Taxonomy

This word taxonomy has its origin in the Greek language. In the ancient Greek language, they were two words – taxis and nomia referring to arrangement and method respectively.

It is that branch of science that deals with the classification of organisms that is called taxonomy.

This classification helps us to easily communicate about organisms. The diversity of life on our planet needs to be understood and organized so this field uses a hierarchical way of classification and organizing.

Alpha taxonomy, evolutionary taxonomy, folk taxonomy etc: are different forms of the subject.

People who are involved in this field are called taxonomists. They generally use observations from behavioural, biochemical, genetic and even morphological traits to a group or arrange the species into a specific classification. However, given the number of life forms, the taxonomic knowledge is still not complete. About 1.7 million species of animals have been named in the past 200 or so years.

Classification

Taxonomy is the concept of naming, describing and classifying organisms and includes all plants, animals and microorganisms of the world. With the help of morphological, behavioural, genetic and biochemical observations, taxonomists identify, describe and arrange species into classifications, including those that are new to science. Taxonomy identifies and elaborates the components of biological diversity providing basic knowledge underpinning management and implementation of the Convention on Biological Diversity. The taxonomy is also considered as a sub-branch of systematics and It is said that the biological nomenclature is either a part of taxonomy or a unit of systematics, it is the consideration to identify the taxonomy of organisms and their nomenclature.

Different kinds of animals and plants are called different “species”. When we say species, we refer to an interbreeding group of organisms that can produce viable next generation which can in turn interbreed. Hence, if we consider a horse and a zebra they cannot interbreed while animals of the same species can interbreed. The taxonomist provides us with unique names for species. It's a label that can help to find more and gain additional knowledge about them. It can sometimes get confusing because if we are discussing, for example, the hedgehog, we need to know if the discussion is about the small spiny insectivore or the orange fungus. All these have the same common name in English. It is for this reason and to provide clarity, the Latin "scientific" name is given as a unique universal identification.

There is a method for naming a species. Specimens are sorted to separate sets which are supposed to be representing a species. Once this first step is done, then they have to see if they already have names. This means reading through descriptions and identification documents generated over the years. They will compare with specimens that seem similar in terms of external characters or sometimes even have to dissect internal structures. In case they don’t find any match, then it could represent a new species, which has not been named before. The taxonomist then will have to write a description, specifying details in which the new species found now can be identified distinctly from others and make up a name in the Latin format. This name and its description must then be formally and properly published so other taxonomists can see what has been done. This process itself can take several years. 

The information from taxonomy is essential for agencies and for the border authorities to manage invasive species from other countries. Effective control can be implemented only if the species is correctly identified. Wrong identification can involve huge money wasted when quick decisions have to be taken. When something is to be eradicated the taxonomist can offer a great level of expertise that is key to developing a very effective yet benign measure of eradication.

The founder of this field is a Swedish botanist named Carl Linnaeus. The system he developed is called Linnaean taxonomy for classifying organisms and binomial nomenclature for naming organisms.

The Basic Scheme of Modern Classification has the Following Levels

1. Life

2. Domain

3. Kingdom

4. Phylum

5. Class

6. Order

7. Family

8. Genus

9. Species.

Domain: 

In Taxonomy, a domain is the highest rank of organisms. Linnaeus did not invent the domain rank, which is new. The three domain-level taxonomies of life are Bacteria, Archaea, and Eukaryota. Archaea are the level that are single-celled organisms similar to bacteria, while some archaea live in extreme environments, but others live in mild ones. Eukaryota is every living thing on earth that is not a bacteria or archaeon and is more closely related to the domain Archaea than to Bacteria.

Kingdom: 

The kingdom was the highest taxonomic rank before the domain was introduced. The different types of kingdoms were Animalia, Plantae, Fungi, Protista, Archaea, and Bacteria. Though some of these groupings, such as Protista, are not very accurate, it includes all eukaryotic organisms that are not animals, plants, or fungi, but some of these organisms are not very closely related to one another. There is no set pattern for the kingdom classification, and some researchers have abandoned it altogether.

Phylum: 

Phylum is the next rank after kingdom and it is more specific than kingdom but less specific than class. There are thirty-five phyla in the kingdom Animalia, including Chordata, Porifera, and Arthropoda.

Class: 

Class was generally the most general rank. There are 108 types of classes in the kingdom Animalia, including Mammalia, Aves, and Reptilia, among many others. The classes of Animalia proposed are similar to the ones used but classes of plants were based on attributes like the arrangement of flowers rather than relatedness. Classes of plants are different from the ones Linnaeus last used, and classes are not frequently used in botany.

Order: 

Order is way more specific than class. Some orders are still used today, such as Lepidoptera. The numbers are between 19-26 orders of Mammalia, depending on organisms that are classified. Various orders of Mammalia are Primates, Cetaceans, Carnivora, and Chiroptera.

Family: 

Family is a more specific type of rank. Some families in the order Carnivora, for example, are Canidae, Felidae, Mephitidae, and Ursidae There are basically 12 total families in the order Carnivora.

Genus: 

Genus is even more specific than family. Genus is the first part of an organism’s scientific name using binomial nomenclature and the second part is the species name, it is always italicized, and the genus name is capitalized while the species name is not. Genus and species are the types of taxonomic ranks that are italicized.

Species: 

Species is the specifically major taxonomic rank in this rank, species are sometimes divided into subspecies, but not all species have multiple forms that are different enough to be called subspecies. There are approximately 8.7 million different species of organisms on Earth, but the vast majority have yet to be discovered and categorized.

In the field of biology, biological taxonomy is a sub-discipline of the main subject of biology. As taxonomy focuses on describing and organize life, the work done by taxonomists is key for biodiversity and in the field of conservation biology. In zoology, there is a code regulated by the International Code of Zoological Nomenclature and in the field of botany, it is governed by the International Code of Nomenclature for algae, fungi, and plants.

There are 5 Important Requirements in the Initial Description of a Taxon 

1. Taxon name must be based on the 26 letters of the Latin alphabet. If it's a new species, then it should be binomial and for other ranks, it should be binomial.

2. The name given must be unique and cannot be a homonym.

3. The description given must be based on a minimum of one name-bearing type specimen.

4. Should include statements about key relevant attributes to describe the taxon or to identify and differentiate it from other taxa.

Other additional information like geographic range, ecological tips, behaviour etc: also, are sometimes included. 

Modern-day taxonomy uses database technologies. This helps to search and catalogue classifications easily. However, there is no common database. There are some comprehensive ones like “Catalogue of Life” which has attempted to list every documented species.