[Taxacom] Reproducibility of descriptive data

[Gurcharan Singh]

I wish we are more realistic about species identity. Evolutionary species 
concept, to me is the most realistic approach: The species should be able to 
maintain its identity through generation. It is understandable to talk of 
reproductive bariers in sexually reproducing organisms, but what about 
apomicts?. What about vicariants? no one thinks of merging Platanus 
orientalis and P. occidentalis. The moot point is, especially in plants that 
species should be remain distinct, and more important than that there should 
be some identifiable features in each species, otherwise a student comes to 
me ask the name of species, and I tell him: let me first try to breed it 
with specimen B and determine if they are twop distinct species.


Dr. Gurcharan Singh
Associate Professor
SGTB Khalsa College
University of Delhi, Delhi
India
http://people.du.ac.in/~singhg45
----- Original Message ----- 
From: "Stephen Thorpe" <s.thorpe at auckland.ac.nz>
To: "Mary Barkworth" <Mary at biology.usu.edu>; "TAXACOM" 
<taxacom at mailman.nhm.ku.edu>
Sent: Thursday, September 10, 2009 5:10 AM
Subject: Re: [Taxacom] Reproducibility of descriptive data


> >So how often do they have to interbreed and produce how fertile an 
> >offspring?
>
> This is a difficult question, but that doesn't mean that it doesn't have 
> an answer! Analogy: Australia (forget Tasmania and smaller islands) has 
> natural boundaries (unlike U.S.A.), but the boundaries are somewhat fuzzy 
> (or "swooshy": the tide goes in and out). So the answer to your question 
> isn't necessarily perfectly precise either. Nevertheless, there is a BIG 
> difference between species (Australia) and genera (U.S.A.)
>
>
>>And what if the isolating mechanism is the Atlantic Ocean - only then some 
>>foolish biped comes along, brings two things together than were once very 
>>effectively isolated by the ocean and find they are interfertile! Does 
>>that negate the impact of the accumulation of other genetic differences 
>>between them?
>
> If they haven't diverged enough to maintain "reproductive integrity" [what 
> a quaint term!] when brought together under natural conditions, then they 
> aren't distinct species! It doesn't negate the genetic differences between 
> them, it just means the differences are not significant enough to count as 
> distinct species...
>
>
> ________________________________________
> From: Mary Barkworth [Mary at biology.usu.edu]
> Sent: Thursday, 10 September 2009 11:18 a.m.
> To: Stephen Thorpe; TAXACOM
> Subject: RE: [Taxacom] Reproducibility of descriptive data
>
> So how often do they have to interbreed and produce how fertile an
> offspring? And what if the isolating mechanism is the Atlantic Ocean -
> only then some foolish biped comes along, brings two things together
> than were once very effectively isolated by the ocean and find they are
> interfertile! Does that negate the impact of the accumulation of other
> genetic differences between them?
> Mary
> _______________________________________________
>
> Taxacom Mailing List
> Taxacom at mailman.nhm.ku.edu
> http://mailman.nhm.ku.edu/mailman/listinfo/taxacom
>
> The Taxacom archive going back to 1992 may be searched with either of 
> these methods:
>
> (1) http://taxacom.markmail.org
>
> Or (2) a Google search specified as: 
> site:mailman.nhm.ku.edu/pipermail/taxacom  your search terms here