Inbreeding and Outbreeding; Their Genetic and Sociological Significance

Inbreeding and Outbreeding; Their Genetic and Sociological Significance PDF

Author: Edward M. East

Publisher: Holloway Press

Published: 2007-10

Total Pages: 312

ISBN-13: 1408606321

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PREFACE. THE Author of this very practical treatise on Scotch Loch - Fishing desires clearly that it may be of use to all who had it. He does not pretend to have written anything new, but to have attempted to put what he has to say in as readable a form as possible. Everything in the way of the history and habits of fish has been studiously avoided, and technicalities have been used as sparingly as possible. The writing of this book has afforded him pleasure in his leisure moments, and that pleasure would be much increased if he knew that the perusal of it would create any bond of sympathy between himself and the angling community in general. This section is interleaved with blank shects for the readers notes. The Author need hardly say that any suggestions addressed to the case of the publishers, will meet with consideration in a future edition. We do not pretend to write or enlarge upon a new subject. Much has been said and written-and well said and written too on the art of fishing but loch-fishing has been rather looked upon as a second-rate performance, and to dispel this idea is one of the objects for which this present treatise has been written. Far be it from us to say anything against fishing, lawfully practised in any form but many pent up in our large towns will bear us out when me say that, on the whole, a days loch-fishing is the most convenient. One great matter is, that the loch-fisher is depend- ent on nothing but enough wind to curl the water, -and on a large loch it is very seldom that a dead calm prevails all day, -and can make his arrangements for a day, weeks beforehand whereas the stream- fisher is dependent for a good take on the state of the water and however pleasant and easy it may be for one living near the banks of a good trout stream or river, it is quite another matter to arrange for a days river-fishing, if one is looking forward to a holiday at a date some weeks ahead. Providence may favour the expectant angler with a good day, and the water in order but experience has taught most of us that the good days are in the minority, and that, as is the case with our rapid running streams, -such as many of our northern streams are, -the water is either too large or too small, unless, as previously remarked, you live near at hand, and can catch it at its best. A common belief in regard to loch-fishing is, that the tyro and the experienced angler have nearly the same chance in fishing, -the one from the stern and the other from the bow of the same boat. Of all the absurd beliefs as to loch-fishing, this is one of the most absurd. Try it. Give the tyro either end of the boat he likes give him a cast of ally flies he may fancy, or even a cast similar to those which a crack may be using and if he catches one for every three the other has, he may consider himself very lucky. Of course there are lochs where the fish are not abundant, and a beginner may come across as many as an older fisher but we speak of lochs where there are fish to be caught, and where each has a fair chance. Again, it is said that the boatman has as much to do with catching trout in a loch as the angler. Well, we dont deny that. In an untried loch it is necessary to have the guidance of a good boatman but the same argument holds good as to stream-fishing...

Inbreeding and Outbreeding; Their Genetic and Sociological Significance

Inbreeding and Outbreeding; Their Genetic and Sociological Significance PDF

Author: Edward Murray East

Publisher: Theclassics.Us

Published: 2013-09

Total Pages: 72

ISBN-13: 9781230314754

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1919 edition. Excerpt: ...starts off poorly, as shown in the accompanying illustration (Fig. 33), but soon catches up and passes the second generation. At maturity the second generation is shorter and less productive, although it has a much greater variability. The third generation from selfed plants of this particular cross has been grown, and there is still further loss of the stimulation which is at its maximum in the first generation. On continued inbreeding these families presumably would exhibit a continuation of the same course of reduction in size, vigor and variability shown in the original inbreeding experiment, until homozygosity was again 100 78 50 29 Sronth Curres of Two Inbred Strains ef Maize and Their Fj and F2 Hybrids. 30 40 50 Gf 7 8 Wumlaer of Days from Planting 9 33.--Qraphs showing growth curves of two inbred strains'of maiie and thier first and second generation hybrids. reached. The resulting inbred strains would have about the same amount of development as the original inbred strains, but would probably differ from them in appearance through the possession of different combinations of characters. The principal point is that the vigor and size lost by inbreeding are immediately restored by crossing, but lost again on further inbreeding. It is a transitory effect, for the most part, impossible of fixation. Increases in yield of grain are also frequently obtained when ordinary commercial varieties of maize are crossed. Earely are the increases greater than 10 per cent., however, and even this is more commonly to be expected when varieties of somewhat different type are used; for example, flint and dent. Most varieties of corn are now so widely crossed and furthermore are so near the limit of production that great advances are not...

Inbreeding and Outbreeding; Their Genetic and Sociological Significance

Inbreeding and Outbreeding; Their Genetic and Sociological Significance PDF

Author: Edward M 1879-1938 East

Publisher: Palala Press

Published: 2015-09-08

Total Pages: 314

ISBN-13: 9781342030221

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This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Inbreeding and Outbreeding

Inbreeding and Outbreeding PDF

Author: Edward M. East

Publisher:

Published: 2015-08-05

Total Pages: 314

ISBN-13: 9781332302420

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Excerpt from Inbreeding and Outbreeding: Their Genetic and Sociological Significance It is inevitable that each work planned as a member of a series of biological monographs should be somewhat technical. Of necessity each must be concise. In view of the difficulties these limitations involve, one may hardly expect to escape the criticism that the subject matter often tends to be esoteric in its nature, for few can say in Shawn's odd fancy, "I tried to do too - much and did it." Nevertheless, there has been a serious effort to avoid a mere record of the development of a specific problem in Genetics as an aid to the general biologist. No one could have a professional interest in a subject of this kind without the desire that there be some practical application of the results to agriculture and to the many phases of sociology where a knowledge of the laws of heredity is a first requisite. Though such applications of the genetic conclusions are touched but lightly here, there is the hope that the non-biological worker interested in problems of human welfare will find some new thoughts and pertinent suggestions in the compelling logic of the controlled experiments described throughout the pages. At least it was with this idea in mind that the authors prepared the first four chapters. For the zoologist and botanist the well-known facts and elementary principles there discussed would have been unnecessary. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

The Natural History of Inbreeding and Outbreeding

The Natural History of Inbreeding and Outbreeding PDF

Author: Nancy Wilmsen Thornhill

Publisher: University of Chicago Press

Published: 1993-08-15

Total Pages: 592

ISBN-13: 9780226798547

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Inbreeding, the mating of close kin, and outbreeding, the mating of distant relatives or unrelated organisms, have long been important subjects to evolutionary biologists. Inbreeding reduces genetic diversity in a population, increasing the likelihood that genetic defects will become widespread and deprive a population of the diversity it may need to cope with its environment. Most plants and animals have evolved behavioral and morphological mechanisms to avoid inbreeding. However, today many endangered species exist only in small, very isolated populations where inbreeding is unavoidable, so it has become a concern for conservationists. In this volume, twenty-six experts in evolution, behavior, and genetics examine the causes and consequences of inbreeding. The authors ask whether inbreeding is as problematic as biologists have thought, under what ecological conditions inbreeding occurs, and whether organisms that inbreed have mechanisms to dampen the anticipated problems of reduced genetic variation. The studies, including theoretical and empirical work on wild and captive populations, demonstrate that many plants and animals inbreed to a greater extent than biologists have thought, with variable effects on individual fitness. Graduate students and researchers in evolutionary biology, animal behavior, ecology, and conservation biology will welcome this wide-ranging collection.