A readily comprehensible guide for biologists, field taxonomists and inte- rested laymen to one of the oldest problems in biology: The Species Problem. Written by a geneticist with extensive experience in field taxonomy, this Kunz practical book provides the sound scientific and philosophical background to the problems arising with classifying organisms according to species. Do Species Exist? It covers the main current theories of speciation and gives a number of taxonomic examples that cannot be explained by any single theory alone. Principles of Taxonomic Classification Further material is available on www.wiley-vch.de/home/species Werner Kunz Currently a professor in Düsseldorf, Germany, Werner Kunz studied biology, chemistry, and physics in Münster and spent two postdoc years at Yale Univer- sity in New Haven, U.S.A. Although he was educated as a zoologist, he switched to Drosophila genetics and worked on chromosomes and ribosomal DNA. He later changed his field of interest again, carrying out research into molecular parasitology, and for the past ten years has been participating in the teaching of philosophy of science. Professor Kunz continues the hobby he began at a very early age, photographing birds and butterflies as a field biologist all over the globe. Do Species Exist? Werner Kunz Do Species Exist? Related Titles Wiley, E. O., Lieberman, B. S. Ayala, F. J., Arp, R. (eds.) Phylogenetics Contemporary Debates in Theory and Practice of Phylogenetic Philosophy of Biology Systematics 2009 2011 ISBN: 978-1-4051-5999-9 ISBN: 978-0-470-90596-8 Rosenberg, A., Arp, R. (eds.) Ladle, R. J., Whittaker, R. J. (eds.) Philosophy of Biology Conservation Biogeography An Anthology 2011 2009 ISBN: 978-1-4443-3504-0 ISBN: 978-1-4051-8316-1 Sarkar, S., Plutynski, A. (eds.) Ruse, M. A Companion to the Philosophy Charles Darwin of Biology 2008 2010 ISBN: 978-1-4051-4913-6 ISBN: 978-1-4443-3785-3 Knowles, L. L., Kubatko, L. S. (eds.) Estimating Species Trees Practical and Theoretical Aspects 2010 ISBN: 978-0-470-52685-9 Werner Kunz Do Species Exist? Principles of Taxonomic Classification Limit of Liability/Disclaimer of Warranty The Author : While the publisher and author have used their best efforts in pre- Prof. Dr. Werner Kunz paring this book, they make no representations or war- Heinrich-Heine-University ranties with respect to the accuracy or completeness of the fi Institute for Genetics contents of this book and speci cally disclaim any fi Universitätsstraße 1 implied warranties of merchantability or tness for a 40225 Düsseldorf particular purpose. No warranty can be created or Germany extended by sales representatives or written sales mate- rials. The Advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to spe- cial, incidental, consequential, or other damages. Library of Congress Card No.: applied for British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. Bibliographic information published by the Deutsche Nationalbibliothek The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at http://dnb.d-nb.de. # 2012 Wiley-VCH Verlag & Co. KGaA, Cover Boschstr. 12, 69469 Weinheim, Germany Diversity of Species in Central American Rain Forest Wiley-Blackwell is an imprint of John Wiley & Sons, ’ fi (photomontage). In the center Resplendent Quetzal formed by the merger of Wiley s global Scienti c, Tech- (Pharomachrus mocinno), on its left on the top Chestnut- nical, and Medical business with Blackwell Publishing. mandibled Toucan (Ramphastos swainsonii) and the All rights reserved (including those of translation into smaller green Emerald Toucanet below (Aulacorhynchus other languages). No part of this book may be reproduced prasinus). In the bottom left corner a flying Swallowtail in any form – by photoprinting, microfilm, or any other (Parides lycimenes). On the right side of the figure from top means – nor transmitted or translated into a machine to bottom Red-lored Parrot (Amazona autumnalis), language without written permission from the publish- Squirrel Monkey (Saimiri oerstedii), Fiery-billed Aracari ers. Registered names, trademarks, etc. used in this book, (Pteroglossus frantzii), a flying Heliconiid butterfly even when not specifically marked as such, are not to be (Dryas julia), Roadside Hawk (Buteo magnirostris), considered unprotected by law. White-headed Capuchin (Cebus capucinus), Ferruginous Cover: Formgeber, Eppelheim Pygmy Owl (Glaucidium brasilianum) and at the bottom in Typesetting: Thomson Digital, Noida, India the sky three Blues of genus Strymon. Printing & Binding: Markono Print Media Pte Ltd, Singapore Print ISBN: 978-3-527-33207-6 ePDF ISBN: 978-3-527-66425-2 ePub ISBN: 978-3-527-66426-9 mobi ISBN: 978-3-527-66427-6 oBook ISBN: 978-3-527-66428-3 V Contents Foreword XI Preface XV Color Plates XVII Introduction 1 1 Are Species Constructs of the Human Mind? 5 2 Why is there a Species Problem? 9 2.1 Objective of the Book 9 2.2 Can Species be Defined and Delimited from one Another? 10 2.3 What Makes Biological Species so Special? 12 2.4 Species: To Exist, or not to Exist, that is the Question 15 2.5 The Reality of Species: Ernst Mayr vs. Charles Darwin 19 2.6 The Constant Change in Evolution and the Quest of Taxonomy for Fixed Classes: can these be Compatible? 20 2.7 Can a Scientist Work with a Species Without Knowing what a Species is? 23 2.8 The Species as an Intuitive Concept and a Cognitive Preset in the Human Mind 24 2.9 Taxonomys Status as a ‘‘Soft’’ or ‘‘Hard Science’’ 27 2.10 The Impact of the Species Concept on Nature Conservation and the Allocation of Tax Money 30 2.11 Sociological Consequences of a Misunderstood Concept of Race 31 2.12 Species Pluralism: How Many Species Concepts Exist? 33 2.13 It is One Thing to Identify a Species, but Another to Define what a Species is 39 2.14 The Dualism of the Species Concept: the Epistemic vs. the Operative Goal 41 VI Contents 3 Is the Biological Species a Class or is it an Individual? 45 3.1 Preliminary Note: Can a Species have Essential Traits? 45 3.2 Class Formation and Relational Group Formation 47 3.3 Is the Biological Species a Universal/Class or an Individual? 49 3.4 The Difference Between a Group of Objects as a Class and a Group of Objects as an Individual is a Fundamental One 51 3.5 Artificial Classes and Natural Kinds 54 3.6 The Biological Species Cannot be a Natural Kind 56 3.7 The Biological Species as a Homeostatic Property Cluster 58 3.8 Polythetic Class Formation or Grouping According to Family Resemblance 60 3.9 The Linnaean System is Based on Fundamental Assumptions that are Irreconcilable with a Contemporary Worldview of Science 61 3.10 Comparison of the System of Organisms with the Periodic Table of Chemical Elements 63 3.11 The Relational Properties of the Members of a Species are the Essence of the Species 64 4 What are Traits in Taxonomy? 67 4.1 Preliminary Note 67 4.2 What Basic Rule Defines Traits as Being Taxonomically Relevant? 68 4.3 What is the Relevance of Differences in Genes Between Two Species? 71 4.4 In Sticklebacks (Gasterosteus aculeatus), a Single Gene Controls Many Phenotypes 73 4.5 What is the Relevance of Differences in Traits between Two Species? 74 4.6 Traits that are Used by the Species to Distinguish Themselves 76 4.7 A Species cannot be Defined by Traits 80 4.8 What are Homologous Traits? 82 4.9 The Vertebrate Eye and the Squid Eye: They Cannot be Homologous Nor can they be Non-Homologous 84 4.10 The DNA Barcoding Approach – is Taxonomy Nothing more than Phylogenetic Distance? 86 5 Diversity within the Species: Polymorphisms and the Polytypic Species 93 5.1 Preliminary Note 93 5.2 Differences in Traits do not Necessarily Mean Species Differences 94 5.3 Superfluous Taxonomic Terms: Variation, Aberration, Form, Phase, Phenon 96 5.4 What are Races or Subspecies? 97 Contents VII 5.5 Are Carrion Crow and Hooded Crow (Corvus corone and C. cornix) in Eurasia and the Guppy Populations on Trinidad Species or Races? 99 5.6 What are Morphs? 100 5.7 What are Mutants (in a Taxonomic Sense)? 103 5.8 Allelic Diversity 104 5.9 How Long is the Lifetime of Allelic Polymorphisms? 105 5.10 Stable Polymorphisms – The Selective Advantage is Diversity 106 5.11 Are Differences between Species Due only to Differences in Allelic Frequency Distribution, Such that there are no Truly Species-Specific Traits? 108 5.12 Partially Migratory Birds – an Example of Genetic Polymorphisms 110 5.13 Intraspecies Morphs in the Burnet Moth Zygaena ephialtes 114 5.14 The Color Pattern Polymorphism of the Shells of the Brown-Lipped Snail Cepaea nemoralis 116 5.15 The Beak Polymorphism in the Black-Bellied Seedcracker Finch Pyrenestes ostrinus 118 5.16 The Beak Polymorphism in the Darwin Finch Geospiza fortis 119 5.17 Intraspecies Morphs in the Garter Snake Thamnophis ordinoides 121 5.18 Urbanization in Certain Bird Species is based on Genetic Polymorphism 121 5.19 The Mimicry Morphs of the Female Swallowtails of the Genus Papilio 123 5.20 The Morphs of the Brood-Parasitic Cuckoo Female Cuculus canorus 125 6 Biological Species as a Gene-Flow Community 127 6.1 The Definition of the Gene-Flow Community 127 6.2 The Connection of Organisms in a Gene-Flow Community Includes the Genealogical Connection 130 6.3 The Species