Re: Species [arbitrary to a degree]

["Jaime A. Headden" <qilongia@yahoo.com>]

Ken Kinman (kinman@hotmail.com) wrote:

<...However, I think it is even more of a mistake to so quickly dismiss the 
important implications
of "ring species" where populations (e.g., subspecies) can interbreed with 
adjacent populations
just fine, until the species circles around (circumpolar, around a mountain 
range or whatever),
and the populations at the end of the ring can no longer interbreed at all.  
I've always regarded
the ring species as a prime example of the "fuzziness" of the boundaries 
between species "in
space".  Throw in the fourth dimension and the fuzziness gets even worse (which 
makes 
paleontological species all the more controversial and difficult).>

  What I feel is being regarded here is the problem with adapting a physical 
species concept and a
genetic species concept, to each other. Many sparrows in Eurasia form ring 
species, in as much as
a series of populations seem to be more genetically compatible as they come 
closer to each other.
Those populations which was most polar are genetically isolated. This is the 
specific grey area.
Once genetic isolation has come into play, one does not get a paraphyly, but a 
split. The remnants
(the populations still in the middle) are an example of either 1) the basic 
population, or
original genetic type or 2) a hybridization of the two parallel species. Since 
it would require
phylogenetic testing of the two distinct polar populations to determine the 
origin, the statement
that there are two species at work here would be assumptive at best.

  Another problem has always been the assumption that a neontological species 
and a
paleontological species are the same thing and should thus be treated the same. 
Neontologists
condemn paleontologists for the species distinctions that are the basis of 
paleontological
taxonomy. I'm sorry, but we severely limited in this facet of distinction. This 
was pointed out by
Jon Wagner. If any neontologist has a solution, it seems invariably to adopt a 
neontological
viewpoint in defining a species by, when describing species. Paleontology notes 
the difficulty
with which a species can be formulated. For ring species, for instance, one has 
such a broad
collection and observation availability not found in paleontology, that it 
becomes ridiculous to
attempt "grafting" one concept onto the other. Paleontology is left with the 
bones of the deal, as
it were, and must be left to morphology for the most part, in defining 
speciation events.
Reduction to a single level, without phyletic or distinctiveness leaps as found 
in strictly
neontological data (based on the ignorance of fossil data), is a solution in 
both cases, but by
which criteria appears to be the main line in the dirt by which workers are 
dividing themselves.
There will _always_ be a line between neontology and paleontology. Get used to 
it.

  Unlike de Queiroz, I do not feel that it is simply easiest to drop to a 
single level of
referrence taxonomy, as delineated by Wagner. While I agree with Brochu, de 
Queiroz, and Wagner in
many of the viewpoints, I cannot see the two groups _capable_ of meeting based 
on the separation
of available data.

  Paleontology has not as much information that can be gleaned from populations 
and individuals as
does neontology, and this has led to the dichotomy, and perhaps intrinsic 
in-sufficientness of the
mess. _Completely separate_ from the whole issue is the issue of formulating 
names and where to
put them.

<The continuity of life is a fact that cannot be escaped even at the species 
level (or at the
population level for that matter).  Even species are somewhat arbitrary at some 
level, and the
arbitrariness of genera is in some ways qualitatively the same, but 
quantitatively very much
magnified.>

  I would argue that I and the gorilla are of such distinctiveness, as well as 
the gorilla from
other Anthropoidea, that we can distinctively isolate specific boundaries. When 
fossil data is
added, there is still a gap between modern gorillas and even the closest 
apparent fossil relative,
that this information suggests a phyletic gap that indicates a collection bias. 
Ken himself must
note this. As must those who claim that phyletic gaps are indicative of 
speciation boundaries. As
noted by [I beleive] Tracy Ford, it is likely that there is probably one single 
autapomorphy for
each species, where a genetic boundary is one which no other population 
crosses. The problem is
that this autapomorphy is probably merely the unique combination of the G, A, 
T, C molecules
within a population. The meter can be how many base-pairs reflect a genetic 
boundary. This may
shift between groups, and as such the meter may be relative, and not "actual" 
or universal. Hence,
a case-by-case basis. Nonetheless, there does not seem to me to be any such 
catch-all explanation
for speciation.

<So maybe we should abandon species as well?????   Obviously not.>

  Why not? There has been a proposal I recal for referring to organisms only by 
their type
specimen numbers. Forget species and genera. Therefore, collections of 
specimens (individuals)
which form an apparent group exclusive of other specimens. The greater the 
nesting, the more
diversity. Solves the problem of individual variation to some level.

  There has also been the [rather attractive, I might add] FMNH proposal to 
name all species by a
single binomen, retaining the useage of the past while dumping the unneccessary 
theory that went
with it, so that there will be a genus for every species. One could extend this 
to Jon Wagner's
proposal slightly, and make his "Iguanodontia foulkii" a "Iguanodontia: 
Hadrosaurus foulkii", and
simply ignore nested species. "Chasmosaurus kaiseni" will be a new genus, maybe 
"Georgia" for
George Kaisen....
  
<Perhaps it is just better to admit ranks are all human constructs on some 
level, and get on with
the job of minimizing the arbitrariness at every rank as best we can.>

  Naw, ignore ranks entirely. Don't even use them in formulation of theory. 
They mean absolutely
nothing. The theory works to some degree, but the names are useful for 
historical purposes only,
they mean nothing beyond that. There was a Family Hadrosauridae, but that makes 
it no more special
or exclusive than Class Reptilia, and vice versa.

  Also, unless we intend to write out theory in latin, we should avoid using 
the Latin names. This
was Linné's constructive language (the language of science, as it was), but 
that's it. This is to
avoid the conflict with attempted standardization of Latin for names in 
taxonomy, or else recent
names like *Khaan* must be abandoned because the name is not "proper" in it's 
formulation. It is
not "Genus Dominus Species McKennai," just *Khaan mckennai*. [sorry, Mike: just 
a gripe]

<Arbitrariness can't be eliminated, and therein lies the blind side of strict 
cladism.>

  Arbitrariness _can_ be eliminated. Even cladists can eliminate it. Take the 
full genetic
sequence of a man and simply formulate relationships. That's all cladistics is. 
You continue to
confuse cladistics with the phylogenetic taxonomy that sometimes is associated, 
or even just
regular taxonomy. Recent genetic cladistic studies of bird species have done 
nothing to affect the
names of the species, or boundaries, etc. So your statement is false to assume 
this has anything
to do with cladistics. I beleive Tom Holtz and Mike Keesey have continued to 
point this out on the
list.

<It therefore seems a good time to end the fruitless struggle to totally 
eliminate formal
paraphyly from classifications, as it is a natural consequence of the 
continuity of evolution.>

  Paraphyly exists by itself. There's no such thing as a formal or informal 
paraphyly of any
group. You can only apply a taxonomy to this, by formulating names or 
nominative/genitive
adjectives which can be applied in a formal or informal manner. Nothing about 
taxonomy is strictly
informal, as well, only it's application in a situation: in reference, for 
instance.


=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

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