Inbreeding and Outbreeding; Their Genetic and Sociological Significance

Inbreeding and Outbreeding; Their Genetic and Sociological Significance

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

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...


The Politics of Heredity

The Politics of Heredity

Author: Diane B. Paul

Publisher: SUNY Press

Published: 1998-01-01

Total Pages: 238

ISBN-13: 9780791438213

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Explores the political forces underlying shifts in thinking about the respective influence of heredity and environment in shaping human behavior, and the feasibility and morality of eugenics.


The American Development of Biology

The American Development of Biology

Author: Ronald Rainger

Publisher: University of Pennsylvania Press

Published: 2016-11-11

Total Pages: 392

ISBN-13: 1512805785

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Selected as one of the Best "Sci-Tech" Books of 1988 by Library Journal The essays in this volume represent original work to celebrate the centenary of the American Society of Zoologists. They illustrate the impressive nature of historical scholarship that has subsequently focused on the development of biology in the United States.