Principles of systematic zoology

[1] Aftab Badshah
[1]
PRINCIPLES OF SYSTEMATIC ZOOLOGY
LECTURE 1
Taxonomy
The term Taxonomy is derived from a Greek word “Taxis” which means arrangement and “Nomos” means laws.
Thus we can define Taxonomy as “The theory and practice of classification of organisms.”
Systematics
The term Systematics is from Latinized Greek word ‘Systema’ which is applied to the earlier classification by the
early Naturalists. Notably Linnaeus.
According to Simpson (1961)”Systematics is the scientific study of the kinds and diversity of organisms and of any
and all relationship among them.
Or Systematics is the science of diversity of organisms.
Systematics is a broad term which includes Taxonomy, Nomenclature and classification etc.
Taxon
A taxon is a group of real organisms recognized as a formal unit at any level of a hierarchic classification.
Or a taxon is a name of taxonomic group of any rank that is considered by taxonomists to be formally recognized
and assigned to a definite category.
The words Blue birds, Song birds, Vertebrates refersto group of organisms .such complete objects of zoological
classification are taxon.
Taxon always refers to concrete zoological object, thus the species of a Robin is not a taxon but a category while
Robin is a taxon.
The taxon must be recognized by the taxonomists within any large genus. They are taxa if they are early recognized
and named.
Category
A category designates rank or level in a hierarchic classification.
OR
A Category is a class whose members are all the taxa assigned a given rank.
• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primates
• Family Hominidae
• Genus Homo
• Species Homo sapiens
LECTURE 2
Contribution of systematics to Biology

[2] Aftab Badshah
[2]
Theoretical biology
Theoretical Biology searches to discover characteristic principles of order within the variety of biological phenomena
by describing the organizational dynamics of living systems in a formal way. In addition to a more profound
understanding of single phenomena, it has brought about new starting points in the search for answers to the most
fundamental questions in biology
Theoretical Biology stays in intimate dialogue with experimental biological research. However,in contrast to the latter
it uses mathematics as its language and computers as the most important tools
The precise definition of biological terms and the characterization of cognition by using formal systems, in general,
are fundamental tasks of Theoretical Biology now and in future.
Theoretical Biology is naturally interdisciplinary. It draws ideas from other disciplines and, in reverse,supports them
by quantification and precision. Therefore, it is on the way to become a generaland extensive structural science of
organized systems,which might be able to point out similarities between the organization of physio-chemical,
biological, economical, and social systems
Population systematics
Ethology
Evolution
Applied biology
Applied Biology is the understanding of how organisms work from subcellular to whole organism level. It also
involves the use of living organisms (mostly microbes) to produce useful products. It includes traditional processes
like brewing, cheese making and modern developments such as genetic engineering which can lead to new drugs
against cancer and other diseases.
Public health
Biological control
Conservation of species
Biological war
LECTURE 3
HISTORY OF TAXONOMY
Mayr describedthe historyof taxonomy infourperiods.
1st
Period 2nd
Period 3rd
Period 4th
Period
1st
Period(Studyof local fauna)
Native of primitivetribeswereexcellentnaturalist.
Studyof faunacame from the contributionof Greekscholars.
Aristotle(384-322 BC) ,knownas the fatherof biological classification,referredtomajorgroupsof animalsasbirds,
fishes,whalesandinsects.
Aristotle thinkingdominatedfornexttwothousandyears.
There are twomajor formof classificationinfirstperiod.
1) Downwardclassification``` 2) Upward classification

[3] Aftab Badshah
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Downward classification
Taxonomybasedonlocal faunareacheditspeakby the work of Linnaeus(1707-1778).
The methodof downwardclassificationare principlesof logical divisionwhichconsistsof dividinglargergroupsby
dichotomyintosmallergroups. E.g.Animals
Linnaeusadoptedthe principle of downwardclassificationin15th
editionof hisbook(Systemanaturae)
He forthe firsttime appliedBinomialnomenclaturetoanimal kingdom.
Linnaeusbelievedinfixityof species.
Upward classification
By the midof 18th
centurythe shortcomings of downwardclassificationwere recognized.
Graduallyitwas replacedbyupwardclassification.
It consistsof assemblingspeciesbyinspectionintoagroupof similarorrelatedspeciesandforminghierarchyby
againgroupingof similartaxaof nextlowerrank.
Thisthoughtwas appliedbyabotanistin1873 and laterby nearlyall zoologists.
Thisshiftfromdownwardclassificationtoupwardclassificationwasamajorphilosophicchange.
2nd
Period(Acceptance of evolution)
Evolutionarythoughtwaswidespreadin18th
centurybut owesitsfoundationtosecondperiod.
Darwinbelievedinfixityof species.butafterobservingnatural faunainGalapagosisland,he begintobelieve inthe
plasticityof species.
Empirical taxonomistswere greatlyinfluencedbyhisidea.
The phylogenetictree of ErnestHaeckel alsostimulatedthe empirical workers.
Large numberof newspecieswere discoveredanddescribed.
3rd
Period(Populationsystematics)
The greatestdevelopmentof moderntaxonomystartedaround1930, whenthe workersrealizedthatthe Linnaeus
speciesbasedonone ortwo specimensare notas perfectasthose whichare basedon population.
Due to thisMayr in1942 consideredspeciesasa groupof interbreedingnatural population.
Thisideaof populationtaxonomywasusefulindevelopingthe polytypicconcept.
Newtermslike newsystematicsandbiosystematicswere addedtoextendthe taxonomictheory.
The publicationof the book‘newsystematicsbecome a landmarkinthe historyof taxonomy.
Thus taxonomygota newlabel of biological taxonomy.
By 1955 taxonomyreachsuch a statusthat it wascalledtaxonomicexplosion.
4th
Period(current trends)
Newsystematicsdeal exclusivelywithspecies.
The presentdaytaxonomicworkinclude all available differencesandsimilarities.

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Insteadof morphologyasan original base,phylogeneticadaptations,embryological patterns,biochemical variations,
geneticvariabilitiesandsimilarities,behavioral characteristicsare all applicabletotaxonomicstudy.
Lecture 4
Speciesconcept
Cuvierin1829 definedspeciesas‘The assemblage descendedfromone anotherorfromcommonparentsandof
those whoresemble one another.
Typological speciesconcept
Accordingto thisspeciesconceptthe observeddiversityof the universereflectsthe existence of alimitednumberof
underline ‘universals’or‘types’.
Individualsdonotstandin anyspecial relationtoeachotherbeingmerelyexpressionsof the same type.
Variationisconsideredasirrelevantphenomena.
Thisspeciesconceptwasthe conceptof Linnaeusandhisfollowersbutitgoesbackto the philosophyof Aristotle
and Plato.
Thisspeciesconceptiscalledessentialisticspeciesconcept. Accordingtothisconceptspecies canbe recognizedby
theiressential charactersandthese are expressedintheirmorphology.
It isalso calledmorphological speciesconcept.
Postulates
1. Speciesconsistsof similarindividuals.
2. Each speciesisseparatedfromall the otherbysharp discontinuity.
3. Each speciesisconstantthroughtime.
4. There are strictlimitstopossible variationswithinanyone species.
Criticism
1. The concept isrejectedbecause of twopractical reasons
2. Individualsare frequentlyfoundinnature thatare clearlyconspecificinspite of strikingdifference resulting
fromsexual dimorphism, age andpolymorphism.
3. There are speciesinnature thatdifferhardlyinmorphologybutare reproductivelyisolated.
Nominalisticspeciesconcept
Thisconceptwas popularinFrance in 18th
centurybut surprisinglyitisstill usedveryrarelybysome botanists.
Theybelievethatonlyindividualsexistwhile speciesare man’sowncreation.

[5] Aftab Badshah
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Accordingto thisconcept‘Nature producesonlyindividualsandnothingmore. Theyare mental conceptsthathave
beencreatedtoreferto greatnumberof individualscollectively.
Criticism
1. No biologistcanagree that the speciesisman- made.
2. It isnow an establishedfactthattheyare products of evolution.
3. The basic drawbacks of the conceptwas the misinterpretationof the relationbetweensimilarityand
relationship.
4. Membersof a speciesare similartoeachotherbecause of commondescend.Itisnottrue that theybelong
to thistaxonbecause theyare similarasclaimedbythisconcept.
Biological speciesconcept
Thisconceptwas introducedbyMayr. Accordingto thisconcept “Speciesare groupof interbreedingnatural
populationsthatare reproductivelyisolatedfromothersuchgroups”
Thus thisspecieshasthree separate functions.
1. Membersof a speciesformareproductive communitythatisindividualsof aspeciesrecognizedeachother
as potential mates.
2. Speciesisanecological unitthatinteractsasa unitwithotherspecieswhichsharesitsenvironment”
3. Speciesisageneticunitthatconsists of a large gene pool where asan individual ismerelyatemporary
vessel holdingasmall portionof a gene.
DIFFICULTIES IN APPLICATIONOF BIOOGICALSPECIES CONCEPT
1… Insufficientinformation: Individual variationsinall itsformsoftenraisesthe doubt
whetheracertain morphtype is a separate speciesoronlya phenonwithinavariable
population.
Organismsmaylook differentandyetbe the same species.Forexample,lookatthese
ants.You mightthinkthat theyare distantlyrelatedspecies.Infact,theyare sisters—twoants
of the species Pheidolebarbata,fulfillingdifferentrolesinthe same colony.
2… Uniparental Reproduction Asexual groupsdonotfulfillthe criteriaof interbreedingwhichisthe foremost
characteristicof biological speciesconcept.
Asexual reproductionisfrequentamonglowerinvertebrateswithparthenogenesis occurringevenininsects, lower
vertebrates uptoreptiles.
3… EvolutionaryIntermediacy Organismsmayappearto be alike and
be differentspecies.Forexample,Westernmeadowlarks(Sturnella
neglecta) and Easternmeadowlarks(Sturnella magna)lookalmost
identical toone another,yetdonotinterbreedwitheachother—thus,
theyare separate speciesaccordingtothisdefinition.
Ring speciesare specieswithageographicdistributionthatformsaring and overlapsatthe ends.The many
subspeciesof Ensatina salamandersinCaliforniaexhibitmorphological andgeneticdifferencesall alongtheir range.
Theyall interbreedwiththeirimmediateneighborswithone exception:where the extremeendsof the range
overlapinSouthernCalifornia, E.klauberiandE. eschscholtzii do notinterbreed.Sowhere dowe markthe pointof
speciation?

[6] Aftab Badshah
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Chronospeciesare differentstagesinthe same evolvinglineagethatexistedatdifferentpointsintime.Obviously,
chronospeciespresentaproblemforthe biological speciesconcept—forexample,itisnotreallypossible(orvery
meaningful!) tofigure outwhether atrilobite living300 millionyearsagowouldhave interbredwithitsancestor
living310 millionyearsago.
4… The occasional breakdownof isolatedmechanism
Reproductive isolationmaybreakdownevenamonggoodspecies.Usuallythisleadtothe productionof occasional
hybridswhichare eithersterileorof lowviabilityandsodonot cause any taxonomicdifficulty. E.g.Mulesandhinny.
(Male) donkeyx (female) horse = mule
(Male) horse x (female) donkey = hinny
Lecture 5
TAXONOMIC CATEGORIES
Hierarchy: In classification the system of ranks which indicates the categorical level of various taxa (i.e ,kingdom to
species). Taxonomic category designate rank or level in hierarchic classification.
The Linnaean hierarchy
Linnaeus was the first taxonomist to establish a definite hierarchy of taxonomic categories.
He recognized only five category within the animal kingdom. i.e. class, order ,genus, species, varieties.
Two additional categories were soon generally adopted when the number of known animals grew – making finer
division necessary:the family (between genus and order) and the phylum (between class and kingdom).
The varieties, used by Linnaeus as an optional category for various types of infraspecific variants was eventually
discarded or replaced by the subspecies.
Any given species thus belong to seven obligatory categories as follows:
Wolf Honey bee
Kingdom Animalia Animalia
Phylum Chordata Arthropoda
Class Mammalia Insecta
Order Carnivora Hymenoptera
Family Canidae Apidae
Genus Canis Apis

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Species C.lupus A.mellifera
As the number of known species increased, the need arose for a more precise indication of the taxonomic position of
species. This was accomplished by splitting the original seven basic categories and inserting additional ones among
them.
The most frequently used additional new category name is the term tribe for a category between genus and family.
Vertebrate paleontologists also used the category cohort between order and class.
The generally accepted categories are the folowing:
1. Kingdom 10. Suborder
2. Phylum 11. Superfamily
3. Subphylum 12. Family
4. Superclass 13. Subfamily
5. Class 14. Tribe
6. Subclass 15. Genus
7. Cohort 16. Subgenus
8. Superorder 17. Species
9. Order 18. Subspecies
Taxonomic category
It is a class into which are placed all the taxa that rank at the same level in a hierarchic classification.
Species is a lower category and from the genus up are higher categories.
Taxa are based on zoological realities, categories are based on concepts. In that respect there is no difference between
the category species and the higher categories. In many other respects there is a great deal of difference between the
concept of the species and the concept of the higher categories.
The category species is “self-operationally” defined by the testing of isolating mechanisms in nature.
The species category signifies singularity, distinctness, and difference, while the higher categories have the function of
grouping and ordering by not emphasizing differences between species rather by emphasizing affinities among group
of species.
Even though an operational definition for the higher categories does not exist, nor for the rank which they signify, they
do have an objective basis because a taxon placed in the higher category is natural consisting of descendants from a
common ancestor.
Lecture 6
ZOOLOGICAl NOMENCLATURE
Zoological nomenclature is the system of scientific names applied to taxonomic units of animals (taxa,taxon), known
to occur in nature ,whether living or extinct.
The term nomenclature comes from latin words : Nomen -------Names , Calare -------to call
And means literally to call by name
Important requisite oftaxa names
Three important requisites should be kept in mind before giving any name to a taxon.

[8] Aftab Badshah
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 Uniqueness – name should be unique
 Universality – name should be name all over the world
 Stability – name should not be changed
The international code ofzoological nomenclature ICZN
A set of rules for naming of animals and for resolution of nomenclatural problems is called the international code of
zoological nomenclature.
After 1800 all the authors adapted Linnaean system-change existing names if they had not been correctly formed
which resulted in nomenclatural confusion. So a need for definite rules or code arose
The first set of rules were presented in the first international congress of zoology in 1889.
The code consists ofthree main parts
 The code proper
 Appendices – a section giving extra information at the end of the book
 Glossary – a list of technical or special words, especially those in the particular text, explaining their
meanings.
Code proper
Preamble –an introduction to a book or written document. 90 articles are grouped in 18 chapters. Each article is
composed of one or more mandatory provision which are followed by recommendations and illustrative examples.
The use of recommendation is not mandatory
Evolution oftheory ofnomenclature
Changes occur in the basic concept of taxonomy like
 Concept of taxa should refer to a population rather than type
 The nature of type as name bearer only on the basis of which a specie might be named.
 Categorical status of infraspecific names. The sub-species names should be hierarchal in accordance to the
specie name
The rules should be adjusted to the conceptual development of taxonomy.
Different needs in different groups---
Parasitologist must make tentative assignment of stages in the life cycle of parasites
Paleontologist may form genera until the true taxonomic status of the taxon is established
Principle of binominal nomenclature
This is the principle that the scientific name of a species, and not of a taxon at any other rank, is a combination of two
names; the use of a trinomen for the name of a subspecies and of uninominal names for taxa above the species group
is in accord with this principle.

[9] Aftab Badshah
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Example house mouse
Kingdom----Animalia
Phylum-----Chordata
Class-------Mammalia
Order-------Rodentia
Family------Muridae
Genus------Mus
Species ----M. musculus Linaeus,1758
Subspecies
Mus musculus bactrianus, Mus musculus castaneus, Mus musculusdomesticus, Mus musculus gentilulus,
Mus musculus musculus.
The subspecie whose specific and subspecific names are similar is called as nominate subspecie.
Synonym:
In zoological nomenclature, synonyms are different scientific names that pertain to the same taxon, for example two
names for the same species. The rule of zoological nomenclature is that the first name to be published is the senior
synonym; any others are junior synonyms and should not be used.
X Antilocapra anteflexa ___ 1855
Species A ……. synonyms example Pronghorn synonyms
Y Antilocapra americana --- 1815
For example, John Edward Gray published the name Antilocapra anteflexa in 1855 for a species of pronghorn, based
on a pair of horns. However,it is now thought that his specimen was an unusual individual of the species Antilocapra
americana published by George Ord in 1815. Ord's name thus takes priority, with Antilocapra anteflexa being a junior
subjective synonym.
Homonym:
In nomenclature, one or two or more identical but independently proposed names for the same or different taxa are
called homonym. A homonym is a name for a taxon that is identical in spelling to another such name that belongs to a
different taxon.
The rule in the International Code of Zoological Nomenclature is that the first such name to be published is the senior
homonym and is to be used (it is "valid"); any others are junior homonyms and must be replaced with new names. It
is, however, possible that if a senior homonym is ancient, and not in "prevailing usage," it may be declared a nomen
oblitum and rendered unavailable, while the junior homonym is preserved as a nomen protectum.
For example: Cuvier proposed the genus Echidna in 1797 for the spiny anteater. However,Forster had already
published the name Echidna in 1777 for a genus of moray eels. Forster's use thus has priority, with Cuvier's being a
junior homonym. Illiger published the replacement name Tachyglossus in 1811.
Species A ---- X ------ 1779 Moray eel --- Echidna ---1777 (Johan Reinhold forster)
-------- homonym -------- homonym
Species B ---- X ------ 1907 Spiny anteater --- Echidna --- 1797 (George cuvier)

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Principle of Priority
Principle of Priority is one of the guiding principles of the International Code of Zoological Nomenclature,defined by
Article 23. It states that the correct formal scientific name for an animal taxon, the name that
is to be used, called the valid name, is the oldest available name that applies to it.
It is the most important principle that preserve stability of zoological nomenclature. It was
first formulated in 1842 by a committee appointed by the British Association to consider the
rules of zoological nomenclature.
Example: Nunneley 1837 give a name Limax maculatus to a species belonging to
Gastropoda(slug), Wiktor 2001 classified it as a junior synonym of Limax maximus Linnæus
1758. Limax maximus was established first, so Limax maximus takes precedence over Limax
maculatus and must be used for the species.
In 1856, Johann Jakob Kaup published the
name Leptocephalus brevirostris for a new species of eel.
However,it was realized in 1893 that the organism described
by Kaup was in fact the juvenile form of the European eel .
The European eel was named Muraena anguilla by Carolus
Linnaeus in 1758. So Muraena anguilla is the name to be
used for the species, and Leptocephalus brevirostris must be
considered as a junior synonym and not be used. Today the
European eel is classified in the genus Anguilla Garsault,1764, so its currently used name is Anguilla
anguilla (Linnaeus,1758).
First revisor principle
The Principle of the First Reviser deals with situations that cannot be resolved by priority, namely where there are two
or more items that have the same date of publication (or the same year of publication when no details are known).
These items may be two or more different names for the same taxon, two or more names
with the same spelling used for different taxa, two or more different spellings of a particular
name, etc. In such cases the first subsequent author who deals with the matter,makes a
choice and publishes the decision in the required manner, the First Reviser, is to be followed.
[Art. 24.2].
Example: Linnæus 1758 established Strix scandiaca and Strix noctua (Aves),for which he
gave different descriptions and referred to different types, but both taxa later turned out to
refer to the same species, the snowy owl. Lönnberg 1931 acted as First Reviser, cited both
names and selected Strix scandiaca to have precedence.
Principle of Typification
This is the principle that each nominal taxon in the family group or species group has,actually or potentially , a name
bearing type fixed to provide the objective standard of refrence by which the application of the name is determined.

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This means that any named taxon would have a name bearing type which allow the objective application of that name.
Any family group name must have a type genus , any genus group have a type species and species group name can
(not must) have one or more type specimens usually deposited in a museum collection.
Family spheniscidae
1. Aptenodytes
2. Pygoscelis
3. Eudyptula
4. Spheniscus --- type specimen
5. Megadyptes
6. Eudyptes
Holotype: If a nominal species is based on a single specimen that specimen is called holotype.
Syntype: |If a new nominal species has no holotype under the provision of code then all the specimen are of
equal value and are called syntypes.
Lectotype: one of a series of syntypes which, subsequent to the publication of the original description, is selected
and designated through publication to serve as “the type’.
Paratype: After the holotype has been labelled, each remaining specimens of the type species should be
conspiciously called paratype.
Neotype: A specimen selected as type subsequent to the original description in cases where the original types
are known to be destroyed or were suppressed by the commission.
Range ofauthority of code
The code applies to both living and extinct animals. If a still living species was first named on the basis of fossil
material,that name is also valid for the living species. If a generic name has been used for a fossil animal,it cannot be
used again for a different genus of living animals. There are ,however separate codes for botanical and bacteriological
nomenclature.
Key: A tabulation of diagnosstic characters of species ( or genera etc) in dichotomous couplets facilitating rapid
identification.
Lecture 7
Taxonomic characters
Definition: A taxonomic character is any attribute of a member of a taxon by which it differs or may differ from a
member of a different taxon.
A characteristic by which members of two taxa agree but differ from members of a third taxon is a taxonomic
character.
Kinds ofcharacters
1. Morphological characters 2. Physiological characters
3. Ecological characters 4. Ethological characters
5. Geographical characters

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1. Morphological characters
a. General external morphology
 Plumage of bird
 Pelage of mammals
 scale counts of fishes and reptiles
b. Special structures (e.g. Genetalia):
Difference in genetalic structure has been used to delimit species. It is very effective in insects where lock and key
relationship exists between male and female copulatory organs. Color pattern and other aspect of coloration are among
the most easily recognized and thus the most convenient characters in certain groups of animals e.g. birds.
C. Internal morphology:
Both the soft as well as hard parts of practically all groups of higher animals have been used as taxonomic characters.
d. Larval stages and embryology:
Various immature or larval stages,the embryology and sometimes even the eggs may provide taxonomic information.
E.g. the various sibling species of the Anopheles maculipenis complex were discovered owing to differences in egg
structure.
The classification of white flies is based primarily on the pupae. Comparative studies of embryological characters like
cleavage pattern, blastulation and gastrulation are also useful in certain phyla.
E. Karyology:
Karyology is the description of chromosome structure,size, shape and number etc. Chromosomes are particularly
useful on two different levels
 They aid in the comparison of closely related species, including sibling species. These are often far more
different chromosomally than in their external morphology.
 Chromosomal patterns are of extreme importance in establishing phyletic lines.
2. Physiological characters
This group of character is hard to define. All structures are the products of physiological processes and are thus
physiological characters. By physiological characters one generally means growth constants, temperature tolerances
and the various processes studied by comparative physiologist. These characters cannot be studied in preserved
material.
Serology: The proteins of one organism will react more strongly with antibodies to the proteins of a closely related
organism than to those of one more distantly related. Sibley analyzed the egg-white proteins of more than 100 species
of birds and was able to establish relationship among them.
3. Ecological characters
Every species has its own niche in nature, differing from its nearest relatives in food preference,breeding season and
tolerance to various physical factors,resistance to predators, competitors and pathogens and in other ecological
factors.
E.g. the larvae of both Drosophila mulleri and aldriachi live simultaneously in the decaying pulp of the fruits of the
cactus Opuntia lindheimeri. The two species are markedly specialized in their preference for certain yeast and
bacteria.
Similarly tapeworms of man and rodents and ascaris of man and pigs though differ very slightly but can be identified
by their host specificity.
Each genus of Galapagos finches is characterized by its utilization of the environment, Geospiza is a ground finch
while Camarhynchus is a tree finch.

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4. Ethological characters
Behavior is one of the most important sources of taxonomic characters. They are clearly superior to morphological
characters in the study of closely related species.
Similarly bioacoustics like matting calls of frogs and toads and crickets are used for species delimitation. Similarly the
pattern of the webbing constructed by spiders can be used at various level in classification.
5. Geographical characters
Geographical characters are among the most useful tools for clarifying a confused taxonomic picture and for testing
taxonomic hypothesis. The taxonomist is primarily interested in two kinds of geographical characters
(1) General biogeographic patterns, which are especially useful in the arrangement of higher taxa.
(2) The allopatric-sympatric relationship, which is most helpful in determining whether or not two populations are
conspecific.
Lecture 8
Taxonomic collection
OUTLINES
 Value of collection
 Purpose of taxonomiccollection
 Collectingandresearch
 Scope of collection
 Where and howto collect
 Contentsof collection
 Preservationof specimens
 Labeling
Value of collections
Biological collectionsare highlyvaluable forthe followingreasons:
 Museumsare onlyplace where extinctspeciesare preserved.
 Specimensof special historical value.
 Specimensrarelyfoundinanycollections.
 Many areas inworldare geographicallyinaccessible.
 A material isof unique value if itformsthe basisof publishedresearch. Itmaybe neededagainfor
verificationof original dataorfor renewedstudyinthe lightof more recentknowledgeorbynew
techniques.
Purpose of scientificcollection
For typologicallyorientedtaxonomistacollectionwasanidentificationcollection. Accordingtocurrentthinking,
biological classificationisthe orderingof populations. Collecting, then, isthe samplingof populations. Anadequate
sample of everypopulationshouldbe collectedandpreserved.
What is adequate collection?
More material isneededinaspecieswithstrongindividual andgeographical variationthaninauniformspecies.
More material isneededforstudiesof specificandsubspecificcharactersthanof the characters of highertaxa.
Collectingand research
On the whole taxonomistsspendonlyasmall fractionof theirtime onthe collectingof new material. Some big
expeditionsof the nineteenthcenturygatheredmaterial thatis still notyetfullyworkedout.
Scope ofcollection

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Onlya fewlarge national museumsattemptworldwidecoverage inall groupsof animals. Mostmuseumare largely
restrictedtoa geographicareaand to certaingroup. Too broad a coverage leadstoshallownessanda failure to
obtainthe depthrequiredfordetail studies.
The late admiral H.Lyneswhowas especiallyinterestedinCisticola.agenusof Africanwarblerswithsome 40
species, made wholeseriesof collectingtripstonearlyeverycornerof Africa. He combinedthe collectingof
specimenswithadetailedstudyof the ecology, songsandnestconstructionof the birds. The resultwasthatthe
genusCisticola,formerlythe despairof the birdtaxonomists,isnow reasonablywell understood.
Where and how to collect?
Anycollectingtripmustbe carefullyplanned.Allpossiblegeographicinformationmustbe obtainedbeforehand,
including
 distributionof vegetable types
 altitudes
 seasons
 Means of transportationetc.
A plottingof collectingstationsand, inparticularamappingof speciesdistributionwillreveal the locationof crucial
gaps.
If the studyof geographicvariationisa majorobjective,the peripheryof the range of eachspeciesshouldbe given
particularattention.Thisiswhere geographicisolatesoccurmore frequently. If the speciesshow seasonalvariations,
the collectionshouldbe spacedseasonally.
How to collect?
Innumerable techniquesforthe collectingof differentgroupsof animalsare describedinstandardcollecting
manuals.
Contentsof collections.
Preservedspecimensare the indispensablebasisof all taxonomicresearch.The informationthatone canderive
fromsuch specimensare limited. The modernsystematistneedsagreatdeal of additional information.

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As faras possible the collectingshouldprovideunbiasedpopulationsamples. Notonlyadultshouldbe collected,but
adequate samplesof all growthstages(includinglarvae) andassociatedparasites.Samplingshouldbe done insucha
wayas to provide studymaterial notonlyforthe speciesbutalsoforthe evolutionist. Collectionof specimensmay
be augmentedbyall sortsof recordingsincluding Filmof courtshipdisplay,Vocalizationof animals, Collectionsor
photographor casts of the work of animals(nests,galls,spiderwebsetc.)
Preservationof specimens
Theydifferfromone taxonomicgrouptothe next. Some are preservedinalcohol. Some are stuffed.We donotuse
formalinforpreservingarthropods,onlyvertebrates.Specimensare notkeptpermanentlyinformalinsince itis
acidicand difficulttohandle. Althoughgenerallyavoidedforlong-termstorage,formalinmaybe usedininstances
where colorisimportantsince alcohol dissolvesmostcolors almostimmediately.Alcoholisusedin longtermstorage
Labeling
A specimenthatisnotaccuratelylabeledisworthlessformosttype of taxonomicresearch.
RECORDINGDATA
 Geographiclocality
 Date
 Stage(adultmale,femaleorimmature form)
 Altitude ordepth.
 Host
 Name of collector
Lecture 9
Intra-populationvariations
 Non-genetic
 Genetic
Non-genetic
a. Individual variationintime
b. Social variations
c. Ecological variations
d. Traumatic variations
a… Individual variations intime
 Age variations
 Seasonal variationsof anindividual
 Seasonal variationsof generations
Age variations
Animalsingeneral passthroughaseriesof juvenile orlarval stagesinwhichtheymaybe quite differentfromadults.
E.g the immature stagesof the eel (Anguilla) wereoriginallydescribedasLeptocephalusbrevirostrisKaup.
Similarlythe difficultiesforthe taxonomistare evengreateringroupswithlarval stageswhichare sodifferentthat
theyhave not eventhe faintestresemblance tothe adult(e.g.caterpillarandbutterfly)

[16] Aftab Badshah
[16]
Seasonal variations of the same individual
In animalsthatlive asadultsthroughseveral breedingseasons,itsometimeshappens
that the same individual hasaverydifferentappearance indifferentpartsof the year.
In arctic and subarcticbirdssuch as Ptarmigans,there maybe a change froma white
winterdresstoa normallycoloredsummerdress.
In the Europeanstarling(Sturnusvulgaris)the freshlymoltedbirdof Octoberiscovered
withwhite spotsandall the feathersshowwhitishmargins.Duringwinterthe edgesof
the featherswearsoff,andinthe spring,at the beginningof the breedingseason,the
whole birdisa beautiful glossyblackwithoutthe moltof a single feather.
Seasonal variation of consecutive generations
These variationsare calledpolyphenism.E.g.AfricanbutterflyBicyclusanynana
Wet seasonform --- eyespotsalongthe margin(onventral side)
Dry seasonform – verysmall oralmostno eyespots
B…Social variations
In social insectslike honeybeesthereare definitegroupsof individualswithinacolonyinadditiontothe
reproductive castes(Queenandmalesordrones),workersandsoldiers.The dronesare the malesinabee colony.
Theyare the product of unfertilizedeggs.The queenisone of manyfemalesinthe colony;however,she isthe only
one that isdevelopedspecifically forlayingeggs.The queenisthe productof a fertilizedeggthatisfedan
abundance of royal jellyduringitsdevelopment.Theyare all femalesand,thus,come fromfertilizedeggs.The
workersare the majorityof the populationof the colony.There are about2,000 to 60,000 workerspercolony
C…Ecological variations
 Habitatvariation
 Variationinducedbytemporaryclimaticconditions
 Host-determinedvariations
 Densitydependentvariations
 Allometricvariation
 Neurogeniccolorvariations
Habitat variations
Populationsof asingle speciesthatthatoccur in differenthabitatsinthe same regionare oftenvisiblydifferent.
Dall gave a veryinstructive accountof all the variationshe observedinastudyof the oyster(Crassostreavirginica)
Whena specimen growsinstill water,ittendstoassume a more roundedorbroaderform.
Whenit growsina strongcurrent the valvesbecome narrow andelongated,usuallyalsoquite straight.
Whenan oystergrowsin cleanwaterona pebble,whichraisesitslightlyabove the bottomlevel,the lowervalve is
usuallydeepandmore orlesssharplyradiallyribbedacquiringthusastrengthwhichisnotneededwhenthe
attachmentisto a perfectlyflatsurface whichactsas a shieldonthatside of the shell.Forthe same reasonoysters
whichlie ina muddybottomwithonlypartsof the valve sabove the surface,are lesscommonlyribbed.

[17] Aftab Badshah
[17]
Variations inducedby temporary climaticconditions
Some animalswithahighlyplasticphenotype mayproduce yearclassesthatdiffervisibly fromthe normowingto
unusual conditions(drought,cold,foodsupply)
Host-determinedvariations
Gerouldhasreportedthatthe braconidwaspApantelesflaviconchae,spinswhitecocoonswhenrearedfromblue-
greencaterpillarsof Coliasephilodice,butgoldencocoonswhenrearedfromyellow-greencaterpillarsfromthe
same species.
Density-dependentvariations
Kennedyandothershave shownthatgregariousspeciesof locustsexistinvariousunstable biological phases.These
phasesdifferinanatomy,color andbehaviorcharacteristicsandhave oftenbeendescribedasdistinctspecies.When
newlyhatchednymphsare rearedundercrowdedconditions,theymostlydevelopedintothe gregariousphase.
Under lesscrowdedconditionsintothe transitional phase andwhenisolatedandrearedseparately,intothe solitary
phase.
Allometricvariations
Allometricgrowthresultinthe disproportionatesize of some structure in
relationtothat of the rest of the body.If individualsof apopulationshow
Allometricgrowth, animalsof differentsize will show allometricvariability.
Neurogenicor neuro-homoral variations
Neurogenicvariationiscolorchange inresponse tothe environment.Chameleonshave specialized
cells, chromatophores,whichcontain pigmentsintheircytoplasm,inthree layersbelow theirtransparentouterskin:
The chromatophoresinthe upperlayer,calledxanthophoresanderythrophores,containyellowandred pigments,
respectively. Below the chromatophoresisasecondlayerof chromatophorescallediridophoresorguanophores;
these contain guanine,appearingblue orwhite. The deepestlayerof chromatophores,calledmelanophores,contain
the dark pigmentmelanin,whichcontrolshowmuchlightisreflected. Chameleonchange colorinreactionto
temperature aswell astocamouflage. Differentchameleonspeciesare able tovarytheircoloration
and patternthroughcombinationsof pink,blue,red,orange,green,black,brown,lightblue,yellow andpurple
Traumatic Variation
1. Accidental and teratological variations
In mostanimalsitmay be readilyidentified.However, inthose formswhichundergometamorphosis,injuriestoan
earlierstage mayproduce laterabnormalitieswhichare notsoeasilyrecognizedassuch. Thisis especiallytrue when
the anomaliesinvolve characterswhichare normallyof taxonomicvalue in the groupconcerned. E.g.symmetrical
modificationof wingpattern.
Post-mortemchanges
In manygroup of animalsitisimpossible topreventpost-mortemchangesof preservedspecimens. Some extreme
casesare knowninbirds. E.g. deeporange yellow plumesof twelve-wire birdsof paradise (Seleucidisignotus) fade in
collectiontowhite
Skinof Chinese jay (Kittachinensis)whose plumage isgreeninlife,turnblue incollections due tochemical actionof
preservative:Waspoverexposedtocyanide turnbright red
Geneticvariations
 Sex-associatedvariations

[18] Aftab Badshah
[18]
 nonsex-associatedvariations
Sex-associatedvariations
 Primarysex differences
 Secondarysex differences
 Alternatinggenerations
Primary sex differences:
These are differencesinvolvingthe primarysex organsutilizedinreproduction. Theyare rarelyasource of
taxonomicconfusion
Secondary sexdifferences:
Sexual dimorphism, insome casesmale andfemaleare strikinglydifferentfromone another
Examples KingparrotEclectusroratus (Male=greenwith an orange bill,Female=redandblue withblackbills).The
twosexeswere considereddifferentspeciesfornearlyone hundredyearsuntilnaturalistprovedconclusivelythat
theybelongedtogether
Alternatinggenerations
In aphidsthe parthenogeneticwinglessfemalesare usuallydifferentfromthe wingedfemaleof the sexual
generations.
Non-sexassociatedvariations
 continuousvariations
 Non-continuousvariations
Continuousvariations
Continuousvariationisthe resultof slightgeneticdifferences which
existbetweenindividuals.
-itis nowevidentthatnoone individual is“typical”of the characters
of a populations. Onlythe statisticsof the whole populationcangive
a true picture of the population. 114 speciesof the snail genus
melaniawere foundtobe nothingbutindividual variants.
Discontinuousvariations
In certainspecies,the membersof apopulationcanbe groupedintoverydefinite classes, determinedbythe
presence of certainconspicuouscharacters.Suchdiscontinuousvariationsiscalledpolymorphism. Commonalfalfa
butterfly ---Coliase eurytheme—hastwostrikinglydifferentfemaleforms-one resemblingthe orange coloredmale
while the otherislargelywhite

Principles of systematic zoology

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Principles of systematic zoology