Linnaean Hierarchy

Questions
(1) What is Hierarchy?.......1/2016TU,2018
(2)What are the obligatory categories used in Linnaean Hierarchy ?...2+2/2016TU
(3)Discuss the present status of Hierarchical Classification ....5/2016TU
(4) Discuss on Linnaean Hierarchy citing example of all taxa in man.....5/2018TU

            Hierarch=a series or succession of different ranks.So, in Systematics the term Hierarchy  is a method of arrangement of categories and taxa in an ascending order so that a higher category includes one or more lower category/categories .
     Linnaean Hierarchy & categories:
      Linnaeus, 1758 first time documented a  definite hierarchy for animals in 10th Edn.of Systema Naturae using only five categories , which are as follows:
(A Car Of Good Spice Varietas)
       (The descending sequence)
    Classis
       Order
          Genus
             Species
                Varietas
The category "varietas"used by Linnaeus was replaced by Sub-species .

               Seven Obligatory categories of a  taxonomic hierarchy:
  (King's PCO for Familie's  Good Security)
            (  The descrnding sequence )
   Kingdom
      Phylum
          Class
              Order
                  Family
                     Genus
                         Species
Linnaean Hierarchy and all taxa of Man 
   Kingdom .....Animalia
      Phylum.......Chordata
          Class........Mammalia
              Order.......Primates
                 Family......Hominidae
                      Genus.....Homo
                            Species....sapiens

  Hierarchical Classification and present status:
                    Advancement of science and technology along with the tedious search of  knowledge result in the increase of the number of known species of organisms . So, a given species requires more specific and precise position in the hierarchic classification .To arrange in a more proper & systemic way original seven obligatory categories are splitted and additional new categories inserted:
     (i) Cohort in between Class and Order,
    (ii) Tribe in between Family and Genus .
    Hence, the arrangement of these nine categories are as follows:
 Kingdom
    Phylum
       Class
           Cohort*
               Order
                   Family
                       Tribe*
                           Genus
                               Species
    Moreover, many more categories are added in the list . These categories are formed by adding prefixes :
(i)  as super- above the basic category ,
(ii) as sub- and infra- successively below the basic category .
e.g. basic category=Class
New categories = Super-Class
                                     (Class)
                                         Sub-Class
                                            Infra-Class
At present 33 categories are in use in the hierarchic classification , out of these 18 (asterisk-marked) are widely practiced . These 33 are as follows:
(First you write the 9 categories, then insert the new ones ...above & below ..Super Sub Inspector)
Kingdom
  Phylum
   Class
     Cohort
       Order
         Family
           Tribe
             Genus
               Species
(Now insert.......)
Kingdom*
  Subkingdom
     Infrakingdom
        Superphylum
          Phylum*
            Subphylum*
              Infraphylum
                Superclass*
                  Class*
                    Subclass*
                      Infraclass
                       Supercohort
                         Cohort*
                           Subcohort
                             Infracohort
                               Superorder*
                                 Order*
                                  Suborder*
                                   Infraorder
                                    Superfamily*(-oidea)
                                     Family*(-idea)
                                      Subfamily*(-inea)
                                       Infrafamily
                                        Supertribe
                                        Tribe*(-ini)
                                         Subtribe(ina)
                                          Infratribe
                                           Supergenus
                                            Genus*
                                             Subgenus*
                                              Superspecies
                                               Species*
                                                 Subspecies*
(No infragenus, infraspecies & Superkingdom )
 Important note*
(i)    A classifier should never leave any one of the seven Obligatory categories while stating the systematic position of an animal ; any violation of this will make the classification unsatisfactory . Therefore, these seven categories are mandatory or obligatory .
(ii) Use of rest categories are optional.
(iii) If a subsidiary level is used within any group , then it should be used for all the organisms of that group.
e.g. if a family is splitted into one or more subfamily , then all the genera should be kept in one or more subfamily.
Merits:
(i) More than one numerical schemes have been proposed to replace the Linnaean Hierarchy, but failed . The fact is that use of definite numerical values to taxa needs a vast knowledge of that taxa, which is not possible in reality.
(ii) In comparison to all other systems the Linnaean Hierarchy provides more and more  flexibility to the taxonomists while he /she is in practical field , by permitting splitting the seven obligatory categories to add new categories.
Therefore, Linnaean Hierarchy will be provisional for ever.




                   


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