Evolution of Nepenthes pitcher plants.

The evolution of carnivorous plants is one topic in particular which befuddles me. Modern genetic evidence indicates that the Venus Fly Trap and all of the Old-World pitcher plants (except Cephalotus, which is a completely separate lineage) share a common ancestor with the Sundews and probably originated from ancestors which would be considered sundews by modern definition.I can see how a Venus Flytrap may have evolved from a sundew; they look very similar at first glance too. I have my own ideas on how exactly the "bear trap" first appeared, but that's not the topic. I just honestly cannot imagine what kind of processes would have been needed to go from a flypaper trap to a pitcher. Does anyone here have any better insight than I do? This one has been giving me a hard time.

Yes. The transformation from a flypaper trap to a pitcher trap looks to me as if it were an example of a "complete hardware rewiring" (or something like that) that Dr. Dawkins says does not happen in Evolution; the argument used to explain the recurrent laryngeal nerve.What I'm having trouble seeing is how the intermediate species between a Sundew and a Pitcher plant could not have been considerably worse off than its ancestor and, thus have been eliminated by natural selection before their evolution progressed any further. Under what conditions was it favorable to develop an intermediate form and what would this intermediate form have even looked like?Edited by Tupinambis, : No reason given.

Ahh, now that you described the cupped-leaf process this is now much easier to visualize. All of the other pitcher plants (Cephalotus is again an exception) were formed from rolled up leaves. Not Nepenthes though, which is why I had so much trouble understanding it.Thank you all for your input!