RE: Speciation & Classification

Thank you, Ian, for the clarification.  I often hear about the
reclassifications but not why the plants are reclassified.  It's nice to
know that cross-fertility is becoming more important in classification.  I
have a very good grasp of taxonomy in the animal kingdom and worked on
population genetics of black flies when I was at university but botany bored
me at that time.  It's something that I regret now.

Maureen Mark
Ottawa, Canada  
> -----Original Message-----
> From:	Ian E. & Shirley Efford [SMTP:avocet.intl@sympatico.ca]
> Sent:	Tuesday, February 24, 1998 10:17 AM
> To:	Multiple recipients of list
> Subject:	Speciation & Classification
> 
> I believe Maureen's statement "it seems to me that other factors
> outweigh cross-fertility in botanical classifications.  But then again,
> plants seem to get reclassified rather frequently which suggests that
> the rules are constantly changing." is misleading.  Classification is
> designed to reflect our best knowledge of evolutionary relationships,
> not convenience for identification.  The central core of species
> separation is the degree of fertility.  This can be the result of
> barriers which are physiological, behavioural or geographic but lower
> fertility is assumed to be the best indicator of greater evolutionary
> separation and this should be reflected in the classification.  Although
> there is a constant ground swell of systematic revision, it is always
> designed to get us closer to the evolutionary relationships and is more
> often at the generic or higher levels.
> 
> Ian, in Ottawa where the snow has cleared over three irises, proof that
> there is life after winter.
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