This appears to be strong support of the exaptive origin of resin defense of seeds and ovaries.
Bracts enveloping the developing and mature fruits appear to be partially exaptive (large bracts that close had already evolved; [ILLUSTRATION FOR FIGURES 3, 4 OMITTED]) and to have evolved twice [ILLUSTRATION FOR FIGURE 8 OMITTED].
This suggests an exaptive origin of foliar resin secretion.
The origin of four defense characteristics in Dalecharnpia was by exaptive evolution and three apparently by simple adaptation (counting the initial resin secretion by staminate bractlets as an adaptation).
In the evolution of both plant-herbivore and plant - pollinator relationships, then, evolutionary novelty appears to have resulted at least as often from exaptive processes as adaptive processes.
One way to clarify, but no doubt also to complicate, the issue is to examine some potential candidates for exaptive changes in more detail.
I would nonetheless like to emphasize the fact that any process of change, including an exaptive one, must have its mechanism of diffusion.
My corpus evidence suggests that inversion after clause-initial negatives is a good example of exaptive change.