1.2 Need for classification

We come across many places where things are arranged in specific categories. In super markets, the shelves can have rows and columns of groceries, cosmetics, toys, stationeries, snacks and utensils. If it is not arranged in a well organized manner, customers and sales persons will waste lot of time in finding an item. In the same way, libraries also organize the books alphabetically or genres- wise into autobiographies, novels, kids stories, science fictions, etc.

Likewise it is nearly impossible to study all the living History of Classification Early classification of organisms were based on only two criteria, beneficial or harmful animals. An ancient classification system recognized animal groups - domestic, wild, creeping, flying and sea animals. Initially the classification was based on organism’s fundamental characteristics such as the habitat and morphology only. Aristotle ( to BC), was the first to classify all animals in his History of Animals ( Historia Animalium in Latin).

He attempted a basic classification of all living organisms into Plants and Animals. Animals were classified based on locomotion; walking (terrestrial), flying (aerial) and swimming (aquatic). Based on the presence or absence of red blood he classified the animals into two as Enaima with blood and those without blood as Anaima. Aristotle’s classification system had limitations and many organisms were not fitting into his classification.

For example, the tadpoles of frogs are born in water and have gills but when they metamorphosed into adult frogs they have lungs and can live both in water and on land. How to classify frogs and where to place them? Aristotle classified organisms based on locomotion, hence, birds, bats, and flying insects were grouped together just by observing one single characteristic feature, the flying ability. On the contrary to the above said example, the ostrich, emu and penguin are all birds but cannot fly.

So Aristotle would not have classified them as birds. In spite of these limitations Aristotle’s classification system was followed for more than years upto . of organisms which includes all flora and fauna including microorganisms of the world. The word taxonomy was coined by Augustin Pyramus de Candole ( ).

Taxonomy is a theoretical study of classification with well defined principles, rules and procedures. Aristotle is called the father of taxonomy (classical) and Carolus Linnaeus is the father of modern taxonomy.