protect biodiversity whilst promoting economic development in the region. Boxes covering specific themes written by scientists who live and work throughout the region are included in each chapter, together with recommended readings and suggested discussion topics. Each chapter also includes an extensive bibliography. Conservation Biology in Sub-Saharan Africa provides the most up-to-date study in the field. It is an essential resource, available on-line without charge, for undergraduate and graduate students, as well as a handy guide for professionals working to stop the rapid loss of biodiversity in Sub-Saharan Africa and elsewhere.