Re: Continuing evolution of Carnivory

Date: Sun May 23 1999 - 16:49:55 PDT

Date:          Sun, 23 May 1999 16:49:55 
Message-Id: <aabcdefg1793$foo@default>
Subject:       Re: Continuing evolution of Carnivory

Dear Chris,

> I was wondering Jan, are plants moving towards or away from carnivory. I
> could be assumed that things being wetter and more tropical and humid in the
> past with larger insects and the fact that triphyophyllum only displays
> carnivory in specific times in its life cycle would hint at the plant
> kingdom moving away from carnivory (that is unless global warming kicks in)

Well, _Triphyophyllum_ is perhaps not representative for the whole
plant kingdom. Anyway, it seems that _Triphyophyllum_ represents a
very old line, and it is probably a relict of an early stage of
carnivory. The tentacles are not able to move (like in the likewise
apparently "primitive" _Drosophyllum_).

> on the other hand there are many intricate traps today which indicate that
> perhaps in the past these complex traps werent developed enough to be
> functional and successful in capturing insects. What would you say?

I would say that it is very difficult to judge things we have not
witnessed. The fossil record does not present much useful data for
such judgements, and carnivory can work quite efficiently with simple
traps. _Aldrovanda_ (an example with a rather elaborate trap
structure) seems to have existed (fossil seeds are known) since Late
Cretaceous, although the oldest known fossils of what might have been
a trap are from the Upper Miocene.

> Also
> could there be more plants that only display carnivory in specific
> environmental conditions which currently do not or rarely exist and thus
> remain undiscovered perhaps genetic remnants of a climate since passed much
> like those genes they recently found in fruit flies which only surface
> during extremely harsh environmental conditions?


Kind regards

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