Classification is grouping together similar things. It is something that you have done in your daily life since you were a child. There are many different ways to classify organisms. There are aquatic and terrestrial animals. Certain plants can be grouped together as either trees or shrubs according to their outward appearance. Using these methods is useful for some purposes. Generally it is more useful to classify organisms in accordance with their relationships with one another. More to the point the systems discussed today are the ones used universally and based upon Carolus Linnaeus' original work. Carolus Linnaeus is probably the single most dominant figure in systematic classification. Born in 1707, he had a mind that was orderly to the extreme. People sent him plants from all over the world, and he would devise a way to relate them. At the age of thirty-two he was the author of fourteen botanical works. His two most famous were Genera Plantarum, developing an artificial sexual system, and Species Plantarum, a famous work where he named and classified every plant known to him, and for the first time gave each plant a binomial. This binomial system was a vast improvement over some of the old descriptive names for plants used formerly. Before Linnaeus, Catnip was known as: "Nepeta floribus interrupte spicatis pedunculatis" which is a brief description of the plant. Linnaeus named it Nepeta cataria--cataria meaning, "pertaining to cats". The binomial nomenclature is not only more precise and standardized; it also relates plants together, thus adding much interest and information in the name. For instance, Solanum relates the potato, the tomato and the Nightshade. Binomial Classification Early on in naming species taxonomists realized that there would have to be a universal system of nomenclature. Why? For example, it would seem to be a lot less complicated to just give a species a vernacular name that is easy to pronounce. Let's look at the loon of the North American lakes for example. In English it is called the common loon in North America. Seems simple enough, but in
it is called the great northern diver. In French it is plongeon imbrin, in , and in Quebec le huart a collier. In Spanish it is called somorguajo comun, Islom in Swedish, and Eistaucher in German. So you see how much time and calling the species Gavia immer can save confusion. Binomial classification in its simplest form is a way of naming a species by means of two names both in Latin. (binomial nomenclature) It was first introduced by Carolus Linnaeus. In Binomial classification the first name, which begins with a capital letter is known as the Genus it is always capitalized. The genus is a group of species more closely related to one another than any other group of species. The genus is more inclusive than the species because it often contains many species. The second part of the binomial represents the species itself and is always printed with all letters in lower case. A species is a group of individuals that are alike in many different ways. Individuals are in the same species if they are: 1. Are able to mate with those similar to themselves. 2. Produce young that are themselves able to reproduce. As an example, in the cat family, the genus Panthera is coupled with the species leo to form Panthera leo, the Lion. Likewise, Panthera is coupled with tigris, to form Panthera tigris the Tiger. In simplified terns both the Lion and Tiger share common traits and a common genus - Panthera, whilst clearly remaining separate species. Closely related species are a genus, closely related genera (plural form of genus) are grouped together in a family. Closely related families are grouped into an order, and so on, into more inclusive categories, or levels in the classification hierarchy. Taxonomic Hierarchy Approximately one and a half million species have been classified and there are estimates that over five million species remain to be discovered. For biologists to order this mass of information, a scientific system called taxonomy was introduced. The basic idea is to group species with similar characteristics together into families, and to group the families together into broader groupings. To this end, the taxonomic categories where devised, and they create the taxonomic hierarchy. The hierarchy goes (with an example): *Categories Example Kingdom Animalia Phylum (Plural = Phyla) Cordata *In plants, this category is often called a division* Class Mammalia Order Carnivora Family Canidae Genus Canis Species Lupus (the Wolf) * Kim Puts Candy Out For Good Students* Every species is in only one genus. Similarly, every genus is in only one family, and so forth up the hierarchy. The most inclusive category for classifying groups of similar organisms is the kingdom. It is argued exactly how many Kingdoms there are though. Up until recently, only two kingdoms were generally used, the plant and animal kingdoms. Now however there are 5 established kingdoms and one controversial unofficial kingdom. The 5 kingdoms: 1. Kingdom Animalia (The Animal Kingdom) ex: Multi-cellular motile organisms, which feed heterotrophically (Humans) 2. Kingdom Plantae (The Plant Kingdom) ex: Multi-cellular organisms, which feed by photosynthesis (Tulips) 3. Kingdom Protista (The Protist Kingdom) ex: Protozoa and single-celled algae 4. Kingdom Fungi (The Fungus Kingdom) ex: Yeast 5. Kingdom Monera (The Monera Kingdom) ex: Bacteria and blue-green algae Parallel to these Kingdoms, but not included, are the Viruses. These are acellular entities with many of the properties of other life forms, but are genetically and structurally too dissimilar to the species categorized above to fit into that scheme of taxonomy.