What is biological classification?
Biological classification is defined as the ordering or ranking of organisms into groups on the basis of similarities or closeness or relationship. As there are large numbers of plants and animals in the world, so it is easier to study them after they are arranged in some small or large groups.
Forms of biological classification: –
Two distinct forms of classification are as follow –
i) Classification of overlapping sequences or Keys.
ii) Classification following taxonomical hierarchy.
Basis of Biological classification: –
i) Biological classification initially was based on superficiality morphological characteristics.
ii) With the development of natural system of classification, the morphological characteristics were considered in every minute detail, along with that, there was also consideration of the reproductive features.
iii) The phylogenetic system of biological classification considered is the gradual evolution of organisms and their phylogenetic relationships.
iv) The modern system considers all the relevant data from other branches of biology and it is developed by adequate computation.
Purposes of biological classification: –
i) Biological classification helps in the arrangement of living plants and animals.
ii) It provides explanation for the diversity of organisms.
iii) It keeps proper knowledge of evolution of organisms.
iv) It gives the scope for the discovery of new spaces.
v) It helps in the storage of data about living organisms in the form of key and utilise them whenever necessary.
vi) It is a tool for identifying organisms.
Types of biological classification: –
There are mainly three types of classification system; those are artificial system, natural system and phylogenetic system of classification.
Artificial system: –
This system is based on one or two superficial characteristic without considering any morphological details or phylogenetic relationships.
Merit of artificial system:
It was the first novel attempts of classification of living organisms and therefore it have some importance of the history of biological classification.
Demerit of artificial system:
In this system closely related species may be placed distinctly apart and distant species might be placed together. The evolutionary relationships were not understood by this type of classification.
Natural system: –
This is the system of biological classification which is based on several natural characteristics. These simplest organisms are placed early while the complex ones are placed latter in this system. This system relied on the constancy of spaces. George Bentham and J. D. Hooker proposed system in 1862 and 1883 respectively. Several morphological characters were taken into consideration in these system and for this reason it is widely accepted and glands are arranged according to this system in many organised botanical Gardens
Merits of natural system:
This system of biological classification gives an easy means of identification of plants which are unknown. Morphological characters of plants have been studied before placing them in their respective positions. It has been widely accepted due to an original novel attempt describing 97,205 spaces.
Demerits of natural system:
Gymnosperms were wrongly placed between dicotyledonous and monocotyledonous plants. There was no phylogenetic consideration in this system and some of the closely related species are placed distantly while distant places are placed close to each other.
Phylogenetic system: –
This system of biological classification is based on evolutionary sequence and genetic relationships taken in consideration. After the publication of Darwin’s theory in 1859 the system was actually developed and along with the natural morphological characteristics which are inputs from fossils records the genetic constitutions were also considered. Due to this it is largely accepted by modern biologist.
Merits of phylogenetic system:
This system gives the phylogenetic relationship and has resulted in the development of experimental taxonomy. It has the estimated hollowness and is widely accepted by the biologist.
Demerits of phylogenetic system:
This system is not quite suitable for practical purpose though these defects are mostly removed in recent classifications.