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Why Classify?. Aids in memory Improve our predictive powers Improves ability to explain relationships among things Provides a stable and unique name for organisms. Diversity on Earth. Diversity: variety of living organisms Estimated between 5-15 million species
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Why Classify? • Aids in memory • Improve our predictive powers • Improves ability to explain relationships among things • Provides a stable and unique name for organisms
Diversity on Earth • Diversity: variety of living organisms • Estimated between 5-15 million species • Only 1.5 million have been described
The History of Classification • Earliest known system invented by Aristotle (470-399 BC) • Classified organisms as plant or animal • Further classified animals to their mode of transportation • Land • Sea • Air • Used until early 16th century
Linnaeus’s Classification System • Swedish botanist (1707-1778) • Binomial Nomenclature – two-part scientific name Genus species • Why Latin? • Latin was the language known universally by the educated • Also used as a descriptor
King Phillip Comes Over For Good Spaghetti • Kingdom • Phylum • Class • Order • Family • Genus • Species
Common vs. Scientific Names • Scientific names eliminate confusion • Binomial nomenclature is the universal language for the organization of species. • Different areas use different common names for the same species. • The same common name is also used for different species.
Robins Erithacus rubecula Turdus migratorius Leiothrix lutea Family Petroicidae
gray silk mangrove snapper mangrove pargue mango snapper pargue black pargue black snapper lawyer silk snapper Common Names for Lutjanus griseus
Cladistics • Today we try to group organisms based on lines of descent based on shared derived characteristics • Derived characters are characteristics that appear in recent ancestry, but not necessarily in older members • Cladograms are used to show these shared derived characters to explain evolutionary relationships.
What We Learned from Darwin • Principles based on the theory that there is unity in life • All organisms related through descent to some unknown prototype in the past • Descendants spilled into various habitats • Accumulated diverse modifications or adaptations that fit them to these habitats
Where do we begin?... • Basic building blocks of life… • Prokaryote • “first kernel” – no true nucleus • No membrane-bound organelles • Single cell • Eukaryote • True nucleus • Membrane-bound organelles • Unicellular or multi-cellular
Wasn’t recognized as a major domain until recently Prokaryotic cells lacking nuclei Same basic structures as Eubacteria Live in extreme environments Thermal vents Hot springs Alkaline, saline or acidic waters Methane producing clusters Domain Archaea
Domain Eubacteria • Monera = Bacteria • Prokaryotic cells lacking nuclei • Has many applications • Cause human disease • Beneficial symbiosis in plants and animals • Make up the base of the food web
Domain Eukarya • Make up the majority of the diversity of life on Earth – Plantae, Animalia, Fungi, Protista • Eukaryotic cells
Six Kingdom System • Six Kingdoms • Eubacteria • Archaeabacteria • Protista • Fungi • Plantae • Animalia