>BUT (and here's the clincher) as far as I know, the last major extinction
>was the famous one that wiped out the dinosaurs. This extinction predates
>angiosperms.
The extinction you mean is the Cretaceous/Tertiary event, isn't it? This
one does not really predate angiosperms as these have existed in the upper
(late) Cretaceous already. Some primitive cp may even have witnessed the
decline of the dinosaurs (...;-)).
>I think that geologic events like ice-ages, and not astronomic
>ones, have far more evolutionary influence on CP.
This is true if long-term development is considered. Astronomic events like
meteorite impacts may influence local floras for limited periods of time,
however.
Steve,
>And the ice ages must have wiped out a lot of plant diversity.
Certainly. But they rather shifted diversity to other habitats (not really
killed it), and (following Tertiary orogeny) they evidently were
responsible for the evolution of new biodiversity not comparable to
anything in previous plant life.
>I am absolutely amazed at what CPs have managed to do over millions
>of years. They all have traps, but what a variety of traps! You
>have a vacuum cleaner trap (Utricularia), a bear claw trap (VFT),
>a drowning trap (Nepenthes/Cephalotus), a flypaper trap (Drosera),
>and a roach motel "go in but don't come out" trap (Sarracenia and
>Darlingtonia). When I see plants like this, it's sometimes hard to
>believe this is a natural development. It seems these plants have a
>well thought out design. Which makes you wonder if nature, or this
>planet, is somehow sentient. If you want to wonder about things,
>look at the plant world. The more you explore it, the more questions
>you have that can't be answered.
Did you ever try to improve on a good idea for 1E8 years? I must admit that
I just cannot imagine such a long long period of time. Thus, I am just
tending to believe my eyes even if I see incredible things in the plant
kingdom. But there is still no reason to doubt a natural origin of cp.
Paul,
>In other words .... Nothing can easily prove a radioactive meteorite
>didn't result in the VFT. However, there is sufficient evidence to
>show that a radioactive meteorite was not necessary. Rapid movement,
>carnivorous nutrition, trapping, etc. have all evolved on several
>occassions and no-one has suggested meteorites or unusual radiation
>were involved.
Furthermore, the relatives (_Drosophyllum_, _Drosera_, _Aldrovanda_) of VFT
show that important adaptations for carnivory (and partially even a
trapping mechanism based on +/- rapid movement of the leaf lamina) must
have existed in the family *before* VFT emerged. If we assume _Dionaea_ to
be an old (relict) genus (even older than _Aldrovanda_ which did exist with
separate lineages as early as the Eocene, and which may have originated in
Paleocene, i.e. in the early Tertiary), VFT has had enough time to attain
its present phenotype without meteorites.
Kind regards
Jan