classification

• Carl Linnaeus proposed the Linnaean system of classification in the 1700s
• The Linnaean system groups species together according to their characteristics and bone structures
• Species are grouped into kingdoms, such as plant or animal, then phylum, class, order, family, genus, and finally species
• The names in the Linnaean system are mostly in Latin
• Linnaeus introduced the binomial naming system, where species are named by their genus and species names in italics
• For example, humans are named Homo sapiens
• Carl Woese proposed the three-domain system in the 1990s
• The three domains are Eukaryota, Bacteria, and Archaea
• Eukaryota contains organisms with eukaryotic cells, such as plants, fungi, protists, and other animals
• Bacteria refers to single-celled prokaryotic organisms found almost everywhere
• Archaea are a different type of prokaryotic cell found in extreme conditions like hot springs and salt lakes
• Evolutionary trees show the evolutionary relationships between different species or groups
• They link common ancestors to show relationships
• Birds are more closely related to Tyrannosaurus rex than to bats
• Bats and birds are more closely related to each other than to spiders
• Different evolutionary trees can look quite different but show the same information
• To remember the order of classification groups, use a mnemonic
• For example, "Dear Kate, please come over for great spaghetti" represents Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species