Phil Poland wrote:
> The problem, Pete, is that there are no clearly definable lines between,
> for example, an /M. c. altispira/ and an /M. c. bicolor/, or between an
> /M. c. johnstonei/ and an /M. c. sprucecreekensis/.
> The material used in Clench & Turner (Johnsonia) was limited. It was
> like looking at a jigsaw puzzle with only 15% of the pieces in place.
> As one slogs up estuaries and looks at new habitats and localities, the
> seemingly unique "subspecies" are found to be just points in a number of
> different clines.

* Brown's Rule states that the lines between subspecies are generally
drawn in the regions from which no specimens are at hand. (see "The
Subspecies Concept and Its Taxonomic Application." E. O. Wilson and W.
L. Brown, Jr., Systematic Zoology, Vol. 2, No. 3 (Sep., 1953), pp.
97-111 - first page at http://www.jstor.org/pss/2411818 )

fred.
------------------------------------------------------------
            Bishops Mills Natural History Centre
          Frederick W. Schueler & Aleta Karstad
       RR#2 Bishops Mills, Ontario, Canada K0G 1T0
    on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W
      (613)258-3107 <bckcdb at istar.ca> http://pinicola.ca
------------------------------------------------------------
If we'd been meant to refer to species by made-up vernacular names,
God wouldn't have created Linnaeus!
------------------------------------------------------------

----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------