Do Species Exist?Principles of Taxonomic Classification

Werner Kunz

Kunz

Do

Sp

ecies Exist?

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 practical book provides the sound scientific and philosophical background to the problems arising with classifying organisms according to species. It covers the main current theories of speciation and gives a number of taxonomic examples that cannot be explained by any single theory alone.

Further material is available onwww.wiley-vch.de/home/species

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.

57268File AttachmentCover.jpg

Werner Kunz

Do Species Exist?

Related Titles

Wiley, E. O., Lieberman, B. S.

Phylogenetics

Theory and Practice of Phylogenetic

Systematics

2011

ISBN: 978-0-470-90596-8

Ladle, R. J., Whittaker, R. J. (eds.)

Conservation Biogeography

2011

ISBN: 978-1-4443-3504-0

Sarkar, S., Plutynski, A. (eds.)

A Companion to the Philosophyof Biology

2010

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

Ayala, F. J., Arp, R. (eds.)

Contemporary Debates inPhilosophy of Biology

2009

ISBN: 978-1-4051-5999-9

Rosenberg, A., Arp, R. (eds.)

Philosophy of Biology

An Anthology

2009

ISBN: 978-1-4051-8316-1

Ruse, M.

Charles Darwin

2008

ISBN: 978-1-4051-4913-6

Werner Kunz

Do Species Exist?

Principles of Taxonomic Classification

The Author

Prof. Dr. Werner KunzHeinrich-Heine-UniversityInstitute for GeneticsUniversitätsstraße 140225 DüsseldorfGermany

Cover

Diversity of Species in Central American Rain Forest(photomontage). In the center Resplendent Quetzal(Pharomachrus mocinno), on its left on the top Chestnut-mandibled Toucan (Ramphastos swainsonii) and thesmaller green Emerald Toucanet below (Aulacorhynchusprasinus). In the bottom left corner a flying Swallowtail(Parides lycimenes). On the right side of the figure from topto bottom Red-lored Parrot (Amazona autumnalis),Squirrel Monkey (Saimiri oerstedii), Fiery-billed Aracari(Pteroglossus frantzii), a flying Heliconiid butterfly(Dryas julia), Roadside Hawk (Buteo magnirostris),White-headed Capuchin (Cebus capucinus), FerruginousPygmyOwl (Glaucidium brasilianum) and at the bottom inthe sky three Blues of genus Strymon.

Limit of Liability/Disclaimer of Warranty: While thepublisher and author have used their best efforts in pre-paring this book, they make no representations or war-ranties with respect to the accuracy or completeness of thecontents of this book and specifically disclaim anyimplied warranties of merchantability or fitness for aparticular purpose. No warranty can be created orextended by sales representatives or written sales mate-rials. The Advice and strategies contained herein may notbe suitable for your situation. You should consult with aprofessional where appropriate. Neither the publisher norauthors shall be liable for any loss of profit or any othercommercial 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 DataA catalogue record for this book is available from theBritish Library.

Bibliographic information published bythe Deutsche NationalbibliothekThe Deutsche Nationalbibliothek lists this publication inthe Deutsche Nationalbibliografie; detailed bibliographicdata are available on the Internet at http://dnb.d-nb.de.

# 2012 Wiley-VCH Verlag & Co. KGaA,Boschstr. 12, 69469 Weinheim, Germany

Wiley-Blackwell is an imprint of John Wiley & Sons,formed by the merger of Wiley’s global Scientific, Tech-nical, and Medical business with Blackwell Publishing.

All rights reserved (including those of translation intoother languages). No part of this book may be reproducedin any form – by photoprinting, microfilm, or any othermeans – nor transmitted or translated into a machinelanguage without written permission from the publish-ers. Registered names, trademarks, etc. used in this book,even when not specifically marked as such, are not to beconsidered unprotected by law.

Cover: Formgeber, EppelheimTypesetting: Thomson Digital, Noida, IndiaPrinting & Binding: Markono Print Media Pte Ltd,Singapore

Print ISBN: 978-3-527-33207-6ePDF ISBN: 978-3-527-66425-2ePub ISBN: 978-3-527-66426-9mobi ISBN: 978-3-527-66427-6oBook ISBN: 978-3-527-66428-3

Contents

Foreword XIPreface XVColor Plates XVII

Introduction 1

1 Are Species Constructs of the Human Mind? 5

2 Why is there a Species Problem? 92.1 Objective of the Book 92.2 Can Species be Defined and Delimited from one Another? 102.3 What Makes Biological Species so Special? 122.4 Species: To Exist, or not to Exist, that is the Question 152.5 The Reality of Species: Ernst Mayr vs. Charles Darwin 192.6 The Constant Change in Evolution and the Quest of Taxonomy

for Fixed Classes: can these be Compatible? 202.7 Can a Scientist Work with a Species Without Knowing what a

Species is? 232.8 The Species as an Intuitive Concept and a Cognitive Preset

in the Human Mind 242.9 Taxonomys Status as a ‘‘Soft’’ or ‘‘Hard Science’’ 272.10 The Impact of the Species Concept on Nature Conservation

and the Allocation of Tax Money 302.11 Sociological Consequences of a Misunderstood Concept

of Race 312.12 Species Pluralism: How Many Species Concepts Exist? 332.13 It is One Thing to Identify a Species, but Another to Define

what a Species is 392.14 The Dualism of the Species Concept: the Epistemic

vs. the Operative Goal 41

V

3 Is the Biological Species a Class or is it an Individual? 453.1 Preliminary Note: Can a Species have Essential Traits? 453.2 Class Formation and Relational Group Formation 473.3 Is the Biological Species a Universal/Class or an Individual? 493.4 The Difference Between a Group of Objects as a Class and a Group

of Objects as an Individual is a Fundamental One 513.5 Artificial Classes and Natural Kinds 543.6 The Biological Species Cannot be a Natural Kind 563.7 The Biological Species as a Homeostatic Property Cluster 583.8 Polythetic Class Formation or Grouping According to Family

Resemblance 603.9 The Linnaean System is Based on Fundamental Assumptions that

are Irreconcilable with a Contemporary Worldview of Science 613.10 Comparison of the System of Organisms with the Periodic

Table of Chemical Elements 633.11 The Relational Properties of the Members of a Species are the Essence

of the Species 64

4 What are Traits in Taxonomy? 674.1 Preliminary Note 674.2 What Basic Rule Defines Traits as Being Taxonomically

Relevant? 684.3 What is the Relevance of Differences in Genes Between Two

Species? 714.4 In Sticklebacks (Gasterosteus aculeatus), a Single Gene Controls

Many Phenotypes 734.5 What is the Relevance of Differences in Traits between Two

Species? 744.6 Traits that are Used by the Species to Distinguish Themselves 764.7 A Species cannot be Defined by Traits 804.8 What are Homologous Traits? 824.9 The Vertebrate Eye and the Squid Eye: They Cannot be Homologous

Nor can they be Non-Homologous 844.10 The DNA Barcoding Approach – is Taxonomy Nothing more than

Phylogenetic Distance? 86

5 Diversity within the Species: Polymorphisms and the PolytypicSpecies 93

5.1 Preliminary Note 935.2 Differences in Traits do not Necessarily Mean Species

Differences 945.3 Superfluous Taxonomic Terms: Variation, Aberration,

Form, Phase, Phenon 965.4 What are Races or Subspecies? 97

VI Contents

5.5 Are Carrion Crow and Hooded Crow (Corvus corone and C. cornix)in Eurasia and the Guppy Populations on TrinidadSpecies or Races? 99

5.6 What are Morphs? 1005.7 What are Mutants (in a Taxonomic Sense)? 1035.8 Allelic Diversity 1045.9 How Long is the Lifetime of Allelic Polymorphisms? 1055.10 Stable Polymorphisms – The Selective Advantage is Diversity 1065.11 Are Differences between Species Due only to Differences in

Allelic Frequency Distribution, Such that there are no TrulySpecies-Specific Traits? 108

5.12 Partially Migratory Birds – an Example of GeneticPolymorphisms 110

5.13 Intraspecies Morphs in the Burnet Moth Zygaena ephialtes 1145.14 The Color Pattern Polymorphism of the Shells of the

Brown-Lipped Snail Cepaea nemoralis 1165.15 The Beak Polymorphism in the Black-Bellied Seedcracker

Finch Pyrenestes ostrinus 1185.16 The Beak Polymorphism in the Darwin Finch Geospiza fortis 1195.17 Intraspecies Morphs in the Garter Snake Thamnophis ordinoides 1215.18 Urbanization in Certain Bird Species is based on Genetic

Polymorphism 1215.19 The Mimicry Morphs of the Female Swallowtails

of the Genus Papilio 1235.20 The Morphs of the Brood-Parasitic Cuckoo Female

Cuculus canorus 125

6 Biological Species as a Gene-Flow Community 1276.1 The Definition of the Gene-Flow Community 1276.2 The Connection of Organisms in a Gene-Flow Community

Includes the Genealogical Connection 1306.3 The Species is a Gene-Flow Community, Not a Reproductive

Community 1316.4 A Species Concept Requires Both Connection and Delimitation 1336.5 The Concept of the Gene-Flow Community in Eukaryotes

and in Bacteria 1346.6 Uniparental Propagation in Eukaryotes 1356.7 Why do the Individuals of a Species Resemble Each Other? 1386.8 Isolation by Distance 1406.9 A Decrease in Lateral Sexual Gene Flow, together with Local

Adaptation, Creates Races 1416.10 The Adaptation of Breeding Times in Birds to the Annual

Maximum Food Supply 1436.11 Are Migratory and Sedentary Birds Able to Crossbreed? 144

Contents VII

6.12 Are Geographically Distant Populations of Stonechats (Saxicola torquata)or Blackcaps (Sylvia atricapilla) Genetically Compatible? 146

6.13 Are Univoltine and Bivoltine Butterflies Able to Crossbreed? 1486.14 Speciation Genes, Pre- and Postzygotic Barriers 1496.15 Hybrid Incompatibility 1516.16 Haldanes Rule and the Genes for Postzygotic Incompatibility 1536.17 Sympatric and Allopatric Speciation 1556.18 Sympatric Speciation in the Fruit fly Rhagoletis, in Cichlids

and in the Fire Salamander 1596.19 Reproductive Incompatibility is Different than Phylogenetic

Distance 1616.20 Phylogenetic Distance and Reproductive Incompatibility in Two Species

Pairs, Polar Bear (Ursus maritimus) and Brown Bear (U. arctos), inComparison to Grey Wolf (Canis lupus) and Coyote (C. latrans) 162

6.21 The Herring Gull (Larus argentatus) and the Greenish Warbler(Phylloscopus trochiloides), a False and a True Modelfor the Ring Species 163

6.22 Allopatrically Separated Populations are Always DifferentSpecies 165

6.23 Species Hybrids as Exceptions without EvolutionaryConsequences 167

6.24 The Example of Some Duck Species: Extinction throughHybridization 169

6.25 The Origin of Reproductive Isolation Through Reinforcement 1716.26 Hybridogenic Speciation 1736.27 Is the Italian Sparrow (Passer italiae) a Hybrid Species? 1766.28 ‘‘Gene theft’’ between two Species of Galapagos Ground Finches 1786.29 ‘‘Gene theft’’ between two Species of Green Frogs (Pelophylax ridibunda

and P. lessonae) 1806.30 How many Genes Must Mutate for the Origin of New Species? 1816.31 The Problem of Smooth Boundaries between two Gene-Flow

Communities 183

7 The Cohesion of Organisms Through GenealogicalLineage (Cladistics) 187

7.1 Preliminary Remarks on Descent Connection 1877.2 The Problem of Displaying the Phylogenetic Tree in the Case

of Biparental Reproduction 1897.3 What are Species Boundaries in Cladistics? 1917.4 How is a Cladistic Bifurcation Defined? Apomorphies and

Autapomorphies 1947.5 Descent is not the Same Thing as Kinship: The Concepts

of Monophyly and Paraphyly 1967.6 Why are Paraphyla used Despite their Inconsistency? 1997.7 Monophyly and Paraphyly on Different Hierarchical Levels 202

VIII Contents

7.8 Gene Trees are not Species Trees 2047.9 The Concepts of Monophyly and Paraphyly cannot be Applied to

Species 2067.10 Paraphyly and Anagenesis are Mixed Classifications 2087.11 The Cladistic Bifurcation of a Stem Species Always Means the

End of the Stem Species 2107.12 The ‘‘Phylocode’’ 212

8 Outlook 217

References 219

Scientific Terms 229

Index 239

Contents IX

Foreword

Do species exist?For Ernst Haeckel, in the midst of nineteenth century, the point was quite easy: In

the beginning, there was a plant and an animal. Evolution started extending andvarying their principal organizations. Accordingly, species were regarded to be justnotes given byman to the continuousflowof evolving life. Classifyingman looked forthese entities to allow him a qualification of the ongoing diversification of life.Taxonomy, thus, supporting such an evolutionary biology should formout somethinglike a phylogenetic systematics thatmay outline the quality of that continuing processof evolution in its details. Haeckel did not succeed to from out such a new taxonomyeven though he was one of the great taxonomists of the late nineteenth century. In anevolutionary perspective, addressing that continuous flow of evolution, species, thus,could be described only as categories formed by the human mind. With theintroduction of population genetics into Darwinism, the situation changed. Geneticsallowed to address a certain base of heredity. Accordingly, the continuous flow ofevolving forms could be outlined in a much more substantiated way, allowing toaddress how far genes were established, varied, or deleted in the course of genera-tions. In fact, more and more extending insights into the functional organization oflife forms established new ideas about life organization, in general. Thus, today, thesituation of taxonomy is far less clear than it was at Haeckels time. Not only that thelast unified common ancestor had to be a prokaryote or we had to address mush-rooms and eventually such prokaryotes and some others of such organizations asprincipally differing basic types of life. We have to integrate morphology, populationbiology, andmolecular genetics and their different accesses toward a species concept.Thus,wehave to address the question ofwhat a species really is, again. Andwehave toclarify several problems: How we can evaluate biological diversity if species do notexist? How we can understand evolution if speciation is not really the motor ofongoing evolutionary development? And how we can compare the accesses ofmolecular biology, the analysis of palaeontology, cladistics, and morphologicalanalyses directed toward the species concept in one run? In his book, Werner Kunzdescribes and analyzes all such various interpretations and concepts dealing withspecies. Thereby, he shows us that the different ideas of Neo-Darwinism, taxonomy,and genetics do not fit into each other. Even worse, he is aware that species have been

jXI

formed out in various solutionswithin different evolutionary settings. Aplant speciesis not directly comparable with an animal or mushroom species. In an evolutionaryperspective, all these species are the outcome of differing evolutionary strategies.That is not true for their differentiation in taxonomic regard, but it is true in regard ofwhat speciesmean in life. Thus far, a species not onlymight be characterized by a set ofattributes allowing a reliable classification but may also offer principal differingmaterials for an ongoing evolution. There, species of plants, various animals,prokaryote species, andmushroomsmay each react differently in evolution. Already,sexuality is organized in all these life forms in a differentway. In any case, there is justsomething transferring a set of genes, certain morphological and functional speci-fications fromone to thenext generations. Themodes bywhich this is being practisedare different, however. What should be done in such a situation?

Werner Kunz did not offer a philosophical solution. He is presenting facts, and heis doing that in a comparative perspective. One point Kunz makes is that thetaxonomists rely on Linnaeus who had a completely different view on nature fromthat we have today. For Linnaeus any species is part of creation. If nature is such acreation done by God, any entity in nature is reflecting an absolute ordering scheme.Systematic will outline this scheme. Thus, live forms a thought to be organized likethe terms in a baroque encyclopedia. There, any term outlines a basic idea. Its truemeaning is intelligible when the order, in which it is used, is made obvious. Theunderlying structure bywhich such ideas could be combined is the idea of a universaltopic reflecting the concept God has had in mind in setting out his creation. Tocombine such a scheme with the Darwinian idea of a continuously varying world isnot possible. Nevertheless, idealistic morphology in the start of twentieth centurytried to do this. The result was a logical scheme adopted in principle byWilli Hennig.He formed out an abstract pattern that allowed a proper classification, but was notinterested to integrate that view with a historical reconstruction of what actuallyhappened in the course of evolution. Cladism adopted Hennigs idea, which is nowforming the conceptual framing for evolutionary interpretation of DNA analyses.When such an idea of a logically consistent scheme is combined with evolutionarypopulation biology, problems occur. Accordingly, in an attempt to combine suchapproaches, one has to address anew the question what a species really is. If speciesare individuals, evolutions will deal with them, resulting in new species. If speciesconsist of populations, and if microevolution works on the level of such population,situations might become more difficult. What a species meant, cannot just be ataxonomic entitywithout any functional relevance in evolutionary biology.Would thatbe the case, we could not describe evolution as a process resulting in speciation. Ifspecies are actually something evolution worked on, then, however, species them-selves (as structural units) might be entities that have been evolved as such oneswithin various evolutionary constraints. Accordingly, a species might address some-thing different in plants, mushrooms, bacteria, viruses, and animals. On the otherhand, what is meant by such different concepts regarding the functionality of thespecies? The resulting idea, describing evolutionary relevance of species within acertain evolutionary process, might differ from what a species meant for other lifeforms. A rodent will eat certain plants and will avoid poisonous ones. Thus, the

XIIj Foreword

species concept somehow is actually valid for it irrespective of the differentevolutionary dynamics of such a poisonous plant and its own species.

Everyone describing biodiversity has to encounter diversification on the specieslevel. He has to think about what it means to be extinct. Hemay even understand thata species is formed by populations and he has to understand that a population is not aspecies. The problems that come out of all that are addressed byWerner Kunz. He isnot offering a new philosophy. He is following the ideas in biology to theirconsequences. This allows an understanding of the various uses and the significanceof species concepts. This enables to address a lot of relevant questions and tounderstand conceptual constraints in modern evolutionary biology. The result is agreat book that should be read by anyone who wants to understand evolution,biodiversification, and the meaning of species in those.

Ernst-Haeckel-Haus, Jena, April 2012 Olaf Breidbach

Foreword jXIII

Preface

What is water? You would not answer ‘‘water is wet’’ or ‘‘water is a liquid’’ becausethese are properties of the water, not definitions. The answer ‘‘water is wet’’ does notexplain what water is. Water is a substance consisting of H2O molecules, and theformula H2O is exhaustively explained by physicists and chemists. It is well knownwhat water is.

However, what is a tiger? If you would answer ‘‘a carnivorous animal which is bigand has black stripes,’’ you would describe only the properties of the tiger. You wouldnot answer the question, what a tiger is. If you try to find the answer to the questionwhat a tiger is, you will notice that the answer is very difficult, if not impossible tofind.

The same becomes apparent if you ask the question ‘‘what is a species?’’ It isrelatively easy to answer the question ‘‘what is a molecule?’’ Amolecule is a group ofatoms that are linked by chemical bonds, and atoms and chemical bonds are welldefined by physicists and chemists.

Like a chemical molecule, a biological species is a group of organisms. But are theorganisms of a species linked by bonds? If yes, the question arises what kind ofbonds these are that hold the organisms of a species together. If there are no bonds,the question arises why the individuals of a species can form a group at all. If thereare no groups, there are no species.

It is absolutely necessary to define the term group in taxonomy because there areseveral kinds of groups that organisms can form in nature. For example, migratingbirds can form stable groups. You also can classify apes and monkeys includinghumans in groups according to their blood group alleles. But such groups oforganisms are not species. What is it that makes a group of organisms to be aspecies? If you try to find the answer to the question what a species is, you will noticethat the answer is very difficult, if not impossible to find.What is it that makes a tigerto be a member of the species tiger? And what is the species tiger?

If you consider all organisms that resemble each other in their traits to belong to aspecies, this view is immediately upset by the phenomenon of distinct trait differ-ences between the two sexes of the same species that often exceed the speciesdifferences. If you consider all organisms to belong to a species that are able tocrossbreed successfully, this view cannot be held out because several individuals of aspecies cannot crossbreed successfully for genetic or other reasons. If you consider

jXV

all organisms to belong to a species whose genomes are similar in DNA sequence,this view will soon be corrected by the awareness that there exist phylogeneticallyyoung species that are genetically homogeneous as well as phylogenetically oldspecies that are genetically heterogeneous. There may be larger genetic differencesamong the members of an evolutionary old species than among the members ofdifferent species if the species are evolutionary young. Evolutionary distance cannotbe a reliable species criterion. At the end, all attempts to discriminate species fromeach other are blurred by the fact that all criteria for these discriminations also mayapply to the individuals within a species. Intraspecific polymorphisms are a mainobstacle for taxonomic classification.It appears that, in contrast to chemical objects, taxonomic objects cannot be

defined. What is it that makes this fundamental difference between chemical andbiological objects? It is very remarkable that taxonomists in most cases abandon thespecies problem and are nevertheless quite able to work with species. How is itpossible to do scientific work and to obtain reproducible results with objects withoutknowing what these objects are? Should it not be irritating or alarming to doresearch with objects that are not defined?Despite several promises, the species problem is not solved, and it cannot be

ignored. This book elucidates the inconsistencies and contradictions that standbehind the conventional species concepts. In this book, it is emphasized repeatedlythat it is a doubtful, if not an unscientific, way to practice taxonomic classificationswhile ignoring the foundations of the species problem. Furthermore, beyond thesetheoretic considerations, uncertainties and ambiguities of the species problem haveconsiderable impact on the strategies of legislation in biodiversity conservationpolitics.

Düsseldorf, April 2012 Werner Kunz

XVIj Preface

Color Plates

jXVII

Do Species Exist? Principles of Taxonomic Classification, First Edition. Werner Kunz.� 2012 Wiley-VCH Verlag GmbH & Co. KGaA. Published 2012 by Wiley-VCH Verlag GmbH & Co. KGaA.

Color Plate 1. Multivoltine Butterflies(photomontage)Several butterfly species can be univoltine orbivoltine or even trivoltine. These are differentmorphs of the same species that differgenetically. Univoltine are individuals whichproduce only one imaginal generation per year;they live in the north. Bi- or trivoltine individuals

generate two or three imaginal generations peryear; in spring, early and late summer. They livein more southern regions. In Europe, well-known examples are the Scarce SwallowtailIphiclides podalirius (top), the CommonSwallowtail Papiliomachaon (left), the CommonBlue Polyommatus icarus (bottom left) and thePeacock butterfly Inachis io (bottom right).

XVIIIj Color Plates

Color Plates jXIX

Color Plate 2. Batesian Mimicry(photomontage)Similarity is not kinship. Heliconiid andIthomiid butterflies are bad-tasting andtherefore avoided as a prey by birds and otherpredators. Representatives of completelydifferent families of butterflies imitate theshapes and color patterns of the unpalatablespecies to be protected, although they are not

unpalatable. Each of the four groups presents aCentral American Heliconiid or Ithomiidtogether with their imitators. 1 Heliconiusismenius together with 2 Eresia eutropia(Nymphalidae); 3 the Heliconiid Eueides isabellatogether with 4 Dismorphia orise (Pieridae); 5 theIthomiid Ithomia heraldica together with 6Actinote anteas (Acraeidae); 7 Eueides isabellatogether with 8 Dismorphia amphiona (Pieridae).

Scheme for Color Plate 2

XXj Color Plates

Color Plates jXXI

Color Plate 3. M€ullerian Mimicry(photomontage)Similarity is not kinship. Different Heliconiidand Ithomiid species in Central Americaresemble each other in shape and color pattern,although they belong to two different butterflyfamilies. Each of the four groups presents a

Heliconiid together with Ithomiids. 1 Heliconiushecale together with 2 Mechanitis lysimnia; 3Eueides isabella together with 4 Hypothyrislycaste; 5 Heliconius ismenius together with 6Napeogenes tolosa and 7 Godyris zavaleta; 8Heliconius hecale together with 9 and 10Melinaea scylax and 11 Mechanitis polymnia.

Scheme for Color Plate 3

XXIIj Color Plates

Color Plates jXXIII

Color Plate 4. Cryptic Species and MimicryMorphs (photomontage)Six different species of European Burnet moths(family Zygaenidae) are very similar inphenotype. They all are black with brilliant redspots. From left to right: Zygaena filipendulae, Z.ephialtes (photo: Jochen Rodenkirchen), Z.transalpina,Z. viciae (on topof bladeof grass),Z.lonicerae (on yellow Birdsfoot Trefoil flower

Lotus corniculatus) and Z. angelicae (on top ofpurple Oregano flower Origanum vulgare). Z.ephialtes, however, is also found in a completelydifferent morph that has white and yellow spots(two examples bottom center and bottomright). This dark morph resembles the nine-spotted moth (Amata phegea), a mothbelonging to the family Arctiidae (bottom left).

XXIVj Color Plates

Color Plates jXXV

Color Plate 5. Sexual Dimorphism(photomontage)Similarity is not kinship. Differences in traitsbetween the morphs within a species can bemuch greater than species differences. Heresexual differences between males and females

of Central American Tanagers are shown. 1 and2 Cherries Tanager (Ramphocelus costaricensis)female and male; 3 and 4 Summer Tanager(Piranga rubra) male and female; 5 and 6Passerinis Tanager (Ramphocelus passerinii)female and male.

Scheme for Color Plate 5

XXVIj Color Plates

Color Plates jXXVII