Classification and Phylogenetics- Lab 14Modified from “Classification & Evolution” By Robert P. Gendron14-1Key Concepts•Classification•Phylogenetics•Cladistics•Phenetics•Classical Evolutionary SystematicsPurpose:•review classification of organisms•compare three schools of classification in biology•construct and map the evolutionary relationships ofCaminalcules, fictitious creatures invented by theevolutionary biologist Joseph CaminNotes:•You must complete the lab exercises &assignment questions before the end of theclass period.I. SystematicsSystematics is the study and classification oforganisms with the goal of reconstructing theirevolutionary history. Taxonomy is more generalthan systematics and can be defined as the scienceof identifying, naming and classifying organismsinto groups.Taxonomists may or may not useevolutionaryprinciplesindevelopingclassification schemes. Most taxonomists use ahierarchical system to classify species intoincreasingly broad groups based on extent ofsimilaritiesinmorphologyandothercharacteristics. Linnaeus, a Swedish physician/botanist in the 1700s, helped develop the two part,or binomial naming system that we use today toclassify organisms. The first word of the name isthegenusto which the species belongs. Thesecond name is thespecific epithet.Thecombination of genus and specific epithet gives usa complete and unique scientific name for anorganism.For example, the scientific name forthe domestic dog isCanis familiaris(underlinedor italicized, genus name capitalized, speciesname lower case). The dog belongs to a largergroup (taxon), thefamilyCanidae. Theclassification process continues hierarchically.The next higher group is theorderCarnivora,which is followed by theclassMammalia,subphylumVertebrata,phylumChordata, andkingdomAnimalia (Table. I).Table I.Classification of the Domestic Dog. Note: Forplants, the term “Division” is sometimes used in place of“Phylum”.Whittaker, in 1969, developed a five kingdomnaming system that includes the kingdomsMonera, Protista, Plantae, Fungi, and Animalia.Other classifications schemes have beenproposed: a six kingdom system that dividesprokaryotes into two kingdoms (Eubacteria andArcheabacteria); a three domain system thatseparates organisms into the superkingdoms ofEubacteria, Archaebacteria, and Eukarya; and aneight kingdom system that divides prokaryotesintotwokingdoms(EubacteriaandArcheabacteria) and divides protists into threekingdoms (Archaezoa, Chromista, and Protista).These different schemes of classification alsoillustrate two extremes among taxonomists --lumpers and splitters. Taxonomists who arelumpersprefer to classify things in only a few,broad groups whilesplittersfavor naming manygroups, resulting in fewer taxa within each group.
