Download or read book Genetic Studies on Drosophila Virilis written by Charles William Metz and published by . This book was released on 1923 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Studies on Drosophila Virilis with Considerations on the Genetics of Other Species of Drosophila written by Charles William Metz and published by Hardpress Publishing. This book was released on 2013-12 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.
Download or read book Genetic Studies on Drosophila Virilis written by Charles W. Metz and published by . This book was released on 2015-07-21 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Genetic Studies on Drosophila Virilis: With Considerations on the Genetics of Other Species of Drosophila In most groups of animals and plants, including those susceptible to genetic study through intensive breeding, the chromosome groups of related species show a high degree of uniformity. The different members of a genus, for instance, usually differ relatively little in this regard. In some cases the uniformity may extend even to subfamilies or families, as, for example, in the Acrididae among the Orthoptera, where all of approximately 40 genera studied agree in having essentially the same chromosome group (cf. McClung, 1914; Harvey, 1916). It would seem probable, a priori, that where many related species exhibit such a constancy in chromosome groups, the apparent homology of chromosomes is real, i. e., similar chromosomes in different species are essentially alike in genetic make-up. On the other hand, there are various exceptions to the general rule of constancy, and a number of cases are known in which closely related species have very dissimilar chromosome groups. Hence it may be argued that even where a constancy exists it may be superficial and not dependent upon, or significant of, a likeness in genetic constitution of similar chromosomes. In fact, very little is known as to how far morphological criteria are trustworthy as indications of homology between chromosomes. In one case recently investigated by Lancefield and Metz (1921, 1922), the results indicate that genetic homology does not correspond to morphological similarity as regards two pairs of chromosomes in Drosophila willistoni compared with two similar pairs in D. melanogaster. These and other considerations serve to emphasize the necessity of learning something of the genetic constitution of chromosomes before they can safely be compared from the evolutionary standpoint. It is believed that the only method of obtaining reliable information on chromosome evolution is by means of genetic analysis combined with cytological observation. Ideal material for such a study would be provided by a group of species satisfying the following four requirements: In the first place, it should exhibit among its members a series of different chromosome groups; secondly, the species should be susceptible to intensive breeding under controlled conditions; in the third place, one or more of the species should be favorable for genetic analysis through the study of mutant races; and lastly, the species should hybridize with one another and give fertile hybrids. 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."
Download or read book Genetic Studies on Drosophila Virilis With Considerations on the Genetics written by Charles W Metz and published by Legare Street Press. This book was released on 2022-10-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 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. 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.
Download or read book Genetic Studies on Drosophila Virilis with Considerations on the Genetics of Other Species of Drosophila written by Charles William Metz and published by Palala Press. This book was released on 2015-09-03 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Genetic Studies on Drosophila Virilis with Considerations on the Genetics Scholar s Choice Edition written by Charles W Metz and published by Scholar's Choice. This book was released on 2015-02-18 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Genetic Studies on Drosophila Virilis with Considerations on the Genetics of Other Species of Drosophila by Charles W Metz Mildred S Moses and Eleanor D Mason written by Charles William Metz and published by . This book was released on 1923 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Studies on Drosophilia Virilis with Considerations on the Genetics of Other Species of Drosophilia written by Charles W. Metz and published by . This book was released on 1923 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Studies on Drosophila Virilis with Considerations on the Genetics of Other Species of Drosophila Primary Source Edition written by Charles William Metz and published by Nabu Press. This book was released on 2013-09 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant marks, etc. that were either part of the original artifact, or were introduced by the scanning process. We believe this work is culturally important, and despite the imperfections, have elected to bring it back into print as part of our continuing commitment to the preservation of printed works worldwide. We appreciate your understanding of the imperfections in the preservation process, and hope you enjoy this valuable book.
Download or read book Genetic Studies on Drosophila Virilis with Considerations on the Geneties of Other Species of Drosophila by Charles W Metz Mildred S Moses and Eleanor D Mason written by Eleanor D. Mason and published by . This book was released on 1923 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Studies on Drosophila Virilis written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Genetics of Drosophila written by Thomas Hunt Morgan and published by Garland Publishing. This book was released on 1988 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Genetics of Species Differences in the Drosophila Virilis Group written by Yasir Ahmed and published by . This book was released on 2015 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: "My dissertation focuses on two aspects of the genetics of species differences: morphological evolution and speciation. In Chapter 1, I genetically analyze the puparium color difference between members of the virilis group of Drosophila. I used backcross hybrids to map the genomic interval responsible for the difference between Drosophila americana and D. virilis. First, I show that the pupal case color difference is caused by a single gene, dopamine N-acetyltransferase (Dat). This gene encodes an enzyme that is known to play a part in the insect pigmentation pathway. Second, I show that this gene is highly expressed at the onset of pupation in D. americana and D. novamexicana (brown pupae) but not in D. virilis (black pupae) and D. lummei (dark-brown pupae). My results demonstrate that a single gene is almost entirely responsible for a morphological difference between species. In Chapter 2, I turn to the genetic and phenotypic basis of postmating prezygotic reproductive isolation (PMPZ) between D. americana and D. virilis. This species pair shows strong PMPZ isolation, especially when D. americana males mate with D. virilis females. Previous work showed that paternal loci contributing to this incompatibility reside on chromosome 5 (likely carries multiple factors) and chromosome 2 (fixed for a large paracentric inversion). First, I show that PMPZ is due largely to defective sperm storage. Second, I identify regions that carry genes capable of rescuing heterospecific fertilization. I conclude that paternal incompatibility between D. americana males and D. virilis females is underlain by several genes. Finally, I discuss the possible role of candidate accessory gland genes in the mapped chromosomal regions. In Chapter 3, I analyze transcriptomes from male reproductive tissues (accessory glands, testes, and ejaculatory bulb) of virilis group members using RNAseq. First, I identify tissue-biased transcripts and describe enriched functional categories. Second, I compare differences in transcript abundance between species to identify lineage-specific reproductive genes. Finally, I estimate nucleotide substitution rates and perform tests of accelerated codon substitution to identify signatures of positive selection. I conclude that adaptive amino-acid substitutions, expression differences, and gene turnover contribute to divergence among reproductive genes in the D. virilis group."--Pages iv-v.
Download or read book Genetics of Speciation written by David L. Jameson and published by . This book was released on 1977 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nature of populations, races, subspecies, and species. Genetic basis of isolation. Origin of isolation - theoretical. Origin of isolation - experimental. The nature of the speciation process.
Download or read book Rapidly Evolving Genes and Genetic Systems written by Rama S. Singh and published by Oxford University Press. This book was released on 2012-06-28 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: A range of theories on the rates of evolution-from static to gradual to punctuated to quantum-have been developed, mostly by comparing morphological changes over geological timescales as described in the fossil record.
Download or read book Sperm Biology written by Scott S. Pitnick and published by Academic Press. This book was released on 2008-11-21 with total page 683 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sperm Biology represents the first analysis of the evolutionary significance of sperm phenotypes and derived sperm traits and the possible selection pressures responsible for sperm-egg coevolution. An understanding of sperm evolution is fast developing and promises to shed light on many topics from basic reproductive biology to the evolutionary process itself as well as the sperm proteome, the sperm genome and the quantitative genetics of sperm. The Editors have identified 15 topics of current interest and biological significance to cover all aspects of this bizarre, fascinating and important subject. It comprises the most comprehensive and up-to-date review of the evolution of sperm and pointers for future research, written by experts in both sperm biology and evolutionary biology. The combination of evolution and sperm is a potent mix, and this is the definitive account. The first review survey of this emerging field Written by experts from a broad array of disciplines from the physiological and biomedical to the ecological and evolutionary Sheds light on the intricacies of reproduction and the coevolution of sperm, egg and reproductive behavior
Download or read book Evolution of Insect Migration and Diapause written by H. Dingle and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is an outgrowth of a Symposium entitled "Evolution of Escape in Space and Time" held at the XV International Congress of Entomology in Washington, D. C., USA in August, 1976. The choice of topic was prompted by recent advances in evolutionary ecology and the apparent suitability of insect migration and dia pause as appropriate material for evolutionary studies. In the event, that choice seems amply justified as I hope a perusal of these papers will show. These Sympos ium papers hardly cover the topic of the evolution of escape mechanisms exhaustively, and I am sure everyone will have his favorite lacuna. Some of the more obvious ones are indicated by Professor Southwood in his Concluding Remarks at the end of the book. The purpose of the Symposium, however, was not complete coverage, but rather to indicate the potential inherent in insect migration and diapause for the study of evolutionary problems. In that I think we have succeeded reasonably well. These papers are expanded and in some cases somewhat altered versions of the papers delivered in Washington. This has allowed greater coverage of the topics in question. I suggested a format of a general overview of a topic emphasizing the author's own research con tributions. In general the papers follow this outline although emphases vary. Two of the authors, Dr. Rainey and Dr. Lumme, were unable to attend the Symposium. Dr. Rainey's paper was read by Mr. Frank Walsh, but Dr.