Definition of "species"

Tiser, Gene M TiserG at
Fri Sep 7 19:56:16 EDT 2001

First, thank you , thank you, thank you for a wonderful and enlightening
discussion - I have enjoyed the points and counter-points enormously!

Regarding the comments about math, I believe there is a math format which is
enlightening in this discussion.  That is the relatively new Chaos theory.

To simplify part of the chaos theory to an extreme (a must since I am NOT a
mathematician!) - any straight line border only looks that way from a
distance.  The closer you inspect it, the more variations and deviations you
find in the edge.  If you print this line ____________ it will look straight
and precise.  But look at it under a microscope and the edge looks much
different due to variations in the paper fibers as well as the way the ink
was sprayed on the paper.  

I think the same rule applies to taxonomy - Ron's child looked at big groups
of things and saw clear, precise lines (boundaries).  However, when we
examine the things closely, we begin to see the little minute differences
that were not apparent at first (swims in the water it is a fish, wait, what
about whales and dolphins).  Thus, the layman may not see two butterfly
species where the expert might see a clear cut difference (or not!).  That
we devise systems to tell them apart would not matter to the butterflies one
iota - they go on their merry way reproducing and producing new variants
that either survive or die. 

So, chaos theory tells us that we can not devise a system that will
perfectly define all situations and groupings - there will always be that
imperfect edge that will defy us!  As I like to tell my staff - the first
rule of biology appears to be: There is an exception to every rule,
including this one!  { ;>) Thus, we need to be flexible in any system or
definition that we mere humans devise!  Hope this makes sense and is not too
much rambling for late on a Friday that finds me still in the office!

Feel free to flame away - I have a three day weekend and will not know until
I come back on Tuesday!  Hope you all have a good weekend yourselves! 

Gene Tiser
Education Coordinator
NE Region Hdqtrs
PO Box 10448
1125 N. Military Ave.
Green Bay, WI  54307-0448

phone: (920) 492-5836
fax:      (920) 492-5913
tiserg at

> ----------
> From: 	Kondla, Norbert FOR:EX[SMTP:Norbert.Kondla at]
> Reply To: 	Norbert.Kondla at
> Sent: 	Friday, September 07, 2001 9:45 AM
> To: 	'1_iron at'; Leps-L
> Subject: 	RE: Definition of "species"
> Fair points. Here are a couple of additional thoughts:
> - even the most elegant structure, if built on a rotten foundation, will
> eventually crumble and cease to be useful
> - Kondla's First Law of Human Behaviour: people will always disagree about
> everything; some will do so with decorum and respect for other people
> while
> some will get obnoxious or even vicious in the process of trying to prove
> they are right 
> - biology is an infinitely more complex science that mathematics :-)
> -----Original Message-----
> From: 1_iron [mailto:1_iron at]
> Sent: Friday, September 07, 2001 1:40 AM
> To: Leps-L
> Subject: Definition of "species"
> Folks:
> I am somewhat aghast at the responses to what I consider a simple
> question.
> Mathematics, for example, begins with definitions - and progresses no
> further until each definition is set in stone. "A point is that which has
> no
> parts." begins Euclid, and goes on to define lines and the like. Upon
> these
> definitions are built an elegant structure. Why should the science of
> Biology be any different?
> I can understand the filing of similar species in genera folders, similar
> genera into families, etc., as an attempt to understand kinships about
> which
> reasonable people might disagree. However, the basic (and as I requested,
> black-and-white) definition of "species" MUST be something all can agree -
> or we are not talking about the same thing.
> Until you get your act together, I shall deem a species to be defined by
> fertile offspring, and I shall deny there is such a thing as a subspecies.
> How can there be under the above definition?
> And I shall go on in my ignorance and isolation enjoying my moths.
> Jim Taylor
>  ------------------------------------------------------------ 
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