Date: Wed, 10 May 2000 11:16:40 -0700 From: Ivan Snyder <bioexp@juno.com> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1474$foo@default> Subject: re: Oldest CP
Hi all again,
I wrote:
>>I think probably the oldest family of CP
>>is the butterwort family ( butterworts, Genlisea, Utricularia ) since
>>they are the most diverse.
Jan replied:
>This is certainly not the case (neither are they the oldest family,
>nor are they the most diverse - above the rank of species). As a
>Scrophularialean (Asterid) family, they belong to the youngest branch
>of dicots,
Ivan again:
Brilliant! but you seem to have missed some of my points Jan, that's OK,
this is a very complicated matter. Let me see if I can put this all
together, please read on. Of course the Scrophulariales are young, but
when did the line achieve carnivory? All agree that the family
Lentibulariaceae has the most diversity in regard to trapping mechanism.
Ranging from butterworts, having the most simple trap ( since it is much
like a nonCP, example -Martynia ), to bladderworts which have the most
complex. Does not this diversity suggest a longer time period to develop,
hence an older age?
Jan:
>The most primitive cp line is possibly Nepenthales (incl.
>Droseraceae, Nepenthaceae, Drosophyllaceae, and Dioncophyllaceae).
>_Nepenthes_ appears in the fossil record of the Tertiary.
>_Byblis_ is apparently the most primitive Scrophularialean cp.
Ivan:
Pollen of Nepenthes and Lentibulariaceae only appear later during the
Miocene (23-5 MYA). In the above you state that that Byblis is apparently
a Scrophularialean, as of course we know Lentibulariaceae are also. Now
consider this, by linking Byblidaceae to Lentibulariaceae a clear already
organized pattern emerges of a lineage running easily back to the time of
the dinosaurs. The Byblidaceae are placed in the Pittosporales. For much
literature citings see Origins of the Genus Byblis, DeGreef, CPN Sept &
Dec 1990. How did the Pittosporales reach Australia? They are believed to
have migrated during the mid-Cretaceous (90 MYA). But the line is traced
back still further! Ancestors of the order identified in two pollen finds
from the U.S.A., are dated 100-90 MYA.
I am aware of the fossil evidence we have of possible Aldrovanda
leaves,-missing important features, and Aldrovanda-like seed, also
Dionaea-like Fisheropolis pollen. My feelings are, take what fossil
evidence we have with a grain of salt. In Lloyd's book is mentioned
fossil bladderwort; most likely erroneous data. I rely on the more
concrete evidence we have in the study now living plants. As I mentioned
above, Lentibulareaceae shows the greatest diversity which suggests it to
be of the oldest CP line. The scant fossil evidence supports this as
well.
Ivan Snyder
Hermosa Beach
California
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