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Click to edit Master subtitlestyle9/14/10Systematics:On HomologyChapter 2
9/14/10SystematicsSystematics - the study of relationships postulatedto exist among species or higher taxa
9/14/10Homology and AnalogySystematics is a tool that helps us determine homology(similarity derived from common ancestry) from analogy(artificial similarity not based on common ancestry) bybuilding phylogenies (cladograms)Homology can also be defined as:Shared similarity due
9/14/10Analogy; ConvergenceConvergence – the independent origin of similar attributes from a dissimilar ancestral condition
9/14/10HomologyTurtleHumanHorseBirdBatSealPhalangesHumerusRadius and ulnaCarpals;Metacarpals
9/14/10Pierre Belon du Mans 1555“equivalences
9/14/10Georges CuvierCorrelation of parts; “fixity of species”Homology –the same organ indifferent organisms underevery form and functionLouis Agassiz(1857) Essay onClassificationThree-Fold ParallelismArchetypes;No evolution requiredNot testableRichard OwenAll similarity due to function
9/14/10Hypothesis of HomologyTurtleHumanHorseBirdBatTailEmbryology; OntogenyGill pouchBirdMammal
9/14/10Ontogeny: Meckel’s Serres LawMeckel Serres Law – as an organism develops they pass through the less complicated forms (pass through adult stages of primitive groups)Recapitulation - Ernst Haeckel (ontogeny recapitulates phylogeny”)Hypothesis of Homology
9/14/10Ontogeny: Von Baer’s LawVon Baer’s Law –  the general characters of the group to which an embryo belongs appear in development earlier than the special characters - terminal additionHypothesis of Homology
9/14/10Ontogeny: Von Baer’s LawVon Baer’s Law –  the general characters of the group to which an embryo belongs appear in development earlier than the special characters - terminal additionGill pouchBirdMammal
9/14/10Hypothesis of HomologyTurtleHumanHorseBirdBatMorphology;physical make-up, topology
9/14/10HumanHorseBirdBatMorphology-TransitionsHypothesis of Homology
9/14/10Genetics-Amino Acid sequence of proteinsHypothesis of Homology

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Term
Fall
Professor
Chakrabarty
Tags
Cladistics, Ichthyology, Phylogenetics, phylogenies, phylogenetic systematics

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