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biol1202notes - BIOL 1202 NOTES The first eukaryotes...

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BIOL 1202 NOTES The first eukaryotes -Oldest fossils of eukaryotic cells are 2.1. Billion years old -Endosymbiotic Theory -Mitochondria and plastids were formerly small prokaryotes loving within larger host cells - Were possibly undigested prey or internal parasites or mutalist (see Fig. 25.9) Clock Analog Show time scales involved in the history of life on Earth Fig 26.10 CHAPTER 26 Phylogeny and the Tree of Life Concept 26.1” Phylogenies show evolutionary relationships -Taxonomy: the ordered division of organisms into categories based on their similarities and differences Binomial nomenclatures -The two part format of the scientific name of an organism -The binomial name consist of : -genus and species -these are always written in a different font (e.g. italics) -Genus is always capitalized; species is always lowercases Ex. Homo sapiens Hierarchical Clasification Linnaeus also introduced the system for grouping species in increasingly broad categories -K eep Pipes Clean OF GaS -Kindly Proffessors Cannot Often Fail Good Students -Do Keep Pipes Clean OF Gas Skyler.** Classification
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Kindom-animalia Phylum-chordata Class-mammalia Order-primates Family-hominidae Genus-homo Species-sapiens Living Classification & Phylogeny -Systematist depict evolutionary relationships in branching phylogenic trees -Each branch point (node) represents the divergence of two species -Deeper branch points represent greater amounts of divergence -Lines represent lineages (fig 26.4) Concept 26.3 Cladistics -Cladogram: a diagram depicting patters of shared characteristics among species -Clade within a cladogram :a group of species that include the ancestral species and all its descendants Fig 26.11 Monophyletic grouping Made up of an ancestral species and all of its descendants 0nly monophyletic groups qualify as legitimate taxa in cladistics Fig 26 10a Paraphyletic Grouping Fig2610b Consist of an ancestor and some, but no all of that ancestors descendants Polyphyletic grouping Grouping that lacks the common ancestor of the species in the group Fig 26.10c Shared Ancestral and Shared Derived Characteristics -Shared ancestral characteristics: homologous structure that predates the branching of a particular clade from other members of that clade -Shared derived characteristics: evolutionary novelty unique to a particular clade Orthologous and Paralogous Genes Orthologous genes: genes found in a single copy of the genome -diverge onli after speciation has taken place
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Paralogous genes: result from gene duplication -more than one copy in the genome
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This note was uploaded on 02/27/2011 for the course BIOL 1202 taught by Professor Gregg during the Spring '08 term at LSU.

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biol1202notes - BIOL 1202 NOTES The first eukaryotes...

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