>No, this is not a good rebuttal because it would imply that species sharing
>the same type of protoconch are more related to eachother than those who
>don't. Which is simply wrong (suppose that all non-planktotrophic triphorids
>are more related to eachother than all planktotrophic species, then how come
>that, say, Iniforis casta and I. turristhomae resemble eachother in a
>combination of almost all their shell characters while there is a choice of
>millions of such combinations?)

There are triphorida and cerithiopsids which are utterly
indistinguishable without the protoconchs.

>
>>  If you take eggs from ONE capsule and hatch them under differing
>>  environmental conditions, and the larvae develop different types of
>>  protoconchs, what conclusion do you come to? That the single capsule
>>  contains eggs of more than one species?
>
>Another good question. thought of that too: most if not all planktotrophic
>species have the possibility to become non-planktotrophic, perhaps by
>activating a suppressor gen, under the (yet unknown) right circumstances.
>This is what happens in nature, this is of course what we should be able to
>repeat in the lab. If you manage to convert the eggs of a specimen of a
>planktotrophic species into non-planktotrophic larvae then by definition you
>have indeed "created" a new species. And there is absolutely nothing wrong
>with that.

No... because that "new" species lays eggs which can produce BOTH
types, so there is in fact only one species.
--
Andrew Grebneff
Dunedin, New Zealand
64 (3) 473-8863
<[log in to unmask]>
Fossil preparator
Seashell, Macintosh & VW/Toyota van nut
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I want your sinistral gastropods!
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