Taxonomy and Classification - Introductory Biology - Lecture Slides, Slides of Biology

Download Taxonomy and Classification - Introductory Biology - Lecture Slides and more Slides Biology in PDF only on Docsity! Taxonomy and Classification Docsity.com Why Classify? • 3 - 20 million species on Earth – Less than 2 million have been identified and named – Rainforests and oceans have lots of unidentified species • Need a way to organize to make organisms easier to identify and relationships easier to understand Docsity.com History of Classification • Carolus Linnaeus – 1707 – 1778 – Based classification system on physical characteristics – Came up with BINOMIAL NOMENCLATURE • System of naming • 2 words – gives species name – Genus » Group of closely related species – Second descriptive word – Example – Homo sapiens; Canis familiaris Docsity.com * Dead language ¢ Never changes * Consistent Why Latin? Docsity.com Characteristics Used by Taxonomists to Classify Organisms • External and internal structures (anatomy) • Chemical make up – DNA – Proteins • Evolutionary relationships Docsity.com How are relationships determined? • Fossil History and Comparison – Structures of modern organisms are compared with those of fossils Docsity.com How are relationships determined? • Development – Embryonic/larval forms of species can reveal relationships and suggest common origin Docsity.com How are relationships determined? • Biochemistry – The more nucleotide sequences OR amino acid sequences that are shared by two species, the more closely related they are – This is the BEST way to determine relationships • Objective • Quantitative Docsity.com Class Mammalia Order Carnivora Family Felidae A — me ; _ . 4 i ad g div Turtle if i : . (outgroup) Horse Wolf Leopard Domestic cat L rvisiy to purr Retractable claws Carnivorous (meat-eating) teeth Hair Copyright @ Pearson Education, lnc., publishing as Benjamin Cummings. Docsity.com Our 6 Kingdom System • Eubacteria • Archaebacteria • Protista • Fungi • Plants • Animals Docsity.com Our 6 Kingdom System • 6 kingdoms determined by – Characteristics of cells – How they obtain food Docsity.com