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Taxonomy. Biologist have identified and named 1.5 million species so far 2 – 100 million additional species have yet to be discovered. Taxonomy : discipline where scientist classify organisms and assign each organism a universally accepted name
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Biologist have identified and named 1.5 million species so far • 2 – 100 million additional species have yet to be discovered
Taxonomy: discipline where scientist classify organisms and assign each organism a universally accepted name • Organisms placed in the same group are more similar than organisms in a different group
Assigning Scientific Names • Common names: vary among regions and are confusing • Ex. Buzzard refers to hawk in some parts but in the US it refers to vultures • Scientific names were assigned in Latin and Greek in the 18thcentury • Latin is a dead language, so if you were to travel to Japan, Latin would still be the same there.
Binomial Nomenclature • Early efforts (Traditional Classification) • Scientific names described physical characteristics • Very long names and difficult to standardize • Binomial Nomenclature: Carolus Linnaeus • Each species assigned 2-part name • Scientific name written and underlined • First word is capitalized and second word is lowercased • First word: Genus • Second word: species
Classification • Based on work from Linnaeus • 8 levels of classification or taxafrom largest to smallest • Domain • Kingdom • Phylum • Class • Order • Family • Genus • Species
Species are grouped according to which organisms individuals will mate • Linnaeus grouped species into larger taxa according to visible similarities and differences • But which characteristics are most important?
Evolutionary relationships • Now use evolutionary descent and not just physical similarities • Members of a genus share a recent common ancestor • Organisms that appear very similar may not share a recent common ancestor
Cladograms • Cladistic analysis considers only new characteristics that arrive over time • Characteristics that appear in recent parts of a lineage but not in older members are called derived characteristics • Cladogram: diagram that shows the evolutionary relationships among a group of organism