- Taxonomy is the discipline of naming, describing and classifying organisms. This system of classifying is used for all plants, animals and microorganisms of the world.
- The term “taxonomy” was devised by AP de Candolle, in 1813.
- Taxonomy deals with;
- Principles and procedures used for identification of organisms.
- Nomenclature of organisms
- Classification of organisms
- The natural and phylogenetic relation among organisms.
- Classical taxonomy is the old method of classifying organisms, in which species is considered as a basic unit.
- It can be described on the basis of one or few preserved specimens.
- Modern taxonomy is the concept of systematic which brings out taxonomic affinity (resemblance suggesting a common descent) on the basis of evolutionary, genetic and morphological traits.
- It is also referred as new systematics or biosystematics
- The concept of modern taxonomy was given by Julian Huxley in 1940.
WHAT IS TAXON
- Taxon (plural Taxa), is the unit of classification in the field of taxonomy.
- A taxon is a group of genetically similar individuals with certain features distinct from the individuals of other groups.
- The living organisms are grouped into species followed by genus, family, order, class etc. Each of these categories represents a taxon.
- A taxonomic category represents the rank of a particular taxon.
- Organisms are divided into seven major taxonomic categories.
- This categorical distribution helps in the identification and recognition of various organisms.
- The kingdom is the highest rank in biological classification.
- A kingdom is a group of closely associated organisms sharing a set of distinguished features.
- All plants have common features of having autotrophic mode of nutrition and the presence of cell wall made up of cellulose. Hence, they are grouped into a single kingdom; Plantae.
- The term phylum is used for animals whereas the termed division is used for the classification of plants.
- A phylum/division is a group of interrelated animal classes. It consists of more than one class sharing some correlated features.
- Birds and mammals are members of the same phylum; Chordata.
- This is because of shared features i.e. the presence of notochord and dorsal hollow nerve cord.
- The class is a group of related orders.
- Class Mammalia consists of orders carnivora along with primata.
- The order Carnivora includes animals like tiger, cat, and dog
- The order Primata consists of monkeys, gorillas and gibbons.
- An order is a group of related families that display a few similar characters.
- Plant families like Convulvaceae, Solanaceae are included in the same order polynomials based on their floral characters.
- Similarly, in animals, the families; Felidae and Canidae are included in the same order Carnivore.
- A family is a group consisting of closely related genera.
- They have a smaller number of similarities as compared to genus and species.
- Families are characterized on the basis of both vegetative and reproductive features.
- In plants three different genus Solanum, petunia and the Torah are placed in the same family Solanaceae.
- In animals, the genus Panthera including lion, tiger, leopard and genus Felisa are classified in the same family Felidae.
- All the animals like lion, tiger, and cats have some similarities but are different from the traits found in dog hence it is placed in another family Canidae.
- Genus is a group of species which are alike in broad features of their organization but different in certain traits.
- Genus consists of species which resemble one another in certain correlated characters.
- Correlated Characters are the alike or common features which are used in limitation of a taxon above the rank of species.
- All the species of genus are assumed to have evolved from a common ancestor.
- The plant genus Rosa, consists of more than 100 species of roses.
- Species are a group of potentially inbreeding population which is reproductively isolated from other such groups.
- It is the lowest and basic rank in taxonomic classification.
- It consists of individuals which have fundamental similarities and can be distinguished from other similar species due to difference in morphological characters.
FOR EXAMPLE: Potato is species tuberosum of genus Solanum (Solanum tuberosum)
Taxonomic hierarchy is the process of arranging taxonomic categories into successive levels of the biological classification either in a decreasing or an increasing order from kingdom to species and vice versa.
FOR EXAMPLE: The following image represents the taxonomic hierarchy of a red fox.
- Arihant’s Handbook of Biology. The Living World. Page no: 1-6.
- NCERT Biology; Textbook for Class 11. The Living World. Page no: 1-62.