So, are you saying that sinistral and dextral snails don't know how to make ends meet? So to speak. Haven't they read the Chama Sutured? David Kirsh Durham, NC On Wed, 10 Apr 2002 10:24:16 -0500 Russell Renka <[log in to unmask]> wrote: I have read, from Geerat Vermeij I believe, that shell coiling may be explainable from two factors. First, right handed coiling may be a "founders effect" that quickly became essential to aquatic gastropod species, not because of a survival factor but rather because it was usually impossible for a left-handed mutation case to reproduce successfully. Thus we regularly get left handed Cymbiola vespertilio among the vast P.I. harvest, but they stay quite rare because they produce no progeny. However, I wonder if any controlled experiments have been done, with live left-handed and right-handed C. vespertilio, to confirm this hypothesis. I suspect not, because the lefties are rare and valuable to collectors in dead rather than live form, and because this is really difficult experimental stuff to conduct in an artificial tank environment. So second, a normally left-handed species like Busycon contrarium has to be explained. I read the speculative argument that one stranded lefty somewhere in time-space got incredibly lucky, and met his or her match, another lefty. Voila! Nature took her course, all lefties were the result (suggesting that this is a recessive trait), and they thrived. Since this species uses the shell edge to lever open Bivalvia species, maybe that left-handed lever conferred a serious predatory advantage. As a lefty myself, I know it's a nice advantage in certain athletic pursuits, such as hitting kill shots in racquetball with the forehand from deep left-side back court. Mostly speculative, but I wonder if science has gotten any further than this. Russell Renka -- Russell D. Renka Department of Political Science Mail Stop 2920, Carnahan 211-L Southeast Missouri State University Cape Girardeau, MO 63701-4799 office: 573/651-2692 Home: 573/334-0039 FAX: 573/651-2695 URL: <A HREF="http://cstl-cla.semo.edu/renka">http://cstl-cla.semo.edu/renka</A>