Menchie zoology

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A. Taxonomy Defined1. Grouping of organisms - the science of classifying living organisms based on shared features

2. Principles of classification the practice or principles of classification

3. Study of classification the study of the rules and practice of classifying living organismsI. INTRODUCTIONQUESTION:

Would you also consider that taxonomy deals with IDENTIFICATION of living organisms? Why or why not?Taxonomy DefinedTaxonomy involves: 1. Classification ranking of groups of organisms in some hierarchical relationship- based on their similarities in their characteristics (genetic relationship, internal and external anatomy, physiology or evolutionary history)

2. Identification separation of one group from other groups according to their unique characteristicsTaxonomy DefinedIdentifying organisms based on their morphology, anatomy, physiology, cytology, biochemistry and geographic distribution


To classify, identify and make a census of the unique characteristics of each species.

To reconstruct the evolutionary history of the present classified species based on morphology, anatomy, chemical composition, geographic distribution, breeding behavior, and chromosome numberTo determine which traits are advanced (derived in time from primitive traits) or primitiveIMPORTANCE of CENSUSTo discover all species of animals.To reconstruct their evolutionary relationships.To classify animals according to their evoutionary relationships.GOALS of SYSTEMATIC ZOOLOGISTSUnexplored areas, only an estimation could be doneContinuous evolution process (diversification)Continuous extinction

How about in local settings?

Some Difficulties in Making a Census of Living Organisms300 BCAristotle used dichotomies or polar opposites Ex. Animals with blood and without blood (vertebrates and invertebrates) - wrote extensively on both plants and animals but his writings on plants were lost Theophrastus Aristotles pupil and applied his approach to the study of plants in his work Inquiry into PlantsHistory of Classification SystemsTheophrastus subdivided plants based on shape, and into broad categories as trees, shrubs, and herbs

Dioscorides developed a more practical approach - Ex. Medicinal herbs were separated from those used in making perfumes300 BCPolynomial System-translation of the common names of organisms into Latin-each species was described in Latin by a sentence limited to 12 words that begins with the genus name-Ex. Spiderwort -Tradescantia ephemerum phalangoides tripetalum non repens virginianum gramineumCommon name: Tradescantia virginianaMiddle Ages (5th 15th Century AD)Translation: The annual, upright Tradescantia from Virginia which has a grasslike habit, 3 petals, and stamens with hairs like spider legs, common name Tradescantia of Virginia

But the polynomial system was simplified into a two-word or BINOMIAL naming system in the mid-16th century to mid-17th century by a group of naturalists known as herbalists.Middle AgesAndrea Cesalpino first scientist to classify plants primarily according to structural characteristics, such as their fruits and seeds

Caspar Bauhin adapted Cesalpinos method; catalogued an extensive list of plants

16th CenturyAnimal Classification Advanced

Pierre Belon extensively studied and catalogued birds-first to use adaptation to habitat to divide birds as AQUATIC, WADING, PERCHING, and LAND BIRDS and BIRDS of PREY16th CenturyJohn Ray used key characteristics such as the shape and size of the birds beak to classify birds

MID 1700sCarolus Linnaeus Binomial system of nomenclature similar organisms are grouped into a genus, and each organism is given a two-word Latin name

17th CenturyCarolus Linnaeus Binomial nomenclaturefirst name genus namesecond name adjective describing the organism, its geographic location or the person who discovered it

Ex. domestic dogCanis familiaris

17th CenturyCanis genus name for the group of animals that includes dogs, wolves, coyotes, and jackals

familiaris acts as a descriptor to further differentiate the domestic dog from its wild cousins17th CenturyCarolus Linnaeus also designed the HIERARCHICAL classification schemeKingdomPhylumClassOrderFamilyGenus Species17th CenturyDevelopment and use of microscopes presented new classification problems which still relied on a 2-kingdom classification system (Plantae and Animalia17th CenturyCharles Darwin-published On the Origin of Species in 1859-argued that classification system should reflect the history of life; species should be related based on their shared ancestry-emphasis on taxonomy shifted to:A search for characters which reflected genetic (evolutionary) relationships; andThe construction of a phylogenetic classification schemeBefore the 19th CenturyPhylogenetic based on genetic, evolutionary relationships- which traits are primitive or advancedBefore the 19th CenturyErnst Haeckel-proposed placing the unicellular forms in kingdom Protista; placed bacteria within this kingdom

1930sEdouard Chatton distinguished prokaryotes and eukaryotes19th CenturyHerbert Copeland-prokaryotes in the 4th kingdom, Monera

1950sRobert Whittaker-proposed adding a 5th kingdom, Fungi

1970sAdvances in molecular systematics1938Polymerase chain reaction permits easy analysis and comparison of DNA structures

Carl Woese determined that archaebacteria were found to have unique molecular structures and physiological characteristics from bacteria-proposed a 6-kingdom classification systemMolecular SystematicsOther scientists propose an 8-kingdom systemMolecular SystematicsModern animal taxonomy was established using evolutionary systematics and recent cladistic revisions.PhyloCode-new taxonomic system-being developed as an alternative to Linnaean taxonomy-replaces Linnaean ranks with codes that denote nested hierarchy of monophyletic groups converged by cladograms

CURRENT STATE of ANIMAL TAXONOMYThe terms primitive, advanced, specialized, and generalized are used for specific characteristics and not for groups as a whole.Current State of Animal Taxonomy