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Darwin-L Message Log 8:28 (April 1994)

Academic Discussion on the History and Theory of the Historical Sciences

This is one message from the Archives of Darwin-L (1993–1997), a professional discussion group on the history and theory of the historical sciences.

Note: Additional publications on evolution and the historical sciences by the Darwin-L list owner are available on SSRN.


<8:28>From DARWIN@iris.uncg.edu  Mon Apr 11 22:32:58 1994

Date: Mon, 11 Apr 1994 23:32:44 -0500 (EST)
From: DARWIN@iris.uncg.edu
Subject: Re: species definitions
To: darwin-l@ukanaix.cc.ukans.edu
Organization: University of NC at Greensboro

Polly Winsor embarrasses me with her effusive praise of a recent paper of
mine on species, but how can I decline her request for the citation?  ;-)
Since the newsstands are probably sold out by now, I offer the abstract
as well, so anyone tempted to look it up can get a better sense of whether
the effort will be worth it.  As Polly mentioned, this is not so much a
practical solution to the so-called species problem (what is a species,
anyway?), as it is an interpretation of why the problem arises in the first
place.

  O'Hara, R. J.  1993.  Systematic generalization, historical fate, and the
  species problem.  _Systematic Biology_, 42:231-246, 1993

  The species problem is one of the oldest controversies in natural history.
  Its persistence suggests that it is something more than a problem of fact
  or definition.  Considerable light is shed on the species problem when it
  is viewed as a problem in the representation of the natural system (sensu
  Griffiths, 1974, Acta Biotheor. 23:85-131; de Queiroz, 1988, Philos. Sci.
  55:238-259).  Just as maps are representations of the earth and are subject
  to what is called cartographic generalization, so diagrams of the natural
  system (evolutionary trees) are representations of the evolutionary
  chronicle and are subject to a temporal version of cartographic
  generalization, which may be termed systematic generalization.  Cartographic
  generalization is based on judgements of geographical importance, and
  systematic generalization is based on judgements of historical importance,
  judgements expressed in narrative sentences (sensu Danto, 1985, Narration
  and knowledge, Columbia Univ. Press, New York).  At higher systematic
  levels, these narrative sentences are conventional and retrospective, but
  near the species level they become prospective, that is, dependent upon
  expectations of the future.  The truth of prospective narrative sentences
  is logically indeterminable in the present, and since all the common species
  concepts depend upon prospective narration, it is impossible for any of
  them to be applied with precision.

I was also following Jim and Iain's comments on species as Polly was, and
thought it might be of interest to note the possibly different traditional
practices or perspectives of systematists who work on different taxa.  For
example, Jim Croft, in speaking of some of the inhabitants of his gardens,
commented:

>There are taxa here that are morphologically virtually indistinguishable,
>have similar habitat requirements but produce pheremones that attract a
>particular species of insect pollinator and their gene pools are totally
>isolated - any sane person would give them the same name and put them in
>the same folder in the herbarium - but should they?

A systematist raised in the ornithological tradition of Ernst Mayr and the
"biological species concept", as I was, would say without hesitation that
the plants that look identical but persist as separate gene pools are
certainly separate species; our inability to distinguish them easily is
irrelevant.  (Our inability to distinguish them easily would make them
by definition "sibling species".)  My sense is that the botanical tradition
has not always seen things this way, but Jim or Iain may be able to correct
my impression. (Ornithologists just wouldn't be sane botanists, maybe.)  ;-)

Linguists, I don't imagine, ever had furious ideological disputes over
the essential difference between a language and a dialect, but in pre-
evolutionary natural history there of course was an essential difference
between species and varieties/subspecies: species were separate creations,
whereas varieties/subspecies were not.  You can't find a distinction more
fundamental than that.

Do linguists who work on different families of languages have different
attitudes or approaches to language evolution?  For example, do Indo-
Europeanists tend to explain (say) sound changes in one way, whereas
American Indianists explain the same sort of thing in some other way?

Bob O'Hara, Darwin-L list owner

Robert J. O'Hara (darwin@iris.uncg.edu)
Center for Critical Inquiry and Department of Biology
100 Foust Building, University of North Carolina at Greensboro
Greensboro, North Carolina 27412 U.S.A.

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