What is difference between Practical , Artificial , Natural and Phenetic classification and Phylogeny terms means ? Natural classification

 

PRACTICAL CLASSIFICATION -:

•  Earliest classification.
•  Based on economic importance and use of organism.

E.G-: Oil yielding plants – mustard,soyabeen,groundnut etc.

Fibre –  Jute ,cotton

Medicinal plant – Rowolfia ,turmeric,chincohna, tulsi etc.

Species – Turmeric,clove,coriander etc.

v Draw back of practical classification

One plant can be member of more than one group.

ARTIFICIAL CLASSIFICATION -:

•  Based on one or more two morphological characters.
•  Complete morphology not considered.
•  In Genera Plantarum Linnaeus classified plants in 24 classes on the basis of number of stamen (single unit of androecium male sex organ).
•  Linnaeus classified phenerogeme (Gymnosperm , Angiosperm) into 23 classes and cryptogeme (Thallophyta , Bryophyta , Pteridophyta ) in one class.
•  Linnaeus classification is artificial classification.
•  Linnaeus classification also called sexual classification.
•  IN artificial classification equal weightage given to both vegetative and reproductive character (Floral character).

NATURAL CLASSIFICATION -:

•  Based on overall morphology.
•  Gross morphology / complete morphology considered.
•  Not only morphology but internal structure embryology, phytochemistry also involve.
•  Natural classification based on natural affinities ( similarities) among organisms.
•  Best classification

Because in natural classification more weightage ( more importance) given to floral/ reproductive character because floral character are more conservative/more stable than vegetative characters.

Type of natural classification

A.    Natural non phylogenetic classification

·      Based on gross morphology.
·      Phylogeny not considered.

B.    Natural phylogenetic classification

·      Based on gross morphology and phylogeny also considered .

Phenetic / Numerical classification -:

•  Based on number of similarities and dissimilarities.
•  Carried out by using of computer.
•  Each character assign code / number.
•  In phenetic classification maximum morphology character can be include .
•  In this type of classification importance to any one character not given.
  

              PHYLOGENY -: Phylogeny terms means history of revolution.

•  This term proposed by Lamarck.
•  Detail explanation of this term given by Charles Darwin and in his books Origin of species .
•  Phylogenetic classification also called cledistic (Tree like representation)