MCAT PRACTICE EXAM AAMC
Taxomony (Gr.) – study of nomenclature,MCAT PRACTICE EXAM AAMC classification and their principles. This word was given by “Candolle” (Taxis – arrangements. Nomos – Law)
HISTORICAL BACKGROUND OF TAXONOMY:
Aristotle : – “father of zoology“. (Book : Historia Animalium) Father of ancient animal – Classification. He classified animals into two groups on the basis of their natural similarities and differences into –
(i) Anaima :- Those animals which don’t have Red blood or in which RBC are absent e.g. Sponges, Cnidaria, Mollusca, Arthropoda. Echinodermata like Invertebrates.
(ii) Enaima :- These animals have red blood. This group includes all vertebrated and it has been further divided into two sub groups.
(a) Vivipara :- It incldues animals which give birth to young-ones e.g. Man, Whale and other mammals.
(b) Ovipara :- It includes animals which lay eggs. e.g. Amphibians, Pisces, Aves, Reptiles etc.
Pliny :– He classified animal into groups :
(a) Flying (b) Non-flying
John-Ray :- He gave & defined the term ” species” as the smallest unit of classfication. He gave “concept of species “. According to him, the organisms which develop from the similar type of parents, belong to the same-species.
Mayr : – According to him similar species are those which are capacble of interbreeding in natureal condtions. Modern definition of species is conied by “Mayr”.
Binomial system of Nomenclature was devised by Gesparrd-Bauhin. But the detailed information about Binomial system was given by Linnaeus. In 1758 in the 10th edition of his book “Systema Naturae” he gave the classification of known 4236 animals and presented the Binomial system of nomenclature of animal. He is also known as “Father of Modern-Taxonomy”
In binomial system the name of each animal has two parts. First part has its genus name and second part has its species name. First letter of genus name must be written in Capital letter and species name is written in small letters eg. Canis familiaris. In certain species, sub-species are also found. For naming the sub species three words are used. First name is for genus, second for species and third for sub species. The method of nomenclature of Sub–species is termed as the Trinomial nomenclature and it was given by “Huxley and Strickland”. eg. Homo sapiens sapiens.
G.L. Cuvier : – Coined the term Phylum.
- Julian-Huxley (1940): – Proposed New systematic.
- Engler and Prantl : – Proposed Phylogenetic classification.
- Key for identification of animal was developed by John Ray.
- Invertebrate and Vertebrate term was given by Lamarck.