[sci.bio] Questions about bio-taxonomic levels?

overt@antony (Christian Overton) (09/27/89)

We are building a taxonomic hierachy based on information supplied to us by 
GenBank.  The information is of the following form:

.  Eukaryota                                      # kingdom 
. .  Metazoa                                      # subkingdom 
. . .  Annelida                                   # phylum 
. . . .  Oligochaeta                              # class 
. . . . .  Enchytraeus albidus                    # species
. . . . .  Perinereis brevicirris                 # species 
. . .  Arthropoda                                 # phylum 
. . . .  Acrididae                                # family
. . . . .  Locusta migratoria                     # species
. . . .  Arachnida                                #
. . . . .  Eurypelma californicum                 # species
. . . . .  Xiphosura                              #  
. . . . . .  Tachypleus tridentatus               # species
. . . .  Crustacea                                # class 
. . . . .  Artemia salina                         # species 
. . . . .  Artemia sp.                            # species 
. . . . .  Cardisoma guanhumi                     # species 
. . . . .  Euphausia sperba                       # species 
. . . . .  Gecarcinus lateralis                   # species
. . . . .  Geryon quinquedens                     # species 
. . . . .  Paguras pollicaris                     # species 
. . . .  Insecta                                  # class 
ETC., ETC., ETC.

We have found some inconsistencies and errors in the file, but right
now our major concern is to determine an unambiguous ordering of the
taxonomic levels from the information provided.  The following
taxonomic levels are present in the GenBank data and correspond to
the standard ordering (although we wondered why there wasn't a
superphylum level):

superkingdom
kingdom
subkingdom


phylum
subphylum

superclass
class
subclass

superorder
order
suborder

superfamily
family
subfamily

genus

species

==========

We are having trouble confirming the correct position within the
taxonomic levels of the following (listed in alphabetical order):


  cohort
  subcohort

  division
  subdivision

  group

  infraclass

  infraorder

  section

  series

  tribe

We can deduce the positions of most from the data, but we would prefer
to have their order confirmed.  Our tentative ordering is:

superkingdom
kingdom
subkingdom

phylum		
subphylum	

superclass	
class		
subclass	
infraclass

cohort	
subcohort       

superorder	
order		
suborder	
infraorder	
		
series / section         

superfamily	
family		
subfamily	

tribe		

genus		
subgenus	

species		
subspecies	


Is the above correct?  In addition, we cannot properly place
'division/subdivision', which occur, for example, both above 'class'
and below 'suborder', and 'section' and 'series' both of which occur
below infraorder, but cannot be ordered relative to each other.

Pointers to an easily accessible text on the subject of bio-taxonomies
would also be appreciated.

Thanks.

   Chris
-- 
+--------------------------------------------------------------------+
| G. Christian Overton, Staff Sci. || Telephone: (215) 648-7533
| Unisys Paoli Resarch Center      || Internet: overt@prc.unisys.com
| P.O.Box 517                      || FAX: (215) 648-7390

snell@utzoo.uucp (snell) (09/28/89)

Re: Questions about bio-taxonomic levels?

In article <11564@burdvax.PRC.Unisys.COM>,
overt@antony (Christian Overton) writes:

[Long lists of higher taxonomic categories... deleted]

>Is the above correct?  In addition, we cannot properly place
>'division/subdivision', which occur, for example, both above 'class'
>and below 'suborder', and 'section' and 'series' both of which occur
>below infraorder, but cannot be ordered relative to each other.

>Pointers to an easily accessible text on the subject of bio-taxonomies
>would also be appreciated.

>Thanks.

Part of the problem is that there is not simply one system, though the
Linnaean system is generally followed.  Levels required to adequately
describe diversification and differentiation within one group
may not be required in another.
As well, taxonomists will not typically be inagreement about the 
position of any particular set of organisms, nor their relationships
to each other.  Any taxonomic hierarchy you come up with, no matter
how careful you are, will be at best tentative.  
To look at the bright side, at least it would be a potentially 
`falsifiable' hypothesis.

For references, try the following book chapter and journal article:
1) Mayr, E. 1969. Principles of Systematic Zoology. McGraw-Hill Inc., 
   New York. (In particular, Chapter 5: The Hierarchy of Categories 
   and the Higher Taxa.)
2) Buck, R.C. and D.L. Hull. 1966. The logical structure
   of the Linnaean hierarchy. Systematic Zoology 15: 97-111.

Both will be in any decent university library.
-- 
Name: Richard Snell
Mail: Dept. Zoology, Univ. Toronto, Toronto, Ontario, Canada    M5S 1A1
UUCP: uunet!attcan!utzoo!snell      BITNET: snell@zoo.utoronto.ca