What's a subspecies was: Species Concept Question

[Ken Kinman]

Hi Rich,
      I agree that subspecies can be viewed as incipient species.  In your Centropyge example, the two populations may well be very far along the road to becoming separate species.  But if they freely interbreed where they come together, then they haven't crossed that line yet (and may never do so).  Changing weather patterns or other circumstances could cause the zone of hybridization to widen in the future, even to the point of making hybrids the "norm" and the original morphs becoming the outlying exceptions.
      To show that these two populations have not crossed the species line, I would call them Centropyge vrolikii vrolikii and Centropyge vrolikii flavissima.  Such a change may be "rocking the boat", but I don't consider it confusing or particularly disruptive.  It's just the least disruptive way to convey new information (they readily hybridize when they come together).  I'm speaking from a zoological perspective, and botanists may well take a different approach (plants are a whole different ball game when it comes to speciation, and asexual organisms are even more so).
         ----- Cheers,
                     Ken Kinman
P.S.  Keeping the two Centropyge populations as separate species is also in line with the phylogenetic species concept.  Unfortunately this probably increases the "bias" to keep them two full species, but I don't agree with that philosophy at all.  The subspecies concept gives us a means to add information into the taxonomic name itself, and in the Centropyge example, no new names are needed (just a change in rank).  I would be hesitant to do this ONLY if Centropyge vrolikii flavissima is a threatened or endangered population (a practical, political "bias"), but that doesn't seem to be the case.
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Date:         Tue, 25 May 2004 21:25:40 -1000
From:         Richard Pyle <deepreef at BISHOPMUSEUM.ORG>
Subject:      RE: What´s a subspecies was: Species Concept Question
Comments: To: Dirk Albach <albach at GMX.NET>

> Maybe it is just my opinion from a plant perspective that I don´t have a problem with two species exchanging genes.
Neither do I, really -- but in vertebrates (moreso than plants), patterns of rampant hybridization are strong evidence of close affinity (i.e., almost always occur between two populations that are deemed to be sister taxa by other criteria).
> At least for me, subspecies are
> geographically separated but not clearly morphologically distinct.
I agree with this, too.  But I think of subspecies more generally as incipient species with clearly modal morphotypes, but which cannot be confidently assumed to be reproductively isolated into perpetuity.  This definition probably wouldn't work for many unicellular organisms, plants, corals, and other forms.