Classification & the New Taxonomy

Classification & the New Taxonomy

Classification & the New Taxonomy 2010-2011 Chapters 25 35 New songs! bJZ0 lUI

What determines life? There are 6 characteristics of life: Organization Metabolism Homeostasis Growth and Development Reproduction Adaptations Finding commonality in variety Organisms classified from most general group, domain, down to most specific, species

domain, kingdom, phylum, class, order, family, genus, species Solar System Eart h No. America U. S. N. Y. L.

I. Nassau Co. use the mnemonic! Levittow n Eukaryote Classification Old 5 Kingdom system Monera, Protists, Plants, Fungi, Animals

Prokaryote New 3 Domain system reflects a greater understanding of evolution & molecular evidence Prokaryote: Bacteria Prokaryote: Archaebacteria Eukaryotes Protists Plants Fungi Animals

Archaebacteria & Bacteria Kingdom Bacteria Kingdom Archaebacteria Kingdom Protist Kingdom Fungi

Kingdom Plant Kingdom Animal Binomial Nomenclature Was established in the 18th century by Carlus Linnaeus Based on structural features as opposed to habitat, size etc. He used genus which acted as a noun telling what it was He also used species name which was an

adjective to describe the genus Taxon Term used for the hierarchical classification groups The smaller the taxon the more similar the organisms within it The Evolutionary Perspective Kingdoms Planta e Fung

i absorptiv e nutrition autotroph s Protist a uni- to multicellula r Eubacteri a

multicellula r Archaebacteri a prokaryote s Single-celled ancestor eukaryote s Animali

a ingestiv e nutritio n heterotroph s Bozeman wGVgIcTpZkk Why are common names bad? The classification system makes it easier and quicker to

locate different species There is a uniform Latin language used so it doesnt have to be translated between languages. It makes it easier for scientists of the world to share information. It avoids the confusion of common names. For example Ragwort is 2 different plants on PEI and outwest (PEIs is poisonous) Puma, Mountain Lion, and Cougar are all the same animals but named different things in different countries Dichotomous Keys Dichotomous means divided into two parts therefore these keys always give 2 choices in each step. Sheet

Evidences for Classification 1. Fossil Record: radiocarbon dating Evolution of birds Archaeopteryx lived about 150 mya links reptiles & birds Smithsonian Museum, Washington, DC 2006 Fossil Discovery of Early Tetrapod Tiktaalik

missing link from sea to land animals 2. Anatomical record Homologous structures similarities in characteristics resulting from common ancestry Homologous structures Similar structure Similar development

Different functions Evidence of close evolutionary relationship recent common ancestor 3. Comparative embryology Similar embryological development in closely related species all vertebrate embryos have similar structures at different stages of development gill pouch in fish, frog, snake, birds, human, etc. 4. Molecular record Comparing DNA & Biochemistry (blood, protein, hormones)

universal genetic code! Why compare these genes? DNA & RNA compare common genes Closely Closely related related species species have have sequences sequences that

that are are more more similar similar than than distantly distantly related related species species DNA & proteins proteins are are aa molecular molecular record record of

evolutionary evolutionary relationships relationships Human/kangaroo 100 Nucleotide substitutions cytochrome C (respiration) hemoglobin (gas exchange) Dog/ cow

75 Human/ cow Rabbit/ rodent Horse/ donkey 50 Llama/ cow

Horse/cow Sheep/ goat 25 Human/rodent Pig/ cow Goat/cow 0

0 25 50 75 100 Millions of years ago 125 5. Behaviour Song Bird: birds that have the same song would be classified more closely

6. Cell Structures Peptidoglycan = bacteria in cell wall Phylogeny Evolutionary history of an organism We often use cladograms to show this history and relationship to other living things Like a tree the organisms at the top are the most recent Comparative hemoglobin structure Human

Macaque Dog Bird Frog Lamprey 32 45 67 125 Why does comparing

amino acid sequence measure evolutionary relationships? 8 0 10 20 30 40 50 60 70 80 90 100 110 120 Number Number of of amino amino acid acid differences differences between between hemoglobin

hemoglobin (146 (146 aa) aa) of of vertebrate vertebrate species species and and that that of of humans humans Book Examples Pg. 115 Horseshoe crab reclassified Interesting chart on pg. 119

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