Why classify? Helps to understand things under the complexity of biological diversity One and half million types of organism have been discovered on this planet and it has been estimated that there may be 10-100 million kinds of organisms.
How Classification Began? Classification began By ancient people that observed nature and had a desire to organize the knowledge gained. Classification- the grouping of objects based on similarities ex:: baseball cards, coins, shoes, etc Ancient Chinese classification of dogs Stray Dogs Those have broken flower vase Resemble flies at a distance
Taxonomy •… the identification, naming, and classification of species Has two parts Nomenclature Systematics Taxonomic hierarchy Kingdom* Phylum (Introduced by Heackel in 19 th century) Class* Order* Family* Genus* Species* * Introduced by Linnaeus
Based on easily observed characters (Ancient Chinese classification)
Linnaeus classification of worms in Vermes (Earthworm, Nematode, Snakes)
Use natural relation between organisms
Use diverse characters like anatomy, physiology, biochemistry etc.
Based on evolutionary relationship
Phenetic Classification – Numerical taxonomy
Aristotle (384-322 B.C.) Developed first widely accepted system of biological classification According to his system, birds, bats, and flying insects are classified together even though they have little in common besides the ability to fly. As time passed, more organisms were discovered and some did not fit easily into Aristotle’s groups, but many centuries passed before Aristotle’s system was replaced Animals (classified based on Habitat) Living on land Living in water Living in air Plants (classified based on structure) Herbs-- has (soft) stems Shrubs-- has several (woody) stems Trees-- has one main (woody) trunk
Linnaeus’s system of binomial nomenclature Carolus Linnaeus (1707—1778) Based on physical and structural similarities of organisms As a result,, the groupings revealed the relationships of the organisms Eventually, some biologists proposed that structural similarities reflect the evolutionary relationships of species Binomial nomenclature system
Kingdom concept Linnaeus (1735) 2 kingdoms Haeckel (1866) 3 kingdoms Chatton (1925) 2 groups Copeland (1938) 4 kingdoms Whittaker (1969) 5 kingdoms Woese (1977,1990) 3 domains Animalia Animalia Eukaryote Animalia Animalia Eukarya Vegetabilia Plantae Plantae Plantae Protoctista Fungi Protista Protista Procaryote Monera Monera Archaea Bacteria