Andrew Vik
Tampa, FL., USA.
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Harry:
 
Thanks for the info. I am myself a sinistral, being a left handed writer. Are there
not humans with their internal anatomy arranged backwards also? It seems like I
heard of this one time, but I can't remember what the condition was called.
 
Andrew
 
Harry G. Lee, MD wrote:
 
> At 01:05 PM 3/27/99 -0500, you wrote:
> >Andrew Vik
> >Tampa, FL., USA.
> >liavik@earthlink,net
> >
> >Harry:
> >
> >I had heard from Phil Poland that you are interested in sinistrals.
>
> Accurate; perhaps understated.
>
> Has anyone
> >tried dissecting a live egg case and raising the few sinistrals in an aquarium?
>
> Not that I know of.  This is not far-fetched; its doable!
>
> >Why aren't sinistrals more common?
>
> Let me consider your question to relate to mutant reversals rather than
> "sinistrals."  The answer is may be something akin to: "If it ain't broke,
> don't fix it."
>
> Are they physically incompatible with the
> >dextrals when attempting copulation?  I have seen certain pulmonate species
> which
> >have 50% dextral, 50% sinistral populations. Is this because they are
> >hermaphroditic, and thus better able to pass on their sinistral genes?
>
> This incompatability is real (and observable).  The hermaphroditic pulmonate
> taxa with amphidromine (mixed dextral-sinistral) populations are, for the
> most part, obligate cross-fertilizers and are effectively unable to
> self-fertilize or efficiently mate with oppositely-coiled partners.  So the
> situation is a bit more complex than we would like it.
>
> >Andrew
> >
> >
> >Harry G. Lee, MD wrote:
> >
> >> Dear Questionman,
> >>
> >> Two interesting observations come to mind:
> >>
> >> Firstly on the subject of shell aberrations being associated with a
> >> selective disadvantage for mollusk within:  I once "dissected" a stranded
> >> egg-case of Busycotypus canaliculatus (Linnaeus, 1758) and counted about 800
> >> (dead, dried) embryos.  Three had sinistral shells.  The late Bob Wagner had
> >> a similar experience in an (unpublished) experiment with the same species.
> >> The frequency of reversed B. canaliculatus adults is much, much lower, I
> >> only know of two shells (among perhaps hundreds of thousands) - both
> >> accounted for by Paul Monfils.  I think it is safe to conclude that the
> >> sinistral condition Bob and I observed was mighty sublethal.
> >>
> >> As regards shell-less mollusks:  There are a few reports of sinistral (soft
> >> parts anatomically reversed) adult pulmonate slugs - just like their
> >> healthy-appearing testaceous relatives.
> >>
> >> Harry
> Harry G. Lee
> mailto: [log in to unmask]
> Suite 500, 1801 Barrs Street
> Jacksonville, FL  32204
> U. S. A.    904-384-6419
> Visit the Jacksonville Shell Club Home Page at:
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>
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