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Classification. Why do we classify living things?. We have about 1.5 million NAMED & classified species. There may be over 30 million species on Earth!! We organize so we can communicate, share information & find information. Taxonomy. …branch of biology for naming & grouping of organisms
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Why do we classify living things? We have about 1.5 million NAMED & classified species. There may be over 30 million species on Earth!! We organize so we can communicate, share information & find information.
Taxonomy …branch of biology for naming & grouping of organisms Can be grouped according to: 1) their characteristics 2) their evolutionary history
History of taxonomy Aristotle – had 2 groups, plants & animals Linnaeus – developed a Hierarchy of levels, according to morphology (physical appearance)
Problems with using morphology to classify • Some things may look different but still be a member of the same species. • Injuries or other events may alter the physical appearance • Some things look alike but are not related (dolphins & fish)
Binomial Nomenclature …is the ”2 part scientific name” of an organism RULES 1) 1st word = genus name, always capitalize 1st letter 2) 2nd word = species name, all lower case 3) italicized or underlined 4) Written in Latin
EXAMPLES Home sapien = humans Pipa pipa = surinam toad P. leo = lion
Phylogeny ..classifying organisms according to their evolutionary history A phylogenetic tree can be created using systematics.
How does systematics work? Use evidence from many sources: 1) fossils 2) morphology (physical appearance) 3) embryological development 4) chromosomes & DNA