Carolus Linnaeus played a vital role in taxonomy, the naming and classifying of animals. Linnaeus put into place binomial nomenclatures. This nomenclature has a two part name: First the genus the organism is in followed by their species. This gives each organisms a universal and scientific name that is understood by all. Without Linnaeus’ system of naming organisms it would be much more difficult to communicate with people of other languages about organisms, as their common name would change between the languages. To write each organism’s scientific name, the first letter in the genus is capitalized and the entire name is italicized. Linnaeus assigned an incredible amount of binomials (more than 11,000!) and most of them are still used today.
Linnaeus also grouped species into categories. The most specific category is the species, followed by the genus, family, order, class, phylum, kingdom, and, finally, domain. Organisms are classified based on their morphological and molecular homologies. Usually, organisms with very similar morphologies or DNA sequences are more closely related than organisms whose morphology or genetics differ vastly.
Previously, taxonomists classified every organisms into just two kingdoms- plants and animals. In the late 1960’s, many taxonomists started recognizing five kingdoms- Monera (prokaryotes), Protista, Plantae, Anamalia, and Fungi. This system set all prokaryotes apart from eukaryotes. But with more research showing the diversity of prokaryotes, taxonomists created three domains (domains being a broader category than kingdoms) called Bacteria, Archaea, and Eukarya. Within domain Eukarya are four kingdoms- Plantae, Fungi, and Animalia. The dog, or Canis lupus familiares, shown in the photo above belongs in the domain Animalia.