On Mon, Aug 20, 2007 at 09:19:21AM +1000, John Murray Penhallurick wrote:
> I do not understand how any sane person can split the Northern (sanfordi)
> and Southern (epomophora) Royal Albatrosses when the Tamura-Nei cytochrome-b
> distance between them is 0.0000.
I don't understand how you can say this. The central criteria of some
species concepts is diagnosability. Evidence of significant recent gene
flow isn't directly relevant. It might give you cause to reconsider
the evidence of diagnosability carefully and it might bear on other
criteria but it certainly doesn't prohibit a split if there is clear
diagnosability.
Some people, like Mike Carter, clearly don't like diagnosis-based species
concepts - I'm not sure about them myself - but you can't call someone
insane for using them.
Strictly even if you are using a species concept centred on reproductive
isolation, the cytochrome-b distance is only evidence of lack of isolation
in the past. It is possible to also have evidence that reproductive
isolation appropriate for your species concept now exists. In general
(not speaking about Royal Albatrosses), a sane taxonomist using a species
concept based entirely on reproductive isolation might accept the
above genetic evidence completely and still split the taxa.
Andrew Taylor
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