Molecular Basis Of Life History Evolution A Tale Of Two Insects
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Molecular Basis Of Life History Evolution A Tale Of Two Insects
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Author : Silvia C. Remolina
language : en
Publisher:
Release Date : 2011
Molecular Basis Of Life History Evolution A Tale Of Two Insects written by Silvia C. Remolina and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
The field of life-history evolution is aimed at understanding the diversity of fertility and longevity patterns observed in nature. These patterns are influenced by the interplay of traits that directly affect the fitness of individuals, including age at first reproduction, growth rate, age-specific fecundity, and age-specific survival. Variation in life-history strategies occurs because of phylogenetic constraints on organisms, influence of extrinsic factors on mortality (i.e. predation), and tradeoffs in energy allocation between competing physiological processes. Differences in life-history strategies have been well documented at the phenotypic level but their causal genetic mechanisms remain largely unknown. At the genetic level, tradeoffs between lifespan and reproduction have been hypothesized to arise because the force of natural selection decreases with advancing age and favors pleiotropic alleles that have beneficial effects on reproduction early in life even at the cost of survival later in life. Experimental evolution studies in Drosophila have highlighted the existence of tradeoffs between lifespan and reproduction that seem to be consistent with the concept of antagonistic pleiotropy. Selection for increased age at first reproduction, as well as selection for lifespan led to increases in lifespan and reduced early life fecundity in these flies. The underlying physiological cause of tradeoffs has been difficult to study because of the diversity of processes that influence life-history traits. Given that increases in lifespan have widespread influence on reproductive output, molecular geneticists interested in aging have documented survival costs of reproduction in long-lived individuals. Mutations in signaling pathways that couple environmental signals to key physiological processes affect growth, reproduction and lifespan. These studies have provided molecular mechanisms that are excellent candidates for regulating life history traits. However, whether natural variation in any of these genes is important in life history evolution remains an open question. My dissertation research focused on understanding differences in life histories in one eusocial and one non-social insect. Eusocial insects are good candidates to study mechanisms of tradeoffs between fecundity and survival. Eusocial insect queens enjoy a long lifespan that does not come at the cost of reduced fecundity, whereas workers are usually short lived and non-reproductive. Both queens and workers can potentially develop from larvae with identical genotypes but yet show strikingly different phenotypes as adults. My work on honey bee aging established the importance of intrinsic physiological factors in regulating differences in lifespan between queen and worker bees, and provided a potential mechanism for such differences. For the second part of my dissertation, I generated fruit fly strains with divergent life-histories to study the molecular underpinnings of life-history evolution. These studies were designed to investigate how phenotypic tradeoffs are regulated at the molecular level. I used a candidate gene approach to evaluate the role of insulin signaling in differential survival and reproduction. Results from this study do not support the involvement of genes in this pathway in life history divergence. A genome-wide screen was also employed to evaluate if other genes were involved in regulating the tradeoff between reproduction and lifespan in my fly strains. Genes involved in nutrient reservoir activity, stress response, and detoxification were differentially expressed between strains. This suggests that life history divergence in my fly lines was possible through differential energy allocation to competing processes (i.e. somatic maintenance vs. reproduction). Understanding variation among organisms in patterns of longevity and reproduction is a key goal of evolutionary biology. Research on the molecular mechanisms that regulate the evolution of life history traits will allow us to link the genetic architecture of these traits to the ecological factors that shape them and this will ultimately help us understand how organisms adapt to their environment. The study of the mechanistic basis of tradeoffs between lifespan and reproduction is also fundamental given the relationship between aging and other life-history traits.
The Molecular Basis Of Evolution
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Author : C. B. Anfinsen
language : en
Publisher:
Release Date : 2003-01
The Molecular Basis Of Evolution written by C. B. Anfinsen and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2003-01 with categories.
Fastende Tiere Auswirkungen Der Nahrungsrestriktion Auf Die Lebensspanne Von Tier Und Mensch
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Author : Bernd Herberth Schelker
language : de
Publisher: disserta Verlag
Release Date : 2015-02
Fastende Tiere Auswirkungen Der Nahrungsrestriktion Auf Die Lebensspanne Von Tier Und Mensch written by Bernd Herberth Schelker and has been published by disserta Verlag this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-02 with Science categories.
Menschen und Tiere waren während der längsten Zeit ihrer Evolution eher mit Problemen des Nahrungsmangels statt des Überflusses konfrontiert. Der moderne Mensch ist nicht mit der Situation der Fülle an Nahrung vertraut. So betrachtet ist nicht das Hungern oder Fasten (Nahrungsrestriktion) sondern die Ernährungssituation in den Industrienationen ein Ausnahmezustand. Die Lebenserwartung in Ländern wie den USA, Frankreich und Deutschland nimmt zwar beim weltweiten Vergleich die oberen Positionen ein. Jedoch leidet in diesen Ländern heute jeder zweite über 65-Jährige an einer Krankheit wie Typ-2-Diabetes, Alzheimer, Herz- Kreislaufstörungen oder Krebs. Essgewohnheiten und Bewegungsmangel stehen in deutlicher Korrelation zu Bluthochdruck, Diabetes und Arteriosklerose. Entsprechend erlebt der Forschungszweig der Caloric Restriction in den letzten 20 Jahren ein enormes Wachstum. Das vorliegende Buch hat die wichtigsten Ergebnisse aus diesem Gebiet zusammengefasst. Darüber hinaus legt es mit zahlreichen Erkenntnissen aus Molekularbiologie, Physiologie, und evolutionärer Ökologie wissenschaftlich fundierte Argumente dafür vor, dass die Nahrungsrestriktion die Lebensspanne des Menschen verlängern kann.
Mechanisms Of Life History Evolution
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Author : Thomas Flatt
language : en
Publisher: OUP Oxford
Release Date : 2011-05-12
Mechanisms Of Life History Evolution written by Thomas Flatt and has been published by OUP Oxford this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011-05-12 with Science categories.
Life history theory seeks to explain the evolution of the major features of life cycles by analyzing the ecological factors that shape age-specific schedules of growth, reproduction, and survival and by investigating the trade-offs that constrain the evolution of these traits. Although life history theory has made enormous progress in explaining the diversity of life history strategies among species, it traditionally ignores the underlying proximate mechanisms. This novel book argues that many fundamental problems in life history evolution, including the nature of trade-offs, can only be fully resolved if we begin to integrate information on developmental, physiological, and genetic mechanisms into the classical life history framework. Each chapter is written by an established or up-and-coming leader in their respective field; they not only represent the state of the art but also offer fresh perspectives for future research. The text is divided into 7 sections that cover basic concepts (Part 1), the mechanisms that affect different parts of the life cycle (growth, development, and maturation; reproduction; and aging and somatic maintenance) (Parts 2-4), life history plasticity (Part 5), life history integration and trade-offs (Part 6), and concludes with a synthesis chapter written by a prominent leader in the field and an editorial postscript (Part 7).
The Molecular Basis Of Evolution
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Author : Christian Boehmer Anfinsen
language : en
Publisher:
Release Date : 1965
The Molecular Basis Of Evolution written by Christian Boehmer Anfinsen and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1965 with Evolution categories.
Insect Metamorphosis
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Author : Xavier Belles
language : en
Publisher: Academic Press
Release Date : 2020-03-14
Insect Metamorphosis written by Xavier Belles and has been published by Academic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-03-14 with Science categories.
Insect Metamorphosis: From Natural History to Regulation of Development and Evolution explores the origin of metamorphosis, how it evolved, and how it is it regulated. The book discusses insect metamorphosis as a key innovation in insect evolution. With most of the present biodiversity on Earth composed of metamorphosing insects—approximately 1 million species currently described, with another 10-30 million still waiting to be discovered, the book delves into misconceptions and past treatments. In addition, the topic of integrating insect metamorphosis into the theory of evolution by natural selection as noted by Darwin in his On the Origin of Species is also discussed. Users will find this to be a comprehensive and updated review on insect metamorphosis, covering biological, physiological and molecular facets, with an emphasis on evolutionary aspects. Features updated knowledge from the past decade on the mechanisms of action of juvenile hormone, the main doorkeeper of insect metamorphosis Aids researchers in entomology or developmental biology dealing with specialized aspects of metamorphosis Provides applied entomologists with recently updated data, especially on regulation, to better face the problems of pest control and management Gives general evolutionary biologists context on the process of metamorphosis in its larger scope
Molecular Evolution
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Author : Roderick D.M. Page
language : en
Publisher: John Wiley & Sons
Release Date : 2009-07-14
Molecular Evolution written by Roderick D.M. Page and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009-07-14 with Science categories.
The study of evolution at the molecular level has given the subject of evolutionary biology a new significance. Phylogenetic 'trees' of gene sequences are a powerful tool for recovering evolutionary relationships among species, and can be used to answer a broad range of evolutionary and ecological questions. They are also beginning to permeate the medical sciences. In this book, the authors approach the study of molecular evolution with the phylogenetic tree as a central metaphor. This will equip students and professionals with the ability to see both the evolutionary relevance of molecular data, and the significance evolutionary theory has for molecular studies. The book is accessible yet sufficiently detailed and explicit so that the student can learn the mechanics of the procedures discussed. The book is intended for senior undergraduate and graduate students taking courses in molecular evolution/phylogenetic reconstruction. It will also be a useful supplement for students taking wider courses in evolution, as well as a valuable resource for professionals. First student textbook of phylogenetic reconstruction which uses the tree as a central metaphor of evolution. Chapter summaries and annotated suggestions for further reading. Worked examples facilitate understanding of some of the more complex issues. Emphasis on clarity and accessibility.
The Princeton Guide To Evolution
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Author : David A. Baum
language : en
Publisher: Princeton University Press
Release Date : 2013-11-04
The Princeton Guide To Evolution written by David A. Baum and has been published by Princeton University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013-11-04 with Science categories.
The Princeton Guide to Evolution is a comprehensive, concise, and authoritative reference to the major subjects and key concepts in evolutionary biology, from genes to mass extinctions. Edited by a distinguished team of evolutionary biologists, with contributions from leading researchers, the guide contains some 100 clear, accurate, and up-to-date articles on the most important topics in seven major areas: phylogenetics and the history of life; selection and adaptation; evolutionary processes; genes, genomes, and phenotypes; speciation and macroevolution; evolution of behavior, society, and humans; and evolution and modern society. Complete with more than 100 illustrations (including eight pages in color), glossaries of key terms, suggestions for further reading on each topic, and an index, this is an essential volume for undergraduate and graduate students, scientists in related fields, and anyone else with a serious interest in evolution. Explains key topics in some 100 concise and authoritative articles written by a team of leading evolutionary biologists Contains more than 100 illustrations, including eight pages in color Each article includes an outline, glossary, bibliography, and cross-references Covers phylogenetics and the history of life; selection and adaptation; evolutionary processes; genes, genomes, and phenotypes; speciation and macroevolution; evolution of behavior, society, and humans; and evolution and modern society
Human Variation In Space And Time
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Author : Kenneth A. R. Kennedy
language : en
Publisher: WCB/McGraw-Hill
Release Date : 1976
Human Variation In Space And Time written by Kenneth A. R. Kennedy and has been published by WCB/McGraw-Hill this book supported file pdf, txt, epub, kindle and other format this book has been release on 1976 with Physical anthropology categories.
Evolution Of The Insects
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Author : David Grimaldi
language : en
Publisher: Cambridge University Press
Release Date : 2005-05-16
Evolution Of The Insects written by David Grimaldi and has been published by Cambridge University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2005-05-16 with Science categories.
Insects are the most diverse group of organisms in the 3 billion-year history of life on Earth, and the most ecologically dominant animals on land. This book chronicles for the first time the complete evolutionary history of insects: their living diversity, relationships and 400 million years of fossils. Whereas other volumes have focused on either living species or fossils, this is the first comprehensive synthesis of all aspects of insect evolution. The book is illustrated with 955 photo- and electronmicrographs, drawings, diagrams, and field photos, many in full colour and virtually all of them original. The book will appeal to anyone engaged with insect diversity: professional entomologists and students, insect and fossil collectors, and naturalists.