The Linnaean System of Classification Grouped organisms by
The Linnaean System of Classification • Grouped organisms by physical characteristics in nested hierarchies – Kingdom – Phylum – Class – Order – Family – Genus – Species
Binomial Nomenclature • Two names – Genus and species • Better than a common name because it is always specific to a single species • Ex: Homo sapiens • Homo neaderthalensis • Gorilla gorilla • Bufo
How biologist classify living things • Physical characteristics – color, size, shape • Genetic similarities and differences - DNA • Fossil records of ancestors • Embryological developement Goal: Classification mirrors evolutionary relationships
Annelids – Segmented Worms Scientists used to think this was their closest relative Arthropods Genetics and Embryology show this is their closest relative Flatworms
Biological Classification • • • Domain - 3 Kingdom Phylum Class Order Family Genus Species - 2 million described, 5 -20 million estimated The scientific name of a species is always its genus and species in italics • Dear King Philip Came Over For Good Soup • Dumb Kids Play Chicken On Freeway, Get Smushed
History of Kingdoms • 1753 - Linnaeaus – two kingdoms: Animalia and Plantae • 1866 – Animalia, Plantae, Protista • 1938 - Animalia, Plantae, Protista, Monera • 1959 - Animalia, Plantae, Protista, Monera, Fungi • 1977 - Animalia, Plantae, Protista, Monera, Fungi, Archaea
Three Domains • Bacteria – no nucleus • Archaea – no nucleus, different cell walls • Eukarya – cells have a nucleus – Animalia – Plantae – Fungi – Protista
Classification of Humans • • Domain: Eukarya Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: Homo sapiens
P. O. D. – Are we as Eukaryotes more related to Bacteria or Archaea?
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