DOCSLIB.ORG

Slow Evolutionary Loss of the Potential for Interspecific

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Slow Evolutionary Loss of the Potential for Interspecific Proc. Nat. Acad. Sci. USA Vol. 72, No. 1, pp. 200-204, January 1975 Slow Evolutionary Loss of the Potential for Interspecific Hybridization in Birds: A Manifestation of Slow Regulatory Evolution (anatomical evolution/protein evolution/chromosomal evolution/frogs/mammals/immunology) ELLEN M. PRAGER AND ALLAN C. WILSON Department of Biochemistry, University of California, Berkeley, Calif. 94720 Communicated by Nathan 0. Kaplan, October 11, 1974 ABSTRACT Birds have lost the potential for inter- hybridization potential and degree of protein sequence dif- specific hybridization slowly. This inference emerges from protein comparisons made on 36 pairs of bird species capa- ference among species. At first thought it might seem likely ble ofhybridization. Micro-complement fixation tests show that degree of protein similarity between parental species that hybridizable pairs of bird species differ by an average should be the major factor affecting the probability of suc- of 12 units of albumin immunological distance and 25 cessful development of an interspecific zygote. The more units of transferrin immunological distance. As these similar the proteins of two species, the more likely it is, one proteins evolve at a known and rather steady rate, it is inferred that the average hybridizable species pair diverged might suppose, that their genomes would be compatible from a common ancestor about 22 million years ago. The enough to permit development of viable hybrids. However, corresponding period for frog species pairs capable of our first study of this produced a result inconsistent with this hybridization is about 21 million years, while for hybrid- expectation. Mammals that can hybridize differ only slightly izable placental mammals it is only 2 to 3 million years. at the at Thus birds resemble frogs in having lost the potential for protein level, whereas frogs that differ substantially interspecific hybridization about 10 times as slowly as have the protein level hybridize readily (6). mammals. To explain this result, it has been proposed that the Birds have also been evolving very slowly at the anatomi- principal molecular barriers to interspecific hybridization are cal level, particularly within the last 25 million years, regulatory differences between the parental genomes and according to Simpson, Romer, and many other vertebrate zoologists. In this respect they resemble frogs and differ that placental mammals appear to have been undergoing from placental mammals, which have been undergoing more rapid regulatory evolution than frogs have (6). We unusually rapid anatomical evolution. Chromosomal consider regulatory differences to be differences in the pat- evolution is also thought to have proceeded very slowly in terns of gene expression. Since mammals have also under- both birds and frogs, relative to mammals. gone more rapid anatomical evolution than frogs it was The above observations are consistent with the hypoth- have, esis that evolutionary changes in regulatory systems, suggested that rapid regulatory evolution in mammals may that is, changes in the patterns of gene expression, provide account for both their rapid anatomical evolution and their the basis for both anatomical evolution and the evolution- rapid evolutionary loss of the potential for interspecific ary loss of hybridization potential. hybridization. In view of the observation that mammals have undergone rapid evolutionary changes in gene arrange- Several authors have suggested that in order to understand the organismal evolution one needs to focus attention on ment compared to frogs (7), it was further suggested that the control of gene expression rather than on the amino phenomenon of gene rearrangement may be an important acid sequences of proteins coded for by structural genes means of achieving new systems of regulation. (1-5). This article and the preceding ones in this series (6-8) To explain the observation that protein evolution has gone the oc- present evidence consistent with this suggestion. This on at the same rate in frogs as in mammals, despite currence of far more rapid organismal evolution in mammals evidence comes from studies of the relative rates of evolution evolution of anatomy, pro- than in frogs, it has been proposed that protein chromosomes, hybridization potential, and not be at the basis of evolution Thus teins in three major groups of vertebrates. The data on frogs may organismal (6, 7). and mammals have already been published (6, 7). We show there may be two types of molecular evolution: (1) protein evolution, which proceeds relentlessly in a predominantly here that similar conclusions may be drawn from analogous which studies on birds. time-dependent manner, and (2) regulatory evolution, The data presented in this article are based on studies of parallels organismal evolution. We now present the results of a study of protein species capable of interspecific hybridization. Studies of inter- of of new in- resemblance within pairs bird species capable hybridiza- specific hybridization have often provided valuable tion. Birds, like frogs, seem to have lost the potential for inter- sights into the mechanism of evolution (9). There are, of specific hybridization slowly. We also review evidence that course, many natural barriers to interspecific hybridization. birds have evolved slowly at both the anatomical and the Geographical, ecological, behavioral, and anatomical barriers levels. normally prevent contact between an egg of one species and chromosomal sperm of another. If these barriers are circumvented and fertilization occurs, the resulting interspecific zygote may MATERIALS AND METHODS develop into a viable hybrid organism. We have examined Avian Samples. Bird egg whites, sera, and tissue extracts the problem of what relationship, if any, exists between were obtained, prepared, and stored as described (10). Thirty-three different avian species capable of hybridizing Abbreviation: MY, million years. with one or more other species were studied. They were 200 Downloaded by guest on September 30, 2021 Proc.PNat.NAcad.c1RegulatorySci. USA 72 (1975) Evolution in Birds 201 TABLE 1. Immunological distances within avian species pairs chosen from three of the 27 bird orders: Rheiformes, contain- capable of hybridization ing the large, flightless rheas of South America; Anseriformes, made up of waterfowl; and Galliformes, consisting of game Immunological distance birds. The- first footnote to Table 1 gives further details re- Pair*t Albumin Transferrin garding the classification of the species examined. This con- stituted a representative sample of hybridizable species pairs, Rheiformes since more than half of all reported cases of avian inter- Rhea americana specific hybrids occur within the orders Anseriformes and X Pterocnemia pennata 0 NDJ Galliformes (11-13). We prepared antisera (see below) to Anseriformes albumin from six species and to transferrin from five species Anas platyrhynchos and made immunological comparisons of the proteins of 36 X Anas laysanensis 0 1 different avian species pairs capable of interspecific hybridiza- X Anas poecilorhyncha 0 2 X Anas castanea 0 3 tion. X Anas rubripes 0 4 Protein Purification. Eleven avian proteins-six serum X Anas bahamensis 2 3 albumins, two serum transferrins, and three ovotransfer- X Anas acuta 0 11 rins-were purified and used as immunogens. The purifica- X Aix galericulata 8 16 tion of common rhea (Rhea americana) albumin and chicken X Aix sponsa 8 29 X Cairina moschata 9 21 (Gallus gallus) ovotransferrin has been described (10). X Netta rufina 8 21 Serum albumin from Peking duck (Anas platyrhynchos), X Tadorna tadorna 13 34 chicken, ring-necked pheasant (Phasianus colchicus), peafowl X Anser cygnoides 10 65 (Pavo cristatus), and turkey (Meleagris gallopavo) was puri- X Anser anser 13 69 fied by Rivanol precipitation and subsequent regeneration of X Branta canadensis 12 61 the albumin (14) followed by preparative polyacrylamide gel Galliformes electrophoresis (15). Eight percent polyacrylamide gels and a Gallus galluw continuous buffer system of 0.1 M Tris plus 0.05 M glycine X Gallus sonnerati ND§ 0 were generally used. Occasionally 6.4% gels and a discon- X Gallus varius 11 6 tinuous buffer system (16) were employed. 8-anilino-l- X Lophophorus impeyanuw 18 33 naphthalene sulfonate (17) or simply the difference in re- X Lophura nycthemera ND§ 50 fractive index was used to detect the albumin band on the X Phasianus colchicus 291 35¶ gels. Elution of the albumin from the polyacrylamide discs X Chrysolophus pictus 26 32 X Pavo cristatus 241 34¶ (15) into isotris buffer (18) containing merthiolate (2.5 4g X Coturnix coturnix 23 35 per ml) was done at room temperature for 1 day and then at 40 X Numida meleagris 34 53 for two or more days with occasional shaking. The albumins X Meleagris gallopavo 185 *325 (except that of the chicken) were then concentrated by Phasianus colchicus vacuum dialysis, further purified by a repetition of the X Lagopu8 mutus ND§ 16 electrophoresis in polyacrylamide, and again eluted. In cer- X Lophura nycthemera ND§ 26 tain cases three polyacrylamide gel purification steps were X Syrmaticus reevesi 18 25 utilized. X Chrysolophus amherstiae 14 13 Duck and peafowl serum transferrin were purified es- X Chrysolophus pictus 12 12 sentially as described (19). A small amount of ferrous am- X Meleagris gallopavo 19w 15I Pavo cristatus monium sulfate was added prior to the Rivanol precipitation X Pavo muticus 0 0 and polyacrylamide gel electrophoresis steps to saturate
Load more

Recommended publications
  • Nogth AMERICAN BIRDS
    CHECK-LIST OF NOgTH AMERICAN BIRDS The Speciesof Birds of North America from the Arctic through Panama, Including the West Indies and Hawaiian Islands PREPARED BY THE COMMITTEE ON CLASSIFICATION AND NOMENCLATURE OF THE AMERICAN ORNITHOLOGISTS' UNION SEVENTH EDITION 1998 Zo61ogical nomenclature is a means, not an end, to Zo61ogical Science PUBLISHED BY THE AMERICAN ORNITHOLOGISTS' UNION 1998 Copyright 1998 by The American Ornithologists' Union All rights reserved, except that pages or sections may be quoted for research purposes. ISBN Number: 1-891276-00-X Preferred citation: American Ornithologists' Union. 1983. Check-list of North American Birds. 7th edition. American Ornithologists' Union, Washington, D.C. Printed by Allen Press, Inc. Lawrence, Kansas, U.S.A. CONTENTS DEDICATION ...................................................... viii PREFACE ......................................................... ix LIST OF SPECIES ................................................... xvii THE CHECK-LIST ................................................... 1 I. Tinamiformes ............................................. 1 1. Tinamidae: Tinamous .................................. 1 II. Gaviiformes .............................................. 3 1. Gaviidae: Loons ....................................... 3 III. Podicipediformes.......................................... 5 1. Podicipedidae:Grebes .................................. 5 IV. Procellariiformes .......................................... 9 1. Diomedeidae: Albatrosses .............................
    [Show full text]
  • Than a Meal: the Turkey in History, Myth
    More Than a Meal Abigail at United Poultry Concerns’ Thanksgiving Party Saturday, November 22, 1997. Photo: Barbara Davidson, The Washington Times, 11/27/97 More Than a Meal The Turkey in History, Myth, Ritual, and Reality Karen Davis, Ph.D. Lantern Books New York A Division of Booklight Inc. Lantern Books One Union Square West, Suite 201 New York, NY 10003 Copyright © Karen Davis, Ph.D. 2001 All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the written permission of Lantern Books. Printed in the United States of America Library of Congress Cataloging-in-Publication Data For Boris, who “almost got to be The real turkey inside of me.” From Boris, by Terry Kleeman and Marie Gleason Anne Shirley, 16-year-old star of “Anne of Green Gables” (RKO-Radio) on Thanksgiving Day, 1934 Photo: Underwood & Underwood, © 1988 Underwood Photo Archives, Ltd., San Francisco Table of Contents 1 Acknowledgments . .9 Introduction: Milton, Doris, and Some “Turkeys” in Recent American History . .11 1. A History of Image Problems: The Turkey as a Mock Figure of Speech and Symbol of Failure . .17 2. The Turkey By Many Other Names: Confusing Nomenclature and Species Identification Surrounding the Native American Bird . .25 3. A True Original Native of America . .33 4. Our Token of Festive Joy . .51 5. Why Do We Hate This Celebrated Bird? . .73 6. Rituals of Spectacular Humiliation: An Attempt to Make a Pathetic Situation Seem Funny . .99 7 8 More Than a Meal 7.
    [Show full text]
  • Onetouch 4.0 Scanned Documents
    / Chapter 2 THE FOSSIL RECORD OF BIRDS Storrs L. Olson Department of Vertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC. I. Introduction 80 II. Archaeopteryx 85 III. Early Cretaceous Birds 87 IV. Hesperornithiformes 89 V. Ichthyornithiformes 91 VI. Other Mesozojc Birds 92 VII. Paleognathous Birds 96 A. The Problem of the Origins of Paleognathous Birds 96 B. The Fossil Record of Paleognathous Birds 104 VIII. The "Basal" Land Bird Assemblage 107 A. Opisthocomidae 109 B. Musophagidae 109 C. Cuculidae HO D. Falconidae HI E. Sagittariidae 112 F. Accipitridae 112 G. Pandionidae 114 H. Galliformes 114 1. Family Incertae Sedis Turnicidae 119 J. Columbiformes 119 K. Psittaciforines 120 L. Family Incertae Sedis Zygodactylidae 121 IX. The "Higher" Land Bird Assemblage 122 A. Coliiformes 124 B. Coraciiformes (Including Trogonidae and Galbulae) 124 C. Strigiformes 129 D. Caprimulgiformes 132 E. Apodiformes 134 F. Family Incertae Sedis Trochilidae 135 G. Order Incertae Sedis Bucerotiformes (Including Upupae) 136 H. Piciformes 138 I. Passeriformes 139 X. The Water Bird Assemblage 141 A. Gruiformes 142 B. Family Incertae Sedis Ardeidae 165 79 Avian Biology, Vol. Vlll ISBN 0-12-249408-3 80 STORES L. OLSON C. Family Incertae Sedis Podicipedidae 168 D. Charadriiformes 169 E. Anseriformes 186 F. Ciconiiformes 188 G. Pelecaniformes 192 H. Procellariiformes 208 I. Gaviiformes 212 J. Sphenisciformes 217 XI. Conclusion 217 References 218 I. Introduction Avian paleontology has long been a poor stepsister to its mammalian counterpart, a fact that may be attributed in some measure to an insufRcien- cy of qualified workers and to the absence in birds of heterodont teeth, on which the greater proportion of the fossil record of mammals is founded.
    [Show full text]
  • Reproductive Mode and Speciation: the Viviparity-Driven Conflict Liypothesis David W
    Hypothesis Reproductive mode and speciation: the viviparity-driven conflict liypothesis David W. Zeh* and Jeanne A. Zeh Summary in the speciation process.*^"®' With patterns in nature (see In birds and frogs, species pairs retain the capacity to below) exhibiting profound between-lineage differences in produce viable hybrids for tens of millions of years, an order of magnitude longer than mammals. What the relative rates at which pre- and postzygotic isolation accounts for these differences in relative rates of pre- evolve,*^~^°' a unifying theory of speciation has remained and postzygotic isolation? We propose that reproduc- elusive. Here, we present a new hypothesis to account for the tive mode is a critically important but previously over- extreme disparity that exists between lineages in patterns of looked factor in the speciation process. Viviparity speciation. This viviparity-driven conflict hypothesis proposes creates a post-fertilization arena for genomic conflicts absent in egg-laying species. With viviparity, conflict that the reproductive stage at which divergence occurs most can arise between: mothers and embryos; sibling rapidly between populations is strongly influenced by the embryos in the womb, and maternal and paternal degree to which embryonic development involves physiolo- genomes within individual embryos. Such intra- and gical interactions between mother and embryo. After briefly intergenomic conflicts result in perpetual antagonistic reviewing between-lineage differences in patterns of specia- coevolution, thereby accelerating interpopulation post- zygotic isolation. In addition, by generating intrapopula- tion, we develop the hypothesis that postzygotic isolation tion genetic incompatibility, viviparity-driven conflict should evolve more rapidly in viviparous animals than in favors polyandry and limits the potential for precopula- oviparous species, because development of the embryo tory divergence.
    [Show full text]
  • Partridges, Quails, Pheasants and Turkeys Phasianidae Vigors, 1825: Zoological Journal 2: 402 – Type Genus Phasianus Linnaeus, 1758
    D .W . .5 / DY a 5D t w[ { wt Ç"" " !W5 í ÇI &'(' / b ù b a L w 5 ! ) " í "* " Ç t+ t " h " * { b ù" t* &)/&0 Order GALLIFORMES: Game Birds and Allies The order of galliform taxa in Checklist Committee (1990) appears to have been based on Peters (1934). Johnsgard (1986) synthesised available data, came up with similar groupings of taxa, and produced a dendrogram indicating that turkeys (Meleagridinae) were the most primitive (outside Cracidae and Megapodiidae), with grouse (Tetraoninae), guineafowl (Numidinae), New World quails (Odontophorinae) and pheasants and kin (Phasianinae) successively more derived. Genetic evidence (DNA-hybridisation data) provided by Sibley & Ahlquist (1990) suggested Odontophorinae were the most basal phasianoids and guineafowl the next most basal group. A basal position of the New World quails among phasianoids has been supported by other genetic data (Kimball et al. 1999, Armstrong et al. 2001). A recent analysis based on morphological characters (Dyke et al. 2003) found support for megapodes as the most basal group in the order, then Cracidae, then Phasianidoidea, and within the latter, Numididae the most basal group. In contrast to the above genetic-based analyses, Dyke et al. (2003) found the Odontophorinae to be the most derived group within the order. A recent analysis using both mitochondrial ND2 and cytochrome-b DNA sequences, however, reinforces the basal position of the Odontophorinae (Pereira & Baker 2006). Here we follow a consensus of the above works and place Odontophorinae basal in the phasianids. Worthy & Holdaway (2002) considered that Cheeseman’s (1891) second-hand record of megapodes from Raoul Island, Kermadec Group, before the 1870 volcanic eruption has veracity.
    [Show full text]
  • Hybridization & Zoogeographic Patterns in Pheasants
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Paul Johnsgard Collection Papers in the Biological Sciences 1983 Hybridization & Zoogeographic Patterns in Pheasants Paul A. Johnsgard University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/johnsgard Part of the Ornithology Commons Johnsgard, Paul A., "Hybridization & Zoogeographic Patterns in Pheasants" (1983). Paul Johnsgard Collection. 17. https://digitalcommons.unl.edu/johnsgard/17 This Article is brought to you for free and open access by the Papers in the Biological Sciences at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Paul Johnsgard Collection by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. HYBRIDIZATION & ZOOGEOGRAPHIC PATTERNS IN PHEASANTS PAUL A. JOHNSGARD The purpose of this paper is to infonn members of the W.P.A. of an unusual scientific use of the extent and significance of hybridization among pheasants (tribe Phasianini in the proposed classification of Johnsgard~ 1973). This has occasionally occurred naturally, as for example between such locally sympatric species pairs as the kalij (Lophura leucol11elana) and the silver pheasant (L. nycthelnera), but usually occurs "'accidentally" in captive birds, especially in the absence of conspecific mates. Rarely has it been specifically planned for scientific purposes, such as for obtaining genetic, morphological, or biochemical information on hybrid haemoglobins (Brush. 1967), trans­ ferins (Crozier, 1967), or immunoelectrophoretic comparisons of blood sera (Sato, Ishi and HiraI, 1967). The literature has been summarized by Gray (1958), Delacour (1977), and Rutgers and Norris (1970). Some of these alleged hybrids, especially those not involving other Galliformes, were inadequately doculnented, and in a few cases such as a supposed hybrid between domestic fowl (Gallus gal/us) and the lyrebird (Menura novaehollandiae) can be discounted.
    [Show full text]
  • The Big Year Ebook Free Download
    THE BIG YEAR PDF, EPUB, EBOOK Mark Obmascik | 320 pages | 08 Dec 2011 | Transworld Publishers Ltd | 9780857500694 | English | London, United Kingdom The Big Year PDF Book Pete Shackelford Steve Darling Archived from the original on January 26, In , Nicole Koeltzow reached the species milestone on July 1, while in August Gaylee and Richard Dean became the first birders to reach species in consecutive years. Highway runs along the California Coast. Crazy Credits. By Noah Strycker July 26, Stu is hiking with his toddler grandson already enamored by birds in the Rockies. Mary Swit Calum Worthy Miller Greg Miller It also replaces Jack Black's narration of the story with a new narration by John Cleese who also receives a credit in the opening title sequence. Narrator voice Jack Black Brad is a skilled birder who can identify nearly any species solely by sound. Category:Birds and humans Zoomusicology. Added to Watchlist. Retrieved January 25, Get Audubon in Your Inbox Let us send you the latest in bird and conservation news. Retrieved Jessica Steve Martin Paul Lavigne Heather Osborne Share this page:. Birds class : Aves. Yukon News. Tony Cindy Busby Wheel of Fortune Underscore. Visit our What to Watch page. Caprimulgiformes nightjars and relatives Steatornithiformes Podargiformes Apodiformes swifts and hummingbirds. In , an unprecedented four birders attempted simultaneous ABA Area big years. Steve's character provides fatherly guidance and support that helps Jack Black's character move forward with his life and relationships. The company is in the middle of complicated negotiations to merge with a competitor, so his two anointed successors keep calling him back to New York for important meetings; to some extent he is a prisoner of his own success.
    [Show full text]
  • An Assessment of the Risk Associated with the Movement Turkeys To
    United States Department of Agriculture Animal and Plant Health Inspection Service Veterinary Services Science, Technology, An Assessment of the Risk Associated with the and Analysis Services Movement Turkeys to Market Into, Within, and Center for Epidemiology and Animal Health Out of a Control Area During a Highly 2150 Centre Avenue Pathogenic Avian Influenza Outbreak in the Building B Fort Collins, CO 80526 United States March 2017 FIRST DRAFT September 2017 SECOND REVIEW January 2018 THIRD REVIEW October 2018 FINAL REVIEW AND CLEARANCE A Collaboration between the Turkey Sector Working Group, the University of Minnesota’s Secure Food Systems Team, and USDA:APHIS:VS:CEAH UNITED STATES DEPARTMENT OF AGRICULTURE ANIMAL AND PLANT HEALTH INSPECTION SERVICE VETERINARY SERVICES CENTER FOR EPIDEMIOLOGY AND ANIMAL HEALTH Turkeys to Market Risk Assessment Suggested bibliographic citation for this report: Carol Cardona, Carie Alexander, Justin Bergeron, Peter Bonney, Marie Culhane, Timothy Goldsmith, David Halvorson, Eric Linskens, Sasidhar Malladi, Amos Ssematimba, Emily Walz, Todd Weaver, Jamie Umber. An Assessment of the Risk Associated with the Movement of Turkeys to Market Into, Within, and Out of a Control Area during a Highly Pathogenic Avian Influenza Outbreak in the United States. Collaborative agreement between USDA:APHIS:VS and University of Minnesota Center for Secure Food Systems. Fort Collins, CO. October 2018. 217 pgs. This document was developed through the Continuity of Business / Secure Food Supply Plans / Secure Poultry Supply
    [Show full text]
  • Coupling, Reinforcement, and Speciation Roger Butlin, Carole Smadja
    Coupling, Reinforcement, and Speciation Roger Butlin, Carole Smadja To cite this version: Roger Butlin, Carole Smadja. Coupling, Reinforcement, and Speciation. American Naturalist, Uni- versity of Chicago Press, 2018, 191 (2), pp.155-172. 10.1086/695136. hal-01945350 HAL Id: hal-01945350 https://hal.archives-ouvertes.fr/hal-01945350 Submitted on 5 Dec 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License vol. 191, no. 2 the american naturalist february 2018 Synthesis Coupling, Reinforcement, and Speciation Roger K. Butlin1,2,* and Carole M. Smadja1,3 1. Stellenbosch Institute for Advanced Study, Wallenberg Research Centre at Stellenbosch University, Stellenbosch 7600, South Africa; 2. Department of Animal and Plant Sciences, The University of Sheffield, Sheffield S10 2TN, United Kingdom; and Department of Marine Sciences, University of Gothenburg, Tjärnö SE-45296 Strömstad, Sweden; 3. Institut des Sciences de l’Evolution, Unité Mixte de Recherche 5554 (Centre National de la Recherche Scientifique–Institut de Recherche pour le Développement–École pratique des hautes études), Université de Montpellier, 34095 Montpellier, France Submitted March 15, 2017; Accepted August 28, 2017; Electronically published December 15, 2017 abstract: During the process of speciation, populations may di- Introduction verge for traits and at their underlying loci that contribute barriers Understanding how reproductive isolation evolves is key fl to gene ow.
    [Show full text]
  • Speciation Through Evolution of Sex-Linked Genes
    Heredity (2009) 102, 4–15 & 2009 Macmillan Publishers Limited All rights reserved 0018-067X/09 $32.00 www.nature.com/hdy SHORT REVIEW Speciation through evolution of sex-linked genes A Qvarnstro¨m and RI Bailey Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Norbyva¨gen, Uppsala, Sweden Identification of genes involved in reproductive isolation expectation but mainly in female-heterogametic taxa. By opens novel ways to investigate links between stages of the contrast, there is clear evidence for both strong X- and speciation process. Are the genes coding for ecological Z-linkage of hybrid sterility and inviability at later stages of adaptations and sexual isolation the same that eventually speciation. Hence genes coding for sexual isolation traits are lead to hybrid sterility and inviability? We review the role of more likely to eventually cause hybrid sterility when they are sex-linked genes at different stages of speciation based on sex-linked. We conclude that the link between sexual four main differences between sex chromosomes and isolation and evolution of hybrid sterility is more intuitive in autosomes; (1) relative speed of evolution, (2) non-random male-heterogametic taxa because recessive sexually antag- accumulation of genes, (3) exposure of incompatible onistic genes are expected to quickly accumulate on the recessive genes in hybrids and (4) recombination rate. At X-chromosome. However, the broader range of sexual traits early stages of population divergence ecological differences that are expected to accumulate on the Z-chromosome may appear mainly determined by autosomal genes, but fast- facilitate adaptive speciation in female-heterogametic spe- evolving sex-linked genes are likely to play an important role cies by allowing male signals and female preferences to for the evolution of sexual isolation by coding for traits with remain in linkage disequilibrium despite periods of gene flow.
    [Show full text]
  • The Genetic Basis of Reproductive Isolation: Insights from Drosophila
    Colloquium The genetic basis of reproductive isolation: Insights from Drosophila H. Allen Orr* Department of Biology, University of Rochester, Rochester, NY 14627 Recent studies of the genetics of speciation in Drosophila have number of new and careful studies of the biogeography, ecology, focused on two problems: (i) identifying and characterizing the and genetics of speciation, and we now understand a good deal genes that cause reproductive isolation, and (ii) determining the about the evolution of reproductive isolation (3). We can, for evolutionary forces that drove the divergence of these ‘‘speciation instance, describe the rate at which this reproductive isolation genes.’’ Here, I review this work. I conclude that speciation genes evolves (Fig. 1), and the ecological factors that drive speciation, correspond to ordinary loci having normal functions within species. at least in some cases (6). We can also point to plausible examples These genes fall into several functional classes, although a role in in which the process of reinforcement may have completed transcriptional regulation could prove particularly common. More speciation (3, 7, 8). Finally, we know a fair amount about the important, speciation genes are typically very rapidly evolving, and number and location of the genes that cause reproductive this divergence is often driven by positive Darwinian selection. isolation (at least in its postzygotic form), and the causes of Finally, I review recent work in Drosophila pseudoobscura on the patterns like Haldane’s rule (3, 9, 10). possible role of meiotic drive in the evolution of the genes that Given this progress, it is natural to ask: What now are the cause postzygotic isolation.
    [Show full text]
  • Inviability of Intergeneric Hybrids Involving Triticum Monococcum and T
    INVIABILITY OF INTERGENERIC HYBRIDS INVOLVING TRITICUM MONOCOCCUM AND T. AEGILOPOIDES’ E. R. SEARS U. S. Department of Agriculture, Columbia, Missouri Received July 26, 1943 INTRODUCTION ITH the development in recent years of colchicine techniques and other wreliable methods for doubling chromosome number in plants, interspecific and intergent -ic hybrids which formerly could not be maintained because of their sterility’can now easily be rendered fertile and true-breeding, The ready source of essehtially new species thereby made available is rather strictly lim- ited, however, by the failure of many crosses between reasonably close rela- tives to yield viable hybrids. Noteworthy progress has recently been made toward extending the limits of crossability. The discovery by LAIBACH(1925) that the embryos of certain inviable hybrid seeds can be dissected out and grown on artificial media, coupled with the recent development by VAN OVERBEEK,CONKLIN, and BLAKESLEE(1942) of methods for culturing extremely young embryos, should permit many otherwise impossible crosses to be made. Certain other devices, notably the style-shortening technique of MANGELSDORFand REEVES(1931) and the mixed pollinations of BEASLEY(1940), have served in special instances to make possible the production of hybrids. An important barrier to hybridization which cannot be overcome by any of the foregoing methods is the lethality of hybrid seedlings. In the genus Crepis, BABCOCKand NAVASHIN(1930) reported that 19 out of 103 interspecif- ic hybrids were abnormal or weak, in most cases dying before reaching the flowering stage; and EAST(1935a) found 14 inviable types in 77 hybrid com- binations in Nicotiana. The very early stage at which,some hybrid seedlings die makes it probable that there are numerous comparable instances where the embryo dies before maturity of the seed.
    [Show full text]