Isolating mechanisms

[Richard Jensen]

I am curious to know how readers of this list respond to the following.
In an article in TREE (vol. 10, pages 294-299), James Mallet refers to
the concept of isolating mechanisms as "...one of the most extraordinary
pieces of philosophical trickery ever foisted successfully on a community
of intelligent human beings."  Further, the use of this expression is
"...anachronistic; few researchers on speciation or hybrid zones
seriously now use these terms."

I will take the position that isolating mechanisms are a legitimate
aspect of our investigation of speciation.  Unless there is something
operating to restrict gene flow between populations, we are not in a
position to argue that the populations belong to different species.
Understanding what it is that prevents gene flow (the isolating mechanism)
is important.

Any thoughts on this?

Richard J. Jensen      |   E-MAIL: rjensen at saintmarys.edu
Dept. of Biology       |   TELEPHONE: 219-284-4674
Saint Mary's College   |   FAX: 219-284-4716
Notre Dame, IN  46556  |