Dear all, and Harry of course,

I think, although there still is no "solid proof" that the evidence as
presented by Harry concerning Cerion is convincing. There might be a maybe
[I don't know anything about Cerion]

"In one scenario, the aboriginal form quickly disappeared, but an
intermediate
(presumably hybrid) form appeared at the same time and persisted in
equilibrium with the invading species."
This hybrid may have reproduced with parthenogenesis, and therefore be able
to reproduce. The shell shape of this presumed hybrid may have better (just
like the invading species) adapted, or the animal may have had some other
advantage over the "original" species.
"In the other situation, at some distance (in space) an original form was
later joined by an invader, a stable hybrid population appeared as the
aboriginal form became extinct, and it persisted for many thousands of years
before becoming extinct.  The
invading form survived the second extinction as the "fittest" survivor."
May have had about the same reason as written above.
But, by all means, it is a very strong case.
Hope to read about more examples, preferrably with living populations, so we
can see haow they behave, reproduce etc..
In my original paper adressing L. arachnoides, I already noted that,
although characters were always intermediate, some specimens were in shell
charaters closer to one of the supposed parental species. This [although not
written down in that paper] may be an indication that L. arachnoides is
capable of producing offspring when it mates with one of the parental
species.
I just wished that the fishermen in the Philippines could only afford not to
collect
solely for the shells. Then the truth about Lambis arachnoides could be
revealed
by observations in the field, or the "laboratorium conditions" I wrote
earlier about in the discussion.

Love this kind of discussion and input by so many.

Gijs


----- Original Message -----
From: "Harry G. Lee" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, March 24, 2004 1:26 AM
Subject: Re: hybrids, Lambis, population

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