Klots and species ---
DR. JAMES ADAMS
JADAMS at em.daltonstate.edu
Thu Sep 6 13:51:03 EDT 2001
Listers,
Jeepers. I certainly didn't mean to start all this. Not that I'm
necessarily complaining, as it is good to have this type of
conversation from time to time. I'm glad Norbert said what he said
about species (see below), as it is really the best species definition
there is (although not one that is necessarily useful to us
humans).
Norbert said:
> animals decide, the opinion of a taxonomist who thinks the difference
> is minor is really irrelevant.
This is really the whole point. A species consist of those individuals
who can recognize (in some fashion) conspecifics, and distinguish
them from non-conspecifics. Ron might say consubspecifics, and
I'm willing to give him that one. Species (and certainly some
named subspecies) are real; just because *humans* have a difficult
time with defining species boundaries, and even the species
themselves have the same difficulty, makes them no less real.
And Jim, unfortunately there is no one easy definition for species,
especially when you start looking at plants, as species maintain
reproductive isolation in so many different ways and, as was
pointed out, we are in a constantly changing environment where
species are redefining themselves (hence subspecies,
"semispecies" and the like). Geez, I hope I haven't opened another
can of worms.
I haven't come close to reading all the responses to this yet,
but I do have a few *opinions* about some of the stuff that has been
said. Excuse me if others have already made the following points.
One: it is remarkable how picky some people can be about
what is said (I include myself here). In my original message, I said
something about "species or *populations of* species evolve", not
any of the higher taxonomic categories. My meaning was that, if a
species consists of just one population, its entire evolution is
therefore connected. Clearly for most species, it is the individual
populations that are the evolutionary units, not the whole species.
I then stated something to the effect that "once a *species* is
separate from any other formerly connected species, it is irrelevant
to that species what happens to those other lineages." Ron called
me on this, saying I was "almost on the money" as it was
"subspecies that evolve, not species". Well, excu-use me!
(tongue in cheek). Species almost invariably will *first exist as
single populations*, and because of this the entire species
evolution is at least initially tied together. Obviously, I'm being
picky now.
Two: subspecies. I have made it abundantly clear in the past
my feelings about this category, or perhaps I should say the
*application of this category*. I have seen this taxonomic category
so misused and misapplied in the past that I have a tendency to be
very skeptical when new subspecies are named. This is by no
fault of the concept itself -- obviously. But an incredibly clear
understanding of existing populations, named or not, and gene flow
between them is necessary before the subspecific, or specific
status of a population can be understood. All I'm going to say
on this topic for now.
Three: I'll restate what I said before; any taxonomic category
not connected currently by some sort of gene flow
(subspecies/species) is an artificial *biological* construct. I never
said that genera/families/orders/classes/phyla (or any super-/sub-
categories thereof) were not useful or biologically informative. But
a child being able to recognize an arthropod, mammal, primate, or
cat does not make the taxa we call "phyla", "class", "order" or
"family" any more non-subjective. And, no, I'm not saying that the
subjectivity is uneducated subjectivity. How do we decide whether
to call a certain group of species a genus or a tribe or a family? By
some level of perceived relatedness based upon a *lot* of research.
It is through all this research that we've come to a tremendous
amount of agreement on classification schemes. However,
*people* are involved, and as such *we cannot* escape some
differences of opinion and interpretation, *some or all* of which may
be well researched, educated opinions!!
James
Dr. James K. Adams
Dept. of Natural Science and Math
Dalton State College
213 N. College Drive
Dalton, GA 30720
Phone: (706)272-4427; fax: (706)272-2533
http://www.daltonstate.edu/galeps/ (Georgia Lepidoptera)
U of Michigan's President James Angell's
Secret of Success: "Grow antennae, not horns"
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