Food Webs and Niche Space. (MPB-11), Volume 11

Food Webs and Niche Space. (MPB-11), Volume 11 PDF Author: Joel E. Cohen
Publisher: Princeton University Press
ISBN: 0691209448
Category : Science
Languages : en
Pages : 210

Get Book Here

Book Description
What is the minimum dimension of a niche space necessary to represent the overlaps among observed niches? This book presents a new technique for obtaining a partial answer to this elementary question about niche space. The author bases his technique on a relation between the combinatorial structure of food webs and the mathematical theory of interval graphs. Professor Cohen collects more than thirty food webs from the ecological literature and analyzes their statistical and combinatorial properties in detail. As a result, he is able to generalize: within habitats of a certain limited physical and temporal heterogeneity, the overlaps among niches, along their trophic (feeding) dimensions, can be represented in a one-dimensional niche space far more often than would be expected by chance alone and perhaps always. This compatibility has not previously been noticed. It indicates that real food webs fall in a small subset of the mathematically possible food webs. Professor Cohen discusses other apparently new features of real food webs, including the constant ratio of the number of kinds of prey to the number of kinds of predators in food webs that describe a community. In conclusion he discusses possible extensions and limitations of his results and suggests directions for future research.

Food Webs and Niche Space. (MPB-11), Volume 11

Food Webs and Niche Space. (MPB-11), Volume 11 PDF Author: Joel E. Cohen
Publisher: Princeton University Press
ISBN: 0691209448
Category : Science
Languages : en
Pages : 210

Get Book Here

Book Description
What is the minimum dimension of a niche space necessary to represent the overlaps among observed niches? This book presents a new technique for obtaining a partial answer to this elementary question about niche space. The author bases his technique on a relation between the combinatorial structure of food webs and the mathematical theory of interval graphs. Professor Cohen collects more than thirty food webs from the ecological literature and analyzes their statistical and combinatorial properties in detail. As a result, he is able to generalize: within habitats of a certain limited physical and temporal heterogeneity, the overlaps among niches, along their trophic (feeding) dimensions, can be represented in a one-dimensional niche space far more often than would be expected by chance alone and perhaps always. This compatibility has not previously been noticed. It indicates that real food webs fall in a small subset of the mathematically possible food webs. Professor Cohen discusses other apparently new features of real food webs, including the constant ratio of the number of kinds of prey to the number of kinds of predators in food webs that describe a community. In conclusion he discusses possible extensions and limitations of his results and suggests directions for future research.

Coexistence in Ecology

Coexistence in Ecology PDF Author: Mark A. McPeek
Publisher: Princeton University Press
ISBN: 0691229228
Category : Science
Languages : en
Pages : 468

Get Book Here

Book Description
A comprehensive framework for understanding species coexistence Coexistence is the central concept in community ecology, but an understanding of this concept requires that we study the actual mechanisms of species interactions. Coexistence in Ecology examines the major features of these mechanisms for species that coexist at different positions in complex food webs, and derives empirical tests from model predictions. Exploring the various challenges species face, Mark McPeek systematically builds a model food web, beginning with an ecosystem devoid of life and then adding one species at a time. With the introduction of each new species, he evaluates the properties it must possess to invade a community and quantifies the changes in the abundances of other species that result from a successful invasion. McPeek continues this process until he achieves a multitrophic level food web with many species coexisting at each trophic level, from omnivores, mutualists, and pathogens to herbivores, carnivores, and basic plants. He then describes the observational and experimental empirical studies that can test the theoretical predictions resulting from the model analyses. Synthesizing decades of theoretical research in community ecology, Coexistence in Ecology offers new perspectives on how to develop an empirical program of study rooted in the natural histories of species and the mechanisms by which they actually interact with one another.

Translational Control in Biology and Medicine

Translational Control in Biology and Medicine PDF Author: Michael Mathews
Publisher: CSHL Press
ISBN: 0879697679
Category : Medical
Languages : en
Pages : 932

Get Book Here

Book Description
Updated and broadened 3rd edition. Since the last edition was published, the structures of the bacterial and eukaryotic ribosomes have been published, adding substantially to our knowledge of the basic mechanisms of translation. Understanding of how translation is regulated, by both protein and RNA regulators, has also advanced considerable. In addition, the current manifesttion of this volume has a significant focus on the role of translational control in human development and disease.

Sex Allocation

Sex Allocation PDF Author: Stuart West
Publisher: Princeton University Press
ISBN: 1400832012
Category : Science
Languages : en
Pages : 480

Get Book Here

Book Description
Recent decades have witnessed an explosion of theoretical and empirical studies of sex allocation, transforming how we understand the allocation of resources to male and female reproduction in vertebrates, invertebrates, protozoa, and plants. In this landmark book, Stuart West synthesizes the vast literature on sex allocation, providing the conceptual framework the field has been lacking and demonstrating how sex-allocation studies can shed light on broader questions in evolutionary and behavioral biology. West clarifies fundamental misconceptions in the application of theory to empirical data. He examines the field's successes and failures, and describes the research areas where much important work is yet to be done. West reveals how a shared underlying theoretical framework unites findings of sex-ratio variation across a huge range of life forms, from malarial parasites and hermaphroditic worms to sex-changing fish and mammals. He shows how research on sex allocation has been central to many critical questions and controversies in evolutionary and behavioral biology, and he argues that sex-allocation research serves as a key testing ground for different theoretical approaches and can help resolve debates about social evolution, parent-offspring conflict, genomic conflict, and levels of selection. Certain to become the defining book on the subject for the next generation of researchers, Sex Allocation explains why the study of sex allocation provides an ideal model system for advancing our understanding of the constraints on adaptation among all living things in the natural world.

Illinois Biological Monographs

Illinois Biological Monographs PDF Author:
Publisher:
ISBN:
Category : Anoplocephalidae
Languages : en
Pages : 640

Get Book Here

Book Description


The Biology of Stentor

The Biology of Stentor PDF Author: Vance Tartar
Publisher: Elsevier
ISBN: 148316456X
Category : Science
Languages : en
Pages : 426

Get Book Here

Book Description
The Biology of Stentor summarizes all that has been learned about the biology of a certain group of ciliate protozoa: the stentors. Topics covered range from form and function in Stentor to behavior, fine structure, growth and division, and reorganization. Regeneration is also discussed, along with polarity, metabolism, genetics, and primordium development. This volume is comprised of 20 chapters and begins with a characterization of Stentor, with emphasis on its particular advantages in addressing general problems of biology. The reader is then introduced to form and function in Stentor, particularly S. coeruleus. The following chapters focus on the behavior (food selection, swimming, response to light, etc.) of stentors and the fine points of structure in terms of which this behavior is to be explained and which demonstrate the highly complex and precise achievements of morphogenesis. The remaining chapters explore growth and division in Stentor as well as the course of reorganization and regeneration; development of the oral primordium and how it is activated and inhibited; rate of regeneration in relation to the polar axis; fusion masses of whole stentors; and reconstitution in disarranged stentors. Various species of Stentor are also described, together with the techniques used to study them. The final chapter deals with hypotheses concerning the morphogenesis of ciliates. This book will be of interest to students and practitioners of biology and physiology.

A Review of Human Carcinogens

A Review of Human Carcinogens PDF Author: IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Conference
Publisher:
ISBN:
Category : Carcinogens
Languages : en
Pages :

Get Book Here

Book Description


Fitness Landscapes and the Origin of Species (MPB-41)

Fitness Landscapes and the Origin of Species (MPB-41) PDF Author: Sergey Gavrilets
Publisher: Princeton University Press
ISBN: 0691187053
Category : Science
Languages : en
Pages : 497

Get Book Here

Book Description
The origin of species has fascinated both biologists and the general public since the publication of Darwin's Origin of Species in 1859. Significant progress in understanding the process was achieved in the "modern synthesis," when Theodosius Dobzhansky, Ernst Mayr, and others reconciled Mendelian genetics with Darwin's natural selection. Although evolutionary biologists have developed significant new theory and data about speciation in the years since the modern synthesis, this book represents the first systematic attempt to summarize and generalize what mathematical models tell us about the dynamics of speciation. Fitness Landscapes and the Origin of Species presents both an overview of the forty years of previous theoretical research and the author's new results. Sergey Gavrilets uses a unified framework based on the notion of fitness landscapes introduced by Sewall Wright in 1932, generalizing this notion to explore the consequences of the huge dimensionality of fitness landscapes that correspond to biological systems. In contrast to previous theoretical work, which was based largely on numerical simulations, Gavrilets develops simple mathematical models that allow for analytical investigation and clear interpretation in biological terms. Covering controversial topics, including sympatric speciation and the effects of sexual conflict on speciation, this book builds for the first time a general, quantitative theory for the origin of species.

The Unified Neutral Theory of Biodiversity and Biogeography

The Unified Neutral Theory of Biodiversity and Biogeography PDF Author: Stephen P. Hubbell
Publisher: Princeton University Press
ISBN: 1400837529
Category : Science
Languages : en
Pages : 390

Get Book Here

Book Description
Despite its supreme importance and the threat of its global crash, biodiversity remains poorly understood both empirically and theoretically. This ambitious book presents a new, general neutral theory to explain the origin, maintenance, and loss of biodiversity in a biogeographic context. Until now biogeography (the study of the geographic distribution of species) and biodiversity (the study of species richness and relative species abundance) have had largely disjunct intellectual histories. In this book, Stephen Hubbell develops a formal mathematical theory that unifies these two fields. When a speciation process is incorporated into Robert H. MacArthur and Edward O. Wilson's now classical theory of island biogeography, the generalized theory predicts the existence of a universal, dimensionless biodiversity number. In the theory, this fundamental biodiversity number, together with the migration or dispersal rate, completely determines the steady-state distribution of species richness and relative species abundance on local to large geographic spatial scales and short-term to evolutionary time scales. Although neutral, Hubbell's theory is nevertheless able to generate many nonobvious, testable, and remarkably accurate quantitative predictions about biodiversity and biogeography. In many ways Hubbell's theory is the ecological analog to the neutral theory of genetic drift in genetics. The unified neutral theory of biogeography and biodiversity should stimulate research in new theoretical and empirical directions by ecologists, evolutionary biologists, and biogeographers.

Biological Monographs

Biological Monographs PDF Author: Lancelot Eric Richdale
Publisher:
ISBN:
Category : Biology
Languages : en
Pages :

Get Book Here

Book Description