[asa] Transitions

From: James Mahaffy <Mahaffy@dordt.edu>
Date: Thu Dec 07 2006 - 11:19:29 EST

>
> Ted replies:
> My sense is that you were dead on target, David. I would add the
general
> prediction that "transitional forms" would be found as more of the
fossil
> record is revealed. Darwin specifically predicted that, and he
appears to
> have been correct. This argument seems to defy closure, of course;
every
> time a good candidate for a transitional form appears, all of a
sudden it
> creates two new "gaps" to be closed rather than filling an existing
one. Or
> so it seems, as we all know. When a position -- that there must be
"gaps"
> in the fossil record -- is not falsifiable, it is not falsifiable.

Keith or David might disagree, however I would say we just have not
found a lot more transitional fossils in the invertebrate record. Yes
you can make a case for finding some more "vertebrate transitions" such
as the whale or dinosaurs with "feathers"

However, we have a decent enough fossil record for the invertebrates
and the groups still tend to appear without transitions in the fossil
record. A similar pattern holds for angiosperms that show a great
radiation in the Cretaceous without good intermediate fossils. Of
course most phylogenies or cladograms are based on living groups without
much reference to fossils.

Of course for the origin of terrestrial plants you have flora like the
Rhynia chert. See:

http://www.uni-muenster.de/GeoPalaeontologie/Palaeo/Palbot/seite3.html

In my area of Pennsylvanian coal-swamp plants, most of the plants fit
well into the modern representatives and I think it is a stretch to make
fossil Lepidodendron or Calamites progenitors of Selaginella or
Equisetum. I would talk about this but there are way to few Christians
studying these areas.

-- 
James Mahaffy (mahaffy@dordt.edu)          Phone: 712 722-6279
498 4th Ave NE
Biology Department                                     FAX :  712
722-1198
Dordt College, Sioux Center IA 51250-1697
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Received on Thu Dec 7 11:20:41 2006

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