Question 6.
Write in brief about progressive changes in animal classification.
Answer:
i. Greek philosopher Aristotle was the first to perform the animal classification. He classified the animals according to the criteria like body size, habits and habitats. It is known as ‘Artificial method’.
ii. Besides Aristotle, artificial method of classification was followed by Theophrastus, Pliny, John Ray, Linnaeus, etc.
iii. Later on, ‘Natural system of classification’ was followed. Natural system of classification was based on various criteria like body organization, types of cells, chromosomes, bio-chemical properties, etc. Dobzhansky and Meyer propagated the use of system of classification based on evolution.
iv. Recently, Carl Woese has also proposed the animal classification. This system of animal classification was in practice till now.
v. At present, according to the five kingdom classification system of Robert Whittaker, all multicellular animals are included in Kingdom: Animalia. This system of classification is based upon some criteria like Body organization, Body symmetry, Body cavity, Germinal layers, Segmentation, etc.
