KEY CONCEPT Organisms can be classified based on physical similarities.

Swedish botanist Carolus Linnaeus developed the scientific naming system (1750’s) still used today. Taxonomy is the science of naming and classifying organisms into seven groups or levels called taxon. plural- taxa White oak: Quercus alba

Each level is included in the level above it. Levels get increasingly specific from kingdom to species.

Binomial nomenclature - a two-part scientific naming system. Latin and italics First part -the genus name, capitalized Second part – the species descriptor, lower case, never written alone Homo sapien (wise man)

A genus includes one or more physically similar species. Tyto alba

Scientific names help scientists to communicate. Some species have very similar common names. Some species have many common names.

The Linnaean classification system has limitations. Did not include Domains Linnaeus taxonomy doesn’t account for molecular evidence, based only on physical similarities Modern the technology did not exist- DNA and Gene sequencing, protein analysis, radiometric dating, relative dating (fossil record).

Physical similarities are not always the result of close relationships. Genetic similarities more accurately show evolutionary relationships.

man Domain eukarya King Kingdom animalia Philip Phylum Chordata Came Class Mammalia Over Order Primate For Family Hominid Great Genus Homo spagetti species sapien