Diversity in the living world is also known as biodiversity. No two individuals can be similar in morphology or behavior and this difference is referred to as a Biodiversity. The different kinds of living beings represent a species. In today time there are around 2 million living beings. More of half of them are animals and plants account for nearly half a million. In order to explore the number of new species a project Global Biodiversity Information Facility & Species 2000 has been started. It is quite difficult to detect new species in dense tropical rain forests and underwater reefs. However, these areas are shrinking due to more of human exploitation.
Fossils are defined as the remains of organisms which are no longer on earth. Microfossils denote to microorganisms. It is quite difficult to track extinct species and keep their respective records.
Systematic is defined as the branch of science that categorizes all living beings (plants, animals and other organisms) according to their names, features. Professionals which are involved in this type of study are known as Taxonomists. Technically, taxonomist and systematic have different meanings.
Different authors have given different definitions of Systematic. According to Simpson (1961) means diversity of organisms. It tells us about the variations occurring in living beings.
History: Different literatures have given different names to animals and plants. There are 740 plants and around one third of animals (250) as compared with plants according to Vedic Literature. Some animals were arranged according to their places of living by Hippocrates and Aristotle. Some used single criteria to classify them. Theophrastus, father of botany classified plants in his book Historia Plantarum. He used multifactor theory for his classification. The first system of artificial classification was given by Pliny the Elder in his book Historia Naturalis. A book named Historia Generalis Plantarum which tells us about 19000 plants was written by John Ray. He introduced the word species and defined it. Carl Linnaeus introduced different books for plants and animals. The former was known as Species Plantarum and later was known as Systema Naturae.
Natural systems of classification come under Classical Taxonomy. Numerical Taxonomy is the modification of this system. It further lead to evolution of phylogenetic (relationship between evolution and genetics) classification or cladistics. It is also known as New Systematic (History as the basis of their evolution).
Characterization, Identification, Classification (arrangement of organisms according to convenience according to certain features) and Nomenclature (giving names for recognition and differentiation from other organisms) are the basics of Systematic study.
Classical Taxonomy deals with size, shape and form of an individual which defines its perfect expression. The remaining features are considered to be imperfect expressions. It involved many authors such as Plato, Aristotle, Theophrastus and Linnaeus. According to this system, species do not change. They are as important as nucleus of cell. While Modern Taxonomy deals with multiple factors (morphology, physiology, cytology, biochemistry, anatomy, genetics) etc. All factors are considered to be equally important. It involved only single author Julian Huxley. In this system species keep on changing and they are not so important.
Use of Taxonomy:
• Evolution & Ecology.
• Study and as indicator of organisms.
• Applied Biology.
Nomenclature (Nomen means name, Calare means call) is divided mainly into two parts: Common and Scientific names. Common Names are given according to the culture, language of specific area. They also rely on certain specific features also. They are also known as Vernacular Names. They are easy to remember but they cannot be used by professionals. Insignificant names, area specifications, and language barriers are the main reason behind it.
Scientific Names are given by professionals and are accepted worldwide. This process of giving scientific names is known as binomial nomenclature. It was given by Carl Linnaeus. It gives specific names and has two words, first means generic (written in capital form) and second responds to specific (written mostly in small form). E.g. Homo Sapiens. Homo is the generic name and sapiens is specific. Some of the scientific names have three words. The third word represents the subspecies (animals) or variety (plants).
There are certain guidelines of binomial nomenclature. These guidelines are provided by certain codes. These codes are updated by the international conferences held every year. Linnaeus made all the rules which are adapted and employed in today time. There are certain features which are quite common in most of species on the basis of which different taxonomic categories can be created are referred to as correlated characters.
