CC BOT 131 Biodiversity and Classification

CC BOT 131 Biodiversity and Classification - For hundreds...

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Unformatted text preview: For hundreds (thousands) of years, people interested in nature classified organisms as either ..... Biodiversity and Classification Animals or Plants Old game called "Is it an animal, vegetable, or mineral?" mineral?" Animal, vegetable or mineral? Animal, vegetable or mineral? Animal, vegetable or mineral? Animal, vegetable or mineral? 1 Animal, vegetable or mineral? Animal, vegetable or mineral? Animal, vegetable or mineral? Animal, vegetable or mineral? Animal, vegetable or mineral? Animal, vegetable or mineral? 2 Animal, vegetable or mineral? Animal, vegetable or mineral? Animal, vegetable or mineral? Biologists now classify living organisms in more complex ways About 15 million different species of organisms exist today About 10% of these 15 million species have been named (the easy ones) Predicted that roughly 25% of these 15 million species will become extinct in the next few decades (your lifetime), due to human destruction of the environment About 1.5 billion species have evolved throughout the history of the earth and roughly 99% have become extinct So... only about 1% of all the species that ever lived So... are alive on earth today 3 flowers perfect? leaves per node What is a species? petal color Characters cotyledon # 1 2 2 1 1 petal # Very complex answer! More to it than just a name American Robin A r o o r w 3 3 5 5 5 + + - - + 2 2 2 1 1 Species B C D E American Robin and English Robin are different species but are both called Robins English Robin What is a species? Very complex answer! TAXONOMY Describing, naming, and classifying organisms Typically thought of as a reproductively isolated group of organisms with a common gene pool and similar physical characteristics Carl von Linne Carl Linnaeus Swedish Naturalist 1707 - 1778 Linneaus invented the.... the.... BINOMIAL SYSTEM OF NOMENCLATURE Linneaus published in book in 1753... 1753... "SPECIES PLANTARUM" Classified and named +/- 7300 species of plants, based mostly on flower characteristics toxin? + + - - - 4 Prior to Linneaus Plants had Loooooonnnnnngggggg names Spiderwort was named.... named... Tradescantia ephemerum phalangoides tripetalum non repens Virginianum gramineum Spiderwort Binomial nomenclature This translates to... to... The annual upright Tradescantia from Virginia with a grasslike habit, three petals, and stamens with hairs like spider legs Linneaus abbreviated this to Tradescantia virginiana GENUS AND SPECIES written in... in... italics or sometimes underlined and first letter of genus is capitalized Corn is Zea mays Humans are Homo sapiens Peaches are Prunus persica Smooth skinned peaches are Prunus persica var. nucipersica Names for organisms usually derived from Greek or Latin words A person's name person' A location A physical characteristic "Taxon" - a taxonomic grouping at any level. Taxon" Could be a species, genus, phylum, etc. TAXONOMISTS - People that Study and For example Quercus alba Clarkia modesta Tradescantia ohioensis Trifolium pratense name organisms SYSTEMATISTS People that figure out the evolutionary relationships between organisms 5 Until Early 1800's..... Monophyletic plants within a taxon share common ancestor Scientists classified living organisms into 2 kingdoms... animals and plants kingdoms... Polyphyletic plants within a taxon share more than one common ancestor 1) Animalia 2) Plantae 1860's Organisms like Euglenoids (and MANY others), didn't quite fit into either the animal or plant group didn' 1938 Bacteria seemed too different from everything else and some thought they should have their own group.... group... Copeland proposed splitting out the bacteria from the Protista and calling them the Monera Hogg and Haeckel proposed addition of the Protista group (also called Protoctista), to contain anything Protoctista), that wasn't clearly animal or plant wasn' So then we had 3 kingdoms ..... 1) Animalia 2) Plantae 3) Protista (huge group including fungi, bacteria, algae, etc) So then we had 4 kingdoms..... kingdoms... 1) Animalia 2) Plantae 3) Protista 4) Monera (bacteria) 1969 Protista group still seemed to big and confusing Whittaker proposed splitting out the fungi from the Protista So then we had 5 groups..... groups... 1) Animalia 2) Plantae 3) Protista 4) Fungi 5) Monera (bacteria) Old classification systems Based mostly on form, other easily observable characteristics 6 1980's Monera group seemed to big and confusing Woese et al., proposed splitting Monera into 2 groups, Archaea and Bacteria So then we had 6 kingdoms..... kingdoms... 1) Animalia 2) Plantae 3) Protista 4) Fungi 5) Bacteria 6) Archea Current classification based less on form and more on genetic characteristics (DNA), etc. Today Based on much DNA and RNA evidence Instead of separating groups into 6 kingdoms, some scientists propose 3 domains Our focus this semester Eukarya Reorganize.... This into this Animals Fungi Plants Protista 3 DOMAIN SYSTEM Bacteria Archaea Eukarya Bacteria Archaea Common ancestor 7 Three Domains: Bacteria Archaea Eukarya Six Kingdoms: Bacteria Archaea Protista Plantae Animalia Fungi Prokaryotes (lack membrane-bound organelles); unicellular; most are heterotrophic (obtain food by eating other organisms), but some are photosynthetic or chemosynthetic Prokaryotes; unicellular; microscopic; most live in extreme environments; differ in biochemistry and in cell wall structure from bacteria Eukaryotes; mainly unicellular or simple multicellular; maybe heterotrophic or photosynthetic; include protozoa, algae, and slime molds Eukaryotes; multicellular; photosynthetic; life cycle with alternation of generations; cell walls of cellulose Eukaryotes; multicellular; heterotrophic; most move about by muscular contraction; nervous system coordinates responses to stimuli Eukaryotes; most multicellular; heterotrophic; absorb nutrients; do not photosynthesize; cell walls of chitin Fig. 1-11, p. 14 8 ...
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This note was uploaded on 04/17/2008 for the course BOT 131 taught by Professor Unknown during the Spring '08 term at Miami University.

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