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 |