This month’s National Geographic features a really beautiful article on carnivorous plants written by Carl Zimmer. The article presents the numerous independently-evolved adaptations possessed by a diversity of plants which live in nitrogen-poor soil. These adaptations are a great example of coarse-scal evolutionary convergence, as a variety of plants have all come up with the same shift in lifestyle (from being exclusively at the base of the food web to occupying multiple potential layers of the consumer levels above). In some cases the actual adaptations for carnivory are radically different (compare a venus fly trap to a pitcher plant), but there are also examples of species which have independently evolved similar adaptations.
The article provides a concise four-page summary of how recent research has unraveled the proximate mechanisms by which plants achieve predatory prowess. It also features beautiful photographs and very instructive illustrations of how each type of plant carnivory works. I will be using this article as a supplementary reading in my Evolution course, as it nicely complements an activity that I do that asks students to come up with hypotheses explaining why/how particular traits of particular organisms evolved. One of the examples I use is that of carnivorous plants.