Lefthandedness:
    My son has a cup that reads: "Hire the left handed. It's fun to watch them
write." That should explain it. After all, only Pen shells  (Pinnidae) can
write. And only the Janthina secretes the proper form of ink for under-water
writing. (although the squid tries). Since these two rarely wind up together,
one can see why left-handedness is so rare. I do hope this clears it all up.
        Question Man

"Harry G. Lee" wrote:

> Dear Morton et al.,
>
> There is a brief mention of the occurrence of "normal" perturbations of
> chirality in the webpages at <http://home.sprynet.com/~wfrank/reverse.htm>.
>  An classic but short paper on the occurrence of "normal" sinistrality in
> evolutionary and phylogenetic context is:
>
> Vermeij, G. J., 1975.  Evolution and distribution of left-handed and
> planispiral coiling in snails. Nature 254(5499): 419-420. April 3.
>
> A more extensive account of "normal" and mutant reverse coiling is:
>
> Robertson, R., 1993.  Snail handedness. National Geographic Research and
> Exploration 9(1): 104-119.
>
> Mutant sinistrality is discussed at greater length in:
>
> Gould, S. J., Young, N. D., and Kasson, B., 1985.  The consequences of
> being different: sinistral coiling in Cerion. Evolution 39(6): 1364-1379.
> (I think this is the same Bill Kasson I roomed with at COA '97; correct,
> Tom Watters?)
>
> And finally, a theory of species origination based on mutant coiling is
> explored in:
>
> Gittenberger, E., 1988.  Sympatric speciation in snails: a largely
> neglected model. Evolution 42(4): 826-828.
>
> Harry
>
> At 10:18 PM 9/18/00 -0400, you wrote:
> >I'm looking at shells from an evolutionary standpoint.  There are so many
> >right handed shells and so very very few left handed shells - worldwide
> >(which rules out Coreolis effect as a cause).  The most common example of a
> >"lefty" here in Florida is Busycon contrarium (sinistrum).  Any thoughts on
> >why this should be so would be welcome to me and maybe to the list.
> >Mort Kessel
>
> Harry G. Lee
> Suite 500
> 1801 Barrs St.
> Jacksonville, FL 32204
> USA   904-384-6419
> <[log in to unmask]>
> Visit the Jacksonville Shell Club Home Page at:
> http://home.sprynet.com/~wfrank/jacksonv.htm
>
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