Linnaeuss System of Taxonomic Classification

A taxonomy is a hierarchical scheme for classifying and identifying organisms. It was developed by Swedish scientist Carl  Linnaeus in the 18th century.  In addition to being a valuable tool for biological classification, Linnaeuss system is also useful for  scientific naming. The two main features of this taxonomy system, binomial nomenclature and categorical classification, make it convenient and effective. Binomial Nomenclature The first feature of Linnaeuss taxonomy, which makes naming organisms uncomplicated, is the use of binomial nomenclature. This naming system devises a scientific name for an organism based on two terms: The name of the organisms genus and the name of its species. Both of these terms are italicized and the genus name is capitalized when writing. Example: The bionomical nomenclature for humans is Homo sapiens. The genus name is Homo and the species name is sapiens. These terms are unique and ensure that no two organisms have the same scientific name. The foolproof method of naming organisms ensures consistency and clarity across the field of biology and makes Linnaeuss system simple. Classification Categories The second feature of Linnaeuss taxonomy, which simplifies organism ordering, is categorical classification. This means narrowing organism types into categories but this approach has undergone significant changes since its inception. The broadest of these categories within Linnaeuss original system is known as kingdom and he divided all of the worlds living organisms into only an animal kingdom and plant kingdom. Linnaeus further divided organisms by shared physical characteristics into classes, orders, genera, and species. These categories were revised to include kingdom, phylum, class, order, family, genus, and species over time. As more scientific advancements and discoveries were made, domain was added to the taxonomic hierarchy and is now the broadest category. The kingdom system of classification was all but replaced by the current domain system of classification. Domain System Organisms are now grouped primarily according to differences in ribosomal  Ã¢â‚¬â€¹RNA structures, not physical properties. The domain system of classification was developed by Carl Woese and places organisms under the following three domains:   Archaea: This  domain includes prokaryotic organisms (which lack a  nucleus) that differ from bacteria in membrane composition and RNA. They are extremophiles capable of living in some of the most inhospitable conditions on earth, such as hydrothermal vents.Bacteria: This domain includes prokaryotic organisms with unique cell wall compositions and RNA types. As part of the human microbiota, bacteria are vital to life. However, some bacteria are pathogenic and cause disease.Eukarya: This domain includes eukaryotes or organisms with a true nucleus. Eukaryotic organisms include plants, animals, protists, and fungi. Under the domain system, organisms are grouped into six kingdoms which include Archaebacteria  (ancient bacteria),  Eubacteria  (true bacteria),  Protista,  Fungi,  Plantae, and  Animalia. The process of classifying organisms by categories was conceived by Linnaeus and has been adapted since. Taxonomy Example The table below includes a list of organisms and their classification within  this taxonomy system using the eight major categories. Notice how closely  dogs and wolves are related. They are similar in every aspect except species name. Taxonomic Hierarchy Example Brown Bear House Cat Dog Killer Whale Wolf Tarantula Domain Eukarya Eukarya Eukarya Eukarya Eukarya Eukarya Kingdom Animalia Animalia Animalia Animalia Animalia Animalia Phylum Chordata Chordata Chordata Chordata Chordata Arthropoda Class Mammalia Mammalia Mammalia Mammalia Mammalia Arachnida Order Carnivora Carnivora Carnivora Cetacea Carnivora Araneae Family Ursidae Felidae Canidae Delphinidae Canidae Theraphosidae Genus Ursus Felis Canis Orcinus Canis Theraphosa Species Ursus arctos Felis catus Canis familiaris Orcinus orca Canis lupus Theraphosa blondi Taxonomic Classification Example Intermediate Categories Taxonomic categories can be even more precisely divided into intermediate categories such as subphyla, suborders, superfamilies, and superclasses. A table of this taxonomy scheme appears below. Each main category of classification has its own subcategory and supercategory. Taxonomic Hierarchy With Subcategory and Supercategory Category Subcategory Supercategory Domain Kingdom Subkingdom Superkingdom (Domain) Phylum Subphylum Superphylum Class Subclass Superclass Order Suborder Superorder Family Subfamily Superfamily Genus Subgenus Species Subspecies Superspecies