The Symbiotic Phenomenon

The Symbiotic Phenomenon PDF

Author: Joanna Mikolajewska

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 356

ISBN-13: 9400929692

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Symbiotic stars were identified spectroscopically as M giants with a very strong He II 4686 emission line. After five decades of study by many astronomers, the first internatioinal meetings devoted to symbiotics were held at the University of Colorado (Boulder) and at the Haute Provence Observatory during the Summer of 1981. These conferences emphasized exciting new results obtained by modern satellite (EINSTEIN, IUE) and ground-based observatories. Although the vast majority of the participants were already fairly sure that symbiotics are almost certainly interacting binary systems, and not extremely peculiar single stars, it was not clear exactly which types of physical processes were needed to be invoked to explain their observed behaviour. Many were even worried that it might not be possible to clearly define a class of "symbiotic stars" , and thus establish a unique model applicable to any system. Since the publication of the Haute-Provence proceedings, our understanding of the physical processes occuring in symbiotic stars (and in related objects such as cataclysmic variables and compact planetary nebulae) has greatly improved. We now speak confidently of a "symbiotic phenomenon" , in which an evolved red giant and a hot companion object (usually thought to be an accreting main sequence star or a luminous white dwarf star) happily coexist.

Biological Individuality

Biological Individuality PDF

Author: Scott Lidgard

Publisher: University of Chicago Press

Published: 2017-05-24

Total Pages: 368

ISBN-13: 022644659X

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Individuals are things that everybody knows—or thinks they do. Yet even scholars who practice or analyze the biological sciences often cannot agree on what an individual is and why. One reason for this disagreement is that the many important biological individuality concepts serve very different purposes—defining, classifying, or explaining living structure, function, interaction, persistence, or evolution. Indeed, as the contributors to Biological Individuality reveal, nature is too messy for simple definitions of this concept, organisms too quirky in the diverse ways they reproduce, function, and interact, and human ideas about individuality too fraught with philosophical and historical meaning. Bringing together biologists, historians, and philosophers, this book provides a multifaceted exploration of biological individuality that identifies leading and less familiar perceptions of individuality both past and present, what they are good for, and in what contexts. Biological practice and theory recognize individuals at myriad levels of organization, from genes to organisms to symbiotic systems. We depend on these notions of individuality to address theoretical questions about multilevel natural selection and Darwinian fitness; to illuminate empirical questions about development, function, and ecology; to ground philosophical questions about the nature of organisms and causation; and to probe historical and cultural circumstances that resonate with parallel questions about the nature of society. Charting an interdisciplinary research agenda that broadens the frameworks in which biological individuality is discussed, this book makes clear that in the realm of the individual, there is not and should not be a direct path from biological paradigms based on model organisms through to philosophical generalization and historical reification.

Microbial Symbioses

Microbial Symbioses PDF

Author: Sebastien Duperron

Publisher: Elsevier

Published: 2016-11-30

Total Pages: 166

ISBN-13: 0081021186

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Plants and animals have evolved ever since their appearance in a largely microbial world. Their own cells are less numerous than the microorganisms that they host and with whom they interact closely. The study of these interactions, termed microbial symbioses, has benefited from the development of new conceptual and technical tools. We are gaining an increasing understanding of the functioning, evolution and central importance of symbiosis in the biosphere. Since the origin of eukaryotic cells, microscopic organisms of our planet have integrated our very existence into their ways of life. The interaction between host and symbiont brings into question the notion of the individual and the traditional representation of the evolution of species, and the manipulation of symbioses facilitates fascinating new perspectives in biotechnology and health. Recent discoveries show that association is one of the main properties of organisms, making a more integrated view of biology necessary. Microbial Symbioses provides a deliberately “symbiocentric outlook, to exhibit how the exploration of microbial symbioses enriches our understanding of life, and the potential future for this discipline. Offers a concise summary of the most recent discoveries in the field Shows how symbiosis is acquiring a central role in the biology of the 21st century by transforming our understanding of living things Presents scientific issues, but also societal and economic related issues (biodiversity, biotechnology) through examples from all branches of the tree of life

In the Light of Evolution

In the Light of Evolution PDF

Author: National Academy of Sciences

Publisher: Sackler Colloquium

Published: 2007

Total Pages: 388

ISBN-13:

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The Arthur M. Sackler Colloquia of the National Academy of Sciences address scientific topics of broad and current interest, cutting across the boundaries of traditional disciplines. Each year, four or five such colloquia are scheduled, typically two days in length and international in scope. Colloquia are organized by a member of the Academy, often with the assistance of an organizing committee, and feature presentations by leading scientists in the field and discussions with a hundred or more researchers with an interest in the topic. Colloquia presentations are recorded and posted on the National Academy of Sciences Sackler colloquia website and published on CD-ROM. These Colloquia are made possible by a generous gift from Mrs. Jill Sackler, in memory of her husband, Arthur M. Sackler.