subspecies standards

[John Grehan]

Erik Runquist wrote

>   Peoples of, say, African decent GENERALLY possess darker skin, hair, 
> and eyes than those of say eastern Asian or Caucasian decent, right? I 
> would contend that these features would stand up to the 75% avian 
> criterion that has been noted by Mike Gochfeld.  This has nothing to do 
> with the superiority of one group over another (we all know what can 
> happen when those beliefs are supported), and I am certainly frightened 
> whenever we begin labeling other humans.  However, skin or hair color are 
> artifacts of one's heritage and the random mutations (some of them 
> adaptive, some of them mal-adaptive, some of them neutral) that chanced 
> upon their progenitors.
>Should we not label these theoretical Leps or other "lower organisms," as 
>different subspecies because we know better than to do it for humans?

My view of this situation is that humans to indeed characterize the 
polytipic nature of many species - that is, species are often already 
differentiated entities. As pointed out on this list, there is no universal 
criterion transcending time and space by which to designate that structure. 
I think this was apparent in one positing (I've lost track as to which) 
where information on locality for a moth or butterfly species was more 
important that having a sub-specific taxonomic label (If I paraphrased that 
correctly).

>  The point of all this is what Andy has been stressing all along: we have 
> varying standards for the designation of taxa, and the status of one 
> labeled taxon is not necessarily equivalent to another (under whatever 
> standard you want).

On this respect I also agree with Andy.

>I also do not want to give anyone the impression that any one standard is 
>"better" than any other standard or that there should even be a definitive 
>standard; you learn Day 1 in biology that 1+1 sometimes equals 3.

Which is why definitions really don't matter all that much. One may define 
the criteria for designating taxa in a particular instance so one may 
understand the decision making process involved (and perhaps this would 
qualify as the defence required by Andy). I have a case where I am in the 
process of designating species for a group of ghost moths ranging between 
Costa Rica and southern Brazil. The total number of specimens are contained 
in about 5 drawers which is an absurdly small sample, but it is all that 
there is to work with. In designating species I will look for 
discontinuities in variation taking into account geographic location. This 
will led to designation of species as hypotheses of lineage 
differentiation. It really does not matter whether the species represented 
are reproductively isolated or not, recognized each other or not, are the 
smallest cluster of uniquely shared genes etc. Al of these criteria may be 
chosen or evaluated by subsequent workers and argued case by case.

John Grehan


 
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