>I am preparing a research paper for my biogeography class at Simon
>Fraser University.
>1.) historical distribution patterns of carvinorous plants throughout
>the world;
>2.) factors that control the distribution of carnivorous plants;
>3.) evolution of morphological features of Sarraceniaceae.
1.) It seems you have chosen a somewhat less than ideal object for your
research paper. The fossil record of all carnivorous plants is rather
scant. Only fossil pollen of (probably) Droseraceae are +/- well
represented in the European Tertiary (and later), and still it would be
very euphemistic to call the few points on a map representing these
specimens a "distribution pattern". Even less can be said about global
distribution patterns of cps. And worst of all, not the tiniest bit of
fossil Sarraceniaceae is known (at least to me).
2.) Virtually nothing about past factors which have controlled the
distribution of cps can be deduced from the fossil data mentioned. You
would have to assess the present factors and to hope that they were similar
in the past.
3.) The general (presently most popular) hypothesis (based mainly on
pitcher structure) states that a progressive series can be formulated with
_Heliamphora_ at the "primitive" and _Darlingtonia_ at the "derived" end of
the scale, with _Sarracenia_ somewhere in between. This is also supported
by chorological and anatomical considerations. Floral ecology and cytology
do not necessarily corroborate this theory, however.
Kind regards
Jan