BIOL 152 1st Edition Lecture 9 Outline of Last Lecture - Speciation Outline of Current Lecture Evolutionary biologyPhylogeny - the evolutionary history of a species or group of speciesSystematic - analytical approach to understanding the diversity and relationships among organisms- Morphological, biochemical and molecular resemblances Taxonomy - ordered division of organisms based on a set of characteristics used to assess similarities anddifferences (Linnaeus)Why fossils are important- 90% of species that ever existed are extinct- Reveal ancestral characteristics- Substantial but incomplete- Biased toward abundant species that dominated regions, widespread and shows a display of only bony structures Analogy versus HomologyBat and bird wings are analogous- Evolved independently via (convergent evolution – evolved separately)Bat and cat forelimbs are homologous- Evolved from a common ancestorThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Bird and bat humorous are homologous depending on the scaleTaxonomyBinomial nomenclature - genus and specific epithet (ex: Panthera pardus = Leopard)- Latin, universal, avoid ambiguityHierarchical classification - species are grouped into increasingly broad (inclusive) categories- Taxonomic unit at any level is called a taxon. For example, domain, kingdom etc.Phylogenetic trees - branching of diagrams that depict hypotheses about evolutionary relationships donethrough:- Series of dichotomous branches- Deeper branch points represent greater amount of divergenceCladisticsCladogram - depicts patterns of shared, (derived characteristics). Present in one population but not in ancestral populations - Does not, by itself, imply evolutionary history- Clade – group of species that include ancestral species and all its descendantsMonophyletic - is a valid clade, branches off one ancestor and shows many of its descendants Paraphyletic - contains only some of descendants of its group Polypyletic - grouping organisms that don’t share a common ancestor Paraphyletic and polyphyletic are wrong versions of a cladogram Two kinds of homologiesShared Ancestral - a character that is shared beyond the taxon we are trying to define- For example, backbones in mammals- AKA: synpleisiomorphicShared Derived - an evolutionary novelty that is unique to a particular clade- For example, hair in mammals, backbones in vertebrates- AKA: synapomorphicOutgroups - are used to differentiate between shared derived and shared primitive charactersSpecies or group of species that is closely related to the ingroup, are specifically the species we are studyingPrinciple of parsimony - the theory that the simplest explanation is the best solution (aka: Occam’s Razor)Molecular systematicsIs used to comparing DNA to infer relatedness- Above and below species level- When morphological process are not possible, researchers use the method of molecular systematics - DNA that codes for rRNA changes slowly, therefore these genes known to be highly conversed. Researchers use this method to distinguish two distant organisms in a phylogeny - mtDNA or mitochondrial DNA changes rapidly and so it is used for distinguishing closely related species FactsBacteria and Archae are prokaryotesNeutral Theory - is the theory that most mutations are neutralGenes that are changing slowly are affected by mutations, which consequently affect survivalGenes that are changing rapidly when affected by mutations do not affect survivalCurrent Lecture- Chemistry of