What Bill says about the fluidity of the species concept is very true.
>From the point of view of scientific constructs, there is not even one 
definition of species but at least 5.  So what might be one species in the 
traditional definition might be several different species in the 
Phylogenetic Species Concept.
Also, whatever definition of species we use, we are trying to impose sharp 
divisions on what is in reality a continuum.
This is one reason why I am relieved that we can look to molecular 
techniques to give us some guidance.  For example, in an article in a recent 
issue of Birding, it was found that most races of an American sparrow 
diverged by less than 1% in genetic terms, but one 'race' differered by 3%, 
a difference comparable to the difference between well-recognised species.  
So it was very logical to recognise that race (I think it was Bell's 
Sparrow) as a species.
John Penhallurick 
John Penhallurick
Office: Faculty of Communication, University of Canberra, PO Box 1, BELCONNEN 
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