Sender: |
|
Date: |
Fri, 8 Jul 2005 12:17:04 -0400 |
Reply-To: |
|
Subject: |
|
MIME-Version: |
1.0 |
Content-Transfer-Encoding: |
7bit |
Content-Type: |
text/plain; charset=us-ascii |
Organization: |
Bishops Mills Natural History Centre |
From: |
|
Parts/Attachments: |
|
|
"Monfils, Paul" wrote:
> If interbreeding is the sole (or principle) criterion for speciation, where do hybrids come from? Hybrids should be impossible if species, by definition, cannot interbreed. Are the domestic dog, the wolf and the coyote conspecific because they sometimes interbreed?
* you'll note that my criterion was: "form a single population when
they're in contact:" a hybrid swarm with a unimodal character
distribution, so that there aren't modes representing unhybridized
parental species in the intergrade population. This is the standard
Mayrian criterion for the biological or polytypic species concept, and
it's inferred (assuming one doesn't have direct data on paternitiy) only
from the pattern of variation, not on the basis of its magnitude.
See: Schueler, Frederick W., and James D. Rising. 1976. Phenetic
evidence of natural hybridization. Systematic Zoology 25:283-289. I
know less demanding species concepts are now prevalent, but I haven't
followed the relevant literature closely in recent decades.
fred.
------------------------------------------------------------
Bishops Mills Natural History Centre
Frederick W. Schueler, Aleta Karstad, Jennifer Helene Schueler
RR#2 Bishops Mills, Ontario, Canada K0G 1T0
on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W
(613)258-3107 <[log in to unmask]> http://pinicola.ca
------------------------------------------------------------
subscribe to the Eastern Ontario Natural History list-serve at
http://mail.thenaturejournal.com/mailman/listinfo/naturelist_thenaturejournal.com
------------------------------------------------------------
----------------------------------------------------------------------
[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.
----------------------------------------------------------------------
|
|
|