- Systematics is the branch of biology that deals with the classification systems and nomenclature of living organisms.
- Systematics is the basis of understanding evolution process of life
FIELDS OF SYSTEMATICS
The study of systematics is comprised of three distinctive fields which aid in the classification of organisms:
- Identification is used to recognize the correct place of an organism in a system of classification.
- It is done with the aid of keys. An identification key, also termed as a taxonomic key, is a useful means of identifying unknown organisms. Keys are used for identification and are based on the alternate characters.
- Classification is the system of arranging organisms into relevant groups.
- Classification system helps the scientists to organize these organisms so that they can be studied easily.
- Classification in Systematics can be divided into two closely related and interconnected levels of classification:
- Taxonomic classification (known as the Linnaean System)
- Phylogenetic classification
- This type of classification groups living things together based on shared traits i.e. what they look like or what their bodies do.
- For example, animals that lay eggs and have scales are called reptiles, and animals that have live births and have fur or hair are called mammals.
- More specifically, all humans share the same characteristics and belong to a group (taxon) of the genus Homo, and species sapiens.
- This type of classification uses the taxonomic names and further groups organisms on the basis of their evolutionary relationships
- If you were to introduce someone to a group of people, you might start with his/her names (taxonomic classification), and then describe whose sister, brother, uncle, friend the person is or a total stranger (phylogeny).
- Nomenclature is the system of naming organisms for easy identification.
- Using the scientific name, an organism can easily be identified as well as information about its taxon can be derived from the name as well
TYPES OF NOMENCLATURE
- Binomial nomenclature
- Polynomials nomenclature
- Trinomial nomenclature
- Binomial nomenclature is a binomial system of naming an organism.
- Each organism’s name consists of two parts, the first name is genus and it starts with capital letter.
- The second part’s name is species and it starts with the small letter.
- This system was developed by Carolus Linnaeus and is used by biologists all over the world.
- Mangifera indica (Mango); here Mangifera is the generic name and indica is the specie name.
- In terms of zoology, it is called binary nomenclature.
- While in botanical terms, it is called a binomial classification system.
RULES FOR BINOMIAL NOMENCLATURE
There are certain rules for naming and classifying organisms to avoid any confusion and error:
- Names should be in Greek or Latin language.
- Generic name begins with capital letter (Mangifera) and is placed before species name, while species name begins with a small letter (indica).
- The scientific name should be either underlined or italicized.
- Name of the author should be written after species name in an abbreviated form. e.g., Homo sapiens Linn.
- It indicates that the species is first described by Linnaeus.
- Before 1750, a polynomial nomenclature system was used.
- In this nomenclature, the organism’s name consists of a series of Latin descriptive words.
This system, devised by Lamarck, the organism is given a name consisting of three words i.e. genus, species, subspecies
FOR EXAMPLE: Brassica oleracea capitata (cabbage)
CODES OF BIOLOGICAL NOMENCLATURE
There are five codes of nomenclature which help to evade errors,
Duplication and uncertainty in scientific names:
- International Code of Botanical Nomenclature (ICBN)
- International Code of Zoological Nomenclature (ICZN),
- International Code of Bacteriological Nomenclature (IC Вас N),
- International Code of Viral Nomenclature (ICVN) and
- International Code of Nomenclature for Cultivated Plants (ICNCP).
DIFFERENCE BETWEEN TAXONOMY AND SYSTEMATICS
- 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.