Are species real?

Steve Manning sdmanning at ASUB.EDU
Sat Apr 15 16:17:48 CDT 2006

At 05:16 PM 4/14/2006 -0500, Jan Metlevski wrote:
>On Thu, 13 Apr 2006 08:28:57 -1000, Richard Pyle <
>deepreef at BISHOPMUSEUM.ORG> wrote:
> >I understand the relevance of Systems Theory to biology and biological
> >systematics.  But I don't see how the application of such will help us
> >address the question of "reality" of taxa (at least in the context of how I
> >perceive the "reality of taxa" debate). Could you explain how you think it
> >(a Systems Theory approach) would help us discern whether species (and other
> >taxa) are "real" (=natural) entities, as opposed to human-defined
> >constructs?
> >
> >If you're thinking in terms of understanding the dynamics of gene flow
> >within and among populations over time, I wonder how practical that approach
> >would be for the vast majority of biodiversity.
> >
> >Aloha,
> >Rich
>There are general rules that work for all systems, doesn't matter what
>kind of system
>they are: physical, chemical, astronomical, social, biological, political
>or whatever
>else. Reality of any system is in the interactions and relations between
>elements. If the interactions between object's elements are stronger (or these
>interactions are specific) than interactions between object's elements and
>objects from the outside, then this object is a system and is real. This
>rule works for
>biological objects too because all biological objects are pure systems.
>I am no an adept of the Biological Species Concept. The gene flow within and
>among populations over time reflects only the ancestry-descent kind of
>between generations. That is an important, but not the only, and probably
>not the
>main, type of relations that maintain the integrity of a species. In my
>opinion, the term
>"gene flow" is not correct because actually, there is flow of gametes, not

But isn't it the ABSENCE of gene flow (or absence of "gamete flow") between
a group, of whatever size, and all other groups, of whatever size, that
maintains the integrity of a group as a species (or, for that matter, of a
higher order taxon such as a genus)?  Of course, not all such groups
(populations) are separate species but they can become separate species if
they eventually lose the capacity to exchange genes between groups.

What else did you have in mind that are types of relations that maintain
the integrity of species?



Dr. Steve Manning
Arkansas State University--Beebe
Mathematics and Science
Professor of Biology
P.O. Box 1000
Beebe, AR  72012
Phone: 501-882-8203
Fax: 501-882-4437

 . Box 1000
Beebe, AR  72012
Phone: 501-882-8203
Fax: 501-882-4437

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